Engine Controls - Self Diagnostics - 2.4L: Diagnosis Mitsubishi Eclipse III

SYSTEM DIAGNOSIS

Note. Engine management is controlled by an Engine Control Module (ECM) on vehicles with Manual Transaxle (M/T) and by a Powertrain Control Module (PCM) on vehicles with Automatic Transaxle (A/T). ECM/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 ECM/PCM is disconnected.

ECM/PCM includes On Board Diagnostics II (OBD-II) software designed to monitor emissions control system over the life of the vehicle. On OBD-II, 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 ECM/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 emissions system 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.

ECM/PCM monitors several different engine control system circuits. If an abnormal input signal occurs, the ECM/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 trips before the MIL is illuminated. For DTCs that use two-trip detection logic, 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, ECM/PCM will enter fail-safe function (limp home mode). In fail-safe mode, ECM/PCM will substitute default values for the faulty component or system.

Each circuit or system monitored by ECM/PCM has particular engine and driving conditions that must be met before ECM/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. 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 ECM/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. A system related Diagnostic Trouble Code (DTC) cannot set until its 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. 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 ECM/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, ECM/PCM can be checked for DTCs.

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-156203-S14766272792003072200000) under SELF-DIAGNOSTIC SYSTEM. Locate OBD-II Data Link Connector (OBD-II DLC) under instrument panel, near steering column.
2. Turn ignition switch to OFF position. Connect scan tool to DLC. Turn ignition switch to ON position. Read and record scan tool self-diagnostic output. Proceed to «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(ref-156203-S10300088412003072200000) . If scan tool will not communicate with ECM/PCM, diagnose communication concern. See «SCAN TOOL WILL NOT COMMUNICATE»(ref-156203-S00596236752003072300000) under DIAGNOSTIC CIRCUIT CHECK. Turn ignition switch to OFF position before disconnecting scan tool.

CLEARING DIAGNOSTIC TROUBLE CODES

To clear DTCs using a scan tool, refer to owner's manual supplied with scan tool. If scan tool is not available, DTCs may be cleared by disconnecting negative battery cable or ECM/PCM for a few minutes. Reconnect negative battery cable. Start and warm up engine. Run vehicle through appropriate drive cycle(s). Check for DTCs to confirm repair.

DTCs will be automatically erased by ECM/PCM under certain conditions

1. If non-emission related fault does not reoccur within 51 engine starts.
2. If emission related fault, except misfire and fuel system lean/rich, does not reoccur in 40 drives.
3. If misfire or fuel system lean/rich fault does not reoccur in 80 drives.

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.

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 .

DIAGNOSTIC TROUBLE CODE INDEX

Scheme 152

Scheme 153

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.

DIAGNOSTIC CIRCUIT CHECK

Note. For terminal identification, see appropriate illustration under TERMINAL IDENTIFICATION . For circuit and wire color identification, see appropriate wiring diagram under ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS.

DTC Set Conditions

1. Check Conditions - Throttle Position sensor output voltage is 1.5 volts or higher. Engine speed is higher than 2000 RPM.
2. Judgement Criteria Volume air flow sensor output frequency has continued to be 60 Hz or lower for 2 seconds.
3. Check Conditions Throttle position sensor output voltage is 2 volts or lower. Engine speed is lower than 2000 RPM.
4. Judgement Criteria Volume air flow sensor output frequency has continued to be 800 Hz or higher for 2 seconds.

