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Home/Mitsubishi/Galant/Mitsubishi Galant VIII рестайлинг (1998-2006)/Repair manual/Testing & Diagnostics/Engine Controls - Self-Diagnostics - 2.4L: Diagnosis
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Engine Controls - Self-Diagnostics - 2.4L: Diagnosis Mitsubishi Galant VIII рестайлинг

Testing & Diagnostics 8 illustrations ~52257 words

SYSTEM DIAGNOSIS

CAUTIONObtain radio anti-theft code before disconnecting battery.

Note. Engine management is controlled by a Powertrain Control Module (PCM). PCM diagnostic memory is retained by direct power supply from battery. Memory is not erased by turning off ignition, but it will be erased if battery or PCM is disconnected.

PCM includes On Board Diagnostics II (OBD-II) software designed to monitor emissions control system over the life of the vehicle. On OBD-II equipped vehicles, the MIL will illuminate only for emissions system related faults. Most of these faults will not cause driveability problems and would go unnoticed by the driver were it not for the MIL. When MIL illuminates, a DTC will be stored. The PCM may also store DTCs that do not illuminate the MIL. These may be DTCs for faults that no longer exist, provisional codes, or for faults that are not emission systems related. DTCs may be retrieved using the manufacturer's MUT-II Scan Tool (MB991502), or a compatible generic scan tool. See ENTERING ON-BOARD DIAGNOSTICS under SELF-DIAGNOSTIC SYSTEM.

PCM monitors several different engine control system circuits. If an abnormal input signal occurs, the PCM will store it in memory as either a provisional code or DTC. A specific DTC indicates a particular system failure, but does not indicate the cause of failure is necessarily within that system. Most faults require that the malfunction be detected during 2 different drive cycles before the MIL is illuminated. On DTCs that use 2 drive cycles, the first occurrence of the fault will store a provisional code. The second occurrence of the fault will set a DTC and illuminate the MIL.

For certain system or component failures, PCM will enter fail-safe function (limp home mode). In fail-safe mode, PCM will substitute default values for the faulty component or system. For more information, see FAILURE MANAGEMENT .

Each circuit or system monitored by PCM has particular engine and driving conditions that must be met before PCM will monitor it. These conditions are the code set criteria. Due to differences in code set criteria, some circuits or systems are monitored almost continuously while others may not be monitored at all during a particular drive cycle. After a repair, it is necessary to run the vehicle under conditions that meet code set criteria in order to verify the repair. This is best done by following the drive cycle related to the DTC. To verify a misfire or fuel trim repair, it is also necessary to operate the vehicle in conditions similar (engine speed, engine load, engine temperature, etc.) to those when the misfire occurred. See VERIFYING REPAIRS . These conditions are recorded as freeze frame data. Check freeze frame data before erasing DTCs, as freeze frame data will also be erased.

Readiness Test Status

During different parameters of engine operation, the PCM monitors and runs tests on various inputs, outputs and system functions. There are 6 monitors. One monitor (Other Monitor) passively monitors for shorts, grounds and out of range parameters. It runs continuously. The other 5 monitors actively test different systems and will only run when very specific engine operating conditions have been met. Those monitors may or may not run during any given drive cycle. These 5 monitors have a system readiness test to show whether the particular monitor has been run or not. For additional information on drive cycles, see VERIFYING REPAIRS . A system related Diagnostic Trouble Code (DTC) cannot set until it's monitor has run successfully and readiness test status indicates COMPLETE.

When DTCs are cleared, each readiness test status is set to INCOMPLETE, or NOT READY. To complete readiness test status, OBD-II drive cycles related to all on-board diagnostic items should be carried out. See OBD-II DRIVE CYCLES . If vehicle is normal, readiness test status will complete by carrying out OBD-II drive cycle once. MUT-II scan tool will then read COMPLETE. Generic scan tool will read READY. If PCM detects a malfunction, OBD-II drive cycle must be carried out again before readiness test status will complete. Once readiness test status is complete, PCM can be checked for DTCs.

Intermittent Diagnostic Trouble Codes

If DTC was set and DTC diagnostic procedure does not locate fault, problem is intermittent. Most intermittent malfunctions occur from vibration, temperature change, moisture change and poor connections. Try to determine under what specific conditions problem occurs. Try to duplicate those conditions while monitoring circuit suspected of being faulty with data recorder function of scan tool. The following additional checks may assist in identifying a possible intermittent problem

  1. Check all pertinent Technical Service Bulletins (TSBs).
  2. Visually inspect related wiring connectors for broken, bent, pushed out or corroded terminals.
  3. Visually inspect related wiring for chafed, pierced or partially broken wires.
  4. Wiggle suspected wire(s) or vibrate suspected component.
  5. Apply heat and/or humidity to suspected component.

Provisional DTC

Provisional DTCs are set only during a single drive cycle. PCM will detect some malfunctions and set DTCs in memory but may not turn on the Malfunction Indicator Light (MIL). Provisional DTCs do not necessarily indicate a failure of a component or system. If a component or system fails for 2 drive cycles, a hard fault will be stored. See HARD FAILURES under ON-BOARD DIAGNOSTICS in SELF-DIAGNOSTIC SYSTEM. For additional information on provisional DTCs, see VERIFYING REPAIRS .

VISUAL INSPECTION

Most driveability problems in the engine control system result from faulty wiring, poor electrical connections or leaking air and vacuum hose connections. To avoid unnecessary component testing, perform a visual inspection before beginning self-diagnostic tests.

ENTERING ON-BOARD DIAGNOSTICS

Note. DO NOT skip any steps in self-diagnostic tests or incorrect diagnosis may result. Ensure self-diagnostic test applies to vehicle being tested.

Using Scan Tool

  1. Refer to manufacturer's operation manual for instructions in use of scan tool. Before entering on-board diagnostics, see «SERVICE PRECAUTIONS»(ref-150942-S33835224732002112700000). Locate Data Link Connector (DLC) under instrument panel, near steering column. (Scheme 105)
  2. Turn the ignition switch to LOCK position. Connect scan tool to DLC. Turn the ignition switch to ON position. Read and record scan tool self-diagnostic output. Proceed to «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(ref-150942-S26611120572002112700000). If scan tool will not communicate with PCM, diagnose communication concern. See «SCAN TOOL COMMUNICATIONS»(ref-150942-S26384602172002112700000). Turn the ignition switch to LOCK position before disconnecting scan tool.

Scheme 105

Scheme 105
Scheme 105

TWO-TRIP DTC MALFUNCTION

When a malfunction initially occurs, Diagnostic Trouble Code (DTC) will be temporarily stored in PCM memory, but MIL on instrument panel will not illuminate. The second time malfunction is detected, MIL on instrument panel will illuminate, provided ignition is turned off and then back on after first malfunction was detected. This applies to specific DTCs.

CLEARING DIAGNOSTIC TROUBLE CODES

CAUTIONAll data will be lost when DTCs are cleared. Record data that may be needed later, such as freeze frame data, before erasing DTCs.

Note. Obtain radio anti-theft code before disconnecting battery. When battery is disconnected, vehicle computer and memory systems may lose memory data. Driveability problems may exist until computer systems have completed a relearn cycle.

To clear DTCs using a scan tool, refer to owner's manual supplied with scan tool. Ensure DTCs do not reset. Start and warm up engine. Run vehicle through appropriate drive cycle(s). See VERIFYING REPAIRS . Check for DTCs to confirm repair.

Note. A drive cycle is when engine goes from start to stop and component is monitored in-between. The component's code set criteria must be met while the engine is operating before it will be monitored. Due to this, component may not be monitored every engine start-to-stop cycle.

Troubleshooting Hints

The most likely causes for this cause are

  1. Burnt-out bulb.
  2. Defective service engine soon/malfunction indicator lamp circuit.
  3. Malfunction of the PCM.

Testing

  1. Connect scan tool to Data Link Connector (DLC). (Scheme 105) Turn the ignition switch to ON position. Using scan tool, check data list item 16: POWER SUPPLY VOLTAGE. If battery voltage exists, go to next step. If battery voltage does not exist, check for battery voltage at PCM. See appropriate SYSTEM & COMPONENT TESTING article.
  2. Turn the ignition switch to LOCK position. Remove instrument cluster and check for burned out Malfunction Indicator Light (MIL) bulb. For removal and installation procedures, see appropriate INSTRUMENT PANELS article in ACCESSORIES & EQUIPMENT. Replace bulb as necessary. If bulb is okay, go to next step.
  3. Check for loose, damaged or corroded terminals at instrument cluster connectors C-29 and C-30. see scheme 46 Repair as necessary. If connections are okay, go to next step.
  4. Turn the ignition switch to ON position. Using DVOM, measure voltage between ground and instrument cluster connector C-29 terminal No. 29 (Black/White wire). If battery voltage is indicated, go to next step. If battery voltage is not indicated, check for loose, damaged or corroded terminals at connectors C-84 and C-87. (Scheme 106) If connections are okay, repair open in Black/White wire between instrument cluster and ignition switch connector C-58 terminal No. 2. see scheme 44
  5. Locate Powertrain Control Module (PCM). See «ELECTRONIC CONTROL MODULE LOCATIONS»(ref-150942-S36194791462002112700000) under SELF-DIAGNOSTIC SYSTEM. Disconnect PCM connector C-39. Check PCM connector C-39 for loose, damaged or corroded terminals. Repair as necessary. If connector is okay, go to next step.
  6. Turn the ignition switch to ON position. Using DVOM, measure voltage between ground and PCM connector C-39 terminal No. 22 (Brown/Black wire). see scheme 53 If battery voltage exists, replace PCM. If battery voltage does not exist, check connector C-17 for loose, damaged or corroded terminals. see scheme 20 Repair as necessary. If connector is okay, repair open in Brown/Black wire between PCM and instrument cluster connector C-29 terminal No. 6.

Scheme 106

Scheme 106
Scheme 106

The most likely causes are

  1. Short-circuit between the service engine soon/malfunction indicator lamp and PCM.
  2. Malfunction of the PCM.
  1. Connect scan tool to Data Link Connector (DLC). (Scheme 105) Turn the ignition switch to ON position. Using scan tool, check for stored DTCs. See «ENTERING ON-BOARD DIAGNOSTICS»(ref-150942-S26272094992002112700000) under SELF-DIAGNOSTIC SYSTEM. If DTCs are present, record all DTCs and go to «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(ref-150942-S26611120572002112700000). If no DTCs are present, go to next step.
  2. Turn the ignition switch to LOCK position. Disconnect instrument cluster connector C-30. see scheme 46 Using DVOM, check for continuity between ground and instrument cluster connector C-30 terminal No. 6 (Brown/Black wire). If continuity does not exist, check connector C-17 for loose, damaged or corroded terminals. see scheme 20 Repair as necessary. If connector is okay, repair short to ground in Brown/Black wire between Powertrain Control Module (PCM) connector C-39 terminal No. 22 and instrument cluster connector C-30 terminal No. 6. see scheme 53 If continuity does not exist, replace PCM.

The most likely causes are

  1. Malfunction of the data link connector.
  2. Damaged wiring harness.
  1. Turn the ignition switch to LOCK position. Using DVOM, measure voltage between ground and Data Link Connector (DLC) terminal No. 16 (Red/Black wire). see scheme 33 If battery voltage exists, go to next step. If battery voltage does not exist, repair connectors and/or wiring between DLC and power supply (fusible link No. 1). see scheme 5 Recheck communication.
  2. Using DVOM, check for continuity between ground and DLC terminals No. 4 and 5 (Black wires). If continuity exists at each terminal, repair or replace scan tool as necessary. If continuity does not exist at one or both terminals, repair appropriate Black wire between ground and DLC. Recheck communication.

The most likely causes are

  1. No power supply to PCM.
  2. Defective ground circuit of PCM.
  3. Defective PCM.
  4. Improper communication line between PCM and scan tool.
  5. Open circuit between PCM and data link connector.
  1. Turn the ignition switch to LOCK position. Locate Powertrain Control Module (PCM). See «ELECTRONIC CONTROL MODULE LOCATIONS»(ref-150942-S36194791462002112700000) under SELF-DIAGNOSTIC SYSTEM. Check PCM connector C-41 for loose, damaged or corroded terminals. see scheme 53 If faulty connections are found, repair as necessary. If connections are okay, go to next step.
  2. Check for loose, damaged or corroded terminals in intermediate connectors C-17 and C-57. If problem does not exist, go to next step. If faulty connections are found, repair as necessary. Recheck communication.
  3. Check for open or short to ground in Red/White wire between Data Link Connector (DLC) terminal No. 7 and PCM connector C-41 terminal No. 85. see scheme 33and see scheme 53. If problem does not exist, check power to PCM. See «WIRING DIAGRAMS»(ref-135498) article. If problem exists, repair Red/White wire. Recheck communication.

DIAGNOSTIC TROUBLE CODE DEFINITIONS

Note. DTCs can only be retrieved by using a scan tool. See ENTERING ON-BOARD DIAGNOSTICS under SELF-DIAGNOSTIC SYSTEM.

When Diagnostic Trouble Code (DTC) is obtained, refer to appropriate DTC test procedure under DIAGNOSTIC TESTS .

DTC (1)Description
P0101Volume Airflow Circuit Range/Performance Problem
P0102Volume Airflow Circuit Low Input
P0106Barometric Pressure Circuit Range/Performance Problem
P0107Barometric Pressure Circuit Low Input
P0108Barometric Pressure Circuit High Input
P0111Intake Air Temperature Circuit Malfunction
P0112Intake Air Temperature Circuit Low Input
P0113Intake Air Temperature Circuit High Input
P0116Engine Coolant Temperature Circuit Range/Performance Problem
P0117Engine Coolant Temperature Circuit Low Input
P0118Engine Coolant Temperature Circuit High Input
P0121Throttle Position Sensor Circuit Range/Performance Problem
P0122Throttle Position Sensor Circuit Low Input
P0123Throttle Position Sensor Circuit High Input
P0125Insufficient Coolant Temperature For Closed Loop Fuel Control
P0128Coolant Thermostat Malfunction
P0132Heated Oxygen Sensor Circuit High Voltage (Sensor 1)
P0133Heated Oxygen Sensor Circuit Slow Response (Sensor 1)
P0134Heated Oxygen Sensor Circuit No Activity Detected (Sensor 1)
P0135Heated Oxygen Sensor Heater Circuit (Sensor 1)
P0137Heated Oxygen Sensor Circuit Low Voltage (Sensor 2)
P0138Heated Oxygen Sensor Circuit High Voltage (Sensor 2)
P0139Heated Oxygen Sensor Circuit Slow Response (Sensor 2)
P0141Heated Oxygen Sensor Heater Circuit (Sensor 2)
P0171System Too Lean Fuel Trim Circuit
P0172System Too Rich Fuel Trim Circuit
P0181Fuel Temperature Sensor Circuit Range/Performance Problem
P0182Fuel Temperature Sensor Circuit Low Input
P0183Fuel Temperature Sensor Circuit High Input
P0201-P0204Injector Circuit
P0300Random/Multiple Cylinder Misfire Detected
P0301-P0304Cylinder 1 Misfire Detected, Cylinder 2 Misfire Detected, Cylinder 3 Misfire Detected, Cylinder 4 Misfire Detected
P0335Crankshaft Position Sensor Circuit
P0340Camshaft Position Sensor Circuit
P0401Exhaust Gas Recirculation Flow Insufficient Detected
P0403Exhaust Gas Recirculation Control Circuit
P0421Warm Up Catalyst Efficiency Below Threshold
P0441Evaporative Emission Control System Incorrect Purge Flow
P0442Evaporative Emission Control System Leak Detected (Small Leak)
P0443Evaporative Emission Control System Purge Control Valve
P0446Evaporative Emission Control System Vent Control Circuit
P0451Evaporative Emission Control System Pressure Sensor Range/Performance
P0452Evaporative Emission Control System Pressure Sensor Low Input
P0453Evaporative Emission Control System Pressure Sensor High Input
P0455Evaporative Emission Control System Leak Detected (Gross Leak)
P0456Evaporative Emission Control System Leak Detected (Very Small Leak)
P0461Fuel Level Sensor Circuit Range/Performance Fuel Gauge Unit Circuit
P0506Idle Control System RPM Less Than Expected Idle Air Control Motor Circuit
P0507Idle Control System RPM More Than Expected Idle Air Control Motor Circuit
P0551Power Steering Pressure Sensor Circuit Range/Performance
P07XX (2)
P1400Manifold Differential Pressure Sensor
P1500Generator FR Terminal Circuit
P1603Battery Backup Circuit Malfunction
P1610Immobilizer Malfunction
(1) Some DTCs use 2 trip malfunction detection logic that required DTC to set 2 times during 2 separate drive cycles for MIL to illuminate. If DTC is for a fault that may affect emissions, MIL will also illuminate. (2) All DTCs P07XX and P1751 are automatic transmission related.
(1)Some DTCs use 2 trip malfunction detection logic that required DTC to set 2 times during 2 separate drive cycles for MIL to illuminate. If DTC is for a fault that may affect emissions, MIL will also illuminate.
(2)All DTCs P07XX and P1751 are automatic transmission related.

DIAGNOSTIC TROUBLE CODE INDEX

DTC Set Conditions

If throttle position sensor output voltage is 1.5 volts or more and engine speed more than 2000 RPM, DTC will set if volume air flow sensor output frequency has continued to be 60 Hz or less for 2 seconds.

If throttle position sensor output voltage is 2 volts or less and engine speed is less than 2000 RPM, DTC will set if volume air flow sensor output frequency has continued to be 800 Hz or more for 2 seconds.

Diagnosis

Note. If PCM is replaced, immobilizer code registration must be performed. See PROGRAMMING .

CAUTIONTo prevent damage to scan tool MB991502, always turn the ignition switch to LOCK position before connecting or disconnecting scan tool.
  1. Connect scan tool to the data link connector. (Scheme 105) Start the engine and run at idle. Set scan tool to the data reading mode for data list item 12: VOLUME AIR FLOW SENSOR. Warm up the engine to normal operating temperature of 178-205°F (80-96°C). The standard value during idling should be 10 Hz or more. When the engine is revved, the frequency should increase according to the increase in engine speed. Turn the ignition switch to LOCK position. If the sensor is not operating properly, go to next step. If the sensor is operating properly, it can be assumed that this malfunction is intermittent.
  2. Check the reset signal voltage at volume air flow sensor connector B-14 by backprobing. Do not disconnect connector B-14. Turn the ignition switch to ON position. Measure the voltage between terminal No. 7 and ground by backprobing. Voltage should be 6.0-9.0 volts. Turn the ignition switch to LOCK position. If voltage is not as specified, go to next step. If voltage is as specified, go to step 5.
  3. Check connector B-14 at volume air flow sensor and connector C-39 at PCM for damage. If the connectors are in good condition, go to next step. If any connector is not in good condition, repair or replace it. Then go to step 9.
  4. Check for short circuit to ground between volume air flow sensor connector B-14 terminal No. 7 and PCM connector C-39 terminal No. 19. If the wiring harness is in good condition, replace the volume air flow sensor. Then go to step 9. If the wiring harness is not in good condition, repair it. Then go to step 9.
  5. Check the reset signal voltage at volume air flow sensor connector B-14 by backprobing. Do not disconnect the connector B-14. Start the engine and run at idle. Measure the voltage between terminal No. 7 and ground by backprobing. When the engine is idling, voltage should be 1.0 volt or less. When the engine speed is 3000 RPM, voltage should be 6.0-9.0 volts. Turn the ignition switch to LOCK position. If voltage is not as specified, go to next step. If voltage is as specified, go to step 8.
  6. Check connector B-14 at volume air flow sensor and connector C-39 at PCM for damage. If the connectors are in good condition, go to next step. If any connector is not in good condition, repair or replace it. Then go to step 9.
  7. Check for open circuit and harness damage between volume air flow sensor connector B-14 terminal No. 7 and PCM connector C-39 terminal No. 19. If the wiring harness is in good condition, replace the PCM. Then go to step 9. If the wiring harness is not in good condition, repair it. Then go to step 9.
  8. Replace the volume air flow sensor. Carry out a test drive with the drive cycle pattern. See «OTHER MONITOR»(ref-150942-S38112384672002112700000) under VERIFYING REPAIRS. Check the DTC. If DTC P0101 is output, replace the PCM. Then go to next step. If DTC P0101 is not output, the inspection is complete.
  9. Carry out test drive with the drive cycle pattern. See «OTHER MONITOR»(ref-150942-S38112384672002112700000) under VERIFYING REPAIRS. Check the DTC. If the DTC P0101 is output, repeat diagnosis. If the DTC P0101 is not output, the inspection is complete.

When engine speed is more than 500 RPM and volume air flow sensor output frequency has continued to be 3.3 Hz or less for 2 seconds.

Note. If PCM is replaced, immobilizer code registration must be performed. See PROGRAMMING .

CAUTIONTo prevent damage to scan tool, always turn the ignition switch to LOCK position before connecting or disconnecting scan tool.
  1. Connect scan tool to the data link connector. (Scheme 105) Start the engine and run at idle. Set scan tool to the data reading mode for data list item 12: VOLUME AIR FLOW SENSOR. Warm up the engine to normal operating temperature of 176-205°F (80-96°C). The standard value during idling should be 10 Hz or more. When the engine is revved, the frequency should increase according to the increase in engine speed. Turn the ignition switch to LOCK position. If the sensor is not operating properly, go to next step. If the sensor is operating properly it can be assumed that this malfunction is intermittent.
  2. Do not disconnect the connector B-14. Turn the ignition switch to ON position. Measure the voltage between volume air flow sensor connector B-14 terminal No. 4 and ground by backprobing. Voltage should be battery positive voltage. Turn the ignition switch to LOCK position. If the voltage is not as specified go to next step. If the voltage is as specified, go to step 5.
  3. Disconnect the connector B-14. Turn the ignition switch to ON position. Measure the voltage between connector B-14 terminal No. 4 and ground. Voltage should be battery positive voltage. Turn the ignition switch to LOCK position. If the voltage is as specified, go to next step. If the voltage is not as specified, repair wiring harness between MFI relay connector B-18X terminal No. 4 and volume air flow sensor connector B-14 terminal No. 4 because of open circuit or short circuit to ground. Then go to step 13.
  4. Check connector B-14 at the volume air flow sensor for damage. If the connector is in good condition, repair wiring harness between MFI relay connector B-18X terminal No. 4 and volume air flow sensor connector B-14 terminal No. 4 because of harness damage. Then go to step 13. If the connector is not in good condition, repair or replace it. Then go to step 13.
  5. Check connector B-14 at volume air flow sensor for damage. If the connector is in good condition, go to next step. If the connector is not in good condition, repair or replace it. Then go to step 13.
  6. Disconnect the volume air flow sensor harness connector B-14 and measure at the harness aide. Turn the ignition switch to ON position. Measure the voltage between terminal No. 3 and ground. Voltage should be 4.8-5.2 volts. Turn the ignition switch to LOCK position. If the voltage is not as specified, go to next step. If the voltage is as specified, go to step 9.
  7. Check connector C-40 at PCM for damage. If the harness connector is in good condition, go to next step. If the harness connector is not in good condition, repair or replace it. Then go to step 13.
  8. Check for short circuit to ground between volume air flow sensor connector B-14 terminal No. 3 and PCM connector C-40 terminal No. 65. If the wiring harness is in good condition, replace the PCM. Then go to step 13. If the wiring harness is not in good condition, repair it. Then go to step 13.
  9. Disconnect the volume air flow sensor connector B-14 and measure terminal No. 5 at harness side. Check for continuity between terminal No. 5 and ground. Resistance should be less than 2 ohms. If the continuity is not as specified, go to next step. If the continuity is as specified, go to step 12.
  10. Check connector C-39 at PCM for damage. If the harness connector is in good condition, go to next step. If the harness connector is not in good condition, repair or replace it. Then go to step 13.
  11. Check for open circuit and harness damage between volume air flow sensor connector B-14 terminal No. 5 and PCM connector C-39 terminal No. 16. If the wiring harness is in good condition, replace the PCM. Then go to step 13. If the wiring harness is not in good condition, repair it. Then go to step 13.
  12. Check connector C-39 at PCM for damage. If the connector is in good condition, replace the volume air flow sensor. Then go to next step. If the connector is not in good condition, repair or replace it. Then go to next step.
  13. Carry out a test drive with the drive cycle pattern. See «OTHER MONITOR»(ref-150942-S38112384672002112700000) under VERIFYING REPAIRS. Check the DTC. If the DTC P0102 is output, repeat diagnosis. If the DTC P0102 is not output, the inspection is complete.

Check conditions are when barometric pressure is less than 76 kPa (11 psi). Judgement criteria is when during 15 times of driving, the changes in the sensor output voltage should be 0.015 volt, equivalent to 0.06 PSI (0.4 kPa) or less. Make sure that the engine coolant temperature is 162°F (72° C) or more during each of the 15 times of driving. Also, during each of the 15 times of driving, make sure that after the engine has been started, the engine coolant temperature has increased 41°F (23°C) or more.

CAUTIONTo prevent damage to scan tool MB991502, always turn the ignition switch to LOCK position before connecting or disconnecting scan tool.

Note. If PCM is replaced, immobilizer code registration must be performed. See PROGRAMMING .

  1. Connect scan tool to the data link connector. (Scheme 105) Turn the ignition switch to ON position. Using scan tool, read the Diagnostic Trouble Code (DTC). Turn the ignition switch to LOCK position. If the DTC P0107 is not output, go to next step. If the DTC P0107 is output, go to «DTC P0107: BAROMETRIC PRESSURE CIRCUIT LOW INPUT»(ref-150942-S01061586192002112700000).
  2. Check connector B-14 at the barometric pressure sensor for damage. If the connector is in good condition, go to next step. If the connector is not in good condition, repair or replace it. Then go to step 9.
  3. Check the continuity at barometric pressure sensor harness side connector B-14. Disconnect the connector B-14 and measure at the harness side. Check for continuity between terminal No. 5 and ground. Resistance should be less than 2 ohms. If the continuity is not as specified, go to next step. If the continuity is as specified, go to step 6.
  4. Check connector C-39 at PCM for damage. If the connector is in good condition, go to next step. If the connector is not in good condition, repair or replace it. Then go to step 9.
  5. Check for open circuit and harness damage between barometric pressure sensor connector B-14 and PCM connector C-39. If the wiring harness is in good condition, replace the PCM. Then go to step 9. If the wiring harness is not in good condition, repair it. Then go to step 9.
  6. Check connector C-40 at PCM for damage. If the connector is in good condition, go to next step. If the connector is not in good condition, repair or replace it. Then go to step 9.
  7. Check for open circuit and harness damage between barometric pressure sensor connector B-14 and PCM connector C-40. If the wiring harness is in good condition, go to next step. If the wiring harness is not in good condition, repair it. Then go to step 9.
  8. Replace the barometric pressure sensor. Carry out a test drive with the drive cycle pattern. See «OTHER MONITOR»(ref-150942-S38112384672002112700000) under VERIFYING REPAIRS. Check the Diagnostic Trouble Code (DTC). If the DTC P0106 is output, replace the PCM. Then go to next step. If the DTC P0106 is not output, the inspection is complete.
  9. Test the OBD-II drive cycle. Carry out a test drive with the drive cycle pattern. See «OTHER MONITOR»(ref-150942-S38112384672002112700000) under VERIFYING REPAIRS. Check the Diagnostic Trouble Code (DTC). If the DTC P0106 is output, repeat diagnosis. If the DTC P0106 is not output, the inspection is complete.

Check conditions are when 2 seconds or more have passed since the starting sequence was completed and battery positive voltage is more than 8 volts. DTC is set when barometric pressure sensor output has continued to be 7.1 psi (49 kPa) or less (approximately 15,000 ft. above sea level) for 10 seconds.

CAUTIONTo prevent damage to scan tool, always turn the ignition switch to LOCK position before connecting or disconnecting scan tool.

Note. If PCM is replaced, immobilizer code registration must be performed. See PROGRAMMING .

  1. Connect scan tool to the data link connector. (Scheme 105) Turn the ignition switch to ON position. Set scan tool to the data reading mode for data list item 25: BAROMETRIC PRESSURE SENSOR. See «BAROMETRIC PRESSURE SENSOR SPECIFICATIONS»(ref-150942-S26616762402002112700000) table. Turn the ignition switch to LOCK position. If the sensor is not operating properly, go to next step. If the sensor is operating properly, it can be assumed that this malfunction is intermittent. BAROMETRIC PRESSURE SENSOR SPECIFICATIONS Altitude - Feet (Meters) Pressure 0 (0) 101 kPa 1969 (600) 95 kPa 3937 (1200) 88 kPa 5906 (1800) 81 kPa
  2. Check the sensor output voltage at barometric pressure sensor connector B-14 by backprobing. Do not disconnect the connector B-14. Turn the ignition switch to ON position. Measure the voltage between terminal No. 2 and ground by backprobing. See «BAROMETRIC PRESSURE SENSOR VOLTAGE OUTPUT»(ref-150942-S12596781182002112700000) table. Turn the ignition switch to LOCK position. If the voltage is as specified, go to next step. If the voltage is not as specified, go to step 7. BAROMETRIC PRESSURE SENSOR VOLTAGE OUTPUT Altitude - Feet (Meters) Voltage 0 (0) 3.7-4.3 1969 (600) 3.4-4.0 3937 (1200) 3.2-3.8 5906 (1800) 2.9-3.5
  3. Check the sensor output voltage at PCM connector C-40 by backprobing. Do not disconnect the connector. Turn the ignition switch to ON position. Measure the voltage between terminal No. 55 and ground by backprobing. See «BAROMETRIC PRESSURE SENSOR VOLTAGE OUTPUT»(ref-150942-S12596781182002112700000) table. Turn the ignition switch to LOCK position. If the voltage is as specified, go to next step. If the voltage is not as specified, go to step 6.
  4. Check connector B-14 at the barometric pressure sensor and connector C-40 at PCM for damage. If the connectors are in good condition, go to next step. If the connectors are not in good condition, repair or replace them. Then go to step 18.
  5. Using scan tool, check barometric pressure sensor. Connect scan tool to the data link connector. Turn the ignition switch to ON position. Set scan tool to the data reading mode for data list item 25: BAROMETRIC PRESSURE SENSOR. See «BAROMETRIC PRESSURE SENSOR SPECIFICATIONS»(ref-150942-S26616762402002112700000) table. Turn the ignition switch to LOCK position. If the sensor is operating properly, it can be assumed that this malfunction is intermittent. If the sensor is not operating properly, replace the PCM. Then go to step 18.
  6. Check connector B-14 at the barometric pressure sensor and connector C-40 at PCM for damage. If the connectors are in good condition, repair wiring harness between barometric pressure sensor connector B-14 terminal No. 2 and PCM connector C-40 terminal No. 55 open circuit or harness damage. Then go to step 18. If the connectors are not in good condition, repair or replace it. Then go to step 18.
  7. Check the sensor supply voltage at barometric pressure sensor connector B-14 by backprobing. Do not disconnect the connector B-14. Turn the ignition switch to ON position. Measure the voltage between terminal No. 1 and ground by backprobing. Voltage should be 4.8-5.2 volts. Turn the ignition switch to LOCK position. If the voltage is not as specified, go to next step. If the voltage is as specified, go to step 12.
  8. Check the sensor supply voltage at PCM connector C-40 by backprobing. Do not disconnect the PCM connector. Turn the ignition switch to ON position. Measure the voltage between terminal or 46 and ground by backprobing. Voltage should be 4.8-5.2 volts. Turn the ignition switch to LOCK position. If the voltage is as specified, go to next step. If the voltage is not as specified, go to step 10.
  9. Check connector B-14 at the barometric pressure sensor and connector C-40 at PCM for damage. If the connectors are in good condition, repair wiring harness between barometric pressure sensor connector B-14 terminal No. 1 and PCM connector C-40 terminal No. 46 for open circuit or harness damage. Then go to step 18. If the connectors are not in good condition, repair or replace them. Then go to step 18.
  10. Check connector B-14 at the barometric pressure sensor and connector C-40 at PCM for damage. If the connectors are in good condition, go to next step. If the connectors are not in good condition, repair or replace them. Then go to step 18.
  11. Check for short circuit to ground between barometric pressure sensor connector B-14 terminal No. 1 and PCM connector C-40 terminal No. 46. If the wiring harness is in good condition, replace the PCM. Then go to step 18. If the wiring harness is not in good condition, repair it. Then go to step 18.
  12. Check the ground voltage at barometric pressure sensor connector B-14 by backprobing. Do not disconnect the connector B-14. Turn the ignition switch to ON position. Measure the voltage between terminal No. 5 and ground by backprobing. Voltage should be 0.5 volt or less. Turn the ignition switch to LOCK position. If the voltage is not as specified, go to next step. If the voltage is as specified, go to step 15.
  13. Check connector B-14 at the barometric pressure sensor and connector C-39 at PCM for damage. If the connectors are in good condition, go to next step. If the connectors are not in good condition, repair or replace them. Then go to step 18.
  14. Check for harness damage between barometric pressure sensor connector B-14 terminal No. 5 and PCM connector C-39 terminal No. 16. If the wiring harness is in good condition, replace the PCM. Then go to step 18. If the wiring harness is not in good condition, repair it. Then go to step 18.
  15. Check connector B-14 at barometric pressure sensor for damage. If the connector is in good condition, go to next step. If the connector is not in good condition, repair or replace it. Then go to step 18.
  16. Check connector C-40 at PCM for damage. If the connector is in good condition, go to next step. If the connector is not in good condition, repair or replace it. Then go to step 18.
  17. Check for short circuit to ground and harness damage between barometric pressure sensor connector B-14 terminal No. 2 and PCM connector C-40 terminal No. 55. If the wiring harness is in good condition, replace the volume air flow sensor. Then go to step 18. If the wiring harness is not in good condition, repair it. Then go to step 18.
  18. Test the OBD-II drive cycle. Carry out a test drive with the drive cycle pattern. See «OTHER MONITOR»(ref-150942-S38112384672002112700000) under VERIFYING REPAIRS. Check the DTC. If the DTC P0107 is output, repeat diagnosis. If the DTC P0107 is not output, the inspection is complete.

Check conditions are when 2 seconds or more have passed since the starting sequence was completed. Battery positive voltage is more than 8 volts. Judgement criteria is when barometric pressure sensor output has continued to be 16 psi (113 kPa) or more (approximately 4000 ft below sea level) for 10 seconds.

The most likely causes for this code to be set are

  1. Barometric pressure sensor failed.
  2. Open or shorted barometric pressure sensor circuit, or loose connector.
  3. PCM failed.
CAUTIONTo prevent damage to scan tool always turn the ignition switch to LOCK position before connecting or disconnecting scan tool.

Note. If PCM is replaced, immobilizer code registration must be performed. See PROGRAMMING .

  1. Using scan tool, check barometric pressure sensor. Connect scan tool to the data link connector. (Scheme 105) Turn the ignition switch to ON position. Set scan tool to the data reading mode for data list item 25: BAROMETRIC PRESSURE SENSOR. Check scan tool output. See «BAROMETRIC PRESSURE SENSOR PRESSURE OUTPUT»(ref-150942-S14820193722002112700000) table. Turn the ignition switch to LOCK position. If the sensor is not operating properly, go to next step. If the sensor is operating properly, it can be assumed that this malfunction is intermittent. BAROMETRIC PRESSURE SENSOR PRESSURE OUTPUT Altitude - Feet (Meters) Scan Tool Output (kPa) 0 (0) 101 1969 (600) 95 3937 (1200) 88 5906 (1800) 81
  2. Check the sensor output voltage at barometric pressure sensor connector B-14 by backprobing. Do not disconnect the connector B-14. Turn the ignition switch to ON position. Measure the voltage between terminal No. 2 and ground by backprobing. See «BAROMETRIC PRESSURE SENSOR VOLTAGE OUTPUT»(ref-150942-S20989627822002112700000) table. Turn the ignition switch to LOCK position. If the voltage is as specified, go to next step. If the voltage is not as specified, go to step 5. BAROMETRIC PRESSURE SENSOR VOLTAGE OUTPUT Altitude - Feet (Meters) Voltage 0 (0) 3.7-4.3 1969 (600) 3.4-4.0 3937 (1200) 3.2-3.8 5906 (1800) 2.9-3.5
  3. Check connector B-14 at the barometric pressure sensor and PCM connector C-40 for damage. If the connector is in good condition, go to next step. If the connector is not in good condition, repair or replace it. Then go to step 12.
  4. Using scan tool, check barometric pressure sensor. Connect scan tool to the data link connector. Turn the ignition switch to ON position. Set scan tool to the data reading mode for data list item 25: BAROMETRIC PRESSURE SENSOR. Check scan tool output. See «BAROMETRIC PRESSURE SENSOR PRESSURE OUTPUT»(ref-150942-S14820193722002112700000) table. Turn the ignition switch to LOCK position. If the sensor is not operating properly, replace the PCM. Then go to step 12. If the sensor is operating properly, it can be assumed that this malfunction is intermittent.
  5. Check the sensor supply voltage at barometric pressure sensor connector B-14 by backprobing. Do not disconnect the connector B-14. Turn the ignition switch to ON position. Measure the voltage between terminal No. 1 and ground by backprobing. Voltage should be 4.8-5.2 volts. Turn the ignition switch to LOCK position. If voltage is not as specified, go to next step. If voltage is as specified, go to step 7.
  6. Check connector C-40 at PCM for damage. If the connector is in good condition, replace the PCM. Then go to step 12. If the connector is in good condition, repair or replace it. Then go to step 12.
  7. Check the ground voltage at barometric pressure sensor connector B-14 by backprobing. Do not disconnect the connector B-14. Turn the ignition switch to ON position. Measure the voltage between terminal No. 5 and ground by backprobing. Voltage should be 0.5 volt or less. Turn the ignition switch to LOCK position. If voltage is not as specified, go to next step. If voltage is as specified, go to step 10.
  8. Check connector B-14 at the barometric pressure sensor and connector C-39 at PCM for damage. If the connectors are in good condition, go to next step. If any connector is not in good condition, repair or replace it. Then go to step 12.
  9. Check for open circuit between barometric pressure sensor connector B-14 terminal No. 5 and PCM connector C-39 terminal No. 16. If wiring harness is in good condition, replace the PCM. Then go to step 12. If wiring harness is not in good condition, repair it. Then go to step 12.
  10. Check connector B-14 at barometric pressure sensor for damage. If the connector is in good condition, go to next step. If the connector is not in good condition, repair or replace it. Then go to step 12.
  11. Check connector C-39 at PCM for damage. If the connector is in good condition, replace the volume air flow sensor. Go to next step. If the connector is not in good condition, repair or replace it. Go to next step.
  12. Test the OBD-II drive cycle. Carry out a test drive with the drive cycle pattern. See «OTHER MONITOR»(ref-150942-S38112384672002112700000) under VERIFYING REPAIRS. Check the diagnostic trouble code (DTC) P0108. If DTC P0108 is output, repeat diagnosis. If DTC P0108 is not output, inspection is complete.