Diagnostic Procedure

1. Connect Scan Tool (MB991502) to the data link connector. Start the engine and run at idle. Set the scan tool to data reading mode for item 12, Volume Air Flow Sensor. Warm up the engine to normal operating temperature: 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 off. If the sensor is operating properly, it can be assumed that this malfunction is intermittent, refer to «INTERMITTENT DIAGNOSTIC TROUBLE CODES»(ref-156203-S19689263182003072200000). If the sensor is malfunctioning, go to next step.
2. Check the reset signal voltage at volume air flow sensor connector B-14 by backprobing. Do not disconnect the connector B-14. Turn on the ignition. Measure the voltage between terminal 7 and ground by backprobing. see scheme 38 Voltage should be between 6.0-9.0 volts. Turn the ignition off. If the voltage is normal, go to step 5, otherwise, go to next step.
3. Check connector B-14 at volume air flow sensor and connector C-49 at ECM (M/T) or connector C-50 at PCM (A/T) for damage. see scheme 15or see scheme 33. If the connector is in good condition, go to next step, otherwise, repair or replace it and go to step 9.
4. Check for short circuit to ground between volume air flow sensor connector B-14, terminal 7 and ECM connector C-49, terminal 19 (M/T) or PCM connector C-50, terminal 19 (A/T). If the harness wire is in good condition, replace the volume air flow sensor and go to step 9, otherwise, repair it and 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 7 and ground by backprobing. see scheme 38 When the engine is idling, voltage should be 1.0 volt or less. When the engine speed is 3000 RPM, voltage should be between 6.0-9.0 volts. Turn the ignition off. If the voltage is normal, go to step 8, otherwise, go to next step.
6. Check connector B-14 at volume air flow sensor and connector C-49 at ECM (M/T) or connector C-50 at PCM (A/T) for damage. If the connector is in good condition, go to next step, otherwise, repair or replace it and go to step 9.
7. Check for open circuit and harness damage between volume air flow sensor connector B-105, terminal 7 and ECM connector C-49, terminal 19 (M/T) or PCM connector C-50, terminal 19 (A/T). If the harness wire is in good condition, replace the ECM or PCM and go to step 9, otherwise, repair it and go to step 9.
8. Replace the volume air flow sensor. Carry out a test drive with the drive cycle pattern. Check the diagnostic trouble codes. If DTC P0101 is output, replace the ECM or PCM and go to next step. If the DTC is absent, the inspection is complete.
9. Carry out a test with the drive cycle pattern, refer to «OTHER MONITOR»(ref-156203-S39011874532003072200000). Check the diagnostic trouble codes. If DTC P0101 is output, retry the troubleshooting. If the DTC is absent, the inspection is complete.

1. Check Conditions - Engine speed is higher than 500 RPM.
2. Judgement Criteria - Volume air flow sensor output frequency has continued to be 3.3 Hz or lower for 2 seconds.