Check conditions are when engine coolant temperature is more than 169°F (76°C). Check conditions must repeat 5 or more times in order; drive 1, stop 2. Drive 1 is when vehicle speed more than 31 mph (50 km/h) lasting a total of more than 60 seconds. Stop 2 is when vehicle speed less than 0.9 mph (1.5 km/h) lasting more than 30 seconds. Judgement criteria is when change in the intake air temperature is less than 1.8°F (1°C).

The most likely causes for this code to be set are

  1. Intake air temperature sensor failed.
  2. Open or shorted intake air temperature sensor circuit, or loose connector.
  3. PCM failed.
CAUTIONTo prevent damage to scan tool, always turn the ignition switch to LOCK position before connecting or disconnecting scan tool.

Note. If PCM is replaced, immobilizer code registration must be performed. See PROGRAMMING .

Scheme 107

Scheme 107
Scheme 107
  1. Using scan tool, check intake air temperature sensor. Connect scan tool to the data link connector. (Scheme 105) Remove the air intake hose from the volume air flow sensor. Turn the ignition switch to ON position. Set scan tool to the data reading mode for data list item 13: INTAKE AIR TEMPERATURE SENSOR. Heat the sensor using a hair drier. (Scheme 107) The indicated temperature should increase. Do not allow sensor temperature to increase over 176°F (80°C). Turn the ignition switch to LOCK position. Attach the air intake hose. If the sensor is operating properly, it can be assumed that this malfunction is intermittent. If the sensor is not operating properly, go to next step.
  2. Check the intake air temperature sensor. Disconnect the intake air temperature sensor connector B-14. Measure the resistance between intake air temperature sensor side connector terminals No. 5 and 6. Measure resistance while heating the sensor using a hair drier. See «INTAKE AIR TEMPERATURE SENSOR RESISTANCE»(ref-150942-S05091851152002112700000) table. If the resistance is as specified, go to next step. If the resistance is not as specified, replace the volume air flow sensor. Then go to step 9. INTAKE AIR TEMPERATURE SENSOR RESISTANCE Temperature - °F (°C) k/Ohms -4 (-20) 13-17 32 (0) 5.3-6.7 68 (20) 2.3-3.0 104 (40) 1.0-1.5 140 (60) 0.56-0.76 176 (80).30-.42
  3. Check connector B-14 at the intake air temperature sensor for damage. If the connector is in good condition, go to next step. If the connector is not in good condition, repair or replace it. Then go to step 9.
  4. Check the continuity at intake air temperature sensor harness side connector B-14. Disconnect the connector B-14 and measure at the harness side. Check for the continuity between terminal No. 5 and ground. Resistance should be less than 2 ohms. If continuity is not as specified, go to next step. If continuity is as specified, go to step 7.
  5. Check connector C-39 at PCM for damage. If the connector is in good condition, go to next step. If the connector is not in good condition, repair or replace it. Then go to step 9.
  6. Check for open circuit and harness damage between intake air temperature sensor connector B-14 and PCM connector C-39. If wiring harness is in good condition, replace the PCM. Then go to step 9. If wiring harness is not in good condition, repair it. Then go to step 9.
  7. Check connector C-40 at PCM for damage. If the connector is in good condition, go to next step. If the connector is not in good condition, repair or replace it. Then go to step 9.
  8. Check for open circuit and harness damage between intake air temperature sensor connector B-14 and PCM connector C-40. If wiring harness is in good condition, replace the PCM. Then go to next step. If wiring harness is not in good condition, repair it. Then go to next step.
  9. Test the OBD-II drive cycle. Carry out a test drive with the drive cycle pattern. See «OTHER MONITOR»(ref-150942-S38112384672002112700000) under VERIFYING REPAIRS. Check the Diagnostic Trouble Code (DTC). If DTC P0111 is output, repeat diagnosis. If DTC P0111 is not output, inspection is complete.

Check conditions are when 2 seconds or more have passed since the starting sequence was completed. Judgement criteria is when intake air temperature sensor output voltage has continued to be 0.2 volt or less, corresponding to an air intake temperature of 239°F (115°C) or more, for 2 seconds.

The most likely causes for this code to be set are

  1. Open or shorted intake air temperature sensor circuit, or loose connector.
  2. Intake Air Temperature (IAT) sensor failed.
  3. PCM failed.
CAUTIONTo prevent damage to scan tool, always turn the ignition switch to LOCK position before connecting or disconnecting scan tool.

Note. If PCM is replaced, immobilizer code registration must be performed. See PROGRAMMING .

  1. Using scan tool, check intake air temperature sensor. Connect scan tool to the data link connector. (Scheme 105) Turn the ignition switch to ON position. Set scan tool to the data reading mode for data list item 13: INTAKE AIR TEMPERATURE SENSOR. The intake air temperature and temperature shown with the scan tool should approximately match. Turn the ignition switch to LOCK position. If the sensor is not operating properly, go to next step. If the sensor is operating properly, it can be assumed that this malfunction is intermittent.
  2. Check connector B-14 at the intake air temperature sensor for damage. If the connector is in good condition, go to next step. If the connector is not in good condition, repair or replace it. Then go to step 6.
  3. Check the intake air temperature sensor. Disconnect the intake air temperature sensor connector B-14. Measure the resistance between intake air temperature sensor side connector terminals No. 5 and 6. There should be continuity (0.30-1.0 k/ohms). If the resistance is as specified, go to next step. If the resistance is not as specified, replace the volume air flow sensor. Then go to step 6.
  4. Check for short circuit to ground between intake air temperature sensor connector B-14 and PCM connector C-40. If wiring harness is in good condition, go to next step. If wiring harness is not in good condition, repair it. Then go to step 6.
  5. Check connector C-40 at PCM for damage. If the connector is in good condition, replace the PCM. Then go to next step. If the connector is in good condition, repair or replace it. Then go to next step.
  6. Test the OBD-II drive cycle. Carry out a test drive with the drive cycle pattern. See «OTHER MONITOR»(ref-150942-S38112384672002112700000) under VERIFYING REPAIRS. Check the Diagnostic Trouble Code (DTC). If DTC P0112 is output, repeat diagnosis. If DTC P0112 is not output, inspection is complete.

Check conditions are when 2 seconds or more have passed since the starting sequence was completed. Judgement criteria is when intake air temperature sensor output voltage has continued to be 4.5 volts or more, corresponding to an air intake temperature of -104°F (-40°C) or less, for 2 seconds.

The most likely causes for this code to be set are

  1. Intake air temperature sensor failed.
  2. Open or shorted intake air temperature sensor circuit, or loose connector.
  3. PCM failed.
CAUTIONTo prevent damage to scan tool, always turn the ignition switch to LOCK position before connecting or disconnecting scan tool.

Note. If PCM is replaced, immobilizer code registration must be performed. See PROGRAMMING .

  1. Using scan tool, check data list item 13: INTAKE AIR TEMPERATURE SENSOR. Connect scan tool to the data link connector. (Scheme 105) Turn the ignition switch to ON position. Set scan tool to the data reading mode for data list item 13: INTAKE AIR TEMPERATURE SENSOR. The intake air temperature and temperature shown with the scan tool should approximately match. Turn the ignition switch to LOCK position. If the sensor is not operating properly, go to next step. If the sensor is operating properly, it can be assumed that this malfunction is intermittent.
  2. Check connector B-14 at the intake air temperature sensor for damage. If the connector is in good condition, go to next step. If the connector is not in good condition, repair or replace it. Then go to step 11.
  3. Check the intake air temperature sensor. Disconnect the intake air temperature sensor connector B-14. Measure the resistance between intake air temperature sensor side connector terminals No. 5 and 6. There should be continuity (0.30-1.0 k/ohms). If the resistance is as specified, go to next step. If the resistance is not as specified, replace the volume air flow sensor. Then go to step 11.
  4. Check the sensor supply voltage at intake air temperature sensor harness side connector B-14. Disconnect the connector B-14 and measure at the harness side. Turn the ignition switch to ON position. Measure the voltage between terminal No. 6 and ground. Voltage should be 4.5-4.9 volts. Turn the ignition switch to LOCK position. If voltage is not as specified, go to next step. If voltage is as specified, go to step 8.
  5. Check the sensor supply voltage at PCM connector C-40 by backprobing. Do not disconnect the PCM connector C-40. Disconnect the intake air temperature sensor connector B-14. Turn the ignition switch to ON position. Measure the voltage between terminal No. 64 and ground by backprobing. Voltage should be 4.5-4.9 volts. Turn the ignition switch to LOCK position. If the voltage is as specified, go to next step. If the voltage is not as specified, go to step 7.
  6. Check connector C-40 at PCM for damage. If the connector is in good condition, repair wiring harness between intake air temperature sensor connector B-14 and PCM connector C-40 because of open circuit. Then go to step 11. If the connector is not in good condition, repair or replace it. Then go to step 11.
  7. Check connector C-40 at PCM for damage. If the connector is in good condition, replace the PCM. Then go to step 11. If the connector is in good condition, repair or replace it. Then go to step 11.
  8. Check the continuity at intake air temperature sensor harness side connector B-14. Disconnect the connector B-14 and measure at the harness side. Check for the continuity between terminal No. 5 and ground. Resistance should be less than 2 ohms. If continuity is not as specified, go to next step. If continuity is as specified, replace the PCM. Then go to step 11.
  9. Check connector C-39 at PCM for damage. If the connector is in good condition, go to next step. If the connector is not in good condition, repair or replace it. Then go to step 11.
  10. Check for open circuit between intake air temperature sensor connector B-14 and PCM connector C-39. If wiring harness is in good condition, replace the PCM. Then go to next step. If wiring harness is not in good condition, repair it. Then go to next step.
  11. Test the OBD-II drive cycle. Carry out a test drive with the drive cycle pattern. See «OTHER MONITOR»(ref-150942-S38112384672002112700000) under VERIFYING REPAIRS. Check the Diagnostic Trouble Code (DTC). If DTC P0113 is output, repeat diagnosis. If DTC P0113 is not output, inspection is complete.

Check conditions are when engine coolant temperature was 45°F (7°C) or more immediately before the engine was stopped at the last drive. Engine coolant temperature was 45°F (7°C) or more when the engine started. Only one monitor during one drive cycle. Judgement criteria is when engine coolant temperature fluctuates within 1.8°F (1°C) after 5 minutes have passed since the engine was started. However, time is not counted if any of the following conditions are met

  1. Intake air temperature is 140°F (60°C) or more.
  2. Volume air flow sensor output frequency is 70 Hz or less.
  3. During fuel shut-off operation.

The most likely causes for this code to be set are

  1. Engine coolant temperature sensor failed.
  2. Open or shorted engine coolant temperature sensor circuit, or loose connector.
  3. PCM failed.
CAUTIONTo prevent damage to scan tool, always turn the ignition switch to LOCK position before connecting or disconnecting scan tool.

Note. If PCM is replaced, immobilizer code registration must be performed. See PROGRAMMING .

  1. Using scan tool, check data list item 21: ENGINE COOLANT TEMPERATURE SENSOR. Connect scan tool to the data link connector. (Scheme 105) Turn the ignition switch to ON position. Set scan tool to the data reading mode for data list item 21: ENGINE COOLANT TEMPERATURE SENSOR. The engine coolant temperature and temperature shown with the scan tool should approximately match. Turn the ignition switch to LOCK position. If the sensor is operating properly, it can be assumed that this malfunction is intermittent. If the sensor is not operating properly, go to next step.
  2. Check the sensor output voltage at engine coolant temperature sensor connector B-13 by backprobing. Do not disconnect the connector B-13. Turn the ignition switch to ON position. Measure the voltage between terminal No. 1 and ground by backprobing. See «ENGINE COOLANT TEMPERATURE SENSOR VOLTAGE»(ref-150942-S07662031222002112700000) table. Turn the ignition switch to LOCK position. If the voltage is as specified, go to next step. If the voltage is not as specified, go to step 5. ENGINE COOLANT TEMPERATURE SENSOR VOLTAGE Temperature - °F (°C) Voltage -4 (-20) 3.9-4.5 32 (0) 3.2-3.8 68 (20) 2.3-2.9 104 (40) 1.3-1.9 140 (60) 0.7-1.3 176 (80) 0.3-0.9
  3. Check connector B-13 at the engine coolant temperature sensor for damage. If the connector is in good condition, go to next step. If the connector is not in good condition, repair or replace it. Then go to step 14.
  4. Using scan tool, check data list item 21: ENGINE COOLANT TEMPERATURE SENSOR. Connect scan tool to the data link connector. (Scheme 105) Turn the ignition switch to ON position. Set scan tool to the data reading mode for data list item 21: ENGINE COOLANT TEMPERATURE SENSOR. The engine coolant temperature and temperature shown with the scan tool should approximately match. Turn the ignition switch to LOCK position. If the sensor is not operating properly, replace the PCM. Then go to step 14. If the sensor is operating properly, it can be assumed that this malfunction is intermittent.
  5. Check connector B-13 at engine coolant temperature sensor for damage. If the connector is in good condition, go to next step. If the connector is not in good condition, repair or replace it. Then go to step 14.
  6. Check the sensor supply voltage at engine coolant temperature sensor harness side connector B-13. Disconnect the connector B-13 and measure at the harness side. Turn the ignition switch to ON position. Measure the voltage between terminal No. 1 and ground. Voltage should be 4.5-4.9 volts. Turn the ignition switch to LOCK position. If voltage is not as specified, go to next step. If voltage is as specified, go to step 8.
  7. Check connector C-40 at PCM for damage. If the connector is in good condition, replace the PCM. Then go to step 14. If the connector is not in good condition, repair or replace it. Then go to step 14.
  8. Check the continuity at engine coolant temperature sensor harness side connector B-13. Disconnect the connector B-13 and measure at the harness side. Check for the continuity between terminal No. 2 and ground. Resistance should be less than 2 ohms. If continuity is not as specified, go to next step. If continuity is as specified, go to step 11.
  9. Check connector C-40 at PCM for damage. If the connector is in good condition, go to next step. If the connector is not in good condition, repair or replace it. Then go to step 14.
  10. Check for harness damage between engine coolant temperature sensor connector B-13 terminal No. 2 and PCM connector C-40 terminal No. 57. If wiring harness is in good condition, replace the PCM. Then go to step 14. If wiring harness is not in good condition, repair it. Then go to step 14.
  11. Check the engine coolant temperature sensor. Disconnect the engine coolant temperature sensor connector B-13. Remove the engine coolant temperature sensor. With the temperature sensing portion of engine coolant temperature sensor immersed in hot water, check resistance. See «ENGINE COOLANT TEMPERATURE SENSOR RESISTANCE»(ref-150942-S30003218732002112700000) table. If the resistance is as specified, replace the PCM. Then go to step 14. If the resistance is not as specified, replace the engine coolant temperature sensor. Apply 3M AAD (8731) on the screw section of the engine coolant temperature sensor. Install the engine coolant temperature sensor, and tighten to 15-29 ft. lbs. (19-39 N.m). Then go to step 14. ENGINE COOLANT TEMPERATURE SENSOR RESISTANCE Temperature °F (°C) k/Ohms -4 (-20) 14-17 32 (0) 5.1 -6.5 68 (20) 2.1 -2.7 104 (40) 0.9 - 1.3 140 (60) 0.48 -0.68 176 (80) 0.26 -0.36
  12. Check connector C-40 at PCM for damage. If the connector is in good condition, go to next step. If the connector is not in good condition, repair or replace it. Then go to step 14.
  13. Check for harness damage between engine coolant temperature sensor connector B-13 terminal No. 1 and PCM connector C-40 terminal No. 44. If wiring harness is in good condition, replace the PCM. Then go to next step. If wiring harness is not in good condition, repair it. Then go to next step.
  14. Test the OBD-II drive cycle. Carry out a test drive with the drive cycle pattern. See «OTHER MONITOR»(ref-150942-S38112384672002112700000) under VERIFYING REPAIRS. Check the Diagnostic Trouble Code (DTC). If DTC P0116 is output, repeat diagnosis. If DTC P0116 is not output, inspection is complete.

Check conditions are when 2 seconds or more have passed since the staring sequence was completed. Judgement criteria is when engine coolant temperature sensor output voltage has continued to be 0.1 volt or less, corresponding to a coolant temperature of 284°F (140°C) or more, for 2 seconds.

The most likely causes for this code to be set are

  1. Engine coolant temperature sensor failed.
  2. Open or shorted engine coolant temperature sensor circuit, or loose connector.
  3. PCM failed.
CAUTIONTo prevent damage to scan tool, always turn the ignition switch to LOCK position before connecting or disconnecting scan tool.

Note. If PCM is replaced, immobilizer code registration must be performed. See PROGRAMMING .

  1. Using scan tool, check data list item 21: ENGINE COOLANT TEMPERATURE SENSOR. Connect scan tool to the data link connector. (Scheme 105) Turn the ignition switch to ON position. Set scan tool to the data reading mode for data list item 21: ENGINE COOLANT TEMPERATURE SENSOR. The engine coolant temperature and temperature shown with the scan tool should approximately match. Turn the ignition switch to LOCK position. If the sensor is not operating properly, go to next step. If the sensor is operating properly, it can be assumed that this malfunction is intermittent.
  2. Check connector B-13 at the engine coolant temperature sensor for damage. If the connector is in good condition, go to next step. If the connector is not in good condition, repair or replace it. Then go to step 6.
  3. Check for short circuit to ground between engine coolant temperature sensor connector B-13 and PCM connector C-40. If wiring harness is in good condition, go to next step. If wiring harness is not in good condition, repair it. Then go to step 6.
  4. Check connector C-40 at PCM for damage. If the connector is in good condition, go to next step. If the connector is not in good condition, repair or replace it. Then go to step 6.
  5. Check the engine coolant temperature sensor. Disconnect the engine coolant temperature sensor connector B-13. Remove the engine coolant temperature sensor. With the temperature sensing portion of engine coolant temperature sensor immersed in hot water, check resistance. See «ENGINE COOLANT TEMPERATURE SENSOR RESISTANCE»(ref-150942-S30003218732002112700000) table. If the resistance is as specified, replace the PCM. Then go to next step. If the resistance is not as specified, replace the engine coolant temperature sensor. Apply 3M AAD (8731) on the screw section of the engine coolant temperature sensor. Install the engine coolant temperature sensor and tighten to 15-29 ft. lbs. (19-39 N.m). Then go to next step.
  6. Test the OBD-II drive cycle. Carry out a test drive with the drive cycle pattern. See «OTHER MONITOR»(ref-150942-S38112384672002112700000) under VERIFYING REPAIRS. Check the Diagnostic Trouble Code (DTC). If DTC P0117 is output, repeat diagnosis. If DTC P0117 is not output, inspection is complete.

Check conditions are when 2 seconds or more have passed since the staring sequence was completed. Judgement criteria is when engine coolant temperature sensor output voltage has continued to be 4.6 volts or more, corresponding to a coolant temperature of -113°F (-45°C) or less for 2 seconds.

The most likely causes for this code to be set are

  1. Engine coolant temperature sensor failed.
  2. Open or shorted engine coolant temperature sensor circuit, or loose connector.
  3. PCM failed.
CAUTIONTo prevent damage to scan tool, always turn the ignition switch to LOCK position before connecting or disconnecting scan tool.

Note. If PCM is replaced, immobilizer code registration must be performed. See PROGRAMMING .

  1. Using scan tool, check data list item 21: ENGINE COOLANT TEMPERATURE SENSOR. Connect scan tool to the data link connector. (Scheme 105) Turn the ignition switch to ON position. Set scan tool to the data reading mode for data list item 21: ENGINE COOLANT TEMPERATURE SENSOR. The engine coolant temperature and temperature shown with the scan tool should approximately match. Turn the ignition switch to LOCK position. If the sensor is not operating properly, go to next step. If the sensor is operating properly, it can be assumed that this malfunction is intermittent.
  2. Check connector B-13 at the engine coolant temperature sensor for damage. If the connector is in good condition, go to next step. If the connector is not in good condition, repair or replace it. Then go to step 11.
  3. Check the sensor supply voltage at engine coolant temperature sensor harness side connector B-13. Disconnect the connector B-13 and measure at the harness side. Turn the ignition switch to ON position. Measure the voltage between terminal No. 1 and ground. Voltage should be 4.5-4.9 volts. Turn the ignition switch to LOCK position. If voltage is not as specified, go to next step. If voltage is as specified, go to step 7.
  4. Check the sensor supply voltage at PCM connector C-40 by backprobing. Do not disconnect the PCM connector C-40. Disconnect the engine coolant temperature sensor connector B-13. Turn the ignition switch to ON position. Measure the voltage between terminal No. 44 and ground by backprobing. Voltage should be 4.5-4.9 volts. Turn the ignition switch to LOCK position. If the voltage is as specified, go to next step. If the voltage is not as specified, go to step 6.
  5. Check connector C-40 at PCM for damage. If the connector is in good condition, repair wiring harness between engine coolant temperature sensor connector B-13 and PCM connector C-40 because of open circuit. Then go to step 11. If the connector is not in good condition, repair or replace it. Then go to step 11.
  6. Check connector C-40 at PCM for damage. If the connector is in good condition, replace the PCM. Then go to step 11. If the connector is in good condition, repair or replace it. Then go to step 11.
  7. Check the continuity at engine coolant temperature sensor harness side connector B-13. Disconnect the connector B-13 and measure at the harness side. Check for the continuity between terminal No. 2 and ground. Resistance should be less than 2 ohms. If continuity is as specified, go to step 10. If continuity is not as specified, go to next step.
  8. Check connector C-40 at PCM for damage. If the connector is in good condition, go to next step. If the connector is not in good condition, repair or replace it. Then go to step 11.
  9. Check for open circuit between engine coolant sensor connector B-13 terminal No. 2 and PCM connector C-40 terminal No. 57. If wiring harness is in good condition, replace the PCM. Then go to step 11. If wiring harness is not in good condition, repair it. Then go to step 11.
  10. Check the engine coolant temperature sensor. Disconnect the engine coolant temperature sensor connector B-13. Remove the engine coolant temperature sensor. With the temperature sensing portion of engine coolant temperature sensor immersed in hot water, check resistance. See «ENGINE COOLANT TEMPERATURE SENSOR RESISTANCE»(ref-150942-S30003218732002112700000) table. Apply 3M AAD (8731) on the screw section of the engine coolant temperature sensor. Install the engine coolant temperature sensor and tighten to 15-29 ft.lbs. (19-39 N.m). If the resistance is as specified, replace the PCM. Then go to next step. If the resistance is not as specified, replace the engine coolant temperature sensor. Then go to next step.
  11. Test the OBD-II drive cycle. Carry out a test drive with the drive cycle pattern. See «OTHER MONITOR»(ref-150942-S38112384672002112700000) under VERIFYING REPAIRS. Check the Diagnostic Trouble Code (DTC). If DTC P0118 is output, repeat diagnosis. If DTC P0118 is not output, inspection is complete.

Check conditions are when 2 seconds or more have passed since the starting sequence was completed, engine speed is more than 2000 RPM and volumetric efficiency is more than 60 percent. Judgement criteria is when TPS output voltage has continued to be 0.8 volt or less for 2 seconds.

Check conditions are when 2 seconds or more have passed since the staring sequence was completed, engine speed is less than 3000 RPM and volumetric efficiency is less than 30 percent. Judgement criteria is when TPS output voltage has continued to be 4.6 volts or more for 2 seconds.

The most likely causes for this code to be set are

  1. TPS failed or misadjusted.
  2. Open or shorted TPS circuit, or loose connector.
  3. PCM failed.
CAUTIONTo prevent damage to scan tool, always turn the ignition switch to LOCK position before connecting or disconnecting scan tool.

Note. If PCM is replaced, immobilizer code registration must be performed. See PROGRAMMING .

  1. Using scan tool, check throttle position sensor. Connect scan tool to the data link connector. (Scheme 105) Turn the ignition switch to ON position. Set scan tool to the data reading mode for data list item 14: THROTTLE POSITION SENSOR. With the throttle valve in the idle position, voltage should be 0.535-0.735 volt. With the throttle valve in the full-open position, voltage should be 4.5-5.5 volts. Turn the ignition switch to LOCK position. If the sensor is not operating properly, go to next step. If the sensor is operating properly, it can be assumed that this malfunction is intermittent.
  2. Check connector B-05 at throttle position sensor for damage. If the connector is in good condition, go to next step. If the connector is not in good condition, repair or replace it. Then go to step 14.
  3. Check the throttle position sensor. Measure the resistance between throttle position sensor side connector terminals No. 1 and 4. Standard value is 3.5-6.5 k/ohms. Measure resistance between the throttle position sensor side connector terminals No. 1 and 3. Move the throttle valve from the idle position to the full-open position. Resistance should change smoothly in proportion to the opening angle of the throttle valve. If the resistance is as specified, go to next step. If the resistance is not as specified, replace the throttle position sensor. Then go to step 14.
  4. Check the sensor supply voltage at throttle position sensor harness side connector B-05. Disconnect the connector B-05 and measure at the harness side. Turn the ignition switch to ON position. Measure the voltage between terminal No. 4 and ground. Voltage should be 4.8-5.2 volts. Turn the ignition switch to LOCK position. If voltage is not as specified, go to next step. If voltage is as specified, go to step 7.
  5. Check connector C-40 at PCM for damage. If the connector is in good condition, go to next step. If the connector is not in good condition, repair or replace it. Then go to step 14.
  6. Check for harness damage between throttle position sensor connector B-05 terminal No. 3 and PCM connector C-40 terminal No. 46. If wiring harness is in good condition, replace the PCM. Then go to step 14. If wiring harness is not in good condition, repair it. Then go to step 14.
  7. Check the continuity at throttle position sensor harness side connector B-05. Disconnect the connector B-05 and measure at the harness side. Measure the continuity between terminal No. 1 and ground. Resistance should be less than 2 ohms. If continuity is not as specified, go to next step. If continuity is as specified, go to step 10.
  8. Check connector C-40 at PCM for damage. If the connector is in good condition, go to next step. If the connector is not in good condition, repair or replace it. Then go to step 14.
  9. Check for open circuit and harness damage between throttle position sensor connector B-05 terminal No. 2 and PCM connector C-40 terminal No. 57. If wiring harness is in good condition, replace the PCM. Then go to step 14. If wiring harness is not in good condition, repair it. Then go to step 14.
  10. Check connectors C-40 and C-41 at PCM for damage. If the connector(s) are in good condition, go to next step. If the connector(s) are not in good condition, repair or replace it. Then go to step 14.
  11. Check for harness damage between throttle position sensor connector B-05 terminal No. 1 and PCM connector C-41 terminal No. 78. If wiring harness is in good condition, go to next step. If wiring harness is not in good condition, repair it. Then go to step 14.
  12. Check the maladjusted throttle position sensor. See THROTTLE POSITION SENSOR under ADJUSTMENTS in SYSTEM & COMPONENT TESTING article. If the output voltage is as specified, go to next step. If the output voltage is not as specified, adjust it. Then go to step 14.
  13. Using scan tool, check throttle position sensor. Connect scan tool to the data link connector. Turn the ignition switch to ON position. Set scan tool to the data reading mode for data list item 14: THROTTLE POSITION SENSOR. With the throttle valve in the idle position, voltage should be 0.535-0.735 volt. With the throttle valve in the full-open position, voltage should be 4.5-5.5 volts. Turn the ignition switch to LOCK position. If the sensor is operating properly, it can be assumed that this malfunction is intermittent. If the sensor is not operating properly, replace the PCM. Then go to next step.
  14. Test the OBD-II drive cycle. Carry out a test drive with the drive cycle pattern. See «OTHER MONITOR»(ref-150942-S38112384672002112700000) under VERIFYING REPAIRS. Check the Diagnostic Trouble Code (DTC). If DTC P0121 is output, repeat diagnosis. If DTC P0121 is not output, inspection is complete.

Check conditions are when 2 seconds or more have passed since the starting sequence was completed. Judgement criteria is when TPS output voltage has continued to be 0.2 volt or less for 2 seconds.

The most likely causes for this code to set are

  1. TPS failed or misadjusted.
  2. Open or shorted TPS circuit, or loose connector.
  3. PCM failed.
CAUTIONTo prevent damage to scan tool, always turn the ignition switch to LOCK position before connecting or disconnecting scan tool.

Note. If PCM is replaced, immobilizer code registration must be performed. See PROGRAMMING .

  1. Using scan tool, check throttle position sensor. Connect scan tool to the data link connector. (Scheme 105) Turn the ignition switch to ON position. Set scan tool to the data reading mode for data list item 14: THROTTLE POSITION SENSOR. With the throttle valve in the idle position, voltage should be 0.535-0.735 volt. With the throttle valve in the full-open position, voltage should be 4.5-5.5 volts. Turn the ignition switch to LOCK position. If the sensor is not operating properly, go to next step. If the sensor is operating properly, it can be assumed that this malfunction is intermittent.
  2. Check connector B-05 at throttle position sensor for damage. If the connector is in good condition, go to next step. If the connector is not in good condition, repair or replace it. Then go to step 11.
  3. Check the sensor supply voltage at throttle position sensor harness side connector B-05. Disconnect the connector B-05 and measure at the harness side. Turn the ignition switch to ON position. Measure the voltage between terminal No. 4 and ground. Voltage should be 4.8-5.2 volts. Turn the ignition switch to LOCK position. If voltage is not as specified, go to next step. If voltage is as specified, go to step 6.
  4. Check connector C-40 at PCM for damage. If the connector is in good condition, go to next step. If the connector is not in good condition, repair or replace it. Then go to step 11.
  5. Check for open circuit and short circuit to ground between throttle position sensor connector B-05 terminal No. 3 and PCM connector C-40 terminal No. 46. If wiring harness is in good condition, replace the PCM. Then go to step 11. If wiring harness is not in good condition, repair it. Then go to step 11.
  6. Check the throttle position sensor. Disconnect the connector B-05. Measure the resistance between throttle position sensor side connector terminals No. 1 and 4. Standard value is 3.5-6.5 k/ohms. Measure resistance between the throttle position sensor side connector terminals No. 1 and 3. Move the throttle valve from the idle position to the full-open position. Resistance should change smoothly in proportion to the opening angle of the throttle valve. If the resistance is as specified, go to next step. If the resistance is not as specified, replace the throttle position sensor. Then go to step 11.
  7. Check connectors C-40 and C-41 at PCM for damage. If the connectors are in good condition, go to next step. If any connector is not in good condition, repair or replace it. Then go to step 11.
  8. Check for open circuit and short circuit to ground between throttle position sensor connector B-05 terminal No. 1 and PCM connector C-41 terminal No. 78. If wiring harness is in good condition, go to next step. If wiring harness is not in good condition, repair it. Then go to step 11.
  9. Check for short circuit to ground between throttle position sensor connector and auto-cruise control-ECU. If wiring harness is in good condition, go to next step. If wiring harness is not in good condition, repair it. Then go to step 11.
  10. Using scan tool, check throttle position sensor. Connect scan tool to the data link connector. Turn the ignition switch to ON position. Set scan tool to the data reading mode for data list item 14: THROTTLE POSITION SENSOR. With the throttle valve in the idle position, voltage should be 0.535-0.735 volt. With the throttle valve in the full-open position, voltage should be 4.5-5.5 volts. Turn the ignition switch to LOCK position. If the sensor is operating properly, it can be assumed that this malfunction is intermittent. If the sensor is not operating properly, replace the PCM. Then go to next step.
  11. Test the OBD-II drive cycle. Carry out a test drive with the drive cycle pattern. See «OTHER MONITOR»(ref-150942-S38112384672002112700000) under VERIFYING REPAIRS. Check the Diagnostic Trouble Code (DTC). If DTC P0122 is output, repeat diagnosis. If DTC P0122 is not output, inspection is complete.

Check conditions are when 2 seconds or more have passed since the starting sequence was completed, engine speed is less than 1000 RPM and volumetric efficiency is less than 60 percent. Judgement criteria is when TPS output voltage has continued to be 2 volts or more for 2 seconds.

The most likely causes for this code to be set are

  1. TPS failed or misadjusted.
  2. Open or shorted TPS circuit, or loose connector.
  3. PCM failed.
CAUTIONTo prevent damage to scan tool, always turn the ignition switch to LOCK position before connecting or disconnecting scan tool.

Note. If PCM is replaced, immobilizer code registration must be performed. See PROGRAMMING .

  1. Using scan tool, check throttle position sensor. Connect scan tool to the data link connector. (Scheme 105) Turn the ignition switch to ON position. Get scan tool to the data reading mode for data list item 14: THROTTLE POSITION SENSOR. With the throttle valve in the idle position, voltage should be 0.535-0.735 volt. With the throttle valve in the full-open position, voltage should be 4.5-5.5 volts. Turn the ignition switch to LOCK position. If the sensor is operating properly, it can be assumed that this malfunction is intermittent. If the sensor is not operating properly, go to next step.
  2. Check connector B-05 at throttle position sensor for damage. If the connector is in good condition, go to next step. If the connector is not in good condition, repair or replace it. Then go to step 8.
  3. Check the continuity at throttle position sensor harness side connector B-05. Disconnect the connector B-05 and measure at the harness side. Measure the continuity between terminal No. 1 and ground. Resistance should be less than 2 ohms. If continuity is not as specified, go to next step. If continuity is as specified, go to step 6.
  4. Check connector C-40 at PCM for damage. If the connector is in good condition, go to next step. If the connector is not in good condition, repair or replace it. Then go to step 8.
  5. Check for open circuit and harness damage between throttle position sensor connector B-05 terminal No. 2 and PCM connector C-40 terminal No. 57. If wiring harness is in good condition, replace the PCM. Then go to step 8. If wiring harness is not in good condition, repair it. Then go to step 8.
  6. Check the throttle position sensor. Disconnect the connector B-05. Measure the resistance between throttle position sensor side connector terminals No. 1 and 4. Standard value is 3.5-6.5 k/ohms. Measure resistance between the throttle position sensor side connector terminals No. 1 and 3. Move the throttle valve from the idle position to the full-open position. Resistance should change smoothly in proportion to the opening angle of the throttle valve. If the resistance is as specified, go to next step. If the resistance is not as specified, replace the throttle position sensor. Then go to step 8.
  7. Using scan tool, check throttle position sensor. Connect scan tool to the data link connector. Turn the ignition switch to ON position. Set scan tool to the data reading mode for data list item 14: THROTTLE POSITION SENSOR. With the throttle valve in the idle position, voltage should be 0.535-0.735 volt. With the throttle valve in the full-open position, voltage should be 4.5-5.5 volts. Turn the ignition switch to LOCK position. If the sensor is operating properly, it can be assumed that this malfunction is intermittent. If the sensor is not operating properly, replace the PCM. Then go to next step.
  8. Test the OBD-II drive cycle. Carry out a test drive with the drive cycle pattern. See «OTHER MONITOR»(ref-150942-S38112384672002112700000) under VERIFYING REPAIRS. Check the Diagnostic Trouble Code (DTC). If DTC P0123 is output, repeat diagnosis. If DTC P0123 is not output, inspection is complete.

Check conditions are when coolant temperature decreases from more than 104°F (40°C) to less than 104°F (40°C). Then the engine coolant temperature has continued to be 104°F (40°C) or less for 5 minutes. Judgement criteria is when about 60-300 seconds have passed for the engine coolant temperature to rise about 45°F (70°C) after starting sequence was completed. However, time is not counted when fuel is shut off.

The most likely causes for this code to be set are

  1. Engine coolant temperature sensor failed.
  2. Open or shorted engine coolant temperature sensor circuit, or loose connector.
  3. PCM failed.
CAUTIONTo prevent damage to scan tool, always turn the ignition switch to LOCK position before connecting or disconnecting scan tool.

Note. If PCM is replaced, immobilizer code registration must be performed. See PROGRAMMING .

  1. Using scan tool, check engine coolant temperature sensor. Connect scan tool to the data link connector. (Scheme 105) Turn the ignition switch to ON position. Get scan tool to the data reading mode for data list item 21: ENGINE COOLANT TEMPERATURE SENSOR. The engine coolant temperature and temperature shown with the scan tool should approximately match. Turn the ignition switch to LOCK position. If the sensor is not operating properly, go to next step. If the sensor is operating properly, it can be assumed the malfunction is intermittent.
  2. Check the sensor output voltage at engine coolant temperature sensor connector B-13 by backprobing. Do not disconnect the connector B-13. Turn the ignition switch to ON position. Measure the voltage between terminal No. 1 and ground by backprobing. See «ENGINE COOLANT TEMPERATURE SENSOR VOLTAGE»(ref-150942-S08724228442002112700000) table. Turn the ignition switch to LOCK position. If the voltage is as specified, go to next step. If the voltage is not as specified, go to step 5. ENGINE COOLANT TEMPERATURE SENSOR VOLTAGE Engine Coolant Temperature - °F (°C) Voltage -4 (-20) 3.9-4.5 32 (0) 3.2-3.8 68 (20) 2.3-2.9 104 (40) 1.3-1.9 140 (60) 0.7-1.3 176 (80) 0.3-0.9
  3. Check connector B-13 at the engine coolant temperature sensor for damage. If the connector is in good condition, go to next step. If the connector is not in good condition, repair or replace it. Then go to step 14.
  4. Using scan tool, check engine coolant temperature sensor. Connect scan tool to the data link connector. Turn the ignition switch to ON position. Set scan tool to the item reading mode for data list item 21: ENGINE COOLANT TEMPERATURE SENSOR. The engine coolant temperature and temperature shown with the scan tool should approximately match. Turn the ignition switch to LOCK position. If the sensor is not operating properly, replace the PCM. Then go to step 14. If the sensor is operating properly, it can be assumed that this malfunction is intermittent.
  5. Check connector B-13 at engine coolant temperature sensor for damage. If the connector is in good condition, go to next step. If the connector is not in good condition, repair or replace it. Then go to step 14.
  6. Check the sensor supply voltage at engine coolant temperature sensor harness side connector B-13. Disconnect the connector B-13 and measure at the harness aide. Turn the ignition switch to ON position. Measure the voltage between terminal No. 1 and ground. Voltage should be 4.5-4.9 volts. Turn the ignition switch to LOCK position. If voltage is not as specified, go to next step. If voltage is as specified, go to step 8.
  7. Check connector C-40 at PCM for damage. If the connector is in good condition, replace the PCM. Then go to step 14. If the connector is in good condition, repair or replace it. Then go to step 14.
  8. Check the continuity at engine coolant temperature sensor harness side connector B-13. Disconnect the connector B-13 and measure at the harness side. Check for the continuity between terminal No. 2 and ground. Resistance should be less than 2 ohms. If continuity is as specified, go to step 11. If continuity is not as specified, go to next step.
  9. Check connector C-40 at PCM for damage. If the connector is in good condition, go to next step. If the connector is not in good condition, repair or replace it. Then go to step 14.
  10. Check for harness damage between engine coolant temperature sensor connector B-13 terminal No. 2 and PCM connector C-40 terminal No. 57. If wiring harness is in good condition, replace the PCM. Then go to step 14. If wiring harness is not in good condition, repair it. Then go to step 14.
  11. Check the engine coolant temperature sensor. Disconnect the engine coolant temperature sensor connector B-13. Remove the engine coolant temperature sensor. With the temperature sensing portion of engine coolant temperature sensor immersed in hot water, check resistance. See «ENGINE COOLANT TEMPERATURE SENSOR RESISTANCE»(ref-150942-S38943387382002112700000) table. If the resistance is as specified, go to next step. If the resistance is not as specified, replace the engine coolant temperature sensor. Apply 3M AAD (8731) on the screw section of the engine coolant temperature sensor. Install the engine coolant temperature sensor, and tighten to 15-29 ft.lbs. (19-39 N.m). Then go to step 14. ENGINE COOLANT TEMPERATURE SENSOR RESISTANCE Engine Coolant Temperature - °F (°C) k/Ohms -4 (-20) 14-17 32 (0) 5.1-6.5 68 (20) 2.1-2.7 104 (40) 0.9-1.3 140 (60) 0.48-0.68 176 (80) 0.20-0.36
  12. Check connector C-40 at PCM for damage. If the connector is in good condition, go to next step. If the connector is not in good condition, repair or replace it. Then go to step 14.
  13. Check for harness damage between engine coolant temperature sensor connector B-13 terminal No. 1 and PCM connector C-40 terminal No. 44. If wiring harness is in good condition, replace the PCM. Then go to next step. If wiring harness is not in good condition, repair it. Then go to next step.
  14. Test the OBD-II drive cycle. Carry out a test drive with the drive cycle pattern. See «OTHER MONITOR»(ref-150942-S38112384672002112700000) under VERIFYING REPAIRS. Check the Diagnostic Trouble Code (DTC). If DTC P0125 is output, repeat diagnosis. If DTC P0125 is not output, inspection is complete.

Check conditions are when engine coolant temperature is 14-171°F (-10 to 77°C), difference between engine coolant temperature and intake air temperature is 9°F (5°C) or less, and the volume air flow sensor output frequency is in the low frequency (50-100 Hz or less) state for 300 seconds or less (not extended idling). Judgment criteria is when the time for the engine coolant temperature to rise to 171°F (77°C) takes longer than approximately 11 to 22 minutes.

The most likely causes for this code to be set are the thermostat is faulty or PCM failed.

Check the cooling system. If the cooling system is normal, replace the PCM. Then check that the DTC P0128 does not reset. If the cooling system is not normal, repair it. Then check that the DTC P0128 does not reset.

Check conditions are when 3 minutes or more have passed since the starting sequence was completed, heated oxygen sensor (front) signal voltage has continued to be 0.2 volt or less, engine coolant temperature is more than 169°F (76°C), engine speed is more than 1200 RPM and volumetric efficiency is more 25 percent. Monitoring time is 7 seconds. Judgment criteria is when input voltage supplied to the PCM interface circuit is more than 4.5 volts when 5 volts is applied to the heated oxygen sensor (front) output line via a resistor. Only one monitor is performed during one drive cycle.

The most likely causes for this code to be set are

  1. Heated oxygen sensor (front) deteriorated.
  2. Open circuit in heated oxygen sensor (front) output line.
  3. Open circuit in heated oxygen sensor (front) ground line.
  4. PCM failed.

Required special tool is Test Harness (MD998464).

CAUTIONTo prevent damage to scan tool, always turn the ignition switch to LOCK position before connecting or disconnecting scan tool.

Note. If PCM is replaced, immobilizer code registration must be performed. See PROGRAMMING .

  1. Using scan tool, check heated oxygen sensor (front). Connect scan tool to the data link connector. (Scheme 105) Start the engine and run at idle. Set scan tool to the data reading mode for data list item 11: HEATED OXYGEN SENSOR (FRONT). Warm engine to operating temperature. When the engine is revved, the output voltage should be 0.6 to 1.0 volt. When the engine is idling, the output voltage should alternate between 0.4 volt or less and 0.6 to 1.0 volt. Turn the ignition switch to LOCK position. If the sensor is not operating properly, go to next step. If the sensor is operating properly, it can be assumed that this malfunction is intermittent.
  2. Check the sensor output voltage at heated oxygen sensor (front) connector B-15 by backprobing. Do not disconnect the connector B-15. Start the engine and run at idle. Measure the voltage between terminal No. 4 and ground by backprobing. Warm engine to operating temperature. When the engine is 2500 RPM, the output voltage should alternate between 0.4 volt or less and 0.6 to 1.0 volt 10 times or more within 10 seconds. Turn the ignition switch to LOCK position. If the voltage is as specified, go to next step. If the voltage is not as specified, go to step 7.
  3. Check the sensor output voltage at PCM connector C-41 by backprobing. Do not disconnect PCM connector C-41. Start the engine and run at idle. Measure the voltage between terminal No. 71 and ground by backprobing. Warm engine to operating temperature. When the engine is 2500 RPM, the output voltage should alternate between 0.4 volt or less and 0.6 to 1.0 volt 10 times or more within 10 seconds. Turn the ignition switch to LOCK position. If the voltage is as specified, go to next step. If the voltage is not as specified, go to step 6.
  4. Check connector B-15 at heated oxygen sensor (front) and connector C-41 at PCM for damage. If the connectors are in good condition, go to next step. If the connectors are not in good condition, repair or replace it. Then go to step 15.
  5. Using scan tool, check heated oxygen sensor (front). Connect scan tool to the data link connector. Start the engine and run at idle. Set scan tool to the data reading mode for data list item 11: HEATED OXYGEN SENSOR (FRONT). Warm engine to operating temperature. When the engine is revved, the output voltage should be 0.6 to 1.0 volt. When the engine is idling, the output voltage should alternate between 0.4 volt or less and 0.6 to 1.0 volt. Turn the ignition switch to LOCK position. If the sensor is not operating properly, replace the PCM. Then go to step 15. If the sensor is operating properly, it can be assumed that this malfunction is intermittent.
  6. Check connector B-15 at heated oxygen sensor (front) and connector C-41 at PCM for damage. If the connector is not in good condition, repair or replace it. Then go to step 15. If the connector is in good condition, repair wiring harness between heated oxygen sensor (front) connector B-15 terminal No. 4 and PCM connector C-41 terminal No. 71 because of open circuit or harness damage. Then go to step 15.
  7. Check connector B-15 at heated oxygen sensor (front) for damage. If the connector is in good condition, go to next step. If the connector is not in good condition, repair or replace it. Then go to step 15.
  8. Check the continuity at heated oxygen sensor (front) harness side connector B-15. Disconnect the connector B-15 and measure at the harness side. Check for the continuity between terminal No. 2 and ground. Resistance should be less than 2 ohms. If continuity is as specified, go to step 11. If continuity is not as specified, go to next step.
  9. Check connector C-40 at PCM for damage. If the connector is in good condition, go to next step. If the connector is not in good condition, repair or replace it. Then go to step 15.
  10. Check for open circuit and harness damage between heated oxygen sensor (front) connector B-15 terminal No. 2 and PCM connector C-40 terminal No. 57. If wiring harness is in good condition, replace the PCM. Then go to step 15. If wiring harness is not in good condition, repair it. Then go to step 15.
  11. Check connector C-41 at PCM for damage. If the connector is in good condition, go to next step. If the connector is not in good condition, repair or replace it. Then go to step 15.
  12. Check for harness damage between heated oxygen sensor (front) connector B-15 terminal No. 2 and PCM connector C-40 terminal No. 57. If wiring harness is in good condition, go to next step. If wiring harness is not in good condition, repair it. Then go to step 15.
  13. Check for short circuit to ground and harness damage between heated oxygen sensor (front) connector B-15 terminal No. 4 and PCM connector C-41 terminal No. 71. If wiring harness is in good condition, go to next step. If wiring harness is not in good condition, repair it. Then go to step 15.
  14. Check the heated oxygen sensor (front). Disconnect the heated oxygen sensor (front) connector B-15 and connect test harness tool to the connector on the heated oxygen sensor (front) side. Warm up the engine until engine coolant is 176°F (80°C) or more. Use the jumper wires to connect terminal No. 1 (red clip) to the positive battery terminal and terminal No. 3 (blue clip) to the negative battery terminal. see scheme 65 Connect a digital volt meter between terminal No. 2 (black clip) and terminal No. 4 (white clip). While repeatedly revving the engine, measure the heated oxygen sensor (front) output voltage. Standard value is 0.6-1.0 volt. If the voltage is as specified, replace the PCM. Then go to next step. If the voltage is not as specified, replace the heated oxygen sensor (front). Then go to next step.
  15. Test the OBD-II drive cycle. Carry out a test drive with the drive cycle pattern. Refer to «HEATED OXYGEN SENSOR MONITOR»(ref-150942-S06904226662002112700000) and «OTHER MONITOR»(ref-150942-S38112384672002112700000) under VERIFYING REPAIRS. Check the Diagnostic Trouble Code (DTC). If DTC P0132 is output, repeat diagnosis. If DTC P0132 is not output, inspection is complete.

Check conditions are when engine coolant temperature is more than 140°F (60°C), engine speed is 1200-3000 RPM, volumetric efficiency is 30-60 percent, vehicle is under closed loop air/fuel control, the throttle valve is open, short-term fuel trim is more than -25 and less than +25 percent and more than 2 seconds have elapsed after the above mentioned conditions have been met. Monitoring time is 10 seconds by 7 times. Judgment criteria is when the heated oxygen sensor (front) sends "lean" and "rich" signals alternately 3 times or less for 10 seconds.

If the sensor switch time is longer than the judgment criteria due to the MUT-II OBD-II test Mode - H02S Test Results, it is assumed that the heated oxygen sensor has deteriorated. If it is short, it is assumed that the harness is damaged or has a short circuit. If the heated oxygen sensor signal voltage has not changed even once (lean/rich) after the DTC was erased, the sensor switch time will display as 0 seconds.

The most likely causes for this code to be set are

  1. Heated oxygen sensor (front) deteriorated.
  2. Open circuit in heated oxygen sensor (front) output line.
  3. Open circuit in heated oxygen sensor (front) ground line.
  4. PCM failed.
CAUTIONTo prevent damage to scan tool, always turn the ignition switch to LOCK position before connecting or disconnecting scan tool.

Note. If PCM is replaced, immobilizer code registration must be performed. See PROGRAMMING .

  1. Using scan tool, check heated oxygen sensor (front). Connect scan tool to the data link connector. (Scheme 105) Start the engine and run at idle. Set scan tool to the data reading mode for data list item 11: HEATED OXYGEN SENSOR (FRONT). Warm engine to operating temperature. With engine at 2500 RPM, output voltage should alternate between 0.4 volt or less and 0.6 to 1.0 volt 10 times or more within 10 seconds. Turn the ignition switch to LOCK position. If the sensor is not operating properly, replace the heated oxygen sensor (front). Then go to next step. If the sensor is operating properly, it can be assumed that this malfunction is intermittent.
  2. Test the OBD-II drive cycle. Carry out a test drive with the drive cycle pattern. See «OTHER MONITOR»(ref-150942-S38112384672002112700000) under VERIFYING REPAIRS. Check the Diagnostic Trouble Code (DTC). If DTC P0133 is output, repeat diagnosis. If DTC P0133 is not output, inspection is complete.

Check conditions are when 30 seconds or more have passed since the starting sequence was completed, engine coolant temperature is more than 169°F (76°C), engine speed is at more than 1200 RPM, volumetric efficiency is more than 30 percent, and throttle position sensor output voltage is less than 4.3 volts. Check conditions are not met when fuel is being shut off. Monitoring time is 30 seconds. Judgment criteria is when heated oxygen sensor (front) output voltage does not get across 0.5 volt within about 30 seconds.

The most likely causes for this code to be set are

  1. PCM failed.
  2. Heated oxygen sensor (front) deteriorated.
  3. Open circuit in heated oxygen sensor (front) output line.
  4. Open circuit in heated oxygen sensor (front) ground line.
  5. Heated oxygen sensor (rear) deteriorated.

When the heated oxygen sensor (front) begins to deteriorate, the heated oxygen sensor output voltage will deviate from the voltage when the sensor was new (normally 0.5 volt at stoichiometric ratio). This deviation will be corrected by the heated oxygen sensor (rear). If the heated oxygen sensor (rear) responds poorly because it has deteriorated, it will improperly correct the heated oxygen sensor (front). Thus, even when closed loop control is being effected, the fluctuation of the heated oxygen sensor (front) output voltage decreases, without intersecting with 0.5 volt. As a result, there is a possibility of DTC P0134 becoming registered.

Required special tool is Test Harness (MD998464).

CAUTIONTo prevent damage to scan tool, always turn the ignition switch to LOCK position before connecting or disconnecting scan tool.

Note. If PCM is replaced, immobilizer code registration must be performed. See PROGRAMMING .

  1. Using scan tool, check heated oxygen sensor (rear). Connect scan tool to the data link connector. (Scheme 105) Start the engine and run at idle. Set scan tool to the data reading mode for data list item 59: HEATED OXYGEN SENSOR (REAR). Warm engine to operating temperature. When the engine is revved, the output voltage should be 0.6 to 1.0 volt. Turn the ignition switch to LOCK position. If the sensor is operating properly, go to next step. If the sensor is not operating properly, refer to «DTC P0137: HEATED OXYGEN SENSOR CIRCUIT LOW VOLTAGE (SENSOR 2)»(ref-150942-S37925420252002112700000), «DTC P0138: HEATED OXYGEN SENSOR CIRCUIT HIGH VOLTAGE (SENSOR 2)»(ref-150942-S08823597482002112700000) and «DTC P0139: HEATED OXYGEN SENSOR CIRCUIT SLOW RESPONSE (SENSOR 2)»(ref-150942-S29004629602002112700000).
  2. Check the exhaust leaks. If there no leaks, go to next step. If there any leaks, repair it. Then go to step 12.
  3. Check the intake system for any vacuum leaks. If there no leaks, go to next step. If there any leaks, repair it. Then go to step 12.
  4. Check connector B-15 at the heated oxygen sensor (front) for damage. If the connector is in good condition, go to next step. If the connector is not in good condition, repair or replace it. Then go to step 12.
  5. Check the heated oxygen sensor (front). Disconnect the heated oxygen sensor (front) connector B-15 and connect test harness special tool to the connector on the heated oxygen sensor (front) side. Warm up the engine until engine coolant is 176°F (80°C) or more. Use the jumper wires to connect terminal No. 1 (red clip) to the positive battery terminal and terminal No. 3 (blue clip) to the negative battery terminal. see scheme 65 Connect a digital volt meter between terminal No. 2 (black clip) and terminal No. 4 (white clip). While repeatedly revving the engine, measure the heated oxygen sensor (front) output voltage. Standard value is 0.6-1.0 volt. If the voltage is as specified, go to next step. If the voltage is not as specified, replace the heated oxygen sensor (front). Then go to step 12.
  6. Check injector connectors B-17, B-19, B-21 and B-22 for damage. If the connector is in good condition, go to next step. If the connector is not in good condition, repair or replace it. Then go to step 12.
  7. Check the injector. Disconnect each injector connector. Measure the resistance between injector side connector terminals No. 1 and 2. Standard value is 13-16 ohms at 68°F (20°C). If resistance is as specified, go to next step. If resistance is not as specified, replace the injector. Then go to step 12.
  8. Check connectors C-39 and C-41 at PCM for damage. If the connectors are in good condition, go to next step. If the connectors are not in good condition, repair or replace it. Then go to step 12.
  9. Check for harness damage between heated oxygen sensor (front) connector B-15 terminal No. 4 and PCM connector C-41 terminal No. 71. If wiring harness is in good condition, go to next step. If wiring harness is not in good condition, repair it. Then go to step 12.
  10. Check for harness damage between injector connectors B-17, B-19, B-21, B-22 and PCM connector C-39. See «INJECTOR CONTROL CIRCUIT IDENTIFICATION»(ref-150942-S04574763352002112700000) table. If wiring harness is in good condition, go to next step. If wiring harness is not in good condition, repair it. Then go to step 12.
  11. Check the fuel pressure. If the fuel pressure is normal, replace the PCM. Then go to next step. If the fuel pressure is not normal, repair it. Then go to next step.
  12. Test the OBD-II drive cycle. Carry out a test drive with the drive cycle pattern. See «OTHER MONITOR»(ref-150942-S38112384672002112700000) under VERIFYING REPAIRS. Check the Diagnostic Trouble Code (DTC). If DTC P0134 is output, repeat diagnosis. If DTC P0134 is not output, inspection is complete.
Cylinder No./Injector Connector No. (1)PCM Connector C-39 Terminal No. (A/T)
1/B-221
2/B-219
3/B-1924
4/B-172
(1) All circuits are at connector terminal No. 2.
(1)All circuits are at connector terminal No. 2.

INJECTOR CONTROL CIRCUIT IDENTIFICATION

Check conditions are when 60 seconds have elapsed from the start of the previous monitoring, engine coolant temperature is more than 68°F (20°C), heated oxygen sensor (front) heater is on and battery positive voltage is 11-16 volts. Judgment criteria is when heater current of the heated oxygen sensor (front) heater has continued to be less than 0.16 amp or more than 7.5 amps for 4 seconds.

The most likely causes for this code to be set are

  1. Open or shorted heated oxygen sensor (front) heater circuit.
  2. Open circuit in heated oxygen sensor (front) heater.
  3. PCM failed.

Required special tool is Test Harness (MD998464).

  1. Check connector B-15 at the heated oxygen sensor (front) for damage. If the connector is in good condition, go to next step. If the connector is not in good condition, repair or replace it. Then go to step 12.
  2. Check the heated oxygen sensor (front). Disconnect heated oxygen sensor (front) connector B-15 and connect test harness special tool to the connector on the heated oxygen (front) sensor side. see scheme 65 Measure the resistance between heated oxygen sensor connector terminals No. 1 (red clip) and terminal No. 3 (blue clip). Standard value is 4.5-8.0 ohms at 68°F (20°C). If the resistance is as specified, go to next step. If the resistance is not as specified, replace the heated oxygen sensor (front). Then go to step 12.
  3. Check the power supply voltage at heated oxygen sensor (front) harness side connector B-15. Disconnect the connector B-15 and measure at the harness side. Turn the ignition switch to ON position. Measure the voltage between terminal No. 1 and ground. Voltage should be battery positive voltage. Turn the ignition switch to LOCK position. If voltage is not as specified, go to next step. If voltage is as specified, go to step 5.
  4. Check connector A-18X at the MFI relay for damage. If the connector is in good condition, repair wiring harness between MFI relay connector A-18X terminal No. 4 and heated oxygen sensor (front) connector B-15 terminal No. 1 because of open circuit or short circuit to ground. Then go to step 12. If the connector is not in good condition, repair or replace it. Then go to step 12.
  5. Check the power supply voltage at PCM connector C-39 by backprobing. Do not disconnect the connector C-39. Turn the ignition switch to ON position. Measure the voltage between terminal No. 3 and ground by backprobing. Voltage should be battery positive voltage. Turn the ignition switch to LOCK position. If voltage is not as specified, go to next step. If voltage is as specified, go to step 8.
  6. Check connector C-39 at PCM for damage. If the connector is in good condition, go to next step. If the connector is not in good condition, repair or replace it. Then go to step 12.
  7. Check for open circuit or short circuit to ground between heated oxygen sensor (front) connector B-15 terminal No. 3 and PCM connector C-39 terminal No. 3. If wiring harness is in good condition, replace the PCM. Then go to step 12. If wiring harness is not in good condition, repair it. Then go to step 12.
  8. Check connector C-39 at PCM for damage. If the connector is in good condition, go to next step. If the connector is not in good condition, repair or replace it. Then go to step 12.
  9. Check for harness damage between MFI relay connector A-18X terminal No. 1 and heated oxygen sensor (front) connector B-15 terminal No. 1. If wiring harness is in good condition, go to next step. If wiring harness is not in good condition, repair it. Then go to step 12.
  10. Check for harness damage between heated oxygen sensor (front) connector B-15 terminal No. 3 and PCM connector C-39 terminal No. 3. If wiring harness is in good condition, go to next step. If wiring harness is not in good condition, repair it. Then go to step 12.
  11. Check the trouble symptoms. Carry out a test drive with the drive cycle pattern. See «OTHER MONITOR»(ref-150942-S38112384672002112700000) under VERIFYING REPAIRS. Check the Diagnostic Trouble Code (DTC). If DTC P0135 is output, replace the PCM. Then go to next step. If DTC P0135 is not output, it can be assumed that this malfunction is intermittent.
  12. Test the OBD-II drive cycle. Carry out a test drive with the drive cycle pattern. See «OTHER MONITOR»(ref-150942-S38112384672002112700000) under VERIFYING REPAIRS. Check the Diagnostic Trouble Code (DTC). If DTC P0135 is output, repeat diagnosis. If DTC P0135 is not output, inspection is complete.

Check conditions are when 3 minutes or more have passed since the starting sequence was completed, heated oxygen sensor (rear) signal voltage has continued to be 0.15 volt or less, engine coolant temperature is more than 169°F (76°C), engine speed is more than 1200 RPM, volumetric efficiency is more than 25 percent, volume air flow sensor output frequency is 88 Hz or more, at least 20 seconds have passed since fuel shut off control was canceled, the heated oxygen sensor (front) outputs 0.5 volts or more, and after the ignition switch is turned ON the changes in the output voltage of the heated oxygen sensor (rear) is less than 0.078 volt. Monitoring time is 10 seconds. Judgement criteria is when making the air/fuel ratio 15 percent richer for 10 seconds does not result in raising the heated oxygen sensor (rear) output voltage beyond 0.15 volt. Only one monitor is performed during one drive cycle.

see scheme 16, see scheme 27 and (Scheme 109).

Scheme 108

Scheme 108: DTC Set Conditions
Scheme 108: DTC Set Conditions

The most likely causes for this code to be set are

  1. Heated oxygen sensor (rear) failed.
  2. Short circuit in heated oxygen sensor (rear) output line.
  3. PCM failed.

Required special tool is Test Harness (MB991658).

CAUTIONTo prevent damage to scan tool, always turn the ignition switch to LOCK position before connecting or disconnecting scan tool.

Note. If PCM is replaced, immobilizer code registration must be performed. See PROGRAMMING .

  1. Using scan tool, check heated oxygen sensor (rear). Connect scan tool to the data link connector. (Scheme 105) Start the engine and run at idle. Set scan tool to the data reading mode for data list item 59: HEATED OXYGEN SENSOR (REAR). Warm engine to operating temperature. When the engine is revved, the output voltage should be 0.6 to 1.0 volt. Turn the ignition switch to LOCK position. If the sensor is not operating properly, go to next step. If the sensor is operating properly, it can be assumed that this malfunction is intermittent.
  2. Check the heated oxygen sensor (rear). Disconnect the heated oxygen sensor (rear) connector C-19 and connect test harness special tool, to the connector on the heated oxygen sensor (front) side. Warm up the engine until engine coolant 176°F (80°C) or more. Use the jumper wires to connect terminal No. 5 to the positive battery terminal and terminal No. 6 to the negative battery terminal. see scheme 68 Connect a digital volt meter between terminal No. 3 and terminal No. 4. While repeatedly revving the engine, measure the heated oxygen sensor (rear) output voltage. Standard value is 0.6 -1.0 volt. If the voltage is as specified, go to next step. If the voltage is not as specified, replace the heated oxygen sensor (rear). Then go to step 5.
  3. Check connector C-19 at heated oxygen sensor (rear) and connector C-41 at PCM for damage. If the connector is in good condition, go to next step. If the connector is not in good condition, repair or replace it. Then go to step 5.
  4. Check for short circuit to ground between heated oxygen sensor (rear) connector C-19 terminal No. 3 and PCM connector C-41 terminal No. 73. If wiring harness is in good condition, replace the PCM. Then go to next step. If wiring harness is not in good condition, repair it. Then go to next step.
  5. Test the OBD-II drive cycle. Carry out a test drive with the drive cycle pattern. See «OTHER MONITOR»(ref-150942-S38112384672002112700000) under VERIFYING REPAIRS. Check the Diagnostic Trouble Code (DTC). If DTC P0137 is output, repeat diagnosis. If DTC P0137 is not output, inspection is complete.

Scheme 109

Scheme 109
Scheme 109

Check conditions are when 3 minutes or more have passed since the starting sequence was completed, heated oxygen sensor (rear) signal voltage has continued to be 0.15 volt or less, engine coolant temperature is more than 169°F (76°C), engine speed is more than 1200 RPM, and volumetric efficiency is more than 25 percent. Monitoring time is 7 seconds. Judgment criteria is when input voltage supplied to the PCM interface circuit is more than 4.5 volts when 5 volts is applied to the heated oxygen sensor (rear) output line via a resistor. Only one monitor is performed during one drive cycle.

The most likely causes for this code to be set are

  1. Heated oxygen sensor (rear) failed.
  2. Open circuit in heated oxygen sensor (rear) output line
  3. Open circuit in heated oxygen sensor (rear) ground line.
  4. PCM failed.

Required special tool is Test Harness (MB991658).

CAUTIONTo prevent damage to scan tool, always turn the ignition switch to LOCK position before connecting or disconnecting scan tool.

Note. If PCM is replaced, immobilizer code registration must be performed. See PROGRAMMING .

  1. Using scan tool, check heated oxygen sensor (rear). Connect scan tool to the data link connector. (Scheme 105) Start the engine and run at idle. Set scan tool to the data reading mode for data list item 59: HEATED OXYGEN SENSOR (REAR). Warm engine to operating temperature. When the engine is revved, the output voltage should be 0.6 to 1.0 volt. Turn the ignition switch to LOCK position. If the sensor is not operating properly, go to next step. If the sensor is operating properly, it can be assumed that this malfunction is intermittent.
  2. Check the sensor output voltage at heated oxygen sensor (rear) connector C-19 by backprobing. Do not disconnect the connector C-19. Start the engine and run at idle. Measure the voltage between terminal No. 3 and ground by backprobing. Warm engine to operating temperature. When the engine is revved, the output voltage should be 0.6 to 1.0 volt. Turn the ignition switch to LOCK position. If the voltage is as specified, go to next step. If the voltage is not as specified, go to step 7.
  3. Check the sensor output voltage at PCM connector C-41 by backprobing. Do not disconnect the connector C-41. Start the engine and run at idle. Measure the voltage between terminal No. 73 and ground by backprobing. Warm engine to operating temperature. When the engine is at 2500 RPM, the output voltage should alternate between 0.4 volt or less and 0.6 to 1.0 volt 10 times or more within 10 seconds. Turn the ignition switch to LOCK position. If the voltage is as specified, go to next step. If the voltage is not as specified, go to step 6.
  4. Check connector C-19 at heated oxygen sensor (rear) and connector C-41 at PCM for damage. If the connector is in good condition, go to next step. If the connector is not in good condition, repair or replace it. Then go to step 14.
  5. Using scan tool, check heated oxygen sensor (rear). Connect scan tool to the data link connector. Start the engine and run at idle. Set scan tool to the data reading mode for data list item 59: HEATED OXYGEN SENSOR (REAR). Warm engine to operating temperature. When the engine is revved, the output voltage should be 0.6 to 1.0 volt. Turn the ignition switch to LOCK position. If the sensor is not operating properly, replace the PCM. Then go to step 14. If the sensor is operating properly, it can be assumed this malfunction is intermittent.
  6. Check connector C-19 at heated oxygen sensor (rear) and connector C-41 at PCM for damage. If the connector is in good condition, repair wiring harness between heated oxygen sensor (rear) connector C-19 terminal No. 1 and PCM connector C-41 terminal No. 73 because of open circuit or harness damage. Then go to step 14. If the connector is not in good condition, repair or replace it. Then go to step 14.
  7. Check connector C-19 at heated oxygen sensor (rear) for damage. If the connector is in good condition, go to next step. If the connector is not in good condition, repair or replace it. Then go to step 14.
  8. Check the continuity at heated oxygen sensor (rear) harness side connector C-19. Disconnect the connector C-19 and measure at the harness side. Check for the continuity between terminal No. 4 and ground. Resistance should be less than 2 ohms. If continuity is as specified, go to step 11. If continuity is not as specified, go to next step.
  9. Check connector C-40 at PCM for damage. If the connector is in good condition, go to next step. If the connector is not in good condition, repair or replace it. Then go to step 14.
  10. Check for open circuit and harness damage between heated oxygen sensor (rear) connector C-19 terminal No. 4 and PCM connector C-40 terminal No. 57. If wiring harness is in good condition, replace the PCM. Then go to step 14. If wiring harness is not in good condition, repair it. Then go to step 14.
  11. Check connector C-41 at PCM for damage. If the connector is in good condition, go to next step. If the connector is not in good condition, repair or replace it. Then go to step 14.
  12. Check for harness damage between heated oxygen sensor (rear) connector C-19 terminal No. 4 and PCM connector C-40 terminal No. 57. If wiring harness is in good condition, go to next step. If wiring harness is not in good condition, repair it. Then go to step 14.
  13. Check the heated oxygen sensor (rear). Disconnect the heated oxygen sensor (rear) connector C-19 and connect test harness tool to the connector on the heated oxygen sensor (front) side. Warm up the engine until engine coolant is 176°F (80°C) or more. Use the jumper wires to connect terminal No. 5 to the positive battery terminal and terminal No. 6 to the negative battery terminal. see scheme 68 Connect a digital volt meter between terminal No. 3 and terminal No. 4. While repeatedly revving the engine, measure the heated oxygen sensor (rear) output voltage. Standard value is 0.6-1.0 volt. If the voltage is as specified, replace the PCM. Then go to next step. If the voltage is not as specified, replace the heated oxygen sensor (rear). Then go to next step.
  14. Test the OBD-II drive cycle. Carry out a test drive with the drive cycle pattern. See «OTHER MONITOR»(ref-150942-S38112384672002112700000) under VERIFYING REPAIRS. Check the Diagnostic Trouble Code (DTC). If DTC P0138 is output, repeat diagnosis. If DTC P0138 is not output, inspection is complete.

Check conditions are when engine coolant temperature is more than 169°F (76°C), the heated oxygen sensor (front) is active and the cumulative volume air flow sensor output frequency is more than 4,000 Hz under the following conditions, repeated 3 or more times: drive 1, stop 2. Drive 1 is when engine speed is more than 1500 RPM, volumetric efficiency is more than 40 percent, vehicle speed is more than 18.7 mph (30 km/h), a total of more than 10 seconds have elapsed with the above mentioned conditions, and more than 2 seconds have elapsed with the fuel shut off. Stop 2 is when vehicle speed must be less than 0.9 mph (1.5 km/h). Judgement criteria is when change in the output voltage of the heater oxygen sensor (rear) is less than 0.078 volt. Monitoring stops after fuel has been shut off for more than 33 seconds.

The most likely causes for this code to be set are

  1. Heated oxygen sensor (rear) failed.
  2. Open circuit in heated oxygen sensor (rear) output line.
  3. Open circuit in heated oxygen sensor (rear) ground line.
  4. PCM failed.
  1. Using scan tool, check heated oxygen sensor (rear). Connect scan tool to the data link connector. (Scheme 105) Start the engine and run at idle. Set scan tool to the data reading mode for data list item 59: HEATED OXYGEN SENSOR (REAR). Warm engine to operating temperature. After increasing the output voltage 0.15 volts or more by revving the engine, allow engine to idle. Then confirm that the output voltage reduces to 0.15 volts or less within 3 seconds. Turn the ignition switch to LOCK position. If the sensor is not operating properly, replace the heated oxygen sensor (rear). Then go to next step. If the sensor is operating properly, it can be assumed that this malfunction is intermittent.
  2. Test the OBD-II drive cycle. Carry out a test drive with the drive cycle pattern. See «OTHER MONITOR»(ref-150942-S38112384672002112700000) under VERIFYING REPAIRS. Check the Diagnostic Trouble Code (DTC). If DTC P0139 is output, repeat diagnosis. If DTC P0139 is not output, inspection is complete.

Check conditions are when 60 seconds have elapsed from the start of the previous monitoring, engine coolant temperature is more than 68°F (20°C), heated oxygen sensor (rear) heater is on and battery positive voltage is 11-16 volts. Judgment criteria is when heater current of the heated oxygen sensor (rear) heater is less than 0.16 amp or more than 5.0 amps for 4 seconds.

The most likely causes for this code to be set are

  1. Open or shorted heated oxygen sensor (rear) heater circuit.
  2. Open circuit in heated oxygen sensor (rear) heater.
  3. PCM failed.

Required special tool is Test Harness (MB991658).