1. Connect Scan Tool (MB991502) to the data link connector and start the engine. Set the scan tool to the data reading mode for item 12, Volume Air Flow Sensor. Warm up the engine to normal operating temperature: 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 off. If the sensor is operating properly, it can be assumed that this malfunction is intermittent, refer to «INTERMITTENT DIAGNOSTIC TROUBLE CODES»(ref-156203-S19689263182003072200000). If the sensor is malfunctioning, go to next step.
2. Do not disconnect the connector B-14. Turn the ignition on. Measure the voltage between terminal 4 and ground of volume air flow sensor connector B-14 by backprobing. see scheme 38 The voltage should be battery positive voltage. Turn the ignition off. If the voltage is normal, go to step 5, otherwise go to next step.
3. Disconnect the connector B-14 and measure at the harness side. Turn the ignition on. Measure the voltage between terminal 4 and ground of the volume air flow sensor harness side connector B-14. Voltage should be battery positive voltage. Turn the ignition off. If the voltage is normal, go to next step. If the voltage is abnormal, repair harness wire between MFI relay connector A-18X, terminal 4 and volume air flow sensor connector B-105, terminal 4 (because of open circuit or short circuit to ground) and go to step 13. see scheme 31and see scheme 38.
4. Check connector B-14 at the volume air flow sensor for damage. If the connector is in good condition, repair harness wire between MFI relay connector A-18X, terminal 4 and volume air flow sensor connector B-14, terminal 4 (because of harness damage) and go to step 13. see scheme 31and see scheme 38. If the connector is damaged, repair or replace it and 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 damaged, repair or replace it and go to step 13.
6. Disconnect the connector B-14 and measure at the harness side. Turn the ignition on. Measure the voltage between terminal 3 and ground of the volume air flow sensor harness side connector B-14. Voltage should be between 4.8-5.2 volts. Turn the ignition off. If the voltage is normal, go to step 9, otherwise go to next step.
7. Check connector C-60 at ECM (M/T) or connector C-54 at PCM (A/T) for damage. see scheme 15or see scheme 33. If the harness connector is in good condition, go to next step. If the harness connector is damaged, repair or replace it and go to step 13.
8. Check for short circuit to ground between volume air flow sensor connector B-14 terminal 3 and ECM connector C-60 terminal 90 (M/T) or PCM connector C-54 terminal 65 (A/T). see scheme 15, see scheme 33 or see scheme 38. If the harness wire is in good condition, replace the ECM or PCM and go to step 13. If the harness wire is damaged, repair it and go to step 13.
9. Disconnect the connector B-14 and measure at the harness side. Check for the continuity between terminal 5 and ground of volume air flow sensor harness side connector B-14. The resistance should be less than 2 ohm. If the continuity is normal, go to step 12, otherwise go to next step.
10. Check connector C-53 at ECM (M/T) or connector C-50 at PCM (A/T) for damage. see scheme 15or see scheme 33. If the connector is in good condition, go to next step. If the connector is damaged, repair or replace it and go to step 13.
11. Check for open circuit and harness damage between volume air flow sensor connector B-14 terminal 5 and ECM connector C-53 terminal 40 (M/T) or PCM connector C-50 terminal 16 (A/T). see scheme 15, see scheme 33 or see scheme 38. If the harness wire is in good condition, replace the ECM or PCM and go to step 13. If the harness wire is damaged, repair it and go to step 13.
12. Check connector C-53 at ECM (M/T) or connector C-50 at PCM (A/T) for damage. If the connector is in good condition, replace the volume air flow sensor and go to next step. If the connector is damaged, repair or replace it and go to next step.
13. Carry out a test drive with the drive cycle pattern, refer to «OTHER MONITOR»(ref-156203-S39011874532003072200000). Check for diagnostic trouble code P0102. If the code is showing, retry the troubleshooting. If the code is absent, the inspection is complete.

1. Check Conditions - Barometric pressure is lower than 11 psi (76 kPa).
2. Judgement Criteria - During 15 drive cycles, 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 higher during each of the 15 drive cycles. Also, during each of the drive cycles, make sure that after the engine has been started, the engine coolant temperature has increased by 41°F (23°C) or more.

1. Connect Scan Tool (MB991502) to the data link connector. Turn the ignition on and read the DTC. Turn the ignition off. If the DTC P0107 is output, refer to «DTC P0107: BAROMETRIC PRESSURE CIRCUIT LOW INPUT»(ref-156203-S04353885502003071000000). If the code is not present, go to next step.
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 damaged, repair or replace it and go to step 9.
3. Disconnect the connector B-14 and measure at the harness side. see scheme 38 Check for the continuity between terminal 5 and ground of barometric pressure sensor harness side connector B-14. The resistance should be less than 2 ohm. If the continuity is normal, go to step 6, otherwise go to next step.
4. Check connector C-53 at ECM (M/T) or connector C-50 at PCM (A/T) for damage. see scheme 15or see scheme 33. If the connector is in good condition, go to next step. If the connector is damaged, repair or replace it and go to step 9.
5. Check for open circuit and harness damage between barometric pressure sensor connector B-14 and ECM connector C-53 (M/T) or PCM connector C-50 (A/T). see scheme 15, see scheme 33 or see scheme 38. If the harness wire is in good condition, replace the ECM or PCM and go to step 9. If the harness wire is damaged, repair it and go to step 9.
6. Check connector C-60 at ECM (M/T) or connector C-54 at PCM (A/T) for damage. see scheme 15or see scheme 33. If the connector is in good condition, go to next step. If the connector is damaged, repair or replace it and go to step 9.
7. Check for open circuit and harness damage between barometric pressure sensor connector B-14 and ECM connector C-60 (M/T) or PCM connector C-54 (A/T). see scheme 15, see scheme 33 or see scheme 38. If the harness wire is in good condition, go to next step. If the harness wire is damaged, repair it and go to step 9.
8. Replace the barometric pressure sensor. Carry out a test drive with the drive cycle pattern, refer to «OTHER MONITOR»(ref-156203-S39011874532003072200000). Check the diagnostic trouble code. If DTC P0106 is output, replace the ECM or PCM and go to next step. If the DTC is not present, the inspection is complete.
9. Carry out a test drive with the drive cycle pattern (OBD-II), refer to «OTHER MONITOR»(ref-156203-S39011874532003072200000). Check the diagnostic trouble code. If DTC P0106 is output, retry the troubleshooting. If the DTC is no longer present, the inspection is complete.