  1. Check connector C-19 at the heated oxygen sensor (rear) for damage. If the connector is in good condition, go to next step. If the connector is not in good condition, repair or replace it. Then go to step 12.
  2. Check the heated oxygen sensor (rear). Disconnect heated oxygen sensor (rear) connector C-19 and connect Test Harness (MB991658) to the connector on the heated oxygen (rear) sensor side. see scheme 68 Do not connect test harness to battery. Measure the resistance between heated oxygen sensor connector terminals No. 5 and terminal No. 6. Standard value is 11-18 ohms at 68°F (20°C). If the resistance is as specified, go to next step. If the resistance is not as specified, replace the heated oxygen sensor (rear). Then go to step 12.
  3. Check the power supply voltage at heated oxygen sensor (rear) harness side connector C-19. Disconnect the connector C-19 and measure at the harness side. Turn the ignition switch to ON position. Measure the voltage between terminal No. 5 and ground. Voltage should be battery positive voltage. Turn the ignition switch to LOCK position. If voltage is not as specified, go to next step. If voltage is as specified, go to step 5.
  4. Check harness connector A-18X at the MFI relay for damage. If the connector is in good condition, repair wiring harness between MFI relay connector A-18X terminal No. 4 and heated oxygen sensor (rear) connector C-19 terminal No. 5 because of open circuit or short circuit to ground. Then go to step 12. If the connector is not in good condition, repair or replace it. Then go to step 12.
  5. Check the power supply voltage at PCM connector C-39 by backprobing. Do not disconnect the connector C-39. Turn the ignition switch to ON position. Measure the voltage between terminal No. 26 and ground by backprobing. Voltage should be battery positive voltage. Turn the ignition switch to LOCK position. If voltage is not as specified, go to next step. If voltage is as specified, go to step 8.
  6. Check connector C-39 at PCM for damage. If the connector is in good condition, go to next step. If the connector is not in good condition, repair or replace it. Then go to step 12.
  7. Check for open circuit or short circuit to ground between heated oxygen sensor (rear) connector C-19 terminal No. 6 and PCM connector C-39 terminal No. 26. If wiring harness is in good condition, replace the PCM. Then go to step 12. If wiring harness is not in good condition, repair it. Then go to step 12.
  8. Check connector C-39 at PCM for damage. If the connector is in good condition, go to next step. If the connector is not in good condition, repair or replace it. Then go to step 12.
  9. Check for harness damage between MFI relay connector A-18X terminal No. 4 and heated oxygen sensor (rear) connector C-19 terminal No. 5. If wiring harness is in good condition, go to next step. If wiring harness is not in good condition, repair it. Then go to step 12.
  10. Check for harness damage between heated oxygen sensor (rear) connector C-19 terminal No. 6 and PCM connector C-39 terminal No. 26. If wiring harness is in good condition, go to next step. If wiring harness is not in good condition, repair it. Then go to step 12.
  11. Check the trouble symptoms. Carry out a test drive with the drive cycle pattern. Check the Diagnostic Trouble Code (DTC). If DTC P0141 is output, replace the PCM. Then go to next step. If DTC P0141 is not output, it can be assumed that this malfunction is intermittent.
  12. Test the OBD-II drive cycle. Carry out a test drive with the drive cycle pattern. See «OTHER MONITOR»(ref-150942-S38112384672002112700000) under VERIFYING REPAIRS. Check the Diagnostic Trouble Code (DTC). If DTC P0141 is output, repeat diagnosis. If DTC P0141 is not output, inspection is complete.

These check conditions apply when engine coolant temperature is less than approximately 212°F (100°C) when the engine is started. Intake air temperature is less than 140°F (60°C) when the engine is started. Under the closed loop air/fuel ratio control. Engine coolant temperature is more than 171°F (77°C). Volume air flow sensor output frequency is 88 Hz or more. Judgment criteria is when long-term fuel trim has continued to be more than +12.5 percent for 5 seconds or short-term fuel trim has continued to be more than +10.0 percent for 5 seconds.

These check conditions apply when engine coolant temperature is less than approximately 212°F (100°C) when the engine is started. Intake air temperature is less than 140°F (60°C) when the engine is started. Under the closed loop air/fuel ratio control. Engine coolant temperature is more than 171°F (77°C). Volume air flow sensor output frequency is 88 Hz or less. Judgment criteria is when long-term fuel trim has continued to be more than +12.5 percent for 5 seconds or short-term fuel trim has continued to be more than +15 percent for 5 seconds.

These check conditions apply when engine coolant temperature is more than approximately 212°F (100°C) when the engine is started. Intake air temperature is more than 140°F (60°C) when the engine is started. Under the closed loop air/fuel ratio control. Engine coolant temperature is more than 171°F (77°C). Volume air flow sensor output frequency is 88 Hz or more. Judgment criteria is when long-term fuel trim has continued to be more than +12.5 percent for 5 seconds or short-term fuel trim has continued to be more than +20.0 percent for 5 seconds.

These check conditions apply when engine coolant temperature is more than approximately 212°F (100°C) when the engine is started. Intake air temperature is more than 140°F (60°C) when the engine is started. Under the closed loop air/fuel ratio control. Engine coolant temperature is more than 171°F (77°C). Volume air flow sensor output frequency is 88 Hz or less. Judgment criteria is when long-term fuel trim has continued to be more than +12.5 percent for 5 seconds or short-term fuel trim has continued to be more than +25.0 percent for 5 seconds.

These check conditions apply when engine coolant temperature is more than 171°F (77°C). Under the closed loop air/fuel ratio control. Judgment criteria is when long-term fuel trim has continued to be +12.5 percent for 5 seconds or short-term fuel trim has continued to be +25.0 percent for 5 seconds.

The most likely causes for this code to be set are

  1. Volume air flow sensor failed.
  2. Injector failed.
  3. Incorrect fuel pressure.
  4. Air drawn in from gaps in gasket, seals, etc.
  5. Heated oxygen sensor failed.
  6. Engine coolant temperature sensor failed.
  7. Intake air temperature sensor failed.
  8. Barometric pressure sensor failed.
  9. Use of incorrect or contaminated fuel.
  10. PCM failed.
CAUTIONTo prevent damage to scan tool, always turn the ignition switch to LOCK position before connecting or disconnecting scan tool.

Note. If PCM is replaced, immobilizer code registration must be performed. See PROGRAMMING .

  1. Check for exhaust leaks. If there are no leaks, go to next step. If there are any leaks, repair it. Then go to step 14.
  2. Check for intake system vacuum leaks. If there are no leaks, go to next step. If there are any leaks, repair it. Then go to step 14.
  3. Using scan tool, check volume air flow sensor. Connect scan tool to the data link connector. Start the engine and run at idle. Set scan tool to the data reading mode for data list item 12: VOLUME AIR FLOW SENSOR. Warm up the engine to normal operating temperature of 176-205°F (80-96°C). When idling, data should be 12-38 Hz (2.5-5.0 grams per second). When engine speed is 2500 RPM, data should be 55-95 Hz (8.5-12.7 grams per second). Turn the ignition switch to LOCK position. If the sensor is operating properly, go to next step. If the sensor is not operating properly, go to «DTC P0101: VOLUME AIRFLOW CIRCUIT RANGE/PERFORMANCE PROBLEM»(ref-150942-S11800112712002112700000) or «DTC P0102: VOLUME AIRFLOW CIRCUIT LOW INPUT»(ref-150942-S20693239592002112700000).
  4. Using scan tool, check intake air temperature sensor. Turn the ignition switch to ON position. Set scan tool to the data reading mode for data list item 13: INTAKE AIR TEMPERATURE SENSOR. The intake air temperature and temperature shown with the scan tool should approximately match. Turn the ignition switch to LOCK position. If the sensor is operating properly, go to next step. If the sensor is not operating properly, go to «DTC P0111: INTAKE AIR TEMPERATURE CIRCUIT MALFUNCTION»(ref-150942-S01268909742002112700000), «DTC 0112: INTAKE AIR TEMPERATURE CIRCUIT LOW INPUT»(ref-150942-S18982875292002112700000) and «DTC P0113: INTAKE AIR TEMPERATURE CIRCUIT HIGH INPUT»(ref-150942-S25178068022002112700000).
  5. Using scan tool, check engine coolant temperature sensor. Turn the ignition switch to ON position. Set scan tool to the data reading mode for data list item 21: ENGINE COOLANT TEMPERATURE SENSOR. The engine coolant temperature and temperature shown with the scan tool should approximately match. Turn the ignition switch to LOCK position. If the sensor is operating properly, go to next step. If the sensor is not operating properly, go to «DTC P0116: ENGINE COOLANT TEMPERATURE CIRCUIT RANGE/PERFORMANCE PROBLEM»(ref-150942-S05594338042002112700000), «DTC P0117: ENGINE COOLANT TEMPERATURE CIRCUIT LOW INPUT»(ref-150942-S24434574082002112700000) or «DTC 0118: ENGINE COOLANT TEMPERATURE CIRCUIT HIGH INPUT»(ref-150942-S02174725722002112700000).
  6. Using scan tool, check barometric pressure sensor. Turn the ignition switch to ON position. Set scan tool to the data reading mode for data list item 25: BAROMETRIC PRESSURE SENSOR. See «BAROMETRIC PRESSURE SENSOR DATA»(ref-150942-S16855617692002112700000) table. Turn the ignition switch to LOCK position. If the sensor is operating properly, go to next step. If the sensor is not operating properly, go to «DTC P0106: BAROMETRIC PRESSURE CIRCUIT RANGE/PERFORMANCE PROBLEM»(ref-150942-S01206497602002112700000), «DTC P0107: BAROMETRIC PRESSURE CIRCUIT LOW INPUT»(ref-150942-S01061586192002112700000) or «DTC P0108: BAROMETRIC PRESSURE CIRCUIT HIGH INPUT»(ref-150942-S07547771052002112700000). BAROMETRIC PRESSURE SENSOR DATA Altitude - Feet (Meters) Pressure 0 (0) 101 kPa 1969 (600) 95 kPa 3937 (1200) 88 kPa 5906 (1800) 81 kPa
  7. Check connectors B-01, B-02, B-05 and B-06 at injectors for damage. see scheme 18 If the connector is in good condition, go to next step. If the connector is not in good condition, repair or replace it. Then go to step 14.
  8. Check the injectors. Disconnect each injector connector. Measure the resistance between injector side connector terminals No. 1 and 2. Standard value is 13-16 ohms at 68°F (20°C). If resistance is as specified, go to next step. If resistance is not as specified, replace the injector. Then go to step 14.
  9. Check connector C-39 at PCM for damage. If the connector is in good condition, go to next step. If the connector is not in good condition, repair or replace it. Then go to step 14.
  10. Check for harness damage between injector connector and PCM connector. See «INJECTOR CONTROL CIRCUIT IDENTIFICATION»(ref-150942-S04574763352002112700000) table. If wiring harness is in good condition, go to next step. If wiring harness is not in good condition, repair it. Then go to step 14.
  11. Check the fuel pressure. See «FUEL PRESSURE»(ref-135483-S11745319792002022200000) in BASIC DIAGNOSTIC PROCEDURES article. If the fuel pressure is normal, go to next step. If the fuel pressure is not normal, repair or replace it. Then go to step 14.
  12. Check for entry of foreign matter (water, kerosene, etc.) into fuel. If there are no abnormalities, go to next step. If there are any abnormalities, replace the fuel. Then go to step 14.
  13. Replace the injector. Carry out a test drive with the drive cycle pattern. See «FUEL TRIM MONITOR»(ref-150942-S39847995762002112700000) under VERIFYING REPAIRS. Check the Diagnostic Trouble Code (DTC). If DTC P0171 is output, replace the PCM. Then go to next step. If DTC P0171 is not output, it can be assumed that this malfunction is intermittent.
  14. Test the OBD-II drive cycle. Carry out a test drive with the drive cycle pattern. See «FUEL TRIM MONITOR»(ref-150942-S39847995762002112700000) under VERIFYING REPAIRS. Check the Diagnostic Trouble Code (DTC). If DTC P0171 is output, repeat diagnosis. If DTC P0171 is not output, inspection is complete.

These check conditions are when under the closed loop air/fuel ratio control, the engine coolant temperature is more than 171°F (77°C) and volume air flow sensor output frequency is 88 Hz or more. Judgment criteria is when long-term fuel trim has continued to be less than -12.5 percent for 5 seconds or short-term fuel trim has continued to be less than -10.0 percent for 5 seconds.

These check conditions are when under the closed loop air/fuel ratio control, the engine coolant temperature is more than 171°F (77°C) and volume air flow sensor output frequency is 88 Hz or less. Judgment criteria is when long-term fuel trim has continued to be less than -12.5 percent for 5 seconds or short-term fuel trim has continued to be less than -15.0 percent for 5 seconds.

These check conditions are when engine coolant temperature is more than 171°F (77°C) under the closed loop air/fuel ratio control. Judgment criteria is when long-term fuel trim has continued to be -12.5 percent for 5 seconds, or short-term fuel trim has continued to be -25.0 percent for 5 seconds.

The most likely causes for this code to be set are

  1. Volume air flow sensor failed.
  2. Injector failed.
  3. Incorrect fuel pressure.
  4. Heated oxygen sensor failed.
  5. Engine coolant temperature sensor failed.
  6. Intake air temperature sensor failed.
  7. Barometric pressure sensor failed.
  8. Exhaust leak.
  9. Use of incorrect or contaminated fuel.
  10. PCM failed.
CAUTIONTo prevent damage to scan tool, always turn the ignition switch to LOCK position before connecting or disconnecting scan tool.

Note. If PCM is replaced, immobilizer code registration must be performed. See PROGRAMMING .

  1. Using scan tool, check volume air flow sensor. Connect scan tool to the data link connector. (Scheme 105) Start the engine and run at idle. Set scan tool to the data reading mode for data list item 12: VOLUME AIR FLOW SENSOR. Warm up the engine to normal operating temperature. When idling, data should be 12-38 Hz (2.5-5.0 grams per second). When engine is at 2500 RPM, data should be 55-95 Hz (8.5-12.7 grams per second). Turn the ignition switch to LOCK position. If the sensor is operating properly, go to next step. If the sensor is not operating properly, refer to «DTC P0101: VOLUME AIRFLOW CIRCUIT RANGE/PERFORMANCE PROBLEM»(ref-150942-S11800112712002112700000) and «DTC P0102: VOLUME AIRFLOW CIRCUIT LOW INPUT»(ref-150942-S20693239592002112700000).
  2. Using scan tool, check intake air temperature sensor. Turn the ignition switch to ON position. Set scan tool to the data reading mode for data list item 13: INTAKE AIR TEMPERATURE SENSOR. The intake air temperature and temperature shown with the scan tool should approximately match. Turn the ignition switch to LOCK position. If the sensor is operating properly, go to next step. If the sensor is not operating properly, refer to «DTC P0111: INTAKE AIR TEMPERATURE CIRCUIT MALFUNCTION»(ref-150942-S01268909742002112700000), «DTC 0112: INTAKE AIR TEMPERATURE CIRCUIT LOW INPUT»(ref-150942-S18982875292002112700000) and «DTC P0113: INTAKE AIR TEMPERATURE CIRCUIT HIGH INPUT»(ref-150942-S25178068022002112700000).
  3. Using scan tool, check engine coolant temperature sensor. Turn the ignition switch to ON position. Set scan tool to the data reading mode for data list item 21: ENGINE COOLANT TEMPERATURE SENSOR. The engine coolant temperature and temperature shown with the scan tool should approximately match. Turn the ignition switch to LOCK position. If the sensor is operating properly, go to next step. If the sensor is not operating properly, refer to «DTC P0116: ENGINE COOLANT TEMPERATURE CIRCUIT RANGE/PERFORMANCE PROBLEM»(ref-150942-S05594338042002112700000), «DTC P0117: ENGINE COOLANT TEMPERATURE CIRCUIT LOW INPUT»(ref-150942-S24434574082002112700000) and «DTC 0118: ENGINE COOLANT TEMPERATURE CIRCUIT HIGH INPUT»(ref-150942-S02174725722002112700000).
  4. Using scan tool, check barometric pressure sensor. Turn the ignition switch to ON position. Set scan tool to the data reading mode for data list item 25: BAROMETRIC PRESSURE SENSOR. See «BAROMETRIC PRESSURE SENSOR DATA»(ref-150942-S16855617692002112700000) table. Turn the ignition switch to LOCK position. If the sensor is operating properly, go to next step. If the sensor is not operating properly, refer to «DTC P0106: BAROMETRIC PRESSURE CIRCUIT RANGE/PERFORMANCE PROBLEM»(ref-150942-S01206497602002112700000), «DTC P0107: BAROMETRIC PRESSURE CIRCUIT LOW INPUT»(ref-150942-S01061586192002112700000) and «DTC P0108: BAROMETRIC PRESSURE CIRCUIT HIGH INPUT»(ref-150942-S07547771052002112700000).
  5. Check the injectors. Disconnect each injector connector. Measure the resistance between injector side connector terminals No. 1 and 2. Standard value is 13-16 ohms at 68°F (20°C). If resistance is as specified, go to next step. If resistance is not as specified, replace the injector. Then go to step 8.
  6. Check the fuel pressure. See appropriate SYSTEM & COMPONENT TESTING article. If the fuel pressure is normal, go to next step. If the fuel pressure is not normal, repair or replace it. Then go to step 8.
  7. Replace the injector. Carry out a test drive with the drive cycle pattern. See «FUEL TRIM MONITOR»(ref-150942-S39847995762002112700000) under VERIFYING REPAIRS. Check the Diagnostic Trouble Code (DTC). If DTC P0172 is output, replace the PCM. Then go to next step. If DTC P0172 is not output, it can be assumed that this malfunction is intermittent.
  8. Test the OBD-II drive cycle. Carry out a test drive with the drive cycle pattern. See «FUEL TRIM MONITOR»(ref-150942-S39847995762002112700000) under VERIFYING REPAIRS. Check the Diagnostic Trouble Code (DTC). If DTC P0172 is output, repeat diagnosis. If DTC P0172 is not output, inspection is complete.

Check conditions are when the difference between engine coolant temperature and intake air temperature is 9°F (5°C) or less when the engine is started, engine coolant temperature is 14-97°F (-10 to 36°C) or more than 140°F (60°C) when engine is started, and maximum vehicle speed is more than 17 mph (30 km/h) after the starting sequence has been completed. Judgement criteria is when the fuel temperature and engine coolant temperature is 27°F (15°C) or more when the engine is started.

The most likely causes for this code to be set are

  1. Fuel temperature sensor failed.
  2. Open or shorted fuel temperature sensor circuit, or loose connector.
  3. PCM failed.

If the engine and the radiator have been flushed repeatedly when the engine coolant temperature was high (or the fuel temperature was high), a Diagnostic Trouble Code (DTC) could be output. Because this is not a failure, the DTC must be erased. Make sure to test drive the vehicle in accordance with the drive cycle pattern in order to verify that a DTC will not be output.

CAUTIONTo prevent damage to scan tool, always turn the ignition switch to LOCK position before connecting or disconnecting scan tool.

Note. If PCM is replaced, immobilizer code registration must be performed. See PROGRAMMING .

  1. Using scan tool, check fuel temperature sensor. Connect scan tool to the data link connector. (Scheme 105) Turn the ignition switch to ON position. Set scan tool to the data reading mode for data list item 4A: FUEL TEMPERATURE SENSOR. Data should be approximately the same as the outside temperature when the engine is cooled. Turn the ignition switch to LOCK position. If the sensor is not operating properly, go to next step. If the sensor is operating properly, it can be assumed that this malfunction is intermittent.
  2. Check connector D-14 at the fuel temperature sensor for damage. see scheme 23 If the connector is in good condition, go to next step. If the connector is not in good condition, repair or replace it. Then go to step 12.
  3. Check the fuel temperature sensor. Disconnect the fuel temperature sensor connector D-14. Measure the resistance between terminal No. 1 and 3 of the fuel temperature sensor. Standard value is 0.5-12.0 k/ohms. If the resistance is as specified, go to next step. If the resistance is not as specified, replace the fuel temperature sensor. Then go to step 12.
  4. Check the continuity at fuel temperature sensor harness side connector D-14. Disconnect the connector D-14 and measure at the harness side. Check for the continuity between terminal No. 1 and ground. Resistance should be less than 2 ohms. If continuity is as specified, go to next step. If continuity is not as specified, repair wiring harness between fuel temperature sensor connector D-14 terminal No. 1 and ground because of open circuit or harness damage. Then go to step 12.
  5. Check the sensor supply voltage at fuel temperature sensor harness side connector D-14. Disconnect the connector D-14 and measure at the harness side. Turn the ignition switch to ON position. Measure the voltage between terminal No. 3 and ground. Voltage should be 4.5-4.9 volts. Turn the ignition switch to LOCK position. If the voltage is as specified, go to next step. If the voltage is not as specified, go to step 10.
  6. Check the sensor supply voltage at PCM connector C-40 by backprobing. Do not disconnect the PCM connector C-40. Turn the ignition switch to ON position. Measure the voltage between terminal No. 51 and ground by backprobing. See «FUEL TEMPERATURE SENSOR OUTPUT VOLTAGE»(ref-150942-S18471716712002112700000) table. Turn the ignition switch to LOCK position. If the voltage is as specified, go to next step. If the voltage is not as specified, go to step 8. FUEL TEMPERATURE SENSOR OUTPUT VOLTAGE Fuel Temperature - °F (°C) Voltage 32 (0) 2.7-3.1 68 (20) 2.1-2.5 104 (40) 1.6-2.0 176 (80) 0.8-1.2
  7. Check connector C-40 at PCM for damage. If the connector is in good condition, check intermediate connectors C-17 and C-71 for damage, and repair or replace as required. If intermediate connectors are in good condition, repair wiring harness between fuel gauge unit connector D-14 terminal No. 3 and PCM connector C-40 terminal No. 51 because of open circuit. Then go to step 12. If the connector is not in good condition, repair or replace it. Then go to step 12.
  8. Check connector C-40 at PCM for damage. If the connector is in good condition, go to next step. If the connector is not in good condition, repair or replace it. Then go to step 12.
  9. Check for short circuit to ground between fuel gauge unit connector D-14 terminal No. 3 and PCM connector C-40 terminal No. 51. If wiring harness is in good condition, replace the PCM. Then go to step 12. If wiring harness is not in good condition, repair it. Then go to step 12.
  10. Check connector C-40 at PCM for damage. If the connector is in good condition, go to next step. If the connector is not in good condition, repair or replace it. Then go to step 12.
  11. Check intermediate connectors C-17 and C-71. see scheme 20and see scheme 21. If intermediate connectors are damaged, repair or replace it. Then go to next step. Check for harness damage between fuel temperature sensor connector D-14 terminal No. 3 and PCM connector C-40 terminal No. 51. If wiring harness is in good condition, replace the PCM. Then go to next step. If wiring harness is not in good condition, repair it. Then go to next step.
  12. Test the OBD-II drive cycle. Carry out a test drive with the drive cycle pattern. See «OTHER MONITOR»(ref-150942-S38112384672002112700000) under VERIFYING REPAIRS. Check the Diagnostic Trouble Code (DTC). If DTC P0181 is output, repeat diagnosis. If DTC P0181 is not output, inspection is complete.

Check conditions are when 2 seconds or more have passed since the starting sequence was completed. Judgement criteria is when sensor output voltage has continued to be 0.1 volt or less for 2 seconds.

The most likely causes for this code to be set are

  1. Fuel temperature sensor failed.
  2. Open or shorted fuel temperature sensor circuit, or loose connector.
  3. PCM failed.
CAUTIONTo prevent damage to scan tool, always turn the ignition switch to LOCK position before connecting or disconnecting scan tool.

Note. If PCM is replaced, immobilizer code registration must be performed. See PROGRAMMING .

  1. Using scan tool, check fuel temperature sensor. Connect scan tool to the data link connector. (Scheme 105) Turn the ignition switch to ON position. Set scan tool to the data reading mode for data list item 4A: FUEL TEMPERATURE SENSOR. Data should be approximately the same as the outside temperature when the engine is cooled. Turn the ignition switch to LOCK position. If the sensor is not operating properly, go to next step. If the sensor is operating properly, it can be assumed that this malfunction is intermittent.
  2. Check the fuel temperature sensor. Disconnect the fuel temperature sensor connector D-14. see scheme 23 Measure the resistance between terminal No. 1 and 3 of the fuel temperature sensor. Standard value is 0.5-12.0 k/ohms. If the resistance is as specified, go to next step. If the resistance is not as specified, replace the fuel temperature sensor. Then go to step 5.
  3. Check connector D-14 at the fuel temperature sensor and connector C-40 at PCM for damage. If the connector is in good condition, go to next step. If the connector is not in good condition, repair or replace it. Then go to step 5.
  4. Check intermediate connectors C-17 and C-71. see scheme 20and see scheme 21. If intermediate connectors are damaged, repair or replace it. Then go to next step. Check for short circuit to ground between fuel temperature sensor connector D-14 and PCM connector C-40. If wiring harness is in good condition, replace the PCM. Then go to next step. If wiring harness is not in good condition, repair it. Then go to next step.
  5. Test the OBD-II drive cycle. Carry out a test drive with the drive cycle pattern. See «OTHER MONITOR»(ref-150942-S38112384672002112700000) under VERIFYING REPAIRS. Check the Diagnostic Trouble Code (DTC). If DTC P0182 is output, repeat diagnosis. If DTC P0182 is not output, inspection is complete.

Check conditions are when 2 seconds or more have passed since the starting sequence was completed. Judgement criteria is when sensor output voltage has continued to be 4.6 volts or more for 2 seconds.

The most likely causes for this code to be set are

  1. Fuel temperature sensor failed.
  2. Open or short fuel temperature sensor circuit, or loose connector.
  3. PCM failed.
CAUTIONTo prevent damage to scan tool, always turn the ignition switch to LOCK position before connecting or disconnecting scan tool.

Note. If PCM is replaced, immobilizer code registration must be performed. See PROGRAMMING .

  1. Using scan tool, check fuel temperature sensor. Connect scan tool to the data link connector. (Scheme 105) Turn the ignition switch to ON position. Set scan tool to the data reading mode for data list item 4A: FUEL TEMPERATURE SENSOR. Data should be approximately the same as the outside temperature when the engine is cooled. Turn the ignition switch to LOCK position. If the sensor is not operating properly, go to next step. If the sensor is operating properly, it can be assumed that this malfunction is intermittent.
  2. Check connector D-14 at the fuel temperature sensor for damage. If the connector is in good condition, go to next step. If the connector is not in good condition, repair or replace it. Then go to step 11.
  3. Check the fuel temperature sensor. Disconnect the fuel temperature sensor connector D-14. Measure the resistance between terminal No. 1 and 3 of the fuel temperature sensor. Standard value is 0.5-12.0 k/ohms. If the resistance is as specified, go to next step. If the resistance is not as specified, replace the fuel temperature sensor. Then go to step 11.
  4. Check the sensor supply voltage at fuel temperature sensor harness side connector D-14. Disconnect the connector D-14 and measure at the harness side. Turn the ignition switch to ON position. Measure the voltage between terminal No. 3 and ground. Voltage should be 4.5-4.9 volts Turn the ignition switch to LOCK position. If voltage is not as specified, go to next step. If voltage is as specified, go to step 8.
  5. Check the sensor supply voltage at PCM connector C-40 by backprobing. Do not disconnect the PCM connector C-40. Disconnect the fuel temperature sensor connector D-14. Turn the ignition switch to ON position. Measure the voltage between terminal No. 51 and ground by backprobing. Voltage should be 4.5-4.9 volts. Turn the ignition switch to LOCK position. If the voltage is as specified, go to next step. If the voltage is not as specified, go to step 7.
  6. Check connector C-40 at PCM for damage. If the connector in good condition, check intermediate connectors C-17 and C-71 for damage, and repair or replace as required. If intermediate connectors are in good condition, repair wiring harness between fuel temperature sensor connector D-14 and PCM connector C-40 because of open circuit. Then go to step 11. If the intermediate connector is not in good condition, repair or replace it. Then go to step 11.
  7. Check connector C-40 at PCM for damage. If the connector is in good condition, replace the PCM. Then go to step 11. If the connector is in good condition, repair or replace it. Then go to step 11.
  8. Check the continuity at fuel temperature sensor harness side connector D-14. Disconnect the connector D-14 and measure at the harness side. Check for the continuity between terminal No. 1 and ground. Resistance should be less than 2 ohms. If continuity is as specified, go to next step. If continuity is not as specified, repair wiring harness between fuel temperature sensor connector D-14 terminal No. 1 and ground because of open circuit or harness damage. Then go to step 11.
  9. Check connector C-40 at PCM for damage. If the connector is in good condition, go to next step. If the connector is not in good condition, repair or replace it. Then go to step 11.
  10. Check intermediate connectors C-17 and C-71. see scheme 20and see scheme 21. If intermediate connectors are damaged, repair or replace it. Then go to next step. Check for open circuit and harness damage between fuel temperature sensor connector D-14 and PCM connector C-40. If wiring harness is in good condition, replace the PCM. Then go to next step. If wiring harness is not in good condition, repair it. Then go to next step.
  11. Test the OBD-II drive cycle. Carry out a test drive with the drive cycle pattern. See «OTHER MONITOR»(ref-150942-S38112384672002112700000) under VERIFYING REPAIRS. Check the Diagnostic Trouble Code (DTC). If DTC P0183 is output, repeat diagnosis. If DTC P0183 is not output, inspection is complete.

Check conditions are when engine speed is less than 1000 RPM and throttle position sensor output voltage is less than 1.16 volts. Judgment criteria is when injector coil surge voltage (battery positive voltage plus 2 volts) has not been detected for 2 seconds.

The most likely causes for this code to be set are

  1. Injector failed.
  2. Open or shorted injector circuit, or loose connector.
  3. PCM failed.

Required special tool is Test Harness (MB991348).

CAUTIONTo prevent damage to scan tool, always turn the ignition switch to LOCK position before connecting or disconnecting scan tool.

Note. If PCM is replaced, immobilizer code registration must be performed. See PROGRAMMING .

  1. Using scan tool, check injectors. Connect scan tool to the data link connector. (Scheme 105) Start the engine and run at idle. Set scan tool to the actuator testing mode for test items No. 01, 02, 03, 04: INJECTORS. Warm up the engine to normal operating temperature. Check if the idle state worsens (unstable idling or engine stall) when suspect injector is cut off. Turn the ignition switch to LOCK position. If actuator is not operating properly, go to next step. If actuator is operating properly, it can be assumed that this malfunction is intermittent.
  2. Check the connector at injector (B-22 for cylinder No. 1, B-21 for cylinder No. 2, B-19 for cylinder No. 3 and/or B-17 for cylinder No. 4) for damage. see scheme 18 If the connector is in good condition, go to next step. If the connector is not in good condition, repair or replace it. Then go to step 10.
  3. Check the injector. Disconnect the affected injector connector. Measure the resistance between injector side connector terminals No. 1 and 2. Standard value is 13-16 ohms at 68°F (20°C). If resistance is as specified, go to next step. If resistance is not as specified, replace the injector. Then go to step 10.
  4. Check the power supply voltage at injector connector. Disconnect affected injector connector and measure at the harness side. Turn the ignition switch to ON position. Measure the voltage between injector connector terminal No. 1 and ground. Voltage should be battery positive voltage. Turn the ignition switch to LOCK position. If voltage is not as specified, go to next step. If voltage is as specified, go to step 6.
  5. Check connector A-18X at MFI relay for damage. If the connector is in good condition, repair wiring harness between MFI relay connector and affected injector connector because of open circuit or short circuit to ground. See «INJECTOR POWER CIRCUIT IDENTIFICATION»(ref-150942-S22741097012002112700000) table. Then go to step 10. If the connector is not in good condition, repair or replace it. Then go to step 10. INJECTOR POWER CIRCUIT IDENTIFICATION Injector (1) Injector Connector 1 B-22 2 B-21 3 B-19 4 B-17 (1) Power is supplied from MFI relay connector A-18X terminal No. 4 to each injector connector terminal No. 1.
  6. Check for harness damage between MFI relay connector and injector connector. See «INJECTOR POWER CIRCUIT IDENTIFICATION»(ref-150942-S22741097012002112700000) table. If wiring harness is in good condition, go to next step. If wiring harness is not in good condition, repair it. Then go to step 10.
  7. Check connector C-39 at PCM for damage. If the connector is in good condition, go to next step. If the connector is not in good condition, repair or replace it. Then go to step 10.
  8. Check for open circuit and short circuit to ground and harness damage between injector connector and PCM connector. See «INJECTOR CONTROL CIRCUIT IDENTIFICATION»(ref-150942-S17140946792002112700000) table. If wiring harness is in good condition, go to next step. If wiring harness is not in good condition, repair it. Then go to step 10. INJECTOR CONTROL CIRCUIT IDENTIFICATION Injector No./Connector No. (1) PCM Connector C-39 Terminal No. 1/B-22 1 2/B-21 9 3/B-19 24 4/B-17 2 (1) Check at injector connector terminal No. 2.
  9. Using an oscilloscope, check the injector. Disconnect the affected injector connector and connect the test harness special tool between connector and injector (all terminals should be connected). Connect the oscilloscope probe to the injector side connector terminal No. 2. Start the engine and run at idle. Measure the waveform. The waveform should show a normal pattern. see scheme 72 Turn the ignition switch to LOCK position. If waveform is not as specified, replace the PCM. Then go to next step. If waveform is as specified, it can be assumed that this malfunction is intermittent.
  10. Test the OBD-II drive cycle. Carry out a test drive with the drive cycle pattern. See «OTHER MONITOR»(ref-150942-S38112384672002112700000) under VERIFYING REPAIRS. Check the Diagnostic Trouble Code (DTC). If DTCs P0201, P0202, P0203 and/or P0204 output, repeat diagnosis. If DTCs are not output, inspection is complete.

Check conditions are when engine speed is 500-6000 RPM, engine coolant temperature is more than -14°F (-10°C), intake air temperature is more than 14°F (-10°C), barometric pressure is more than 76 kPa (11 psi) and adaptive learning is complete for the vane which generates a crankshaft position signal. Engine must be running, excluding gear shifting, deceleration, sudden acceleration/deceleration and A/C compressor switching and the throttle deviation is -0.059 v/10 ms to +0.059 v/10 ms. Judgement criteria is when misfire has occurred more frequently than allowed during the last 200 revolutions when the catalyst temperature is more than 1742°F (950°C), or misfire has occurred in 20 or more of the last 1000 revolutions (corresponding to 1.5 times the limit of emission standard). Change in the angular acceleration of the crankshaft is used for misfire detection.

The most likely causes for this code to be set are

  1. Ignition system related part(s) failed.
  2. Faulty crankshaft position sensor.
  3. Incorrect air/fuel ratio.
  4. Low compression pressure.
  5. Skipping of timing belt teeth.
  6. EGR system and/or EGR valve failed.
  7. PCM failed.
CAUTIONTo prevent damage to scan tool, always turn the ignition switch to LOCK position before connecting or disconnecting scan tool.

Note. If PCM is replaced, immobilizer code registration must be performed. See PROGRAMMING .