1. Check Conditions - 2 seconds or more have passed since the starting sequence was completed. Battery positive voltage is higher than 8 volts.
2. Judgement Criteria - Barometric pressure sensor output has continued to be 7.1 psi (49 kPa) or lower approximately 15,000 ft above sea level for 10 seconds.

1. Connect Scan Tool (MB991502) to the data link connector. Turn the ignition switch to the "ON" position. Set scan tool to the data reading mode for item 25, Barometric Pressure Sensor. Turn the ignition switch to the "LOCK" (OFF) position. If the sensor is operating properly, it can be assumed that the malfunction is intermittent, refer to «INTERMITTENT DIAGNOSTIC TROUBLE CODES»(ref-156203-S19689263182003072200000). If the sensor is malfunctioning, go to next step.
2. Do not disconnect the connector B-14. Turn the ignition on. Measure the voltage between terminal 2 and ground by backprobing. see scheme 38 Turn the ignition off. If the voltage is normal, go to next step, otherwise go to step 7.
3. Do not disconnect the connector C-60 (M/T) or C-54 (A/T). Turn the ignition on. Measure the voltage between terminal 85 (M/T) or terminal 55 (A/T) and ground by backprobing. see scheme 15or see scheme 33. Turn the ignition off. If the voltage is normal, go to next step, otherwise go to step 6.
4. Check connector B-14 at the barometric pressure sensor and connector C-60 at ECM (M/T) or connector C-54 at PCM (A/T) for damage. If the connector is in good condition, go to next step. If the connector is damaged, repair or replace it and go to step 18.
5. Connect scan tool to the data link connector. Turn the ignition on. Set the scan tool to data reading mode for item 25, Barometric Pressure Sensor. Turn the ignition off. If the sensor is operating properly, it can be assumed that the malfunction is intermittent. If the sensor is malfunctioning, replace the ECM or PCM and go to step 18.
6. Check connector B-14 at the barometric pressure sensor and connector C-60 at ECM (M/T) or connector C-54 at PCM (A/T) for damage. see scheme 15, see scheme 33 or see scheme 38. If the connector is in good condition, repair harness wire between barometric pressure sensor connector B-14 terminal 2 and ECM connector C-60 terminal 85 (M/T) or PCM connector C-54 terminal 55 (A/T) (because of open circuit or harness damage) and go to step 18. If the connector is damaged, repair or replace it and go to step 18.
7. Do not disconnect the connector B-14. Turn the ignition on. Measure the voltage between terminal 1 and ground of barometric pressure sensor connector B-14 by backprobing. Voltage should be between 4.8-5.2 volts. Turn the ignition off. If the voltage is normal, go to step 12, otherwise go to next step.
8. Do not disconnect the connector C-60 (M/T) or C-54 (A/T). Turn the ignition on. Measure the voltage between terminal 81 (connector C-60 - M/T) or 46 (connector C-54 - A/T) and ground by backprobing. Voltage should be between 4.8-5.2 volts. Turn the ignition off. If the voltage is normal, go to next step, otherwise go to step 10.
9. Check connector B-14 at the barometric pressure sensor and connector C-60 at ECM (M/T) or connector C-54 at PCM (A/T) for damage. If the connector is in good condition, repair harness wire between barometric pressure sensor connector B-105 terminal 1 and ECM connector C-60 terminal 81 (M/T) or PCM connector C-54 terminal 46 (A/T) (because of open circuit or harness damage) and go to step 18. If the connector is damaged, repair or replace it and go to step 18.
10. Check connector B-14 at the barometric pressure sensor and connector C-60 at ECM (M/T) or connector C-54 at PCM (A/T) for damage. If the connector is in good condition, go to next step. If the connector is damaged, repair or replace it and go to step 18.
11. Check for short circuit to ground between barometric pressure sensor connector B-14 terminal 1 and ECM connector C-60 terminal 81 (M/T) or PCM connector C-54 terminal 46 (A/T). If the harness wire is in good condition, replace the ECM or PCM and go to step 18. If the harness wire is damaged, repair it and go to step 18.
12. Do not disconnect the connector B-14. Turn the ignition on. Measure the voltage between terminal 5 and ground by backprobing. Voltage should be 0.5 volt or less. Turn the ignition off. If the voltage is normal, go to step 15, otherwise go to next step.
13. Check connector B-14 at the barometric pressure sensor and connector C-53 at ECM (M/T) or connector C-50 at PCM (A/T) for damage. see scheme 15, see scheme 33 or see scheme 38. If the connector is in good condition, go to next step. If the connector is damaged, repair or replace it and go to step 18.
14. Check for harness damage between barometric pressure sensor connector B-14 terminal 5 and ECM connector C-53, terminal 40 (M/T) or PCM connector C-50, terminal 16 (A/T). If the harness wire is in good condition, replace the ECM or PCM and go to step 18. If the harness wire is damaged, repair it and 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 damaged, repair or replace it and go to step 18.
16. Check connector C-60 at ECM (M/T) or connector C-54 at PCM (A/T) for damage. If the connector is in good condition, go to next step. If the connector is damaged, repair or replace it and go to step 18.
17. Check for short circuit to ground and harness damage between barometric pressure sensor connector B-14 terminal 2 and ECM connector C-60, terminal 85 (M/T) or PCM connector C-54, terminal 55 (A/T). see scheme 15, see scheme 33 or see scheme 38. If the harness wire is in good condition, replace the volume air flow sensor and go to next step. If the harness wire is damaged, repair it and go to next step.
18. Carry out a test drive with the drive cycle pattern (OBD-II), refer to «OTHER MONITOR»(ref-156203-S39011874532003072200000). Check diagnostic trouble code P0107. If DTC P0107 is output, retry the troubleshooting. If the DTC is absent, the inspection is complete.