  1. Using scan tool, check crankshaft position sensor. Connect scan tool to the data link connector. (Scheme 105) Start the engine and run at idle. Set scan tool to the data reading mode for data list item 22: CRANKSHAFT POSITION SENSOR. Check the waveform of the crankshaft position sensor while keeping the engine speed constant. The pulse width should be constant. Turn the ignition switch to LOCK position. If the sensor is operating properly, go to next step. If the sensor is not operating properly, go to «DTC P0335: CRANKSHAFT POSITION SENSOR CIRCUIT»(ref-150942-S16925928492002112700000).
  2. Using scan tool, check long-term fuel compensation (trim). Start the engine and run at idle. Set scan tool to the data reading mode for data list item 81, LONG-TERM FUEL COMPENSATION (TRIM). The fuel trim should be between -12.5 and +12.5 when the load is 2500 RPM (during closed loop) after the engine is at operating temperature. Turn the ignition switch to LOCK position. If the specification is as specified, go to next step. If the specification is not as specified, go to «DTC P0171: SYSTEM TOO LEAN FUEL TRIM CIRCUIT»(ref-150942-S02919125352002112700000) or «DTC: P0172: SYSTEM TOO RICH FUEL TRIM CIRCUIT»(ref-150942-S05916705072002112700000).
  3. Using scan tool, check short-term fuel compensation (trim). Start the engine and run at idle. Set scan tool to the data reading mode for data list item 82: SHORT-TERM FUEL COMPENSATION (TRIM). The fuel trim should be between -25 and +16.8 when the load is 2500 RPM (during closed loop) after the engine is at operating temperature. Turn the ignition switch to LOCK position. If the fuel trim is as specified, go to next step. If the fuel trim is not as specified, go to «DTC P0171: SYSTEM TOO LEAN FUEL TRIM CIRCUIT»(ref-150942-S02919125352002112700000) or «DTC: P0172: SYSTEM TOO RICH FUEL TRIM CIRCUIT»(ref-150942-S05916705072002112700000).
  4. Check the ignition coil spark. Check each ignition coil spark. Remove the intake manifold. Remove the spark plug and connect to the spark plug cable. Ground the spark plug side electrode securely. When the engine is cranked, the spark plug should spark. If spark does not exist, go to next step. If spark exists, go to step 7.
  5. Check the spark plugs. Check that the plug is not burned, that the insulator is not damaged, and that the plug is not seized. If cleaning is required due to carbon deposits, etc., clean using a plug cleaner or wire brush, etc. Check the plug gap using a plug gap gauge, and adjust if not 0.039-0.043" (1.0-1.1 mm). If the spark plug is in good condition, go to next step. If the spark plug is not in good condition, replace the faulty spark plug. Then go to step 13.
  6. Check the spark plug cable. Check the boot and coating for cracks. Measure the resistance. Limit is 19 k/ohms maximum. If the resistance is as specified, check ignition system. See appropriate SYSTEM & COMPONENT TESTING article. If the resistance is not as specified, replace the faulty spark plug cable. Then go to step 13.
  7. Check the injector. Disconnect the injector connector. Measure the resistance between each injector side connector terminals No. 1 and 2. Standard value is 13-16 ohms [at 68°F (20°C)]. If resistance is as specified, go to next step. If resistance is not as specified, replace the faulty injector. Then go to step 13.
  8. Check injector connectors B-17, B-19, B-21 and B-22 for damage. If the connector is in good condition, go to next step. If the connector is not in good condition, repair or replace it. Then go to step 13.
  9. Check connector C-39 at PCM for damage. If the connector is in good condition, go to next step. If the connector is not in good condition, repair or replace it. Then go to step 13.
  10. Check for harness damage between injector connector and or PCM connector. See «INJECTOR CONTROL CIRCUIT IDENTIFICATION»(ref-150942-S17140946792002112700000) table. If wiring harness is in good condition, go to next step. If wiring harness is not in good condition, repair it. Then go to step 13.
  11. Check the following items: Skipped timing belt teeth. Compression. EGR valve. If there are no abnormalities, go to next step. If there are any abnormalities, repair or replace it. Then go to step 13.
  12. Replace the injector. Carry out a test drive with the drive cycle pattern. See «OTHER MONITOR»(ref-150942-S38112384672002112700000) under VERIFYING REPAIRS. Check the Diagnostic Trouble Code (DTC). If DTC P0300 is output, replace the PCM. Then go to next step. If DTC P0300 is not output, inspection is complete.
  13. Test the OBD-II drive cycle. Carry out a test drive with the drive cycle pattern. See «OTHER MONITOR»(ref-150942-S38112384672002112700000) under VERIFYING REPAIRS. Check the Diagnostic Trouble Code (DTC). If DTC P0300 is output, repeat diagnosis. If DTC P0300 is not output, inspection is complete.

Check conditions are when engine speed is 500-6000 RPM, engine coolant temperature is more than 14°F (-10°C), intake air temperature is more than 14°F (-10°C), barometric pressure is 76-106 kPa (11-15 psi) and adaptive learning is complete for the vane which generates a crankshaft position signal. It is checked when the engine is running, excluding gear shifting, deceleration, sudden acceleration/deceleration and A/C compressor switching and the throttle deviation is -0.059 v/10 ms to +0.059 v/10 ms. Judgement criteria is when a misfire has occurred more frequently than allowed during the last 200 revolutions, when the catalyst temperature is more than 1742°F (950°C), or misfire has occurred in 20 or more of the last 1000 revolutions (corresponding to 1.5 times the limit of emission standard). A change in the angular acceleration of the crankshaft is used for misfire detection.

The most likely causes for this code to be set are

  1. Ignition system related part (s) failed.
  2. Low compression pressure.
  3. Injector failed.
  4. PCM failed.
  1. Check the spark plugs. Check that the plug is not burned, that the insulator is not damaged, and that the plug is not seized. If cleaning is required due to carbon deposits, etc., clean using a plug cleaner or wire brush, etc. Check the plug gap using a plug gap gauge, and adjust if not 0.039-0.043" (1.0-1.1 mm). If the spark plug is in good condition, go to next step. If the spark plug is not in good condition, replace the spark plug. Then go to step 9.
  2. Check the spark plug cable. Check the cap and coating for cracks. Measure the spark plug cable resistance. Maximum resistance is 19 k/ohms. If the resistance is as specified, go to next step. If the resistance is not as specified, replace the spark plug cable. Then go to step 9.
  3. Check the injector. Disconnect the affected injector connector. see scheme 18 Measure the resistance between injector side connector terminals No. 1 and 2. Standard value is 13-16 ohms at 68°F (20°C). If resistance is as specified, go to next step. If resistance is not as specified, replace the injector. Then go to step 9.
  4. Check connector at affected injector for damage. If the connector is in good condition, go to next step. If the connector is not in good condition, repair or replace it. Then go to step 9.
  5. Check connector C-39 at PCM for damage. see scheme 27 If the connector is in good condition, go to next step. If the connector is not in good condition, repair or replace it. Then go to step 9.
  6. Check for harness damage between injector connector and PCM connector. See «INJECTOR CONTROL CIRCUIT IDENTIFICATION»(ref-150942-S17140946792002112700000) table. If wiring harness is in good condition, go to next step. If wiring harness is not in good condition, repair it. Then go to step 9.
  7. Check engine compression. If there any abnormalities, repair or replace it. Then go to step 9. If there no abnormalities, go to next step.
  8. Replace the injector. Carry out a test drive with the drive cycle pattern. See «OTHER MONITOR»(ref-150942-S38112384672002112700000) under VERIFYING REPAIRS. Check the Diagnostic Trouble Code (DTC). If DTC P0301, P0302, P0303 and/or P0304 is output, replace the PCM. Then go to next step. If DTC P0301, P0302, P0303 and P0304 are not output, inspection is complete.
  9. Test the OBD-II drive cycle. Carry out a test drive with the drive cycle pattern. See «OTHER MONITOR»(ref-150942-S38112384672002112700000) under VERIFYING REPAIRS. Check the Diagnostic Trouble Code (DTC). If DTC P0301, P0302, P0303 and/or P0304 is output, repeat diagnosis. If no DTCs are output, inspection is complete.

Check condition is when engine is being cranked. Judgment criteria is when crankshaft position sensor output voltage has not changed (no pulse signal is input) for 2 seconds. Check conditions and judgment criteria are when normal signal pattern has not been input for cylinder identification from the crankshaft position sensor signal and camshaft position sensor signal for 2 seconds.

The most likely causes for this code to be set are

  1. Crankshaft position sensor failed.
  2. Open or shorted crankshaft position sensor circuit, or loose connector.
  3. PCM failed.
CAUTIONTo prevent damage to scan tool, always turn the ignition switch to LOCK position before connecting or disconnecting scan tool.

Note. If PCM is replaced, immobilizer code registration must be performed. See PROGRAMMING .

  1. Using scan tool, check crankshaft position sensor. Connect scan tool to the data link connector. (Scheme 105) Start the engine and run at idle. Set scan tool to the data reading mode for data list item 22: CRANKSHAFT POSITION SENSOR. The tachometer and engine speed indicated on the scan tool should match. Turn the ignition switch to LOCK position. If the sensor is not operating properly, go to next step. If the sensor is operating properly, it can be assumed that this malfunction is intermittent.
  2. Using the oscilloscope, check the crankshaft position sensor. Do not disconnect the crankshaft position sensor connector B-20. Connect the oscilloscope probe to terminal No. 2 of the crankshaft position sensor by backprobing. Start the engine and run at idle. Check the waveform. The waveform should show a normal pattern. see scheme 74 Turn the ignition switch to LOCK position. If the waveform is as specified, go to next step. If the waveform is not as specified, go to step 5.
  3. Check connector B-20 at the crankshaft position sensor for damage. If the connector is in good condition, go to next step. If the connector is not in good condition, repair or replace it. Then go to step 21.
  4. Using scan tool, check crankshaft position sensor. Connect scan tool to the data link connector. Turn the ignition switch to ON position. Set scan tool to the data reading mode for data list item 22: CRANKSHAFT POSITION SENSOR. The tachometer and engine speed indicated on the scan tool should match. Turn the ignition switch to LOCK position. If the sensor is not operating properly, replace the PCM. Then go to step 21. If the sensor is operating properly, it can be assumed that this malfunction is intermittent.
  5. Check connector B-20 at the crankshaft position sensor for damage. If the connector is in good condition, go to next step. If the connector is not in good condition, repair or replace it. Then go to step 21.
  6. Check the sensor supply voltage at crankshaft position sensor harness side connector B-20. Disconnect the connector B-20 and measure at the harness side. Turn the ignition switch to ON position. Measure the voltage between terminal No. 2 and ground. Voltage should be 4.8-5.2 volts. Turn the ignition switch to LOCK position. If voltage is not as specified, go to next step. If voltage is as specified, go to step 11.
  7. Check the sensor supply voltage at PCM connector C-40 by backprobing. Do not disconnect the PCM connector. Disconnect the crankshaft position sensor connector B-20. Turn the ignition switch to ON position. Measure the voltage between PCM connector C-40 terminal No. 45 and ground by backprobing. Voltage should be 4.8-5.2 volts. Turn the ignition switch to LOCK position. If the voltage is as specified, go to next step. If the voltage is not as specified, go to step 9.
  8. Check connector C-40 at PCM for damage. If the connector is in good condition, repair open circuit between crankshaft position sensor connector B-20 terminal No. 2 and PCM connector C-40 terminal No. 45. Then go to step 21. If the connector is not in good condition, repair or replace it. Then go to step 21.
  9. Check connector C-40 at PCM for damage. If the connector is in good condition, go to next step. If the connector is not in good condition, repair or replace it. Then go to step 21.
  10. Check for short circuit to ground between crankshaft position sensor connector B-20 terminal No. 2 and PCM connector C-40 terminal No. 45. If wiring harness is in good condition, replace the PCM. Then go to step 21. If wiring harness is not in good condition, repair it. Then go to step 21.
  11. Check the power supply voltage at crankshaft position sensor harness side connector B-20. Disconnect the connector B-20 and measure at the harness side. Turn the ignition switch to ON position. Measure the voltage between terminal No. 3 and ground. Voltage should be battery positive voltage. Turn the ignition switch to LOCK position. If voltage is not as specified, go to next step. If voltage is as specified, go to step 13.
  12. Check connector B-18X at MFI relay for damage. If the connector is in good condition, repair wiring harness between MFI relay connector B-18X terminal No. 4 and crankshaft position sensor connector B-20 terminal No. 3 because of open circuit or short circuit to ground. Then go to step 21. If the connector is not in good condition, repair or replace it. Then go to step 21.
  13. Check the continuity at crankshaft position sensor harness side connector B-20. Disconnect connector B-20 and measure at the harness side. Check for continuity between terminal No. 1 and ground. Resistance should be less than 2 ohms. If resistance is as specified, go to step 16. If resistance is not as specified, go to next step.
  14. Check connector C-39 at PCM for damage. If the connector is in good condition, go to next step. If the connector is not in good condition, repair or replace it. Then go to step 21.
  15. Check for open circuit and harness damage between crankshaft position sensor connector B-20 terminal No. 1 and PCM connector C-39 terminal No. 16. If wiring harness is in good condition, replace the PCM. Then go to step 21. If wiring harness is not in good condition, repair it. Then go to step 21.
  16. Check connector B-18X at the MPI relay for damage. If the connector is in good condition, go to next step. If the connector is not in good condition, repair or replace it. Then go to step 21.
  17. Check connector C-40 at PCM for damage. If the connector is in good condition, go to next step. If the connector is not in good condition, repair or replace it. Then go to step 21.
  18. Check for harness damage between MFI relay B-18X terminal No. 4 and crankshaft position sensor connector B-20 terminal No. 3. If the connector is in good condition, go to next step. If the connector is not in good condition, repair or replace it. Then go to step 21.
  19. Check for harness damage between crankshaft position sensor connector B-20 terminal No. 2 and PCM connector C-40 terminal No. 45. If wiring harness is in good condition, go to next step. If wiring harness is not in good condition, repair it. Then go to step 21.
  20. Check the crankshaft position sensor vane. If the vane is in good condition, replace the crankshaft position sensor. Then go to next step. If the vane is not in good condition, repair it. Then go to next step.
  21. Test the OBD-II drive cycle. Carry out a test drive with the drive cycle pattern. See «OTHER MONITOR»(ref-150942-S38112384672002112700000) under VERIFYING REPAIRS. Check the Diagnostic Trouble Code (DTC). If DTC P0335 is output, repeat diagnosis. If DTC P0335 is not output, inspection is complete.

Check conditions are when engine speed is more than 50 RPM. Judgment criteria is when camshaft position sensor output voltage has not changed (no pulse signal is input) for 2 seconds.

Check conditions are when engine speed is more than 50 RPM. Judgment criteria is when normal signal pattern has not been input for cylinder identification from the crankshaft position sensor signal and camshaft position sensor signal for 2 seconds.

The most likely causes for this code to be set are

  1. Camshaft position sensor failed.
  2. Open or shorted camshaft position sensor circuit, or loose connector.
  3. PCM failed.
  1. Using the oscilloscope, check the camshaft position sensor. Disconnect the camshaft position sensor connector B-12, and connect Test Harness (MB991709) between connectors. All terminals should be connected. Connect the oscilloscope probe to the camshaft position sensor side connector terminal No. 2. Start the engine and run at idle. Check the waveform. The waveform should show a normal pattern. see scheme 76 Turn the ignition switch to LOCK position. If the waveform is as specified, go to next step. If the waveform is not as specified, go to step 4.
  2. Check connector B-12 at camshaft position sensor for damage. If the connector is in good condition, go to next step. If the connector is not in good condition, repair or replace it. Then go to step 20.
  3. Check the trouble symptoms. Carry out a test drive with the drive cycle pattern. See «OTHER MONITOR»(ref-150942-S38112384672002112700000) under VERIFYING REPAIRS. Check the Diagnostic Trouble Code (DTC). If DTC P0340 is output, replace the PCM. Then go to step 20. If DTC P0340 is not output, it can be assumed that this malfunction is intermittent.
  4. Check connector B-12 at camshaft position sensor for damage. If the connector is in good condition, go to next step. If the connector is not in good condition, repair or replace it. Then go to step 20.
  5. Check the sensor supply voltage at camshaft position sensor connector B-12. Disconnect the connector B-12 and measure at the harness side. Turn the ignition switch to ON position. Measure the voltage between terminal No. 2 and ground. Voltage should be 4.8-5.2 volts. Turn the ignition switch to LOCK position. If voltage is not as specified, go to next step. If voltage is as specified, go to step 10.
  6. Check the sensor supply voltage at PCM connector C-40 by backprobing. Do not disconnect the PCM connector. Disconnect the camshaft position sensor connector B-12. Turn the ignition switch to ON position. Measure the voltage between terminal No. 56 and ground by backprobing. Voltage should be 4.8-5.2 volts. Turn the ignition switch to LOCK position. If the voltage is as specified, go to next step. If the voltage is not as specified, go to step 8.
  7. Check connector C-40 at PCM for damage. If the connector is in good condition, repair wiring harness between camshaft position sensor connector B-12 terminal No. 2 and PCM connector C-40 terminal No. 56 because of open circuit. Then go to step 20. If the connector is not in good condition, repair or replace it. Then go to step 20.
  8. Check connector C-40 at PCM for damage. If the connector is in good condition, go to next step. If the connector is not in good condition, repair or replace it. Then go to step 20.
  9. Check for short circuit to ground between camshaft position sensor connector B-12 terminal No. 2 and PCM connector C-40 terminal No. 56. If wiring harness is in good condition, replace the PCM. Then go to step 20. If wiring harness is not in good condition, repair it. Then go to step 20.
  10. Check the power supply voltage at camshaft position sensor connector B-12. Disconnect connector B-12 and measure at the harness side. Turn the ignition switch to ON position. Measure the voltage between terminal No. 3 and ground. Voltage should be battery positive voltage. Turn the ignition switch to LOCK position. If voltage is not as specified, go to next step. If voltage is as specified, go to step 12.
  11. Check connector B-18X at MFI relay for damage. If the connector is in good condition, repair wiring harness between MFI relay connector B-18X terminal No. 4 and camshaft position sensor connector B-12 terminal No. 3 because of open circuit or short circuit to ground. Then go to step 20. If the connector is not in good condition, repair or replace it. Then go to step 20.
  12. Check the continuity at camshaft position sensor connector B-12. Disconnect the connector B-12 and measure at be harness aide. Check for the continuity between terminal No. 1 and ground. Resistance should be less than 2 ohms. If continuity is as specified, go to step 15. If continuity is not as specified, go to next step.
  13. Check connector C-39 at PCM for damage. If the connector is in good condition, go to next step. If the connector is not in good condition, repair or replace it. Then go to step 20.
  14. Check for open circuit or harness damage between camshaft position sensor connector B-12 terminal No. 1 and PCM connector C-39 terminal No. 16. If wiring harness is in good condition, replace the PCM. Then go to step 20. If wiring harness is not in good condition, repair it. Then go to step 20.
  15. Check connector B-18X at the MFI relay for damage. If the connector is in good condition, go to next step. If the connector is not in good condition, repair or replace it. Then go to step 20.
  16. Check connector C-40 at PCM for damage. If the connector is in good condition, go to next step. If the connector is not in good condition, repair or replace it. Then go to step 20.
  17. Check for harness damage between MFI relay connector B-18X terminal No. 4 and camshaft position sensor connector B-12 terminal No. 3. If wiring harness is in good condition, go to next step. If wiring harness is not in good condition, repair it. Then go to step 20.
  18. Check for harness damage between camshaft position sensor connector B-12 terminal No. 2 and PCM connector C114 terminal No. 56. If wiring harness is in good condition, go to next step. If wiring harness is not in good condition, repair it. Then go to step 20.
  19. Check the camshaft position sensor vane. If the vane is in good condition, replace the camshaft position sensor. Then go to next step. If the vane is not in good condition, repair it. Then go to next step.
  20. Test the OBD-II drive cycle. Carry out a test drive with the drive cycle pattern. See «OTHER MONITOR»(ref-150942-S38112384672002112700000) under VERIFYING REPAIRS. Check the Diagnostic Trouble Code (DTC). If DTC P0340 is output, repeat diagnosis. If DTC P0340 is not output, inspection is complete.

Check conditions are when at least 20 seconds have passed since the last monitor was complete, engine coolant temperature is more than 169°F (76°C), engine speed is 940-2000 RPM, intake air temperature is more than 32°F (0°C), barometric pressure is more than 76 kPa (11 psi), vehicle speed is more than 8.7 mph (30 km/h), and at least 90 seconds have passed since manifold differential pressure sensor output voltage fluctuated 1.5 volts or more. The throttle valve must be closed, volumetric efficiency is less than 24 percent, and 20 seconds have elapsed from the start of the previous monitoring. Monitoring time is 2 seconds by 3 times. Judgement criteria is when intake manifold pressure fluctuations width is less than 2.6 kPa (0.37 psi) when the EGR solenoid is turned on.

The most likely causes for this code to be set are

  1. EGR valve does not open.
  2. EGR control vacuum is too low.
  3. EGR solenoid failed.
  4. Open or shorted EGR solenoid circuit, or loose connector.
  5. Manifold differential pressure sensor failed.
  6. PCM failed.
CAUTIONTo prevent damage to scan tool, always turn the ignition switch to LOCK position before connecting or disconnecting scan tool.

Note. If PCM is replaced, immobilizer code registration must be performed. See PROGRAMMING .

  1. Check the EGR system. If there are no abnormalities, go to next step. If there are any abnormalities, repair it. Then go to step 3.
  2. Using scan tool, check manifold differential pressure sensor. Connect scan tool to the data link connector. (Scheme 105) Start the engine and run at idle. Set scan tool to the data reading mode for data list item 95: MANIFOLD DIFFERENTIAL PRESSURE SENSOR. Warm up the engine to normal operating temperature. Data should be 64-78 kPa with engine idling. Turn the ignition switch to LOCK position. If the sensor is operating properly, clean the EGR valve and EGR passage. Then go to next step. If the sensor is not operating properly, go to «DTC P1400: MANIFOLD DIFFERENTIAL PRESSURE SENSOR»(ref-150942-S06347845552002112700000).
  3. Test the OBD-II drive cycle. Carry out a test drive with the drive cycle pattern. See «EGR MONITOR»(ref-150942-S13108925402002112700000) under VERIFYING REPAIRS. Check the Diagnostic Trouble Code (DTC). If DTC P0401 is output, repeat diagnosis. If DTC P0401 is not output, inspection is complete.

Check conditions are when engine is being cranked and battery positive voltage is 10-16 volts. Judgment criteria is when the EGR solenoid coil surge voltage (battery positive voltage plus 2 volts) is not detected for 0.2 second. Only one monitor is performed during one drive cycle.

Check conditions are when battery positive voltage is 10-16 volts, ON duty cycle of the EGR solenoid is 10-90 percent, ON duty cycle of the evaporative emission purge solenoid is 0 percent, evaporative emission ventilation solenoid is OFF and more than 1 second has elapsed after the conditions have been met. Judgment criteria is when the EGR solenoid coil surge voltage (battery positive voltage plus 2 volts) is not detected for 1 second.

The most likely causes for this code to be set are

  1. EGR solenoid failed.
  2. Open or shorted EGR solenoid circuit, or loose connector.
  3. PCM failed.
CAUTIONTo prevent damage to scan tool, always turn the ignition switch to LOCK position before connecting or disconnecting scan tool.

Note. If PCM is replaced, immobilizer code registration must be performed. See PROGRAMMING .

  1. Using scan tool, check EGR solenoid. Connect scan tool to the data link connector. (Scheme 105) Turn the ignition switch to ON position. Set scan tool to the actuator test mode for item 10: EGR SOLENOID. An operation sound should be heard and vibration should be felt when the EGR solenoid is operated. Turn the ignition switch to LOCK position. If the solenoid is not operating properly, go to next step. If the solenoid is operating properly, it can be assumed that this malfunction is intermittent.
  2. Check connector B-03 at the EGR solenoid for damage. If the connector is in good condition, go to next step. If the connector is not in good condition, repair or replace it. Then go to step 12.
  3. Check the EGR solenoid. Disconnect the EGR solenoid connector B-03. Measure the resistance between EGR solenoid side connector terminals No. 1 and 2. Standard value is 29-35 ohms at 68°F (20°C). If the resistance is as specified, go to next step. If the resistance is not as specified, replace the EGR solenoid. Then go to step 12.
  4. Check the power supply voltage at EGR solenoid harness side connector B-03. Disconnect the connector B-03 and measure at the harness side. Turn the ignition switch to ON position. Measure the voltage between terminal No. 1 and ground. Voltage should be battery positive voltage. Turn the ignition switch to LOCK position. If voltage is as specified, go to step 6. If voltage is not as specified, go to next step.
  5. Check connector A-18X at MFI relay for damage. If the connector in good condition, check intermediate connector B-11 for damage, and repair or replace as required. If intermediate connectors are in good condition, repair wiring harness between MFI relay connector A-18X terminal No. 4 and EGR solenoid connector B-03 terminal No. 1 because of open circuit or short circuit to ground. Then go to step 12. If the connector is not in good condition, repair or replace it. Then go to step 12.
  6. Check the power supply voltage at PCM connector C-39 by backprobing. Do not disconnect the PCM connector. Turn the ignition switch to ON position. Measure the voltage between terminal No. 6 and ground by backprobing. Voltage should be battery positive voltage. Turn the ignition switch to LOCK position. If voltage is not as specified, go to next step. If voltage is as specified, go to step 9.
  7. Check connector C-39 at PCM for damage. If the connector is in good condition, go to next step. If the connector is not in good condition, repair or replace it. Then go to step 12.
  8. Check intermediate connector B-11. If intermediate connector is damaged, repair or replace it. Then go to step 12. If intermediate connector B-11 is okay, check for open circuit and short circuit to ground between EGR solenoid connector B-03 terminal No. 2 and PCM connector C-39 terminal No. 6. If wiring harness is in good condition, replace the PCM. Then go to step 12. If wiring harness is not in good condition, repair it. Then go to step 12.
  9. Check connector C-39 at PCM for damage. If the connector is in good condition, go to next step. If the connector is not in good condition, repair or replace it. Then go to step 12.
  10. Check intermediate connector B-11. If intermediate connectors are damaged, repair or replace them. Then go to step 12. Check for harness damage between MFI relay connector A-18X terminal No. 4 and EGR solenoid connector B-03 terminal No. 1. If wiring harness is in good condition, go to next step. If wiring harness is not in good condition, repair it. Then go to step 12.
  11. Check intermediate connector B-11. If intermediate connector is damaged, repair or replace it. Then go to next step. If intermediate connector B-11 is okay, check for harness damage between EGR solenoid connector B-03 terminal No. 2 and PCM connector C-39 terminal No. 6. If wiring harness is in good condition, replace the PCM. Then go to next step. If wiring harness is not in good condition, repair it. Then go to next step.
  12. Test the OBD-II drive cycle. Carry out a test drive with the drive cycle pattern. See «OTHER MONITOR»(ref-150942-S38112384672002112700000) under VERIFYING REPAIRS. Check the Diagnostic Trouble Code (DTC). If DTC P0403 is output, repeat diagnosis. If DTC P0403 is not output, inspection is complete.

Check conditions are when engine speed is less than 3000 RPM, volume air flow sensor output frequency is 63-169 Hz, intake air temperature is more than 14°F (-10°C) barometric pressure is more than 76 kPa (11 psi), the throttle valve is open, vehicle is under the closed loop air/fuel ratio control and vehicle speed is 1.5 km/h (0.93 mph) or more. Monitoring time is 10 seconds by 7 times, short-term fuel trim is more than -25 percent and less than +25 percent, and the cumulative volume air flow sensor output frequency is more than 4000 Hz. Judgment criteria is when the heated oxygen sensor (rear) signal frequency plus heated oxygen sensor (front) signal frequency equals 0.8 or more.

The most likely causes for this code to be set are

  1. Catalytic converter deteriorated.
  2. Heated oxygen sensor failed.
  3. PCM failed.
  1. Check for exhaust leaks. If there are no abnormalities, go to next step. If there are any abnormalities, repair it. Then go to next step.
  2. Using scan tool, check heated oxygen sensor (rear). Connect scan tool to the data link connector. (Scheme 105) Start the engine and run at idle. Set scan tool to the data reading mode for data list item 59: HEATED OXYGEN SENSOR (REAR). Warm engine to operating temperature. When the engine is revved, the output voltage should be 0.6 to 1.0 volt. Turn the ignition switch to LOCK position. If the sensor is operating properly, go to next step. If the sensor is not operating properly, refer to «DTC P0137: HEATED OXYGEN SENSOR CIRCUIT LOW VOLTAGE (SENSOR 2)»(ref-150942-S37925420252002112700000), «DTC P0138: HEATED OXYGEN SENSOR CIRCUIT HIGH VOLTAGE (SENSOR 2)»(ref-150942-S08823597482002112700000) and «DTC P0139: HEATED OXYGEN SENSOR CIRCUIT SLOW RESPONSE (SENSOR 2)»(ref-150942-S29004629602002112700000).
  3. Using scan tool, check heated oxygen sensor (front). Connect scan tool to the data link connector. Start the engine and run at idle. Set scan tool to the data reading mode for data list item 11: HEATED OXYGEN SENSOR (FRONT). Warm engine to operating temperature. When the engine is revved, the output voltage should be 0.6 to 1.0 volt. When the engine is idling, the output voltage should alternate between 0.4 volt or less and 0.6 to 1.0 volt. Turn the ignition switch to LOCK position. If the sensor is operating properly, go to next step. If the sensor is not operating properly, refer to «DTC P0132: HEATED OXYGEN SENSOR CIRCUIT HIGH VOLTAGE (SENSOR 1)»(ref-150942-S27871645762002112700000), «DTC P0133: HEATED OXYGEN SENSOR CIRCUIT SLOW RESPONSE (SENSOR 1)»(ref-150942-S24991863812002112700000) and «DTC P0134: HEATED OXYGEN SENSOR CIRCUIT NO ACTIVITY DETECTED (SENSOR 1)»(ref-150942-S40103678722002112700000).
  4. Using scan tool, check heated oxygen sensor (front). Connect scan tool to the data link connector. (Scheme 105) Start the engine and run at idle. Set scan tool to the data reading mode for data list item 11: HEATED OXYGEN SENSOR (FRONT). Warm engine to operating temperature. With engine at 2500 RPM, output voltage should alternate between 0.4 volt or less and 0.6 to 1.0 volt 10 times or more within 10 seconds. Turn the ignition switch to LOCK position. If the sensor is operating properly, go to next step. If the sensor is not operating properly, replace the heated oxygen sensor (front). Then go to step 7.
  5. Test the OBD-II drive cycle. Carry out a test drive with the drive cycle pattern. See «CATALYTIC CONVERTER MONITOR»(ref-150942-S20541946592002112700000) under VERIFYING REPAIRS. Check the Diagnostic Trouble Code (DTC). If DTC P0421 is output, replace the catalytic converter. Then go to next step. If DTC P0421 is not output, inspection is complete.
  6. Test the OBD-II drive cycle. Carry out a test drive with the drive cycle pattern. See «CATALYTIC CONVERTER MONITOR»(ref-150942-S20541946592002112700000) under VERIFYING REPAIRS. Check the Diagnostic Trouble Code (DTC). If DTC P0421 is output, replace the PCM. Then go to next step. If DTC P0421 is not output, inspection is complete.
  7. Test the OBD-II drive cycle. Carry out a test drive with the drive cycle pattern. See «CATALYTIC CONVERTER MONITOR»(ref-150942-S20541946592002112700000) under VERIFYING REPAIRS. Check the Diagnostic Trouble Code (DTC). If DTC P0421 is output, repeat diagnosis. If DTC P0421 is not output, inspection is complete.

Check conditions are when ON duty cycle of the evaporative emission purge solenoid is 0 percent and 20 seconds have elapsed from the time the duty cycle of the evaporative emission purge solenoid has turned to 0 percent. Judgment criteria is when the pressure in the fuel tank is -2 kPa (0.29 psi) or less.

The most likely causes for this code to be set are

  1. Evaporative emission purge solenoid failed.
  2. Evaporative emission ventilation solenoid failed.
  3. Choking up of hose between evaporative emission canister and evaporative emission ventilation solenoid.
CAUTIONTo prevent damage to scan tool, always turn the ignition switch to LOCK position before connecting or disconnecting scan tool.

Note. If PCM is replaced, immobilizer code registration must be performed. See PROGRAMMING .

  1. Using scan tool, check evaporative emission purge solenoid. Connect scan tool to the data link connector. (Scheme 105) Turn the ignition switch to ON position. Set scan tool to the actuator test mode for actuator test item 08: EVAPORATIVE EMISSION PURGE SOLENOID. An operation sound should be heard and vibration should be felt when the evaporative emission purge solenoid is operated. Turn the ignition switch to LOCK position. If the solenoid is operating properly, go to next step. If the solenoid is not operating properly, replace the evaporative emission purge solenoid. Then go to step 4.
  2. Using scan tool, check evaporative emission ventilation solenoid. Turn the ignition switch to ON position. Set scan tool to the actuator test mode for actuator test item 29: EVAPORATIVE EMISSION VENTILATION SOLENOID. An operation sound should be heard and vibration should be felt when the evaporative emission ventilation solenoid is operated. Turn the ignition switch to LOCK position. If the solenoid is operating properly, go to next step. If the solenoid is not operating properly, replace the evaporative emission ventilation solenoid. Then go to step 4.
  3. Check for clogging in the vent hose and air filter. If there are any clogs, repair or replace it. Then go to next step. If there are no clogs, go to «DTC P0451: EVAPORATIVE EMISSION CONTROL SYSTEM PRESSURE SENSOR RANGE/PERFORMANCE»(ref-150942-S22281798922002112700000), «DTC P0452: EVAPORATIVE EMISSION CONTROL SYSTEM PRESSURE SENSOR LOW INPUT»(ref-150942-S13164230812002112700000) or «DTC P0453: EVAPORATIVE EMISSION CONTROL SYSTEM PRESSURE SENSOR HIGH INPUT»(ref-150942-S01087724102002112700000).
  4. Test the OBD-II drive cycle. Carry out a test drive with the drive cycle pattern. See «EVAP SYSTEM LEAK MONITOR»(ref-150942-S05135908802002112700000) under VERIFYING REPAIRS. Read the diagnostic trouble code. If diagnostic trouble code P0441 is set, repeat diagnosis. If diagnostic trouble code P0441 is not set, diagnosis is complete.

Note. The monitoring time depends on the fuel level and the temperature in the fuel tank (75-125 seconds). Check conditions require remaining fuel amount to be 15-40 percent (fuel level sensor output voltage is 1.4-2.4 volts).

Test Conditions A: Intake air temperature is 97°F (36°C) or less and engine coolant temperature 97°F (36°C) or less when the engine is started.

Test Conditions B: For test to run, following conditions must be met: Fuel temperature is 97°F (36°C) or less, engine coolant temperature is more than 140°F (60°C) within 16 minutes after the engine is started, power steering pressure switch is OFF, barometric pressure is above 11 psi (76 kPa), volumetric efficiency is 20-80 percent, fuel tank differential pressure sensor output voltage is 1-4 volts and vehicle speed is 12.4 mph (20 km/h) or more.

Test Conditions C: For test to stop, following conditions must be met: Intake air temperature must be less than 41°F (5°C). When the evaporative emission purge solenoid and evaporative emission ventilation solenoid are closed, the pressure rises more 0.065 psi (451 kPa). The pressure fluctuation width is more than 0.094 psi (647 kPa).

Judgment criteria is when internal pressure of the fuel tank has changed more than 0.122 psi (843 kPa) in 20 seconds after the tank and vapor line were closed.

Note. The monitoring time depends on the fuel level and the temperature in the fuel tank (10-14 minutes). Check conditions require remaining fuel amount to be 40-75 percent (fuel level sensor output voltage is 2.4-3.7 volts).

Test Conditions A: At start up intake air temperature is 97°F (36°C) or less when the engine is started. The engine coolant temperature 97°F (36°C) or less when the engine is started.

Test Conditions B: For test to run, following conditions must be met. Fuel temperature is 97°F (36°C) or less. Barometric pressure is above 11 psi (76 kPa). Volumetric efficiency is 20-80 percent. Fuel tank differential pressure sensor output voltage is 1-4 volts.

Test Conditions C: For test to stop, following conditions must be met: Intake air temperature is less than 14°F (-10°C). Engine coolant temperature is less than 68°F (20°C). When the evaporative emission purge solenoid and evaporative emission ventilation solenoid are closed, the pressure rises more 0.047 psi (324 kPa).

Judgment criteria is when internal pressure of the fuel tank has changed more than 0.29 psi (2 kPa) in 128 seconds after the tank and vapor line were closed.

The most likely causes for this code to be set are

  1. Loose fuel cap.
  2. Fuel cap relief pressure is incorrect.
  3. Evaporative emission canister seal is faulty.
  4. Fuel tank, purge line or vapor line seal failed.
  5. Evaporative emission ventilation solenoid failed.

To determine the cause of DTC P0442, a performance test is needed. The performance test uses a mechanical vacuum gauge and scan tool set on the fuel tank differential pressure sensor (TANK PRES SNER 73). The mechanical gauge reading is used to verify scan tool reading. A comparison of the mechanical gauge to scan tool determines the problem in the system. Prior to doing the performance test, several simple inspections are needed to exclude some possibilities of the symptom.

CAUTIONTo prevent damage to scan tool, always turn the ignition switch to LOCK position before connecting or disconnecting scan tool.

Note. If PCM is replaced, immobilizer code registration must be performed. See PROGRAMMING .

Note. With this monitor, the PCM automatically increases the engine speed to 1600 RPM or more.