1. Check Conditions - 2 seconds or more have passed since the starting sequence was completed. Battery positive voltage is higher than 8 volts.
2. Judgement Criteria - Barometric pressure sensor output has continued to be 16 psi (113 kPa) or higher approximately 4000 ft below sea level for 10 seconds.

1. Connect Scan Tool (MB991502) to the data link connector. Turn the ignition on. Set the scan tool to data reading mode for item 25, Barometric Pressure Sensor. Turn the ignition off. If the sensor is operating properly, it can be assumed that this malfunction is intermittent, refer to «INTERMITTENT DIAGNOSTIC TROUBLE CODES»(ref-156203-S19689263182003072200000). If the sensor is malfunctioning, go to next step.
2. Do not disconnect the connector B-14. Turn the ignition switch on. Measure the voltage between terminal 2 and ground by backprobing. see scheme 38 Turn the ignition off. If the voltage is normal, go to next step, otherwise go to step 5.
3. Check connector B-14 at the barometric pressure sensor and connector C-60 at ECM (M/T) or connector C-54 at PCM (A/T) for damage. see scheme 15, see scheme 33 or see scheme 38. If the connector is in good condition, go to next step. If the connector is damaged, repair or replace it and go to step 12.
4. Connect scan tool to the data link connector. Turn the ignition on. Set the scan tool to data reading mode for item 25, Barometric Pressure Sensor. Turn the ignition off. If the sensor is operating properly, it can be assumed that the malfunction is intermittent. If the sensor is malfunctioning, replace the ECM or PCM and go to step 12.
5. Do not disconnect the connector B-14. Turn the ignition on. Measure the voltage between terminal 1 and ground by backprobing. Voltage should be between 4.8-5.2 volts. Turn the ignition off. If the voltage is normal, go to step 7, otherwise go to next step.
6. Check connector C-60 at ECM (M/T) or connector C-54 at PCM (A/T) for damage. see scheme 15or see scheme 33. If the connector is in good condition, replace the ECM or PCM and go to step 12. If the connector is damaged, repair or replace it and go to step 12.
7. Do not disconnect the connector B-14. Turn the ignition on. Measure the voltage between terminal 5 and ground by backprobing. Voltage should be 0.5 volt or less. Turn the ignition off. If the voltage is normal, go to step 10, otherwise go to next step.
8. Check connector B-14 at the barometric pressure sensor and connector C-53 at ECM (M/T) or connector C-50 at PCM (A/T) for damage. see scheme 15or see scheme 33. If the connector is in good condition, go to next step. If the connector is damaged, go to step 12.
9. Check for open circuit between barometric pressure sensor connector B-14 terminal 5 and ECM connector C-53, terminal 40 (M/T) or PCM connector C-50, terminal 16 (A/T). see scheme 15, see scheme 33 or see scheme 38. If the harness wire is in good condition, replace the ECM or PCM and go to step 12. If the harness wire is damaged, repair it and 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 damaged, repair or replace it and go to step 12.
11. Check connector C-53 at ECM (M/T) or connector C-50 at PCM (A/T) for damage. If the connector is in good condition, replace the volume air flow sensor and go to step 12. If the connector is damaged, repair or replace it and go to step 12.
12. Carry out a test drive with the drive cycle pattern (OBD-II), refer to «OTHER MONITOR»(ref-156203-S39011874532003072200000). Check the diagnostic trouble codes. If DTC P0108 is output, retry the troubleshooting. If the code is absent, the inspection is complete.

1. Check Conditions - Engine coolant temperature is higher than 169°F (76°C). Repeat 5 or more times: drive, stop. Drive: Vehicle speed higher than 31 mph (51 km/h) lasting a total of more than 60 seconds. Stop: Vehicle speed lower than 0.9 mph (1.5 km/h) lasting more than 30 seconds.
2. Judgement Criteria - Changes in the intake air temperature are lower than 1.8°F (1°C).

1. Connect Scan Tool (MB991502) to the data link connector. Remove the air intake hose from the volume air flow sensor. Turn the ignition on. Set the scan tool to data reading mode for item 13, Intake Air Temperature Sensor. Heat the sensor using a hair drier. Do NOT allow the temperature to exceed 176°F (80°C). Turn the ignition off and attach the air intake hose. If the sensor is operating properly, it can be assumed that this malfunction is intermittent, refer to «INTERMITTENT DIAGNOSTIC TROUBLE CODES»(ref-156203-S19689263182003072200000). If the sensor is malfunctioning, go to next step.
2. Disconnect the intake air temperature sensor connector B-14. Measure the resistance between intake air temperature sensor side connector terminal 5 and 6. Measure resistance while heating the sensor using a hair drier. If the resistance is at the standard value, go to next step. If the resistance is off, replace the volume air flow sensor and go to step 9.
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 damaged, repair or replace it and go to step 9.
4. Disconnect the connector B-14 and measure at the harness side. Check the continuity between terminal 5 and ground. see scheme 38 The resistance should be less than 2 ohm. If the continuity is normal, go to step 7, otherwise go to next step.
5. Check connector C-53 at ECM (M/T) or connector C-50 at PCM (A/T) for damage. see scheme 15or see scheme 33. If the connector is in good condition, go to next step. If the connector is damaged, repair or replace it and go to step 9.
6. Check for open circuit and harness damage between intake air temperature sensor connector B-14 and ECM connector C-53 (M/T) or PCM connector C-50 (A/T). If the harness wire is in good condition, replace the ECM or PCM and go to step 9. If the harness wire is damaged, repair it and go to step 9.
7. Check connector C-60 at ECM (M/T) or connector C-54 at PCM (A/T) for damage. see scheme 15or see scheme 33. If the connector is in good condition, go to next step. If the connector is damaged, repair or replace it and go to step 9.
8. Check for open circuit and harness damage between intake air temperature sensor connector B-14 and ECM connector C-60 (M/T) or PCM connector C-54 (A/T). If the harness wire is in good condition, replace the ECM or PCM and go to next step. If the harness wire is damaged, repair it and go to next step.
9. Carry out a test drive with the drive cycle pattern (OBD-II), refer to «OTHER MONITOR»(ref-156203-S39011874532003072200000). Check for diagnostic trouble codes. If DTC P0111 is output, retry the troubleshooting. If the code is absent, the inspection is complete.