Scheme 110

Scheme 110
Scheme 110

Scheme 111

Scheme 111
Scheme 111
  1. Using scan tool, check evaporative emission system monitor test. Check that the transaxle is set to "P" position. Connect scan tool to the data link connector. (Scheme 105) Turn the ignition switch to ON position. Erase the DTCs using the scan tool. Check that the fuel cap is securely closed. (Tighten until three clicks are heard.) Start the engine. Select SYSTEM TEST, and press YES key. Select EVAP LEAK MON, and press YES key. During the monitor, keep the accelerator pedal at the idling position. If the engine speed does not reach 2000 RPM during the monitor test, adjustment of the Speed Adjusting Screw may be needed. Adjust to the specification. Keep the engine speed and engine load within the specified range. When the monitor test starts, the in Progress item on scan tool will change from NO to YES. Turn the ignition switch to LOCK position, and disconnect scan tool. If EVAP LEAK MON. COMPLETED TEST PASSED is displayed on the scan tool, the evaporative emission system is working properly at this time. Explain to customer that an improperly tightened fuel cap can cause MIL to turn on, and return the vehicle. If EVAP LEAK MON. COMPLETED. TEST FAILED AND DTCS SET is displayed on the scan tool, a malfunction has been detected during the monitor test. Go to next step. If EVAP LEAD MON. DISCONTINUED. RETEST AGAIN FROM THE FIRST is displayed on the scan tool, the monitor was discontinued for a certain reason (vehicle speed input from computer, engine speed and engine load deviating from specified range). Turn the ignition switch to LOCK position once, and repeat step.
  2. Check evaporative emission purge solenoid for leaks. Remove the battery. Remove the air intake hose. Disconnect hose "B" from the evaporative emission purge solenoid side, and connect a hand vacuum pump to the nipple of the evaporative emission purge solenoid. Apply pressure on hand vacuum pump, and confirm that air is maintained. Disconnect the hand vacuum pump, and connect hose "B" to the evaporative emission purge solenoid. If the evaporative emission purge solenoid is in good condition, go to next step. If the evaporative emission purge solenoid is not in good condition, replace the evaporative emission purge solenoid. Then go to step 18.
  3. Check for leaks in the evaporator line hose "A" to hose "C". Perform leakage test with a hand vacuum pump on each hose from hose "A" to hose "C". If hoses are in good condition, go to next step. If hoses are not in good condition, replace the faulty hose. Then go to step 18.
  4. Check for leaks in the chamber. Connect a hand vacuum pump to the nipple. Plug the other nipple. Apply vacuum with the hand vacuum pump and confirm that the applied vacuum does not fluctuate. If the chamber is in good condition, go to next step. If the chamber is not in good condition, replace the chamber. Then go to step 18.
  5. Check the evaporative emission ventilation solenoid. Connect scan tool to the data link connector. Disconnect hose "E" from the evaporative emission ventilation solenoid aide. Connect the hand vacuum pump to the nipple of the evaporative emission ventilation solenoid from which the hoses have been disconnected. Turn the ignition switch to ON position. Set scan tool to actuator test mode for item actuator test item 29: EVAPORATIVE EMISSION VENTILATION SOLENOID. When the evaporative emission ventilation solenoid is operated, apply pressure on the hand vacuum pump and confirm that pressure is maintained. Turn the ignition switch to LOCK position. Disconnect scan tool. Disconnect the hand vacuum pump, and connect hose "E" to the evaporative emission canister. If the evaporative emission ventilation solenoid is in good condition, go to next step. If the evaporative emission ventilation solenoid is not in good condition, replace the evaporative emission ventilation solenoid. Then go to step 18.
  6. Pressure test for evaporator line from hose "D" to hose "N". Remove the module bracket mounting bolts, and disconnect hose "E" from the evaporative emission ventilation solenoid side and plug the hoses from which the hoses have been disconnected. Confirm that the evaporative emission system pressure pump (Miller number 6872A) is operating properly. Perform the self-test as described in the manufacturer's instructions. Connect an evaporative emission system pressure pump to the fuel filler neck. Pressure test the system to determine whether any leaks are present. If the evaporator lines are not in good condition, go to next step. If the evaporator lines are in good condition, go to step 17.
  7. Pressure test for evaporator line from hose "G" to hose "N". Disconnect hose "G" from the evaporative emission canister side, and plug the hose from which the pipes have been disconnected. Perform the pressure test again. If the evaporator lines are in good condition, go to next step. If the evaporator lines are not in good condition, go to step 10.
  8. Check for leaks in the evaporator line hose "D" to hose "F". Remove the fuel tank. Perform the leakage test with a hand vacuum pump on each hose from hose "D" to hose "F". If the hoses are in good condition, go to next step. If the hoses are not in good condition, replace that hose and reinstall the fuel tank. Then go to step 18.
  9. Check for leaks in the evaporative emission canister. Connect a hand vacuum pump to the vent nipple of the evaporative emission canister. Plug the other two nipples or loop a hose between the other nipples. Apply a vacuum with the hand vacuum pump, and confirm that the applied vacuum does not fluctuate. If the evaporation emission canister is in good condition, go to step 18. If the evaporation emission canister is not in good condition, replace the evaporative emission canister and reinstall the fuel tank. Then go to step 18.
  10. Check for leaks in the evaporator line from hose "H" and hose "I". Remove the fuel filler neck protector. Disconnect hose "H" at the liquid separator, and then connect a hand vacuum pump to the hose. Disconnect hose "I" at the fuel tank side, and then plug the hose. Apply vacuum with the hand vacuum pump and confirm that the applied vacuum does not fluctuate. If the evaporator lines are in good condition, go to next step. If the evaporator lines are not in good condition, replace faulty hose and reinstall the fuel filler neck protector. Then go to step 18.
  11. Check for leaks in the evaporator line hose "G", "J", "K" "L" and "M". Remove the fuel tank and fuel filler neck assembly. Perform the leakage test with a hand vacuum pump on each hose from hose "G", "J", "K" "L" and "M". If the hoses are in good condition, go to next step. If the hoses are not in good condition, replace the faulty hose(s), reinstall the fuel tank and fuel filler neck assembly. Then go to step 18.
  12. Check check valve "A". Check valve should pass air only from the direction shown. see scheme 90 If check valve "A" is in good condition, go to next step. If check valve "A" is not in good condition, replace the check valve "A", reinstall the fuel tank and fuel filler neck assembly. Then go to step 18.
  13. Check check valve "B". see scheme 91 When you blow through check valve (Step 1), it should pass more air. When you blow through check valve in the other direction (Step 2), it should pass less air. No air should leak from the check valve body. If check valve "B" is in good condition, go to next step. If check valve "B" is not in good condition, replace check valve "B", reinstall the fuel tank and fuel filler neck assembly. Then go to step 18.
  14. Check for leaks in the evaporator line hose "N". Perform the leakage test with a hand vacuum pump on each hose from hose "N". If the hose is in good condition, go to next step. If the hose is not in good condition, replace the hose, reinstall the fuel tank and fuel filler neck assembly. Then go to step 18.
  15. Visually check for cracks in the fuel filler neck assembly. If the fuel filler neck assembly is in good condition, go to next step. If the fuel filler neck assembly is not in good condition, replace the fuel filler neck assembly, reinstall the fuel tank and fuel filler neck assembly. Then go to step 18.
  16. Check for leaks in the fuel tank. Visually check for cracks and leaks, etc. Carefully check the fuel pump assembly and the inner pressure sensor installation section in the fuel tank. Connect an evaporative emission system pressure pump to the leveling valve nipple. Plug the filler hose, feed pipe, return pipe and rollover valve nipple connected to the fuel tank. If these items are not securely plugged here, fuel could leak. Apply pressure with the evaporative emission system pressure pump. In the pressurized state, check for the leak by applying soap water, etc. to each section. If the fuel tank is in good condition, go to next step. If the fuel tank is not in good condition, replace the fuel tank, reinstall the fuel tank and fuel filler neck assembly Then go to step 18.
  17. Using scan tool, check evaporative emission system monitor test. Check that the transaxle is set to "P" position. Connect scan tool to the data link connector. Turn the ignition switch to ON position. Erase the DTCs using scan tool. Check that the fuel cap is securely fastened. (Tighten until three clicks are heard.) Start the engine. Select SYSTEM TEST, and press YES key. Select EVAP LEAK MON, and press YES key. During the monitor, keep the accelerator pedal at the idling position. Keep the engine speed and engine load within the specified range. When the monitor test starts, the IN PROGRESS item on the scan tool will change from NO to YES. Turn the ignition switch to LOCK position. Disconnect scan tool. If EVAP LEAK MON. COMPLETED. TEST PASSED is displayed on scan tool, the evaporative emission system is working properly at this time. Go to next step. If EVAP LEAK MON. COMPLETED. TEST FAILED AND DTCS SET is displayed on scan tool, replace the PCM. Then go to next step. If EVAP LEAD MON. DISCONTINUED. RETEST AGAIN FROM THE FIRST is displayed on scan tool, the monitor was discontinued for a certain reason (vehicle speed input from PCM, engine speed and engine load deviating from specified range). Turn the ignition switch to LOCK position once, and recheck evaporative emission system monitor test.
  18. Test the OBD-II drive cycle. Carry out a test drive with the drive cycle pattern. See «EVAP SYSTEM LEAK MONITOR»(ref-150942-S05135908802002112700000) under VERIFYING REPAIRS. Read the diagnostic trouble code. If diagnostic trouble code P0442 is reset, go to step 1. If diagnostic trouble code P0442 is not reset, diagnosis is complete.

Check conditions are when battery positive voltage is 10-16 volts. Judgment criteria is when the evaporative emission purge solenoid coil surge voltage (battery positive voltage plus 2 volts) is not detected for 0.2 second. Only one monitor is performed during one drive cycle.

Check conditions are when more than 1 second has elapsed after battery positive voltage is 10-16 volts, on duty cycle of the evaporative emission purge solenoid is 10-90 percent, on duty cycle of the EGR solenoid is 0 percent and evaporative emission ventilation solenoid is off. Judgment criteria is when the evaporative emission purge solenoid coil surge voltage (battery positive voltage plus 2 volts) is not detected for 1 second.

The most likely causes for this code to be set are

  1. Evaporative emission purge solenoid failed.
  2. Open or shorted evaporative emission purge solenoid circuit, or loose connector.
  3. PCM failed.
CAUTIONTo prevent damage to scan tool, always turn the ignition switch to LOCK position before connecting or disconnecting scan tool.

Note. If PCM is replaced, immobilizer code registration must be performed. See PROGRAMMING .

  1. Using scan tool, check evaporative emission purge solenoid. Connect scan tool to the data link connector. (Scheme 105) Turn the ignition switch to ON position. Set scan tool to the actuator test mode for actuator test item 08: EVAPORATIVE EMISSION PURGE SOLENOID. An operation sound should be heard and vibration should be felt when the evaporative emission purge solenoid is operated. Turn the ignition switch to LOCK position. If the solenoid is not operating properly, go to next step. If the solenoid is operating properly, it can be assumed that this malfunction is intermittent.
  2. Check connector B-04 at the evaporative emission purge solenoid for damage. If the connector is in good condition, go to next step. If the connector is not in good condition, repair or replace it. Then go to step 12.
  3. Check the evaporative emission purge solenoid. Disconnect the evaporative emission purge solenoid connector B-04. Measure the resistance between evaporative emission purge solenoid side connector terminals No. 1 and 2. Standard value is 30-34 ohms at 68°F (20°C). If the resistance is as specified, go to next step. If the resistance is not as specified, replace the evaporative emission purge solenoid. Then go to step 12.
  4. Check the power supply voltage at evaporative emission purge solenoid harness side connector B-04. Disconnect connector B-04 and measure at the harness side. Turn the ignition switch to ON position. Measure the voltage between terminal No. 2 and ground. Voltage should be battery positive voltage. Turn the ignition switch to LOCK position. If voltage is not as specified, go to next step. If voltage is as specified, go to step 6.
  5. Check connector A-18X at MFI relay for damage. If the connector is in good condition, repair wiring harness between MFI relay connector A-21X terminal No. 4 and evaporative emission purge solenoid connector B-04 terminal No. 2 because of open circuit or short circuit to ground. Then go to step 12. If the connector is not in good condition, repair or replace it. Then go to step 12.
  6. Check the power supply voltage at PCM connector C-39 by backprobing. Do not disconnect the PCM connector. Turn the ignition switch to ON position. Measure the voltage between terminal No. 34 and ground by backprobing. Voltage should be battery positive voltage. Turn the ignition switch to LOCK position. If voltage is not as specified, go to next step. If voltage is as specified, go to step 9.
  7. Check connector C-39 at PCM for damage. If the connector is in good condition, go to next step. If the connector is not in good condition, repair or replace it. Then go to step 12.
  8. Check for open circuit and short circuit to ground between evaporative emission purge solenoid connector B-04 terminal No. 1 and PCM connector C-39 terminal No. 34. If wiring harness is in good condition, replace the PCM. Then go to step 12. If wiring harness is not in good condition, repair it. Then go to step 12.
  9. Check connector C-39 at PCM for damage. If the connector is in good condition, go to next step. If the connector is not in good condition, repair or replace it. Then go to step 12.
  10. Check for harness damage between MFI relay connector A-18X terminal No. 4 and evaporative emission purge solenoid connector B-04 terminal No. 2. If wiring harness is in good condition, go to next step. If wiring harness is not in good condition, repair it. Then go to step 12.
  11. Check for harness damage between evaporative emission purge solenoid connector B-04 terminal No. 1 and PCM connector C-39 terminal No. 34. If wiring harness is in good condition, replace the PCM. Then go to next step. If wiring harness is not in good condition, repair it. Then go to next step.
  12. Test the OBD-II drive cycle. Carry out a test drive with the drive cycle pattern. See «OTHER MONITOR»(ref-150942-S38112384672002112700000) under VERIFYING REPAIRS. Check the Diagnostic Trouble Code (DTC). If DTC P0443 is output, repeat diagnosis. If DTC P0443 is not output, inspection is complete.

Check condition is when battery positive voltage is 10-16 volts. Judgment criteria is when the evaporative emission ventilation solenoid coil surge voltage (battery positive voltage plus 2 volts) is not detected for 0.2 second. There is only one monitor during one drive cycle.

Check conditions are when more than 1 second has elapsed after battery positive voltage is 10-16 volts, on duty cycle of the evaporative emission purge solenoid is 0 percent, on duty cycle of the EGR solenoid is 0 percent and evaporative emission ventilation solenoid is on. Judgment criteria is when the evaporative emission ventilation solenoid coil surge voltage (battery positive voltage plus 2 volts) is not detected for 1 second.

The most likely causes for this code to be set are

  1. Evaporative emission ventilation solenoid failed.
  2. Open or shorted evaporative emission ventilation solenoid circuit, or loose connector.
  3. PCM failed.
CAUTIONTo prevent damage to scan tool, always turn the ignition switch to LOCK position before connecting or disconnecting scan tool.

Note. If PCM is replaced, immobilizer code registration must be performed. See PROGRAMMING .

  1. Using scan tool, check evaporative emission ventilation solenoid. Connect scan tool to the data link connector. (Scheme 105) Turn the ignition switch to ON position. Set scan tool to actuator test mode for item actuator test item 29: EVAPORATIVE EMISSION VENTILATION SOLENOID. An operation sound should be heard and vibration should be felt when the evaporative emission ventilation solenoid is operated. Turn the ignition switch to LOCK position. If the solenoid is not operating properly, go to next step. If the solenoid is operating properly, it can be assumed that this malfunction is intermittent.
  2. Check connector D-13 at the evaporative emission ventilation solenoid for damage. If the connector is in good condition, go to next step. If the connector is not in good condition, repair or replace it. Then go to step 12.
  3. Check the evaporative emission ventilation solenoid. Disconnect the evaporative emission ventilation solenoid connector D-13. Measure the resistance between evaporative emission ventilation solenoid side connector terminals No. 1 and 2. Standard value is 17 - 21 ohms at 68°F (20°C). If the resistance is as specified, go to next step. If the resistance is not as specified, replace the over vent valve module. Then go to step 12.
  4. Check the power supply voltage at evaporative emission ventilation solenoid harness side connector D-13. Disconnect the connector D-13 and measure at the harness side. Turn the ignition switch to ON position. Measure the voltage between terminal No. 2 and ground. Voltage should be battery positive voltage. Turn the ignition switch to LOCK position. If voltage is not as specified, go to next step. If voltage is as specified, go to step 6.
  5. Check connector A-18X at MFI relay for damage. If the connector in good condition, check intermediate connectors D-15, C-17 and C-71 for damage, and repair or replace as required. If intermediate connectors are in good condition, repair wiring harness between MFI relay connector A-18X terminal No. 4 and evaporative emission ventilation solenoid connector D-13 terminal No. 2 because of open circuit or short circuit to ground. Then go to step 12. If the connector is not in good condition, repair or replace it. Then go to step 12.
  6. Check the power supply voltage at PCM connector C-39 by backprobing. Do not disconnect the PCM connector. Turn the ignition switch to ON position. Measure the voltage between terminal No. 35 and ground by backprobing. Voltage should be battery positive voltage. Turn the ignition switch to LOCK position. If voltage is not as specified, go to next step. If voltage is as specified, go to step 9.
  7. Check connector C-39 at PCM for damage. If the connector is in good condition, go to next step. If the connector is not in good condition, repair or replace it. Then go to step 12.
  8. Check intermediate connectors D-15, C-17 and C-71. see scheme 20, see scheme 21 and see scheme 22. If intermediate connectors are damaged, repair or replace them. Then go to step 12. If intermediate connectors are okay, check for open circuit and short circuit to ground between evaporative emission ventilation solenoid connector D-13 terminal No. 1 and PCM connector C-39 terminal No. 35. If wiring harness is in good condition, replace the PCM. Then go to step 12. If wiring harness is not in good condition, repair it. Then go to step 12.
  9. Check connector C-39 at PCM for damage. If the connector is in good condition, go to next step. If the connector is not in good condition, repair or replace it. Then go to step 12.
  10. Check intermediate connectors D-15, C-17 and C-71. see scheme 20, see scheme 21 and see scheme 22. If intermediate connectors are damaged, repair or replace them. Then go to step 12. If intermediate connectors are okay, check for harness damage between MFI relay connector A-18X terminal No. 4 and evaporative emission ventilation solenoid connector C-12 terminal No. 2. If wiring harness is in good condition, go to next step. If wiring harness is not in good condition, repair it. Then go to step 12.
  11. Check intermediate connectors D-15, C-17 and C-71. If intermediate connectors are damaged, repair or replace them. Then go to step 12. If intermediate connectors are okay, check for harness damage between evaporative emission ventilation solenoid connector D-13 terminal No. 1 and PCM connector C-39 terminal No. 35. If wiring harness is in good condition, replace the PCM. Then go to next step. If wiring harness is not in good condition, repair it. Then go to next step.
  12. Test the OBD-II drive cycle. Carry out a test drive with the drive cycle pattern. See «OTHER MONITOR»(ref-150942-S38112384672002112700000) under VERIFYING REPAIRS. Check the Diagnostic Trouble Code (DTC). If DTC P0446 is output, repeat diagnosis. If DTC P0446 is not output, inspection is complete.

Note. If the number of the sudden pressure fluctuation does not reach twenty during one engine idling, the counter will be reset to zero. If the ignition switch is turned off, it will be also reset to zero.

Test conditions are when idle switch is on, throttle valve is closed and vehicle speed is 0.93 mph (1.5 km/h) or less. Judgment criteria is when the event that the output voltage from the fuel tank differential pressure sensor changes by 0.2 volts or more (i.e. sudden pressure fluctuation) is counted at least twenty times during one engine idling, and then consecutively eight times during normal driving conditions.

The conditions for deviating from idling operation are as follows: Engine speed is more than 2500 RPM, vehicle speed is 9.3 mph (15 km/h) or more, or volumetric efficiency is 55 percent or more.

The most likely causes for this code to be set are

  1. Fuel tank differential pressure sensor failed.
  2. Damaged harness in the fuel tank differential pressure sensor circuit.
  3. PCM failed.

Required Special Tools are Test Harness Set (MB991658) and Test Harness Set (MB991709).

CAUTIONTo prevent damage to scan tool, always turn the ignition switch to LOCK position before connecting or disconnecting scan tool.

Note. If PCM is replaced, immobilizer code registration must be performed. See PROGRAMMING .

  1. Using scan tool, check fuel tank differential pressure sensor. Connect scan tool to the data link connector. (Scheme 105) Disconnect hose "G" from the evaporative emission canister side, and plug the hose from which the pipes have been disconnected. Turn the ignition switch to ON position. Remove the fuel cap. Set scan tool to the data reading mode for data list item 73: FUEL TANK DIFFERENTIAL PRESSURE SENSOR. The fuel tank pressures should be -285 to 285 in. Hg. (-1.5 to 1.5 kPa). Connect an evaporative emission system pressure pump to the fuel filler neck, and apply pressure. The scan tool reading should increase. Turn the ignition switch to LOCK position. Disconnect scan tool. If the scan tool reading is not within the specified value, go to next step. If the scan tool reading is within the specified value, go to step 28.
  2. Check the output circuit voltage at intermediate connector D-15. Remove the rear seat cushion. Remove the protector. Disconnect intermediate connector D-15. Use special tools (MB991658 and MB991709) to connect terminals No. 5, 6 and 8 between connectors of the intermediate connector respectively. see scheme 68 Turn the ignition switch to ON position. Remove the fuel cap. Measure the voltage between terminal No. 5 and ground. Voltage should be 2.0-3.0 volts. Turn the ignition switch to LOCK position. If the voltage is as specified, go to next step. If the voltage is not as specified, go to step 6.
  3. Check the output circuit voltage at PCM connector C-41 by backprobing. Do not disconnect the PCM connector C-41. Turn the ignition switch to ON position. Remove the fuel cap. Measure the voltage between terminal No. 92 and ground by backprobing. Voltage should be 2.0-3.0 volts. Turn the ignition switch to LOCK position. If the voltage is not as specified, go to next step. If the voltage is as specified, go to step 27.
  4. Check intermediate connectors D-15, C-17 and C-71, and connector C-41 at PCM for damage. see scheme 20, see scheme 21 and see scheme 22. If the connectors are in good condition, go to next step. If the connectors are not in good condition, repair or replace it. Then go to step 28.
  5. Check the wiring harness between PCM connector C-41 terminal No. 92 and intermediate connector D-15 terminal No. 5 for damage. If wiring harness is in good condition, go to step 28. If wiring harness is not in good condition, repair it. Then go to step 28.
  6. Check the 5-volt supply circuit voltage at intermediate connector D-15. Disconnect intermediate connector D-15. Use special tools (MB991658 and M13991709) to connect terminals No. 5, 6 and 8 between connectors of the intermediate connector respectively. see scheme 68 Turn the ignition switch to ON position. Measure the voltage between terminal No. 8 and ground. Voltage should be 4.8-5.2 volts. Turn the ignition switch to LOCK position. If voltage is not as specified, go to next step. If voltage is as specified, go to step 11.
  7. Check the 5-volt supply circuit voltage at PCM connector C-40 by backprobing. Do not disconnect PCM connector C-40. Turn the ignition switch to ON position. Measure the voltage between terminal No. 46 and ground by backprobing. Voltage should be 4.8-5.2 volts. Turn the ignition switch to LOCK position. If voltage is not as specified, go to next step. If voltage is as specified, go to step 9.
  8. Check PCM connector C-40 for damage. If the connector is in good condition, go to step 27. If the connector is not in good condition, repair or replace it. Then go to step 28.
  9. Check intermediate connectors C-17, C-71 and D-15 for damage. see scheme 20, see scheme 21 and see scheme 22. If the connectors are in good condition, go to next step. If the connectors are not in good condition, repair or replace it. Then go to step 28.
  10. Check the wiring harness between PCM connector C-40 terminal No. 46 and intermediate connector D-15 terminal No. 8 for damage. If wiring harness is in good condition, go to step 28. If wiring harness is not in good condition, repair it. Then go to step 28.
  11. Check the circuit voltage at intermediate connector D-15. Disconnect intermediate connector D-15. Use special tool (MB991709) to connect terminal No. 6 between connectors of the intermediate connector. Turn the ignition switch to ON position. Measure the voltage at the male side connector between terminal No. 6 and ground. Voltage should be 4.8-5.2 volts. Turn the ignition switch to LOCK position. If the voltage is as specified, go to next step. If the voltage is not as specified, go to step 15.
  12. Check the ground voltage at PCM connector C-40 by backprobing. Do not disconnect PCM connector C-40. Turn the ignition switch to ON position. Measure the voltage between terminal No. 57 and ground by backprobing. The voltage should be 0.5 volt or less. Turn the ignition switch to LOCK position. If voltage is not as specified, go to next step. If voltage is as specified, go to step 28.
  13. Check intermediate connectors C-17, C-71 and D-15, and connector C-40 at PCM for damage. see scheme 20, see scheme 21 and see scheme 22. If the connectors are in good condition, go to next step. If the connectors are not in good condition, repair or replace it. Then go to step 28.
  14. Check the wiring harness between PCM connector C-40 terminal No. 57 and intermediate connector D-15 terminal No. 6 for damage. If wiring harness is in good condition, go to step 27. If wiring harness is not in good condition, repair it. Then go to step 28.
  15. Check the 5-volt supply circuit voltage at fuel tank differential pressure sensor connector D-11. Remove the center exhaust pipe. Remove the fuel band assembly and tilt the fuel tank. Disconnect fuel tank differential pressure sensor connector D-11. see scheme 13 Use special tool (MB991658) to connect terminals No. 1, 2 and 3 of the disconnected sensor connector and those of the harness side connector respectively. see scheme 68 Turn the ignition switch to ON position. Measure the voltage between terminal No. 3 and ground. Voltage should be 4.8-5.2 volts. Turn the ignition switch to LOCK position. If voltage is not as specified, go to next step. If voltage is as specified, go to step 18.
  16. Check intermediate connector D-15 and connector D-11 at fuel tank differential pressure sensor for damage. If the connectors are in good condition, go to next step. If the connectors are not in good condition, repair or replace it. Then go to step 28.
  17. Check the wiring harness between intermediate connector D-15 terminal No. 8 and fuel tank differential pressure sensor connector D-11 terminal No. 3 for damage. If wiring harness is in good condition, go to step 28. If wiring harness is not in good condition, repair it. Then go to step 28.
  18. Check the ground circuit voltage at fuel tank differential pressure sensor connector D-11. Disconnect fuel tank differential pressure sensor connector D-11. see scheme 13 Use special tool (MS991658) to connect terminal No. 3 of the disconnected sensor connector and those of the harness side connector respectively. Turn the ignition switch to ON position. Measure the voltage at the fuel tank differential pressure sensor side connector between terminal No. 2 and ground. Voltage should be 4.8-5.2 volts. Turn the ignition switch to LOCK position. If voltage is as specified, go next step. If voltage is not as specified, replace the fuel tank differential pressure sensor. Then go to step 28.
  19. Check the ground voltage at PCM connector C-40 by backprobing. Do not disconnect PCM connector C-40. Turn the ignition switch to ON position. Measure the voltage between terminal No. 57 and ground by backprobing. The voltage should be 0.5 volt or less. Turn the ignition switch to LOCK position. If voltage is not as specified, go to next step. If voltage is as specified, go to step 28.
  20. Check intermediate connectors C-17, C-71 and D-15, connector C-40 at PCM, and connector D-11 at fuel tank differential pressure sensor for damage. see scheme 13, see scheme 20, see scheme 21 and see scheme 22. If the connectors are in good condition, go to next step. If the connectors are not in good condition, repair or replace it. Then go to step 28.
  21. Check the wiring harness between PCM connector C-40 terminal No. 57 and fuel tank differential pressure sensor connector D-11 terminal No. 2 for damage. If wiring harness is in good condition, go to next step. If wiring harness is not in good condition, repair it. Then go to step 28.
  22. Check the ground voltage at PCM connector C-40 by backprobing. Do not disconnect PCM connector C-40. Turn the ignition switch to ON position. Measure the voltage between terminal No. 57 and ground by backprobing. The voltage should be 0.5 volt or less. Turn the ignition switch to LOCK position. If the voltage is as specified, go to next step. If the voltage is not as specified, go to step 27.
  23. Check the output circuit voltage at fuel tank differential pressure connector D-11. Disconnect fuel tank differential pressure sensor connector D-11. see scheme 13 Use special tool (MB991658) to connect terminals No. 1, 2 and 3 of the disconnected sensor connector and those of the harness side connector respectively. see scheme 68 Turn the ignition switch to ON position. Remove the fuel cap. Measure the voltage between terminal No. 1 and ground. Voltage should be 2.0-3.0 volts. Turn the ignition switch to LOCK position. If the voltage is as specified, go to next step. If the voltage is not as specified, replace the fuel tank differential pressure sensor. Then go to step 28.
  24. Check the output circuit voltage at PCM connector C-41 by backprobing. Do not disconnect PCM connector C-41. Turn the ignition switch to ON position. Remove the fuel cap. Measure the voltage between terminal No. 92 and ground by backprobing. Voltage should be 2.0-3.0 volts. Turn the ignition switch to LOCK position. If voltage is not as specified, go to next step. If voltage is as specified, go to step 27.
  25. Check intermediate connectors C-17, C-71 and D-15, connector C-41 at PCM, and D-11 at fuel tank differential pressure sensor for damage. see scheme 13, see scheme 20, see scheme 21 and see scheme 22. If the connectors are in good condition, go to next step. If the connectors are not in good condition, repair or replace it. Then go to step 28.
  26. Check the wiring harness between PCM connector C-41 terminal No. 92 and fuel tank differential pressure sensor connector D-11 terminal No. 1 for damage. If wiring harness is in good condition, go to step 28. If wiring harness is not in good condition, repair it. Then go to step 28.
  27. Using scan tool, check fuel tank differential pressure sensor. Connect scan tool to the data link connector. Disconnect hose "G" from the evaporative emission canister side, and plug the hose from which the pipes have been disconnected. Turn the ignition switch to ON position. Remove the fuel cap. Set scan tool to the data reading mode for data list item 73: FUEL TANK DIFFERENTIAL PRESSURE SENSOR. The fuel tank pressures should be -285 to 285 in. Hg. (-1.5 to 1.5 kPa). Connect an evaporative emission system pressure pump to the fuel filler neck, and apply pressure. The scan tool reading should increase. Turn the ignition switch to LOCK position. Then disconnect scan tool. If the scan tool reading is not within the specified value, replace the PCM. Then go to next step. If the scan tool reading is within the specified value, malfunction is intermittent malfunction. Go to next step.
  28. Test the OBD-II drive cycle. Carry out a test drive with the drive cycle pattern. See «EVAP SYSTEM LEAK MONITOR»(ref-150942-S05135908802002112700000) under VERIFYING REPAIRS. Read the diagnostic trouble code. If diagnostic trouble code P0451 is reset, go to step 2. If diagnostic trouble code P0451 is not reset, diagnosis is complete.

Test conditions are when intake air temperature is more than 41°F (5°C), engine speed is 1600 RPM or more and volumetric efficiency is 20-80 percent. Judgment criteria is when the evaporative emission purge solenoid is off and the fuel differential pressure sensor output voltage remains 1.0 volt or less for ten seconds.

The most likely causes for this code to be set are

  1. Fuel tank differential pressure sensor failed.
  2. Open fuel tank differential pressure sensor circuit, or loose connector.
  3. PCM failed.

Required Special Tools are Test Harness Set (MB991658) and Test Harness Set (MB991709).

CAUTIONTo prevent damage to scan tool, always turn the ignition switch to LOCK position before connecting or disconnecting scan tool.

Note. If PCM is replaced, immobilizer code registration must be performed. See PROGRAMMING .

  1. Using scan tool, check fuel tank differential pressure sensor. Connect scan tool to the data link connector. (Scheme 105) Disconnect hose "G" from the evaporative emission canister side, and plug the hose from which the pipes have been disconnected. Turn the ignition switch to ON position. Remove the fuel cap. Set scan tool to the data reading mode for data list item 73: FUEL TANK DIFFERENTIAL PRESSURE SENSOR. The fuel tank pressures should be -285 to 285 in. Hg. (-1.5 to 1.5 kPa). Connect an evaporative emission system pressure pump to the fuel filler neck, and apply pressure. The scan tool reading should increase. Turn the ignition switch to LOCK position. Then disconnect scan tool. If the scan tool reading is not within the specified value, go to next step. If the scan tool reading is within the specified value, go to step 28.
  2. Check the output circuit voltage at intermediate connector D-15. Remove the rear seat cushion. Remove the protector. Disconnect intermediate connector D-15. see scheme 22 Use special tools (MB991658 and MB991709) to connect terminals No. 5, 6 and 8 between connectors of the intermediate connector respectively. see scheme 68 Turn the ignition switch to ON position. Remove the fuel cap. Measure the voltage between terminal No. 5 and ground. Voltage should be 2.0-3.0 volts. Turn the ignition switch to LOCK position. If the voltage is as specified, go to next step. If the voltage is not as specified, go to step 6.
  3. Check the output circuit voltage at PCM connector C-41 by backprobing. Do not disconnect the PCM connector C-41. Turn the ignition switch to ON position. Remove the fuel cap. Measure the voltage between terminal No. 92 and ground by backprobing. Voltage should be 2-3.0 volts. Turn the ignition switch to LOCK position. If voltage is not as specified, go to next step. If voltage is as specified, go to step 27.
  4. Check intermediate connectors C-17, C-71 and D-15 and connector C-41 at PCM for damage. see scheme 20, see scheme 21 and see scheme 22. If the connectors are in good condition, go to next step. If the connectors are not in good condition, repair or replace it. Then go to step 28.
  5. Check the wiring harness between PCM connector C-41 terminal No. 92 and intermediate connector D-15 terminal No. 5 for damage. If wiring harness is in good condition, go to step 28. If wiring harness is not in good condition, repair it. Then go to step 28.
  6. Check the 5-volt supply circuit voltage at intermediate connector D-15. Disconnect intermediate connector D-15. Use special tools (MB991658 and M13991709) to connect terminals No. 5, 6 and 8 between connectors of the intermediate connector respectively. see scheme 68 Turn the ignition switch to ON position. Measure the voltage between terminal No. 8 and ground. Voltage should be 4.8-5.2 volts. Turn the ignition switch to LOCK position. If voltage is not as specified, go to next step. If voltage is as specified, go to step 11.
  7. Check the 5-volt supply circuit voltage at PCM connector C-40 by backprobing. Do not disconnect PCM connector C-40. Turn the ignition switch to ON position. Measure the voltage between terminal No. 46 and ground by backprobing. Voltage should be 4.8-5.2 volts. Turn the ignition switch to LOCK position. If voltage is not as specified, go to next step. If voltage is as specified, go to step 7.
  8. Check connector C-40 at PCM for damage. If the connector is in good condition, go to step 27. If the connector is not in good condition, repair or replace it. Then go to step 28.
  9. Check intermediate connectors C-17, C-71 and D-15 for damage. see scheme 20, see scheme 21 and see scheme 22. If the connectors are in good condition, go to next step. If the connectors are not in good condition, repair or replace it. Then go to step 28.
  10. Check the wiring harness between PCM connector C-40 terminal No. 46 and intermediate connector D-15 terminal No. 8 for damage. If wiring harness is in good condition, go to step 28. If wiring harness is not in good condition, repair it. Then go to step 28.
  11. Check the circuit voltage at intermediate connector D-15. Disconnect intermediate connector D-15. Use special tool (MB991709) to connect terminal No. 6 between connectors of the intermediate connector. Turn the ignition switch to ON position. Measure the voltage at the male side connector between terminal No. 6 and ground. Voltage should be 4.8-5.2 volts. Turn the ignition switch to LOCK position. If voltage is as specified, go to next step. If voltage is not as specified, go to step 15.
  12. Check the ground voltage at PCM connector C-40 by backprobing. Do not disconnect PCM connector C-40. Turn the ignition switch to ON position. Measure the voltage between terminal No. 57 and ground by backprobing. The voltage should be 0.5 volt or less. Turn the ignition switch to LOCK position. If voltage is not as specified, go to next step. If voltage is as specified, go to step 28.
  13. Check intermediate connectors C-17, C-71 and D-15, and connector C-40 at PCM for damage. see scheme 20, see scheme 21 and see scheme 22. If the connectors are in good condition, go to next step. If the connectors are not in good condition, repair or replace it. Then go to step 28.
  14. Check the wiring harness between PCM connector C-40 terminal No. 57 and intermediate connector D-15 terminal No. 6 for damage. If wiring harness is in good condition, go to step 27. If wiring harness is not in good condition, repair it. Then go to step 28.
  15. Check the 5-volt supply circuit voltage at fuel tank differential pressure sensor connector D-11. Remove the center exhaust pipe. Remove the fuel band assembly and tilt the fuel tank. Disconnect fuel tank differential pressure sensor connector D-11. see scheme 13 Use special tool (MB991658) to connect terminals No. 1, 2 and 3 of the disconnected sensor connector and those of the harness side connector respectively. see scheme 68 Turn the ignition switch to ON position. Measure the voltage between terminal No. 3 and ground. Voltage should be 4.8-5.2 volts. Turn the ignition switch to LOCK position. If voltage is not as specified, go to next step. If voltage is as specified, go to step 18.
  16. Check intermediate connector D-15 and connector D-11 at fuel tank differential pressure sensor for damage. see scheme 13and see scheme 22. If the connectors are in good condition, go to next step. If the connectors are not in good condition, repair or replace it. Then go to step 28.
  17. Check the wiring harness between intermediate connector D-15 terminal No. 8 and fuel tank differential pressure sensor connector D-11 terminal No. 3 for damage. If wiring harness is in good condition, go to step 28. If wiring harness is not in good condition, repair it. Then go to step 28.
  18. Check the ground circuit voltage at fuel tank differential pressure sensor connector D-11. Disconnect fuel tank differential pressure sensor connector D-11. see scheme 13 Use special tool (MB991658) to connect terminal No. 3 of the disconnected sensor connector and those of the harness side connector respectively. see scheme 68 Turn the ignition switch to ON position. Measure the voltage at the fuel tank differential pressure sensor side connector between terminal No. 2 and ground. Voltage should be 4.8-5.2 volts. Turn the ignition switch to LOCK position. If voltage is as specified, go to next step. If voltage is not as specified, replace the fuel tank differential pressure sensor. Then go to step 28.
  19. Check the ground voltage at PCM connector C-40 by backprobing. Do not disconnect PCM connector C-40. Turn the ignition switch to ON position. Measure the voltage between terminal No. 57 and ground by backprobing. The voltage should be 0.5 volt or less. Turn the ignition switch to LOCK position. If voltage is not as specified, go to next step. If voltage is as specified, go to step 28.
  20. Check intermediate connectors C-17, C-71 and D-15, connector C-40 at PCM and connector D-11 at fuel tank differential pressure sensor for damage. see scheme 13, see scheme 20, see scheme 21 and see scheme 22. If the connectors are in good condition, go to next step. If the connectors are not in good condition, repair or replace it. Then go to step 28.
  21. Check the wiring harness between PCM connector C-40 terminal No. 57 and fuel tank differential pressure sensor connector D-11 terminal No. 2 for damage. If wiring harness is in good condition, go to next step. If wiring harness is not in good condition, repair it. Then go to step 28.
  22. Check the ground voltage at PCM connector C-40 by backprobing. Do not disconnect PCM connector C-40. Turn the ignition switch to ON position. Measure the voltage between terminal No. 57 and ground by backprobing. The voltage should be 0.5 volt or less. Turn the ignition switch to LOCK position. If the voltage is as specified, go to next step. If the voltage is not as specified, go to step 27.
  23. Check the output circuit voltage at fuel tank differential pressure connector D-11. Disconnect fuel tank differential pressure sensor connector D-11. see scheme 13 Use special tool (MB991658) to connect terminals No. 1, 2 and 3 of the disconnected sensor connector and those of the harness side connector respectively. see scheme 68 Turn the ignition switch to ON position. Remove the fuel cap. Measure the voltage between terminal No. 1 and ground. Voltage should be 2.0-3.0 volts. Turn the ignition switch to LOCK position. If the voltage is as specified, go to next step. If the voltage is not as specified, replace the fuel tank differential pressure sensor. Then go to step 28.
  24. Check the output circuit voltage at PCM connector C-41 by backprobing. Do not disconnect the PCM connector C-41. Turn the ignition switch to ON position. Remove the fuel cap. Measure the voltage between terminal No. 92 and ground by backprobing. Voltage should be 2.0-3.0 volts. Turn the ignition switch to LOCK position. If voltage is not as specified, go to next step. If voltage is as specified, go to step 27.
  25. Check intermediate connectors C-17, C-71 and D-15, connector C-41 at PCM and connector D-11 at fuel tank differential pressure sensor for damage. see scheme 13, see scheme 20, see scheme 21 and see scheme 22. If the connectors are in good condition, go to next step. If the connectors are not in good condition, repair or replace it. Then go to step 28.
  26. Check the wiring harness between PCM connector C-41 terminal No. 92 and fuel tank differential pressure sensor connector D-11 terminal No. 1 for damage. If wiring harness is in good condition, go to step 28. If wiring harness is not in good condition, repair it. Then go to step 28.
  27. Using scan tool, check fuel tank differential pressure sensor. Connect scan tool to the data link connector. Disconnect hose "G" from the evaporative emission canister side, and plug the hose from which the pipes have been disconnected. Turn the ignition switch to ON position. Remove the fuel cap. Set scan tool to the data reading mode for data list item 73: FUEL TANK DIFFERENTIAL PRESSURE SENSOR. The fuel tank pressures should be -285 to 285 in. Hg. (-1.5 to 1.5 kPa). Connect an evaporative emission system pressure pump to the fuel filler neck, and apply pressure. The scan tool reading should increase. Turn the ignition switch to LOCK position. Then disconnect scan tool. If the scan tool reading is not within the specified value, replace the PCM. Then go to next step. If the scan tool reading is within the specified value, malfunction is intermittent malfunction. Then go to next step.
  28. Test the OBD-II drive cycle. Carry out a test drive with the drive cycle pattern. See «EVAP SYSTEM LEAK MONITOR»(ref-150942-S05135908802002112700000) under VERIFYING REPAIRS. Read the diagnostic trouble code. If diagnostic trouble code P0451 is reset, go to step 2. If diagnostic trouble code P0451 is not reset, diagnosis is complete.