1. Check Conditions - 2 seconds or more have passed since the starting sequence was completed.
2. Judgement Criteria - Intake air temperature sensor output voltage has continued to be 0.2 volt or lower (corresponding to an air intake temperature of 239°F (115°C) or higher) for 2 seconds.

1. Connect Scan Tool (MB991502) to the data link connector. Turn the ignition on. Set the scan tool to data reading mode for item 13, Intake Air Temperature Sensor. The intake air temperature and the temperature shown with the scan tool should approximately match. Turn the ignition off. If the sensor is operating properly, it can be assumed that this malfunction is intermittent, refer to «INTERMITTENT DIAGNOSTIC TROUBLE CODES»(ref-156203-S19689263182003072200000). If the sensor is malfunctioning, go to next step.
2. Check connector B-14 at the intake air temperature sensor for damage. see scheme 38 If the connector is in good condition, go to next step. If the connector is damaged, repair or replace it and go to step 6.
3. Disconnect the intake air temperature sensor connector B-14. Measure the resistance between intake air temperature sensor side connector terminal 5 and 6. There should be continuity (300-1000 ohm). If the resistance is normal, go to next step. If the resistance is off, replace the volume air flow sensor and go to step 6.
4. Check for short circuit to ground between intake air temperature sensor connector B-14 and ECM connector C-60 (M/T) or PCM connector C-54 (A/T). see scheme 15, see scheme 33 or see scheme 38. If the harness wire is in good condition, go to next step. If the harness wire is damaged, repair it and go to step 6.
5. Check connector C-60 at ECM (M/T) or connector C-54 at PCM (A/T) for damage. see scheme 15or see scheme 33. If the connector is in good condition, replace the ECM or PCM and go to next step. If the connector is damaged, repair or replace it and go to next step.
6. Carry out a test drive with the drive cycle pattern (OBD-II). Check for diagnostic trouble codes. If the DTC P0112 is output, retry the troubleshooting. If the DTC is absent, the inspection is complete.

1. Check Conditions 2 seconds or more have passed since the starting sequence was completed.
2. Judgement Criteria Intake air temperature sensor output voltage has continued to be 4.5 volts or higher (corresponding to an air intake temperature of -104°F (-40°C) or lower) for 2 seconds.