Test conditions are when intake air temperature is 41-113°F (5-45°C) or more, engine speed is 1600 RPM or more and volumetric efficiency is 20-80 percent. Judgment criteria is when the evaporative emission purge solenoid valve is activating at 100 percent ratio and the fuel differential pressure sensor output voltage remains 4.0 volts or more for ten seconds.

The most likely causes for this code to be set are

  1. Fuel tank differential pressure sensor failed.
  2. Open fuel tank differential pressure sensor circuit, or loose connector.
  3. PCM failed.

Required Special Tools are Test Harness Set (MB991658) and Test Harness Set (MB991709).

CAUTIONTo prevent damage to scan tool, always turn the ignition switch to LOCK position before connecting or disconnecting scan tool.

Note. If PCM is replaced, immobilizer code registration must be performed. See PROGRAMMING .

  1. Using scan tool, check fuel tank differential pressure sensor. Connect scan tool to the data link connector. (Scheme 105) Disconnect hose "G" from the evaporative emission canister side, and plug the hose from which the pipes have been disconnected. Turn the ignition switch to ON position. Remove the fuel cap. Set scan tool to the data reading mode for data list item 73: FUEL TANK DIFFERENTIAL PRESSURE SENSOR. The fuel tank pressures should be -285 to 285 in. Hg. (-1.5 to 1.5 kPa). Connect an evaporative emission system pressure pump to the fuel filler neck, and apply pressure. The scan tool reading should increase. Turn the ignition switch to LOCK position. Disconnect scan tool. If the scan tool reading is not within the specified value, go to next step. If the scan tool reading is within the specified value, go to step 28.
  2. Check the output circuit voltage at intermediate connector D-15. Remove the rear seat cushion. Remove the protector. Disconnect intermediate connector D-15. Use special tools (MB991658 and MB991709) to connect terminals No. 5, 6 and 8 between connectors of the intermediate connector respectively. see scheme 68 Turn the ignition switch to ON position. Remove the fuel cap. Measure the voltage between terminal No. 5 and ground. Voltage should be 2-3 volts. Turn the ignition switch to LOCK position. If the voltage is as specified, go to next step. If the voltage is not as specified, go to step 6.
  3. Check the output circuit voltage at PCM connector C-41 by backprobing. Do not disconnect the PCM connector C-41. Turn the ignition switch to ON position. Remove the fuel cap. Measure the voltage between terminal No. 92 and ground by backprobing. Voltage should be 2-3 volts. Turn the ignition switch to LOCK position. If voltage is not as specified, go to next step. If voltage is as specified, go to step 27.
  4. Check intermediate connectors C-17, C-71 and D-15, and connector C-41 at PCM for damage. see scheme 20, see scheme 21 and see scheme 22. If the connectors are in good condition, go to next step. If the connectors are not in good condition, repair or replace it. Then go to step 28.
  5. Check the wiring harness between PCM connector C-41 terminal No. 92 and intermediate connector D-15 terminal No. 5 for damage. If wiring harness is in good condition, go to step 28. If wiring harness is not in good condition, repair it. Then go to step 28.
  6. Check the 5-volt supply circuit voltage at intermediate connector D-15. Disconnect intermediate connector D-15. Use special tools (MB991658 and MB991709) to connect terminals No. 5, 6 and 8 between connectors of the intermediate connector respectively. see scheme 68 Turn the ignition switch to ON position. Measure the voltage between terminal No. 8 and ground. Voltage should be 4.8-5.2 volts. Turn the ignition switch to LOCK position. If voltage is not as specified, go to next step. If voltage is as specified, go to step 11.
  7. Check the 5-volt supply circuit voltage at PCM connector C-40 by backprobing. Do not disconnect PCM connector C-40. Turn the ignition switch to ON position. Measure the voltage between terminal No. 46 and ground by backprobing. Voltage should be 4.8-5.2 volts. Turn the ignition switch to LOCK position. If voltage is not as specified, go to next step. If voltage is as specified, go to step 9.
  8. Check connector C-40 at PCM for damage. If connector is in good condition, go to step 27. If the connector is not in good condition, repair or replace it. Then go to step 28.
  9. Check intermediate connectors C-17, C-71, D-15 for damage. see scheme 20, see scheme 21 and see scheme 22. If the connectors are in good condition, go to next step. If the connectors are not in good condition, repair or replace it. Then go to step 28.
  10. Check the wiring harness between PCM connector C-40 terminal No. 46 and intermediate connector D-15 terminal No. 8 for damage. If wiring harness is in good condition, go to step 28. If wiring harness is not in good condition, repair it. Then go to step 28.
  11. Check the circuit voltage at intermediate connector D-15. Disconnect intermediate connector D-15. Use special tool (MB991709) to connect terminal No. 6 between connectors of the intermediate connector. Turn the ignition switch to ON position. Measure the voltage at the male side connector between terminal No. 6 and ground. Voltage should be 4.8-5.2 volts. Turn the ignition switch to LOCK position. If the voltage is as specified, go to next step. If the voltage is not as specified, go to step 15.
  12. Check the ground voltage at PCM connector C-40 by backprobing. Do not disconnect PCM connector C-40. Turn the ignition switch to ON position. Measure the voltage between terminal No. 57 and ground by backprobing. The voltage should be 0.5 volt or less. Turn the ignition switch to LOCK position. If voltage is not as specified, go to next step. If voltage is as specified, go to step 28.
  13. Check intermediate connectors C-17, C-71 and D-15, and connector C-40 at PCM for damage. see scheme 20, see scheme 21 and see scheme 22. If the connectors are in good condition, go to next step. If the connectors are not in good condition, repair or replace it. Then go to step 28.
  14. Check the wiring harness between PCM connector C-40 terminal No. 57 and intermediate connector D-15 terminal No. 6 for damage. If wiring harness is in good condition, go to step 27. If wiring harness is not in good condition, repair it. Then go to step 28.
  15. Check the 5-volt supply circuit voltage at fuel tank differential pressure sensor connector D-11. Remove the center exhaust pipe. Remove the fuel band assembly and tilt the fuel tank. Disconnect fuel tank differential pressure sensor connector D-11. see scheme 13 Use special tool (MB991658) to connect terminals No. 1, 2 and 3 of the disconnected sensor connector and those of the harness side connector respectively. see scheme 68 Turn the ignition switch to ON position. Measure the voltage between terminal No. 3 and ground. Voltage should be 4.8-5.2 volts. Turn the ignition switch to LOCK position. If voltage is not as specified, go to next step. If voltage is as specified, go to step 18.
  16. Check intermediate connector D-15 and connector D-11 at fuel tank differential pressure sensor for damage. If the connectors are in good condition, go to next step. If the connectors are not in good condition, repair or replace it. Then go to step 28.
  17. Check the wiring harness between intermediate connector D-15 terminal No. 8 and fuel tank differential pressure sensor connector D-11 terminal No. 3 for damage. If wiring harness is in good condition, go to step 28. If wiring harness is not in good condition, repair it. Then go to step 28.
  18. Check the ground circuit voltage at fuel tank differential pressure sensor connector D-11. Disconnect fuel tank differential pressure sensor connector D-11. see scheme 13 Use special tool (MB991658) to connect terminal No. 3 of the disconnected sensor connector and those of the harness side connector respectively. see scheme 68 Turn the ignition switch to ON position. Measure the voltage at the fuel tank differential pressure sensor side connector between terminal No. 2 and ground. Voltage should be 4.8-5.2 volts. Turn the ignition switch to LOCK position. If voltage is as specified, go to next step. If voltage is not as specified, replace the fuel tank differential pressure sensor. Then go to step 28.
  19. Check the ground voltage at PCM connector C-40 by backprobing. Do not disconnect PCM connector C-40. Turn the ignition switch to ON position. Measure the voltage between terminal No. 57 and ground by backprobing. The voltage should be 0.5 volt or less. Turn the ignition switch to LOCK position. If voltage is not as specified, go to next step. If voltage is as specified, go to step 28.
  20. Check intermediate connectors C-17, C-71 and D-15, connector C-40 at PCM and connector D-11 at fuel tank differential pressure sensor for damage. see scheme 13, see scheme 20, see scheme 21 and see scheme 22. If the connectors are in good condition, go to next step. If the connectors are not in good condition, repair or replace it. Then go to step 28.
  21. Check the wiring harness between PCM connector C-40 terminal No. 57 and fuel tank differential pressure sensor connector D-11 terminal No. 2 for damage. If wiring harness is in good condition, go to next step. If wiring harness is not in good condition, repair it. Then go to step 28.
  22. Check the ground voltage at PCM connector C-40 by backprobing. Do not disconnect PCM connector C-40. Turn the ignition switch to ON position. Measure the voltage between terminal No. 57 and ground by backprobing. The voltage should be 0.5 volt or less. Turn the ignition switch to LOCK position. If the voltage is as specified, go to next step. If the voltage is not as specified, go to step 27.
  23. Check the output circuit voltage at fuel tank differential pressure connector D-11. Disconnect fuel tank differential pressure sensor connector D-11. Use special tool (MB991658) to connect terminals No. 1, 2 and 3 of the disconnected sensor connector and those of the harness side connector respectively. see scheme 68 Turn the ignition switch to ON position. Remove the fuel cap. Measure the voltage between terminal No. 1 and ground. Voltage should be 2.0-3.0 volts. Turn the ignition switch to LOCK position. If the voltage is as specified, go to next step. If the voltage is not as specified, replace the fuel tank differential pressure sensor. Then go to step 28.
  24. Check the output circuit voltage at PCM connector C-41 by backprobing. Do not disconnect the PCM connector C-41. Turn the ignition switch to ON position. Remove the fuel cap. Measure the voltage between terminal No. 92 and ground by backprobing. Voltage should be 2.0-3.0 volts. Turn the ignition switch to LOCK position. If the voltage is not as specified, go to next step. If the voltage is as specified, go to step 27.
  25. Check intermediate connectors C-17, C-71, D-15, connector C-41 at PCM, and D-11 at fuel tank differential pressure sensor for damage. see scheme 13, see scheme 20, see scheme 21 and see scheme 22. If the connectors are in good condition, go to next step. If the connectors are not in good condition, repair or replace it. Then go to step 28.
  26. Check the wiring harness between PCM connector C-41 terminal No. 92 and fuel tank differential pressure sensor connector D-11 terminal No. 1 for damage. If wiring harness is in good condition, go to step 28. If wiring harness is not in good condition, repair it. Then go to step 28.
  27. Using scan tool, check fuel tank differential pressure sensor. Connect scan tool to the data link connector. Disconnect hose "G" from the evaporative emission canister side, and plug the hose from which the pipes have been disconnected. Turn the ignition switch to ON position. Remove the fuel cap. Set scan tool to the data reading mode for data list item 73: FUEL TANK DIFFERENTIAL PRESSURE SENSOR. The fuel tank pressures should be -285 to 285 in. Hg. (-1.5 to 1.5 kPa). Connect an evaporative emission system pressure pump to the fuel filler neck, and apply pressure. The scan tool reading should increase. Turn the ignition switch to LOCK position. Disconnect scan tool. If the scan tool reading is within the specified value, malfunction is intermittent malfunction. If the scan tool reading is not within the specified value, replace the PCM. Then go to next step.
  28. Test the OBD-II drive cycle. Carry out a test drive with the drive cycle pattern. See «EVAP SYSTEM LEAK MONITOR»(ref-150942-S05135908802002112700000) under VERIFYING REPAIRS. Read the diagnostic trouble code. If diagnostic trouble code P0451 is reset, go to step 2. If diagnostic trouble code P0451 is not reset, diagnosis is complete.

Test Conditions A: At start up intake air temperature is 97°F (36°C) or less when the engine is started. The engine coolant temperature 97°F (36°C) or less when the engine is started.

Test Conditions B: For test to run, the engine coolant temperature is 136°F (58°C) or more with fuel level of 15-40 percent or the engine coolant temperature 68°F (20°C) or more with fuel level of 40-80 percent, engine speed is 1600 RPM or more, barometric pressure is above 76 kPa (11 psi), volumetric efficiency is 20-80 percent, the fuel temperature is 97°F (36°C) or less, and fuel tank differential pressure sensor output voltage 1-4 volts.

Test Conditions C: For test to stop, intake air temperature is less than 41°F (5°C), when the evaporative emission purge solenoid and evaporative emission ventilation solenoid are closed, the pressure rises more 0.065 psi (451 kPa), when the evaporative emission purge solenoid and evaporative emission ventilation solenoid are closed, the pressure rises more 324 kPa (0.047 psi).

Note. The monitoring time (75-125 seconds) depends on the fuel level and the temperature in the fuel tank.

Judgment criteria is when the fuel tank internal pressure is 2 kPa (0.29 psi) or more after the evaporative emission purge solenoid has been driven when the fuel tank and vapor line were closed.

The most likely causes for this code to be set are

  1. Loose fuel cap.
  2. Fuel cap relief pressure is incorrect.
  3. Fuel overflow limiter valve failed.
  4. Purge line or vapor line is clogged.
  5. Fuel tank, purge line or vapor line seal failed.
  6. Evaporative emission purge solenoid failed.
  7. Evaporative emission ventilation solenoid failed.
  8. Fuel tank differential pressure sensor failed.
  9. Evaporative emission canister seal is faulty.
  10. Evaporative emission canister is clogged.
CAUTIONTo prevent damage to scan tool, always turn the ignition switch to LOCK position before connecting or disconnecting scan tool.

Note. If PCM is replaced, immobilizer code registration must be performed. See PROGRAMMING .

Note. If the engine speed does not reach 2000 RPM during the monitor test, adjustment of the speed adjusting screw may be needed. And adjust to the standard value.

  1. Using scan tool, check evaporative emission system monitor test. With this monitor, the PCM automatically increases the engine speed to 1600 RPM or more. Check that the transaxle is set to "P" position. Connect scan tool to the data link connector. (Scheme 105) Turn the ignition switch to ON position. Erase the DTCs using the scan tool. Check that the fuel cap is securely closed. (Tighten until three clicks are heard.) Start the engine. Select System Test, and press the YES key. Select EVAP LEAK MON, and press the YES key. During the monitor, keep the accelerator pedal at the idling position. Keep the engine speed and engine load within the specified range. When the monitor test starts, the IN PROGRESS item on scan tool will change from NO to YES. If EVAP LEAK MON. COMPLETED. TEST PASSED is displayed on scan tool, evaporative emission system is working properly at this time. Explain to customer that improperly tightened fuel cap can cause MIL to turn on, and return the vehicle. If EVAP LEAK MON. COMPLETED. TEST FAILED AND DTCS SET is displayed on scan tool, a malfunction has been detected during the monitor test. Go to next step. If EVAP LEAD MON. DISCONTINUED. RETEST AGAIN FROM THE FIRST is displayed on scan tool, monitor was discontinued for a certain reason (vehicle speed input from computer, engine speed and engine load deviating from specified range). Turn the ignition switch to LOCK position once, and repeat the monitoring from beginning of step.
  2. Using scan tool, check solenoid for clogging of the purge control. Disconnect hoses "A" and "B" from the evaporative emission purge solenoid side, and connect the hand vacuum pump to the evaporative emission purge solenoid instead of hose "B". Turn the ignition switch to ON position. Set scan tool to actuator test mode item 08: EVAPORATIVE EMISSION PURGE SOLENOID. When the evaporative emission purge solenoid is operated, apply a pressure on the hand vacuum pump and confirm that air is blown from the other side nipple. Turn the ignition switch to LOCK position. Disconnect scan tool. Disconnect the hand vacuum pump, and connect hoses "A" and "B" to the evaporative emission purge solenoid. If the solenoid is in good condition, go to next step. If the solenoid is not in good condition, replace the evaporative emission purge solenoid. Then go to step 27.
  3. Check for leaks and clogging in the evaporator line hose "A" to hose "C". If the hoses are in good condition, go to next step. If the hoses are in not good condition, replace the faulty hose(s). Then go to step 27.
  4. Check for leaks and clogging in the chamber. When you blow through the chamber, it should pass less air. No air should leak from the chamber body. If the chamber is in good condition, go to next step. If the chamber is not in good condition, replace the chamber. Then go to step 27.
  5. Check the evaporative emission ventilation solenoid using scan tool. Connect scan tool to the data link connector. Disconnect hose "E" from the evaporative emission ventilation solenoid side, and connect a hand vacuum pump. Turn the ignition switch to ON position. Set scan tool to actuator test mode for item actuator test item 29: EVAPORATIVE EMISSION VENTILATION SOLENOID. When the evaporative emission ventilation solenoid is operated, apply a pressure on the hand vacuum pump and confirm that air is maintained. Turn the ignition switch to LOCK position. Then disconnect scan tool. Disconnect the hand vacuum pump, and connect hose "E" to the evaporative emission canister. If the solenoid valve is in good condition, go to next step. If the solenoid valve is not in good condition, replace the evaporative emission ventilation solenoid. Then go to step 27.
  6. Pressure test for leaks in the evaporator line from hose "D" to hose "N". Disconnect hose "E" from the evaporative emission ventilation solenoid side, and plug the hoses. Remove the fuel cap. Connect the evaporative emission system pressure pump to the fuel filler neck. Apply a pressure on the evaporative emission system pressure pump, and confirm that air is maintained. Disconnect the evaporative emission system pressure pump, and reinstall the fuel cap. Connect hose "E" to the evaporator line. If air is not maintained, go to next step. If air is maintained, go to step 17.
  7. Pressure test for leaks in the evaporator line from hose "G" to hose "N". Disconnect hose "G" from the evaporative emission canister side, and plug the hose. Perform the pressure test again. If air is not maintained, go to next step. If air is maintained, go to step 10.
  8. Check for leaks in the evaporator line from hose "D" to hose "F". Remove the fuel tank. The leakage test with a hand vacuum pump on each hose from hose "D" to hose "F". If the hoses are in good condition, go to next step. If any hose(s) is not in good condition, replace the faulty hose(s), and reinstall the fuel tank. Then go to step 27.
  9. Check for leaks in the evaporative emission canister. Connect a hand vacuum pump to the vent nipple of the evaporative emission canister. Plug the other two nipples or loop a hose between the other nipples. Apply a vacuum with the hand vacuum pump, and confirm that air is maintained. If the evaporative emission canister is in good condition, go to step 27. If the evaporative emission canister is not in good condition, replace the evaporative emission canister and reinstall the fuel tank. Then go to step 27.
  10. Check for leaks in the evaporator line from hose "H" to hose "I". Remove the fuel tank. Disconnect hose "H" at the liquid separator side, and then connect a hand vacuum pump to the hose. Plug the hose "I" at the fuel tank aide. Apply vacuum by using the hand vacuum pump, and confirm that the applied vacuum does not fluctuate. If air is maintained, go to next step. If air is not maintained, replace the faulty hose, and reinstall the fuel tank. Then go to step 27.
  11. Check for leaks in the evaporator line hoses "G", "J", "K", "L" and "M". Remove the filler neck assembly. Perform leakage test with a hand vacuum pump on each hose from hoses "G", "J", "K", "L" and "M". If the hoses are in good condition, go to next step. If the hoses are not in good condition, replace the faulty hose, and reinstall the filler neck assembly. Then go to step 27.
  12. Check check valve "A". Check valve should pass air only from the direction shown. see scheme 90 If check valve "A" is in good condition, go to next step. If check valve "A" is not in good condition, replace the check valve "A", and reinstall the filler neck assembly. Then go to step 27.
  13. Check check valve "B". see scheme 91 When you blow through the check valve (Step 1), it should pass more air. When you blow through the check valve in the other direction (Step 2), it should pass less air. No air should leak from the check valve body. If check valve "B" is in good condition, go to next step. If check valve "B" is not in good condition, replace the check valve "B", and reinstall the filler neck assembly. Then go to step 27.
  14. Check for leaks in the evaporator line from hose "N". The leakage test with a hand vacuum pump on the hose "N". If the hose "N" is in good condition, go to next step. If the hose "N" is not in good condition, replace the hose "N", and reinstall the fuel tank. Then go to step 27.
  15. Check for leaks in the fuel tank. Visually check for cracks and leaks, etc. Carefully check the fuel pump assembly and the inner pressure sensor installation in the fuel tank. Connect an evaporative emission system pressure pump to the leveling valve nipple. Plug the filler hose, feed pipe, return pipe and rollover valve nipple connected to the fuel tank. Apply pressure with the evaporative emission system pressure pump. In the pressurized state, check for the leak by applying soap water, etc. to each section. If there are leaks at the fuel pump module or the fuel tank differential pressure sensor section, reassemble parts. After reassembling the leaking parts, check again that there are no leaks. Then reinstall the fuel tank. Then go to step 27. If there are leaks at the fuel tank, replace the fuel tank. Reinstall fuel tank. Then go to step 27. If there are no leaks, go to next step.
  16. Visually check for cracks in the fuel tank filler neck. Visually check for cracks in the fuel tank filler neck. If the fuel filler neck assembly is in good condition, reinstall the fuel tank and fuel filler neck assembly. Then go to step 27. If the fuel filler neck assembly is in good condition, replace the fuel tank filler neck assembly. Reinstall fuel tank. Then go to step 27.
  17. Pressure test for clogging in the evaporator line from hose "G" to hose "N". Disconnect hose "G" from the evaporative emission canister side, and unplug the hose "G". On the EVAP pressure pump, set the pressure/hold valve to OPEN, and set the vent valve to CLOSED. Turn the pump timer to ON. You can reset the timer as required. These settings are listed under LEAK TEST in the pump instructions. Air should pass through hose "G". If air is blown from hose "G", connect the hose "G". Then go to next step. If air is not blown from hose "G", go to step 22.
  18. Pressure test for clogging in the evaporator line from hose "D" to hose "F". Unplug hose "E". On the EVAP pressure pump, set the pressure/hold valve to OPEN, and set the vent valve to CLOSED. Turn the pump timer to ON. You can reset the timer as required. (These settings are listed under LEAK TEST in the pump instructions.) Air should pass through hose "E". If air is blown from hose "E", connect hose "E". Then go to next step. If air is not blown from hose "E", go to step 20.
  19. Using scan tool, check evaporative emission system monitor test. With this monitor, the PCM automatically increases the engine speed to 1600 RPM or more. Check that the transaxle is set to "P" position. Connect scan tool to the data link connector. Turn the ignition switch to ON position. Erase the DTCs using scan tool. Check that the fuel cap is securely closed. (Tighten until three clicks are heard.) Start the engine. Select SYSTEM TEST, and press the YES key. Select EVAP LEAK MON, and press the YES key. During the monitor, keep the accelerator pedal at the idling position. If the engine speed does not reach 2000 RPM during the monitor test, adjustment of Speed Adjusting Screw may be needed. Adjust to the standard value. Keep the engine speed and engine load within the specified range. When the monitor test starts, the IN PROGRESS item on the scan tool will change from NO to YES. Turn the ignition switch to LOCK position. Then disconnect scan tool. If EVAP LEAK MON. COMPLETED. TEST PASSED is displayed on scan tool, evaporative emission system is working properly at this time. Go to step 27. If EVAP LEAK MON. COMPLETED. TEST FAILED AND DTCS SET is displayed on scan tool, replace the PCM. Then go to step 27. If EVAP LEAD MON. DISCONTINUED. RETEST AGAIN FROM THE FIRST is displayed on scan tool, the monitor was discontinued for a certain reason (vehicle speed input from PCM, engine speed and engine load deviating from specified range). Turn the ignition switch to LOCK position once, and recheck evaporative emission system monitor test.
  20. Check for clogging in the evaporator line hose "D" to hose "F". Remove the fuel tank. The clogging test with a hand vacuum pump on each hose from hose "D" to hose "F". If the hoses are in good condition, go to next step. If the hoses are not in good condition, replace the faulty hose, reinstall the fuel tank. Then go to step 27.
  21. Check for clogging in the evaporative emission canister. Connect a hand vacuum pump to the vent nipple of the evaporative emission canister. Plug the other two nipples or loop a hose between the other nipples. Apply a pressure on the vacuum pump. When each nipple is unplugged, air should pass through the unplugged nipple. If the evaporative emission canister is in good condition, reinstall the fuel tank. Then go to step 27. If the evaporative emission canister is in good condition, replace the evaporative emission canister and reinstall the fuel tank. Then go to step 27.
  22. Check for clogging in the evaporator line from hose "H" to hose "I". Remove the fuel tank. Disconnect hose "H" at the liquid separator side, and then connect a hand vacuum pump to the hose. Unplug the hose "I" at the fuel tank side. Apply a pressure on the vacuum pump, air should pass through the hose "I". If the hoses are in good condition, go to next step. If the hoses are not in good condition, replace the faulty hose, and reinstall the filler neck assembly. Then go to step 27.
  23. Check for clogging in the evaporator line hose "G", "J", "K", "L" and hose "M". Remove the filler neck assembly. The clogging test with a hand vacuum pump on each hose from hoses "G", "J", "K", "L" and "M". If the hoses are in good condition, go to next step. If the hoses are not in good condition, replace the faulty hose, and reinstall the filler neck assembly. Then go to step 27.
  24. Check check valve "A". Check valve should pass air only from the direction shown. see scheme 90 If check valve "A" is in good condition, go to next step. If check valve "A" is not in good condition, replace check valve "A", and reinstall the filler neck assembly. Then go to step 27.
  25. Check check valve "B". see scheme 91 When you blow through check valve (Step 1), it should pass more air. When you blow through check valve in the other direction (Step 2), it should pass less air. No air should leak from the check valve body. If check valve "B" is in good condition, go to next step. If check valve "B" is not in good condition, replace the check valve "B", and reinstall the filler neck assembly. Then go to step 27.
  26. Check for clogging in the evaporator line from hose "N". The clogging test with a hand vacuum pump on the hose "N". If hose "N" is in good condition, go to next step. If hose "N" is not in good condition, replace the hose "N", and reinstall the fuel tank. Then go to next step.
  27. Test the OBD-II drive cycle. Carry out a test drive with the drive cycle pattern. See «EVAP SYSTEM LEAK MONITOR»(ref-150942-S05135908802002112700000) under VERIFYING REPAIRS. Read the diagnostic trouble code. If diagnostic trouble code P0455 is reset, go to step 1. If diagnostic trouble code P0455 is not reset, diagnosis is complete.

Test Conditions A: At start up, the fuel level sensor output voltage is 2.4-3.7 volts when the engine starts (i.e., the amount of remaining fuel is 40-85 percent), intake air temperature is 91°F (33°C) or less and the engine coolant temperature is 91°F (33°C) or less.

Test Conditions B: For test to run, barometric pressure is above 76 kPa (11 psi), volumetric efficiency is 20-80 percent, fuel temperature is 91°F (33°C) or less, and fuel tank differential pressure sensor output voltage is 1-4 volts.

Test Conditions C: For test to stop, engine coolant temperature is less than 68°F (20°C) and intake air temperature is less than 14°F (-10°C). When the evaporative emission purge solenoid and evaporative emission ventilation solenoid are closed, the pressure rises more 324 kPa (0.047 psi).

Note. The judgment criteria monitoring time depends on the fuel level and the temperature in the fuel tank (10-14 minutes).

Judgment criteria is when internal pressure of the fuel tank fluctuates 1177-1373 kPa (0.177-0.199 psi) or more in 10 seconds after the tank and vapor line were closed.

The most likely causes for this code to be set are

  1. Loose fuel cap.
  2. Fuel cap relief pressure is incorrect.
  3. Evaporative emission canister seal is faulty.
  4. Fuel tank, purge line or vapor line seal failed.
  5. Evaporative emission ventilation solenoid valve failed.
CAUTIONTo prevent damage to scan tool, always turn the ignition switch to LOCK position before connecting or disconnecting scan tool.

Note. If PCM is replaced, immobilizer code registration must be performed. See PROGRAMMING .

Note. If the engine speed does not reach 2000 RPM during the monitor test, adjustment of the speed adjusting screw may be needed. Adjust to the standard value.

  1. Using scan tool, check evaporative emission system monitor test. With this monitor, the PCM automatically increases the engine speed to 1600 RPM or more. Check that the transaxle is set to "P" position. Connect scan tool to the data link connector. (Scheme 105) Turn the ignition switch to ON position. Erase the DTCs causing the scan tool Check that the fuel cap is securely closed. (Tighten until three clicks are heard.) Start the engine. Select SYSTEM TEST and press the YES key. Select EVAP LEAK MON, and press the YES key. During the monitor, keep the accelerator pedal at the idling position. Keep the engine speed and engine load within the specified range. When the monitor test starts, the in progress item on scan tool will change from NO to YES. Turn the ignition switch to LOCK position, and disconnect scan tool. If EVAP LEAK MON. COMPLETED TEST PASSED is displayed on the scan tool, evaporative emission system is working properly at this time. Explain to customer that improperly tightened fuel cap can cause MIL to turn on, and return the vehicle. If EVAP LEAK MON. COMPLETE, TEST FAILED AND DTCS SET is displayed on the scan tool, a malfunction has been detected during the monitor test. Go to next step. If EVAP LEAD MON. DISCONTINUED. RETEST AGAIN FROM THE FIRST is displayed on the scan tool, the monitor is discontinued for a certain reason (vehicle speed input from computer, engine speed and engine load deviating from specified range). Turn the ignition switch to LOCK position once, and repeat the monitoring from beginning of step.
  2. Check evaporative emission purge solenoid for leaks. Remove the battery. Remove the air intake hose. Disconnect hose "B" from the evaporative emission purge solenoid side, and connect a hand vacuum pump to the nipple of the evaporative emission purge solenoid. Apply vacuum with hand vacuum pump, and confirm that vacuum is maintained. Disconnect the hand vacuum pump, and connect hose "B" to the evaporative emission purge solenoid. If the evaporative emission purge solenoid is in good condition, go to next step. If the evaporative emission purge solenoid is not in good condition, replace the evaporative emission purge solenoid. Then go to step 18.
  3. Check for leaks in the evaporator line hose "A" to hose "C". The leakage test with a hand vacuum pump on each hose from hose "A" to hose "C". If the hoses are in good condition, go to next step. If the hoses are not in good condition, replace the faulty hose. Then go to step 18.
  4. Check for leaks in the chamber. Connect a hand vacuum pump to the nipple. Plug the other nipple. Apply vacuum with the hand vacuum pump, and confirm that the applied vacuum does not fluctuate. If the chamber is in good condition, go to next step. If the chamber is not in good condition, replace the chamber. Then go to step 18.
  5. Check the evaporative emission ventilation solenoid using scan tool. Connect scan tool to the data link connector. Disconnect the hose "E" from the evaporative emission ventilation solenoid side. Connect the hand vacuum pump to the nipple of the evaporative emission ventilation solenoid from which the hoses have been disconnected. Turn the ignition switch to ON position. Set scan tool to actuator test mode for item actuator test item 29: EVAPORATIVE EMISSION VENTILATION SOLENOID. When the evaporative emission ventilation solenoid is operated, apply a pressure on the hand vacuum pump and confirm that air is maintained. Turn the ignition switch to LOCK position, and disconnect scan tool. Disconnect the hand vacuum pump, and connect hose "E" to the evaporative emission canister. If the evaporative emission ventilation solenoid is in good condition, go to next step. If the evaporative emission ventilation solenoid is not in good condition, replace the evaporative emission ventilation solenoid. Then go to step 18.
  6. Pressure test for evaporator line from hose "D" to hose "N". Remove the module bracket mounting bolts, and disconnect hose "E" from the evaporative emission ventilation solenoid side, and plug the hoses from which the hoses have been disconnected. Confirm that the evaporative emission system pressure pump is operating properly. Perform the self-test as described in the manufacturer's instructions. Connect an evaporative emission system pressure pump to the fuel filler neck. Pressure test the system to determine whether any leaks are present. If the evaporator lines are not in good condition, go to next step. If the evaporator lines are in good condition, go to step 17.
  7. Pressure test for evaporator line from hose "G" to hose "N". Disconnect hose "G" from the evaporative emission canister side, and plug the hose from which the pipes have been disconnected. Perform the pressure test again. If the evaporator lines are in good condition, go to next step. If the evaporator lines are not in good condition, go to step 10.
  8. Check for leaks in the evaporator line hose "D" to hose "F". Remove the fuel tank. Perform leakage test with a hand vacuum pump on each hose from hose "D" to hose "F". If the hoses are in good condition, go to next step. If the hoses are not in good condition, replace faulty hose and reinstall the fuel tank. Then go to step 18.
  9. Check for leaks in the evaporative emission canister. Connect a hand vacuum pump to the vent nipple of the evaporative emission canister. Plug the other two nipples or loop a hose between the other nipples. Apply a vacuum with the hand vacuum pump, and confirm that the applied vacuum does not fluctuate. If the evaporation emission canister is in good condition, go to step 18. If the evaporation emission canister is not in good condition, replace the evaporative emission canister and reinstall the fuel tank. Then go to step 18.
  10. Check for leaks in the evaporator line from hose "H" and hose "I". Remove the fuel filler neck protector. Disconnect hose "H" at the liquid separator, and then connect a hand vacuum pump to the hose. Disconnect hose "I" at the fuel tank side, and then plug the hose. Apply vacuum with the hand vacuum pump, and confirm that the applied vacuum does not fluctuate. If the evaporator lines are in good condition, go to next step. If the evaporator lines are not in good condition, replace that hose, reinstall the fuel filler neck protector. Then go to step 18.
  11. Check for leaks in the evaporator line hose "G", "J", "K", "L" and "M". Remove the fuel tank and fuel filler neck assembly. The leakage test with a hand vacuum pump on each hose from hose "G", "J", "K", "L" and "M". If the hoses are in good condition, go to next step. If the hoses are not in good condition, replace the hose, reinstall the fuel tank and fuel filler neck assembly. Then go to step 18.
  12. Check check valve "A". Check valve should pass air only from the direction shown. see scheme 90 If the check valve "A" is in good condition, go to next step. If the check valve "A" is not in good condition, replace the check valve "A", reinstall the fuel tank and fuel filler neck assembly. Then go to step 18.
  13. Check check valve "B". see scheme 91 When you blow through the check valve (Step 1), it should pass more air. When you blow through the check valve in the other direction (Step 2), it should pass less air. No air should leak from the check valve body. If the check valve "B" is in good condition, go to next step. If the check valve "B" is not in good condition, replace the check valve "B", reinstall the fuel tank and fuel filler neck assembly. Then go to step 18.
  14. Check for leaks in the evaporator line hose "N". The leakage test with a hand vacuum pump on each hose from hose "N". If the hose is in good condition, go to next step. If the hose is not in good condition, replace the hose, reinstall the fuel tank and fuel filler neck assembly. Then go to step 18.
  15. Visually check for cracks in the fuel filler neck assembly. Visually check for cracks in the fuel filler neck assembly. If the fuel filler neck assembly is in good condition, go to next step. If the fuel filler neck assembly is not in good condition, replace the fuel filler neck assembly, reinstall the fuel tank and fuel filler neck assembly. Then go to step 18.
  16. Check for leaks in the fuel tank. Visually check for cracks and leaks, etc. Carefully check the fuel pump assembly and the inner pressure sensor installation in the fuel tank. Connect an evaporative emission system pressure pump to the leveling valve nipple. Plug the filler hose, feed pipe, return pipe and rollover valve nipple connected to the fuel tank. Apply pressure with the evaporative emission system pressure pump. In the pressurized state, check for the leak by applying soap water, etc. to each section. If the fuel tank is in good condition, go to next step. If the fuel tank is not in good condition, replace the fuel tank, reinstall the fuel tank and fuel filler neck assembly. Then go to step 18.
  17. Using scan tool, check evaporative emission system monitor test. Check that the transaxle is set to "P" position. Connect scan tool to the data link connector. Turn the ignition switch to ON position. Erase the DTCs using scan tool. Check that the fuel cap is securely closed. (Tighten until three clicks are heard.) Start the engine. Select SYSTEM TEST and press the YES key. Select EVAP LEAK MON, and press the YES key. During the monitor, keep the accelerator pedal at the idling position. If the engine speed does not reach 2000 RPM during the monitor test, adjustment of the Speed Adjusting Screw may be needed. Adjust to the standard value. Keep the engine speed and engine load within the specified range. When the monitor test starts, the in progress item on the scan tool will change from NO to YES. Turn the ignition switch to LOCK position. Then disconnect scan tool. If EVAP LEAK MON. COMPLETED. TEST PASSED is displayed on scan tool, evaporative emission system is working properly at this time. Go to next step. If EVAP LEAK MON. COMPLETED. TEST FAILED AND DTCS SET is displayed on scan tool, replace the PCM. Then go to next step. If EVAP LEAD MON. DISCONTINUED. RETEST AGAIN FROM THE FIRST is displayed on the scan tool, the monitor is discontinued for a certain reason (vehicle speed input from computer, engine speed and engine load deviating from specified range). Turn the ignition switch to LOCK position once, and repeat the monitoring from step 1.
  18. Test the OBD-II drive cycle. Carry out a test drive with the drive cycle pattern. See «EVAP SYSTEM LEAK MONITOR»(ref-150942-S05135908802002112700000) under VERIFYING REPAIRS. Read the diagnostic trouble code. If diagnostic trouble code P0442 is reset, go to step 1. If diagnostic trouble code P0442 is not reset, diagnosis is complete.

Check conditions and judgement criteria are when the fuel consumption calculated from the operation time of the injector amounts to 20 liters, but the change in amount of fuel in tank calculated from the fuel level sensor is 2 liters or less.

The most likely causes for this code to be set are

  1. Fuel gauge unit failed.
  2. Open or shorted fuel gauge unit circuit, or loose connector.
  3. PCM failed.
CAUTIONTo prevent damage to scan tool, always turn the ignition switch to LOCK position before connecting or disconnecting scan tool.

Note. If PCM is replaced, immobilizer code registration must be performed. See PROGRAMMING .

  1. Using scan tool, check fuel level sensor. Connect scan tool to the data link connector. (Scheme 105) Turn the ignition switch to ON position. Set scan tool to the data reading mode for data list item 4B: FUEL LEVEL SENSOR. When the fuel gauge is near FULL, voltage should be 100-3,600 mV. When the fuel gauge is near EMPTY, voltage should be 2700-6200 mV. Turn the ignition switch to LOCK position. If the sensor is operating properly, it can be assumed that this malfunction is intermittent. If the sensor is not operating properly, go to next step.
  2. Check connector D-14 at the fuel gauge unit for damage. If connector is in good condition, go to next step. If connector is not in good condition, replace connector. Then go to step 12.
  3. Check the continuity at fuel gauge unit harness side connector D-14. Disconnect the connector D-14 and measure at the harness aide. Check for the continuity between terminal No. 1 and ground. Resistance should be less than 2 ohms. If continuity is as specified, go to next step. If continuity is not as specified, repair wiring harness between fuel gauge unit connector D-14 terminal No. 1 and ground because of open circuit or harness damage. Then go to step 12.
  4. Check the sensor supply voltage at fuel gauge unit harness side connector D-14. Disconnect the connector D-14 and measure at the harness side. Disconnect the combination connector C-29. Turn the ignition switch to ON position. Measure the voltage between terminal No. 24 and ground. Voltage should be battery positive voltage. Turn the ignition switch to LOCK position. If the voltage is as specified, go to step 9. If the voltage is not as specified, go to next step.
  5. Check the sensor supply voltage at PCM connector C-40 by backprobing. Do not disconnect PCM connector C-40. Disconnect combination meter connector C-29. Turn the ignition switch to ON position. Measure the voltage between terminal No. 60 and ground by backprobing. When the fuel gauge is near FULL, voltage should be 0.1 and 3.6 volts. When the fuel gauge is near EMPTY, voltage should be 2.7 and 6.2 volts. Turn the ignition switch to LOCK position. If the voltage is as specified, go to next step. If the voltage is not as specified, go to step 7.
  6. Check connector C-40 at PCM for damage. If the connector is in good condition, check intermediate connectors C-17 and C-71 for damage, and repair or replace as required. If intermediate connectors are in good condition, repair wiring harness between fuel gauge unit connector D-14 terminal No. 2 and PCM connector C-40 terminal No. 60 because of open circuit. Then go to step 12. If the connector is not in good condition, repair or replace it. Then go to step 12.
  7. Check connector C-40 at PCM for damage. If the connector is in good condition, go to next step. If the connector is not in good condition, repair or replace it. Then go to step 12.
  8. Check for short circuit to ground between fuel gauge unit connector D-14 terminal No. 2 and PCM connector C-40 terminal No. 60. If wiring harness is in good condition, replace the PCM. Then go to step 12. If wiring harness is not in good condition, repair it. Then go to step 12.
  9. Check the fuel gauge unit. If the fuel gauge unit is as specified, go to next step. If the fuel gauge unit is not as specified, replace the fuel gauge unit. Then go to step 12.
  10. Check connector C-40 at PCM for damage. If the connector is in good condition, go to next step. If the connector is not in good condition, repair or replace it. Then go to step 12.
  11. Check for harness damage between fuel gauge unit connector D-14 terminal No. 2 and PCM connector C-40 terminal No. 60. If wiring harness is in good condition, replace the PCM. Then go to next step. If wiring harness is not in good condition, repair it. Then go to next step.
  12. Test the OBD-II drive cycle. Carry out a test drive with the drive cycle pattern. See «OTHER MONITOR»(ref-150942-S38112384672002112700000) under VERIFYING REPAIRS. Check the Diagnostic Trouble Code (DTC). If DTC P0460 is output, repeat diagnosis. If DTC P0460 is not output, inspection is complete.

Check conditions are when vehicle is under closed loop idle speed control, engine coolant temperature is more than approximately 171°F (77°C), battery positive voltage is more than 10 volts, power steering pressure switch is off, volumetric efficiency is less than 40 percent, barometric pressure is more than 76 kPa (11 psi), intake air temperature is more than 14°F (-10°C), 25 seconds have elapsed from the start of the previous monitoring and target idle air control motor position is more than 100 steps.

Judgment criteria is when actual idle speed is more than 100 RPM less than the target idle speed for 12 seconds.

The most likely causes for this code to be set are

  1. Idle air control motor failed.
  2. Open or shorted idle air control motor circuit, or loose connector.
  3. PCM failed.
CAUTIONTo prevent damage to scan tool, always turn the ignition switch to LOCK position before connecting or disconnecting scan tool.

Note. If PCM is replaced, immobilizer code registration must be performed. See PROGRAMMING .

Scheme 112

Scheme 112
Scheme 112
  1. Using scan tool, read the diagnostic trouble code (DTC). Connect scan tool to the data link connector. (Scheme 105) Turn the ignition switch to ON position. Set scan tool to read the DTC. Turn the ignition switch to LOCK position. If a diagnostic trouble code other than P0506 is output, go to appropriate DTC test. If a diagnostic trouble code other than P0506 is not output, go to next step.
  2. Check the throttle body (throttle valve area). If the throttle valve area is clean, go to next step. If the throttle valve area is dirty, perform cleaning. Then go to step 14.
  3. Check connector B-06 at idle air control motor for damage. If the connector is in good condition, go to next step. If the connector is not in good condition, repair or replace it. Then go to step 14.
  4. Check the idle air control motor coil resistance. Disconnect the idle air control motor connector B-06. Measure the resistance between idle air control motor connector terminal No. 2 and either terminal No. 1 or terminal No. 3. Standard value is 28-33 ohms at 68°F (20°C). Measure the resistance between idle air control motor connector terminal No. 5 and either terminal No. 4 or terminal No. 6. Standard value is 28-33 ohms at 68°F (20°C). If the resistance is as specified, go to next step. If the resistance is not as specified, replace the idle air control motor. Then go to step 14.
  5. Check the power supply voltage at idle air control motor harness side connector B-06. Disconnect the connector B-06 and measure at the harness side. Turn the ignition switch to ON position. Measure the voltage between ground and terminals No. 2 and 5. Voltage should be battery positive voltage. Turn the ignition switch to LOCK position. If voltage is not as specified, go to next step. If voltage is as specified, go to step 7.
  6. Check connector A-18X at MFI relay for damage. If the connector is in good condition, repair wiring harness between MFI relay connector A-18X terminal No. 4 and idle air control motor connector B-06 terminals No. 2 and 5 because of open circuit or short circuit to ground. Then go to step 14. If the connector is not in good condition, repair or replace it. Then go to step 14.
  7. Check the power supply voltage at PCM connector C-39 by backprobing. Do not disconnect the PCM connector C-39. Measure the voltage between terminals No. 14, 15, 28 and 29) and ground by backprobing. The voltage is one volt or less for approximately 3 seconds, then changes to battery positive voltage when ignition switch is turned from the LOCK position to ON position. Turn the ignition switch to LOCK position. If voltage is not as specified, go to next step. If voltage is as specified, go to step 10.
  8. Check connector C-39 at PCM for damage. If the connector in good condition, go to next step. If the connector is not in good condition, repair or replace it. Then go to step 14.
  9. Check for open circuit and short circuit to ground between idle air control motor connector B-06 and PCM connector C-39. See «IDLE AIR CONTROL MOTOR CIRCUIT TERMINAL IDENTIFICATION»(ref-150942-S30828108462002112700000) table. If wiring harness is in good condition, replace the PCM. Then go to step 14. If wiring harness is not in good condition, repair it. Then go to step 14. IDLE AIR CONTROL MOTOR CIRCUIT TERMINAL IDENTIFICATION Idle Air Control Motor Connector B-06 Terminal No. PCM Connector C-39 Terminal No. 1 14 3 28 4 15 6 29
  10. Check connector C-39 at PCM for damage. If the connector is in good condition, go to next step. If the connector is not in good condition, repair or replace it. Then go to step 14.
  11. Check the idle air control motor operation using special tool. Remove the idle air control motor. Connect special tool (MB991709) to the idle air control motor. see scheme 97 All terminals should be connected. Use the jumper wires to connect terminal No. 2 of the idle air control motor connector to the battery positive terminal. Check the ensure that the motor operates when terminals No. 1 and 3 of the idle air control motor connector are respectively connected to the battery negative terminal using a jumper wire. Vibration should be present at each application of voltage to test clip combination. Use jumper wires to connect terminal No. 5 of the idle air control motor connector to the battery positive terminal. Check to ensure that the motor operates when terminals No. 4 and 6 of the idle air control motor connector are respectively connected to the battery negative terminal using a jumper wire. Vibration should be present at each application of voltage to test clip combination. Install the idle air control motor. If the idle air control motor is operating properly, go to next step. If the idle air control motor is not operating properly, replace the idle air control motor. Then go to step 14.
  12. Check for harness damage between MFI relay connector A-18X terminal No. 4 and idle air control motor connector B-06 terminals No. 2 and 5. If wiring harness is in good condition, go to next step. If wiring harness is not in good condition, repair it. Then go to step 14.
  13. Check for harness damage between idle air control motor connector B-06 and PCM connector C-39. See «IDLE AIR CONTROL MOTOR CIRCUIT TERMINAL IDENTIFICATION»(ref-150942-S30828108462002112700000) table. If wiring harness is in good condition, replace the PCM. Then go to next step. If wiring harness is not in good condition, repair it. Then go to next step.
  14. Test the OBD-II drive cycle. Carry out a test drive with the drive cycle pattern. See «OTHER MONITOR»(ref-150942-S38112384672002112700000) under VERIFYING REPAIRS. Check the Diagnostic Trouble Code (DTC). If DTC P0506 is output, repeat diagnosis. If DTC P0506 is not output, inspection is complete.

Check conditions are when vehicle speed has reached 0.93 mph (1.5 km/h) or more at least once, vehicle is under closed loop idle speed control, engine coolant temperature is more than 170°F (77°C), battery positive voltage is more than 10 volts, barometric pressure is more than 76 kPa (11 psi), intake air temperature is more than 14°F (-10°C), 25 seconds have elapsed from the start of the previous monitoring and target idle air control motor position is 0 steps.

Judgment criteria is when actual idle speed has continued to be more than the target idle speed by 200 RPM or more for 12 seconds if the maximum air temperature during the previous operation was less than 113°F (45°C).

Judgment criteria is when actual idle speed has continued to be more than the target idle speed by 300 RPM or more for 12 seconds if the maximum air temperature during the previous operation was more than 113°F (45°C).

Troubleshooting Hunts

The most likely causes for this code to be set are

  1. Idle air control motor failed.
  2. Open or shorted idle air control motor circuit, or loose connector.
  3. PCM failed.
CAUTIONTo prevent damage to scan tool, always turn the ignition switch to LOCK position before connecting or disconnecting scan tool.

Note. If PCM is replaced, immobilizer code registration must be performed. See PROGRAMMING .

  1. Using scan tool, read the Diagnostic Trouble Code (DTC). Connect scan tool to the data link connector. (Scheme 105) Turn the ignition switch to ON position. Using scan tool, read the DTC. Turn the ignition switch to LOCK position. If any diagnostic trouble code other than P0507 is output, perform appropriate DTC test. If any diagnostic trouble code other than P0507 is not output, go to next step.
  2. Check for intake system vacuum leaks. If there are no abnormalities, go to next step. If there are any abnormalities, repair it. Then go to step 14.
  3. Check connector B-06 at idle air control motor for damage. If the connector is in good condition, go to next step. If the connector is not in good condition, repair or replace it. Then go to step 14.
  4. Check the idle air control motor coil resistance. Disconnect the idle air control motor connector B-06. Measure the resistance between idle air control motor connector terminal No. 2 and either terminal No. 1 or terminal No. 3. Standard value is 28-33 ohms at 68°F (20°C). Measure the resistance between idle air control motor connector terminal No. 5 and either terminal No. 4 or terminal No. 6. Standard value is 28-33 ohms at 68°F (20°C). If the resistance is as specified, go to next step. If the resistance is not as specified, replace the idle air control motor. Then go to step 14.
  5. Check the power supply voltage at idle air control motor harness side connector B-06. Disconnect the connector B-06 and measure at the harness side. Turn the ignition switch to ON position. Measure the voltage between terminals No. 2 and 5, and ground. Voltage should be battery positive voltage. Turn the ignition switch to LOCK position. If voltage is not as specified, go to next step. If voltage is as specified, go to step 7.
  6. Check connector A-18X at MFI relay for damage. If the connector is in good condition, repair wiring harness between MFI relay connector A-18X terminal No. 4 and idle air control motor connector B-06 terminals No. 2 and/or No. 5 because of open circuit or short circuit to ground. Then go to step 14. If the connector is not in good condition, repair or replace it. Then go to step 14.
  7. Check the power supply voltage at PCM connector C-39 by backprobing. Do not disconnect the PCM C-39. Measure the voltage between terminals No. 14, 15, 28 and 29, and ground by backprobing. The voltage is one volt or less for approximately 3 seconds, then changes to the battery positive voltage when the ignition switch is turned from OFF position to ON position. Turn the ignition switch to LOCK position. If voltage is not as specified, go to next step. If voltage is as specified, go to step 10.
  8. Check connector C-39 at PCM for damage. If the connector is in good condition, go to next step. If the connector is not in good condition, repair or replace it. Then go to step 14.
  9. Check for open circuit and short circuit to ground between idle air control motor connector B-06 and PCM connector C-39. See «IDLE AIR CONTROL MOTOR CIRCUIT TERMINAL IDENTIFICATION»(ref-150942-S30828108462002112700000) table. If wiring harness is in good condition, replace the PCM. Then go to step 14. If wiring harness is not in good condition, repair circuit. Then go to step 14.
  10. Check connector C-39 at PCM for damage. If the connector is in good condition, go to next step. If the connector is not in good condition, repair or replace it. Then go to step 14.
  11. Check the idle air control motor operation using special tool. Remove the idle air control motor. Connect special tool to the idle air control motor. see scheme 97 All terminals should be connected. Use the jumper wires to connect terminal No. 2 of the idle air control motor connector to the battery (+) terminal. Check to ensure that the motor operates when terminals No. 1 and 3 of the idle air control motor connector are respectively connected to the battery (-) terminal using a jumper wire. Vibration should be present at each application of voltage to test clip combination. Use jumper wires to connect the terminal No. 5 of the idle air control motor connector to the battery (+) terminal. Check to ensure that the motor operates when terminals No. 4 and 6 of the idle air control motor connector are respectively connected to the battery (-) terminal using a jumper wire. Vibration should be present at each application of voltage to test clip combination. Install the idle air control motor. If the idle air control motor is operating properly, go to next step. If the idle air control motor is not operating properly, replace the idle air control motor. Then go to step 14.
  12. Check for harness damage between MFI relay connector A-18X terminal No. 4 and idle air control motor connector B-06 terminals No. 2 and 5. If wiring harness is in good condition, go to next step. If wiring harness is not in good condition, repair it. Then go to step 14.
  13. Check for harness damage between idle air control motor connector B-06 and PCM connector C-39. See «IDLE AIR CONTROL MOTOR CIRCUIT TERMINAL IDENTIFICATION»(ref-150942-S30828108462002112700000) table. If wiring harness is in good condition, replace the PCM. If wiring harness is not in good condition, repair it. Then go to next step.
  14. Test the OBD-II drive cycle. Carry out a test drive with the drive cycle pattern. See «OTHER MONITOR»(ref-150942-S38112384672002112700000) under VERIFYING REPAIRS. Check the Diagnostic Trouble Code (DTC). If DTC P0507 is output, repeat diagnosis. If DTC P0507 is not output, inspection is complete.

Check conditions are when engine coolant temperature is more than 86°F (30°C), drive for 4 seconds or more with the vehicle speed 50 km/h (31 mph) or more and stop the vehicle, vehicle speed is 0.93 mph (1.5 km/h) or less. Repeat drive and stop 10 times or more. Judgment criteria is when power steering pressure switch continues to be ON.

The most likely causes for this code to be set are

  1. Power steering pressure switch failed.
  2. Open or shorted power steering pressure switch circuit, or loose connector.
  3. PCM failed.
CAUTIONTo prevent damage to scan tool, always turn the ignition switch to LOCK position before connecting or disconnecting scan tool.

Note. If PCM is replaced, immobilizer code registration must be performed. See PROGRAMMING .

  1. Using scan tool, check power steering pressure switch. Connect scan tool to the data link connector. (Scheme 105) Start the engine and run at idle. Set scan tool to the data reading mode for data list item 27: POWER STEERING PRESSURE SWITCH. If the steering wheel is stopped while idling, OFF will be displayed. If the steering wheel is steered while idling, ON will be displayed. Turn the ignition switch to LOCK position. If the sensor is operating properly, it can be assumed that this malfunction is intermittent. If the sensor is not operating properly, go to next step.
  2. Check the power supply voltage at power steering pressure switch connector B-44 by backprobing. see scheme 26 Do not disconnect the connector B-44. Start the engine and run at idle. Measure the voltage between terminal No. 1 and ground by backprobing. When steering wheel is stationary, voltage should be battery positive voltage. When steering wheel is turned, voltage should be one volt or less. Turn the ignition switch to LOCK position. If the voltage is as specified, go to next step. If the voltage is not as specified, go to step 5.
  3. Check connector B-44 at power steering pressure switch for damage. If the connector is in good condition, go to next step. If the connector is not in good condition, repair or replace it. Then go to step 14.
  4. Using scan tool, check power steering pressure switch. Connect scan tool to the data link connector. Start the engine and run at idle. Set scan tool to the data reading mode for data list item 27: POWER STEERING PRESSURE SWITCH. If the steering wheel is stopped while idling, OFF will be displayed. If the steering wheel is steered while idling, ON will be displayed. Turn the ignition switch to LOCK position. If the sensor is operating properly, it can be assumed that this malfunction is intermittent. If the sensor is not operating properly, replace the PCM. Then go to step 14.
  5. Check connector B-44 at power steering pressure switch for damage. If the connector is in good condition, go to next step. If the connector is not in good condition, repair or replace it. Then go to step 14.
  6. Check the power supply voltage at power steering pressure switch harness side connector B-44. Disconnect the connector B-44 and measure at the harness side. Turn the ignition switch to ON position. Measure the voltage between terminal No. 1 and ground. Voltage should be battery positive voltage. Turn the ignition switch to LOCK position. If voltage is not as specified, go to next step. If voltage is as specified, go to step 11.
  7. Check the power supply voltage at PCM connector C-40 by backprobing. Do not disconnect the PCM connector C-40. Disconnect the power steering pressure switch connector B-44. Turn the ignition switch to ON position. Measure the voltage between terminal No. 52 and ground by backprobing. Voltage should be battery positive voltage. Turn the ignition switch to LOCK position. If the voltage is as specified, go to next step. If the voltage is not as specified, go to step 9.
  8. Check connector C-40 at PCM for damage. If the connector is in good condition, If the connector is not in good condition, repair wiring harness between power steering pressure switch connector B-44 terminal No. 1 and PCM connector C-40 terminal No. 52 because of open circuit. Then go to step 14. If the connector is not in good condition, repair or replace it. Then go to step 14.
  9. Check connector C-40 at PCM for damage. If the connector is in good condition, go to next step. If the connector is not in good condition, repair or replace it. Then go to step 14.
  10. Check for short to ground between power steering pressure switch connector B-44 terminal No. 1 and PCM connector C-40 terminal No. 52. If wiring harness is in good condition, replace the PCM. Then go to step 14. If wiring harness is not in good condition, repair it. Then go to step 14.
  11. Replace the power steering pressure switch. Recheck for trouble symptoms. Check for Diagnostic Trouble Codes (DTC). If DTC P0551 is output, go to next step. If DTC P0551 is not output, go to step 14.
  12. Check connector C-40 at PCM for damage. If the connector is in good condition, go to next step. If the connector is not in good condition, repair or replace it. Then go to step 14.
  13. Check for harness damage between power steering pressure switch connector B-44 terminal No. 1 and PCM connector C-40 terminal No. 52. If wiring harness is in good condition, replace the PCM. Then go to next step. If wiring harness is not in good condition, repair it. Then go to next step.
  14. Using scan tool, check power steering pressure switch. Connect scan tool to the data link connector. Start the engine and run at idle. Set scan tool to the data reading mode for data list item 27: POWER STEERING PRESSURE SWITCH. If the steering wheel is stopped while idling, OFF will be displayed. If the steering wheel is steered while idling, ON will be displayed. Turn the ignition switch to LOCK position. If the switch is operating properly, inspection is complete. If the switch is not operating properly, repeat diagnosis.

Note. This is only if the engine coolant temperature is less than 32°F (0°C) when starting.

Check conditions are when 8 minutes or more have passed after starting the engine, engine coolant temperature is more than 113°F (45°C), intake air temperature is more than 32°F (0°C) and volumetric efficiency is 30-45 percent. Judgment criteria is when manifold differential pressure sensor output voltage has continued to be more than 4.6 volts, corresponding to an absolute pressure of 17 psi (118 kPa) or more for 2 seconds or manifold differential pressure sensor output voltage has continued to be less than 0.1 volt, corresponding to an absolute pressure of 0.3 psi (2.4 kPa) or less, for 2 seconds.

Note. This is only if the engine coolant temperature is 32°F (0°C) or more when starting.

Check conditions are when 8 minutes or more have passed after starting the engine, engine coolant temperature is more than 113°F (45°C), intake air temperature is more than 32°F (0°C) and volumetric efficiency is less than 30 percent. Judgment criteria is when manifold differential pressure sensor output voltage has continued to be more than 4.2 volts, corresponding to an absolute pressure of 16 psi (108 kPa) or more, for 2 seconds.

Note. This is only if the engine coolant temperature is 32°F (0°C) or more when starting.

Check conditions are when 8 minutes or more have passed after starting the engine, engine coolant temperature is more than 113°F (45°C), intake air temperature is more than 32°F (0°C) and volumetric efficiency is more than 70 percent. Judgment criteria is when manifold differential pressure sensor output voltage has continued to be less than 1.8 volts, corresponding to an absolute pressure of 4.6 psi (46 kPa) or less, for 2 seconds.

The most likely causes for this code to be set are

  1. Manifold differential pressure sensor failed.
  2. Open or shorted manifold differential pressure sensor circuit, or loose connector.
  3. PCM failed.
CAUTIONTo prevent damage to scan tool, always turn the ignition switch to LOCK position before connecting or disconnecting scan tool.

Note. If PCM is replaced, immobilizer code registration must be performed. See PROGRAMMING .

  1. Using scan tool, check manifold differential pressure sensor. Connect scan tool to the data link connector. (Scheme 105) Start the engine and run at idle. Set scan tool to the data reading mode for data list item 95: MANIFOLD DIFFERENTIAL PRESSURE SENSOR. While engine is idling, pressure should be 64-76 kPa. Turn the ignition switch to LOCK position. If the sensor is operating properly, it can be assumed that this malfunction is intermittent. If the sensor is not operating properly, go to next step.
  2. Check connector B-18 at manifold differential pressure sensor for damage. If the connector is in good condition, go to next step. If the connector is not in good condition, repair or replace it. Then go to step 12.
  3. Check the sensor supply voltage at manifold differential pressure sensor harness side connector B-18. Disconnect the connector B-18 and measure at the harness side. Turn the ignition switch to ON position. Measure the voltage between terminal No. 3 and ground. Voltage should be 4.8-5.2 volts. Turn the ignition switch to LOCK position. If voltage is not as specified, go to next step. If voltage is as specified, go to step 6.
  4. Check connector C-40 at PCM for damage. If the connector is in good condition, go to next step. If the connector is not in good condition, repair or replace it. Then go to step 12.
  5. Check for open circuit and short circuit to ground between manifold differential pressure sensor connector B-18 terminal No. 3 and PCM connector C-40 terminal No. 46. If wiring harness is in good condition, replace the PCM. Then go to step 12. If wiring harness is not in good condition, repair it. Then go to step 12.
  6. Check the continuity at manifold differential pressure sensor harness side connector B-18. Disconnect the connector B-18 and measure at the harness side. Measure the continuity between terminal No. 2 and ground. Resistance should be less than 2 ohms. If continuity is as specified, go to step 9. If continuity is not as specified, go to next step.
  7. Check connector C-40 at PCM for damage. If the connector is in good condition, go to next step. If the connector is not in good condition, repair or replace it. Then go to step 12.
  8. Check for open circuit and harness damage between manifold differential pressure sensor connector B-18 terminal No. 2 and PCM connector C-40 terminal No. 57. If wiring harness is in good condition, replace the PCM. Then go to step 12. If wiring harness is not in good condition, repair it. Then go to step 12.
  9. Check connector C-41 at PCM for damage. If the connector is in good condition, go to next step. If the connector is not in good condition, repair or replace it. Then go to step 12.
  10. Check for harness damage between manifold differential pressure sensor connector B-18 terminal No. 3 and PCM connector C-40 terminal No. 46. If wiring harness is in good condition, go to next step. If wiring harness is not in good condition, repair it. Then go to step 12.
  11. Check for open circuit and short circuit to ground and harness damage between manifold differential pressure sensor connector B-18 terminal No. 1 and PCM connector C-41 terminal No. 91. If wiring harness is in good condition, replace the manifold differential pressure sensor. Then go to next step. If wiring harness is not in good condition, repair it. Then go to next step.
  12. Test the OBD-II drive cycle. Carry out a test drive with the drive cycle pattern. See «OTHER MONITOR»(ref-150942-S38112384672002112700000) under VERIFYING REPAIRS. Check the Diagnostic Trouble Code (DTC). If DTC P1400 is output, repeat diagnosis. If DTC P1400 is not output, inspection is complete.

Check conditions are when engine speed is more than 50 RPM. Judgement criteria is when input voltage from the generator FR terminal has continued to be approximately battery positive voltage for 20 seconds.

The most likely causes for this code to be set are

  1. Open circuit in generator FR terminal circuit.
  2. PCM failed.
  1. Check the voltage at generator intermediate connector B-11 by backprobing. Do not disconnect the connector B-11. Start the engine and run at idle. Ensure engine is warmed up and radiator fan is stopped. Measure the voltage between terminal No. 3 and ground by backprobing. Check during the following conditions: Headlight switch turned from OFF to ON. Rear defogger switch turned from OFF to ON. Stoplight switch turned from OFF to ON. Voltage should drop when each switch is actuated. Turn the ignition switch to LOCK position. If the voltage is as specified, go to next step. If the voltage is not as specified, go to step 4 .
  2. Check connector B-11 at generator intermediate connector for damage. If the connector is in good condition, go to next step. If the connector is not in good condition, repair or replace it. Then go to step 11 .
  3. Check the trouble symptoms. Carry out a test drive with the drive cycle pattern. See «OTHER MONITOR»(ref-150942-S38112384672002112700000) under VERIFYING REPAIRS. Check the Diagnostic Trouble Code (DTC). If DTC P1500 is output, replace the PCM. Then go to next step. If DTC P1500 is not output, it can be assumed that this malfunction is intermittent.
  4. Check connector B-11 at generator intermediate connector for damage. If the connector is in good condition, go to next step. If the connector is not in good condition, repair or replace it. Then go to step 11 .
  5. Check connector B-46 at generator connector for damage. If the connector is in good condition, go to next step. If the connector is not in good condition, repair or replace it. Then go to step 11 .
  6. Check the voltage at generator harness side connector B-46. Disconnect the connector B-46 and measure at the harness side. Turn the ignition switch to ON position. Measure the voltage between terminal No. 4 and ground. Voltage should be 4.8-5.2 volts. Turn the ignition switch to LOCK position. If voltage is not as specified, go to next step. If voltage is as specified, go to step 9 .
  7. Check connector C-40 at PCM for damage. If the connector is in good condition, go to next step. If the connector is not in good condition, repair or replace it. Then go to step 11 .
  8. Check for open circuit and short circuit to ground between generator connector B-46 terminal No. 4 and PCM connector C-40 terminal No. 54. If wiring harness is in good condition, replace the PCM. Then go to step 11 . If wiring harness is not in good condition, repair it. Then go to step 11 .
  9. Check connector C-40 at PCM for damage. If the connector is in good condition, go to next step. If the connector is not in good condition, repair or replace it. Then go to step 11 .
  10. Check for harness damage between generator connector B-46 terminal No. 4 and PCM connector C-40 terminal No. 54. If wiring harness is in good condition, replace the generator. Then go to next step. If wiring harness is not in good condition, repair it. Then go to next step.
  11. Test the OBD-II drive cycle. Carry out a test drive with the drive cycle pattern. See «OTHER MONITOR»(ref-150942-S38112384672002112700000) under VERIFYING REPAIRS. Check the Diagnostic Trouble Code (DTC). If DTC P1500 is output, repeat diagnosis. If DTC P1500 is not output, inspection is complete.

Check conditions are when starting sequence was completed and battery positive voltage is more than 10 volts. Judgement criteria is when battery backup line voltage has continued to be 6 volts or less for 2 seconds.

The most likely causes for this code to be set are

  1. Open or shorted battery backup line, or loose connector.
  2. PCM failed.
CAUTIONTo prevent damage to scan tool, always turn the ignition switch to LOCK position before connecting or disconnecting scan tool.

Note. If PCM is replaced, immobilizer code registration must be performed. See PROGRAMMING .

  1. Using scan tool, read the Diagnostic Trouble Code (DTC). Connect scan tool to the data link connector. (Scheme 105) Turn the ignition switch to ON position. Erase the DTC. Start the engine and run it at idle. Read the DTC. Turn the ignition switch to LOCK position. If DTC P1603 is output, go to next step. If DTC P1603 is not output, inspection is complete.
  2. Check the backup power supply voltage at PCM connector C-40 by backprobing. Do not disconnect the PCM connector C-40. Measure the voltage between terminal No. 66 and ground by backprobing. Voltage should be battery positive voltage. If voltage is not as specified, go to next step. If voltage is as specified, go to step 5.
  3. Check the backup power supply voltage at PCM harness side connector C-40. Disconnect the PCM connector C-40 and measure at the harness side. Measure the voltage between terminal No. 66 and ground. Voltage should be battery positive voltage. If the voltage is as specified, go to next step. If the voltage is not as specified, check intermediate connectors C-17 and C-66 for damage, and repair or replace as required. If intermediate connectors are in good condition, repair wiring harness between battery and PCM connector C-40 terminal No. 66 because of open circuit or short circuit to ground. Then go to step 6.
  4. Check connector C-40 at PCM for damage. If the harness connector in good condition, check intermediate connectors C-17 and C-66 for damage, and repair or replace as required. If intermediate connectors are in good condition, repair wiring harness between battery and PCM connector C-40 terminal No. 66 because of harness damage. Then go to step 6. If the harness connector is not in good condition, repair or replace it. Then go to step 6.
  5. Check connector C-40 at PCM for damage. If the harness connector is in good condition, replace the PCM. Then go to next step. If the harness connector is not in good condition, repair or replace it. Then go to next step.
  6. Using scan tool, read the Diagnostic Trouble Code (DTC). Connect scan tool to the date link connector. Turn the ignition switch to ON position. Read the DTC. Turn the ignition switch to LOCK (OFF) position. If DTC P1603 is output, repeat diagnosis. If DTC P1603 is not output, the inspection is complete.

Check conditions are when ignition switch is ON. Judgment criteria is when the communication error between PCM and the immobilizer-ECU continues for 2 seconds or more.

The most likely causes for this code to be set are

  1. Malfunction of harness or connector.
  2. Malfunction of immobilizer-ECU.
  3. PCM failed.
CAUTIONTo prevent damage to scan tool, always turn the ignition switch to LOCK position before connecting or disconnecting scan tool.

Note. If PCM is replaced, immobilizer code registration must be performed. See PROGRAMMING .

Using scan tool, read the immobilizer diagnostic trouble code (DTC). Connect scan tool to the data link connector. (Scheme 105) Turn the ignition switch to ON position. Read the immobilizer system DTC. Turn the ignition switch to LOCK position. If the immobilizer system DTC is output, clear DTC. Recheck for DTCs. If DTC P1610 is reset, replace the PCM. Then check that the DTC P1610 does not reset. If the immobilizer system DTC is not output, refer to ignition system check. See appropriate SYSTEM & COMPONENT TESTING article.

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