1. Connect Scan Tool (MB991502) to the data link connector. Turn the ignition on. Set the scan tool to data reading mode for item 13, Intake Air Temperature Sensor. The intake air temperature and temperature shown with the scan tool should approximately match. Turn the ignition off. If the sensor is operating properly, it can be assumed that this malfunction is intermittent, refer to «INTERMITTENT DIAGNOSTIC TROUBLE CODES»(ref-156203-S19689263182003072200000). If the sensor is malfunctioning, go to next step.
2. Check connector B-14 at the intake air temperature sensor for damage. see scheme 38 If the connector is in good condition, go to next step. If the connector is damaged, repair or replace it and go to step 11.
3. Disconnect the intake air temperature sensor connector B-14. Measure the resistance between intake air temperature sensor side connector terminal 5 and 6. There should be continuity (300-1000 ohm). If the resistance is normal, go to next step. If the resistance is out of range, replace the volume air flow sensor and go to step 11.
4. Disconnect the connector B-14 and measure at the harness side. Turn the ignition on. Measure the voltage between terminal 6 and ground. Voltage should be between 4.5-4.9 volts. Turn the ignition off. If the voltage is normal, go to step 8, otherwise go to next step.
5. Do not disconnect the ECM connector C-60 (M/T) or PCM connector C-54 (A/T). Disconnect the intake air temperature sensor connector B-14. Turn the ignition on. Measure the voltage between terminal 72 (C-60 - M/T) or 64 (C-54 - A/T) and ground by backprobing. see scheme 15or see scheme 33. Voltage should be between 4.5-4.9 volts. Turn the ignition off. If the voltage is normal, go to next step, otherwise go to step 7.
6. Check connector C-60 at ECM (M/T) or connector C-54 at PCM (A/T) for damage. see scheme 15or see scheme 33. If the connector is in good condition, repair harness wire between intake air temperature sensor connector B-14 and ECM connector C-60 (M/T) or PCM connector C-54 (A/T) (because of open circuit) and go to step 11. If the connector is damaged, repair or replace it and go to step 11.
7. Check connector C-60 at ECM (M/T) or connector C-54 at PCM (A/T) for damage. If the connector is in good condition, replace the ECM or PCM and go to step 11. If the connector is damaged, repair or replace it and go to step 11.
8. Disconnect the connector B-14 and measure the harness side. Check for continuity between terminal 5 and ground. The resistance should be less than 2 ohm. If the continuity is normal, replace the ECM or PCM and go to step 11. If the continuity is abnormal, go to next step.
9. Check connector C-53 at ECM (M/T) or connector C-50 at PCM (A/T) for damage. see scheme 15or see scheme 33. If the connector is in good condition, go to next step. If the connector is damaged, repair or replace it and go to step 11.
10. Check for open circuit between intake air temperature sensor connector B-14 and ECM connector C-53 (M/T) or PCM connector C-50 (A/T). see scheme 15, see scheme 33 or see scheme 38. If the harness wire is in good condition, replace the ECM or PCM and go to next step. If the harness wire is damaged, repair it and go to next step.
11. Carry out a test drive with the drive cycle pattern (OBD-II). Check the diagnostic trouble codes. If DTC P0113 is output, retry the troubleshooting. If the code is absent, the inspection is complete.

1. Check Conditions - Engine coolant temperature was 45°F (7°C) or more immediately before the engine was stopped during the last drive cycle. Engine coolant temperature was 45°F (7°C) or more when the engine started.
2. Judgement Criteria 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 during the following conditions: Intake air temperature is 140°F (60°C) or more. Volume air flow sensor output frequency is 70 Hz or less. During fuel shut-off operation. Only one monitor during each drive cycle.

1. Connect Scan Tool (MB991502) to the data link connector. Turn the ignition on. Set the scan tool to data reading mode for item 21, Engine Coolant Temperature Sensor. The engine coolant temperature and temperature shown with the scan tool should approximately match. Turn the ignition off. If the sensor is operating properly, it can be assumed that the malfunction is intermittent, refer to «INTERMITTENT DIAGNOSTIC TROUBLE CODES»(ref-156203-S19689263182003072200000). If the sensor is malfunctioning, go to next step.
2. Do not disconnect the connector B-11. Turn the ignition on. Measure the voltage between engine coolant temperature sensor connector B-11, terminal 1 and ground by backprobing. see scheme 14 Turn the ignition off. If the voltage is normal, go to next step. If the voltage is abnormal, go to step 5.
3. Check connector B-11 at the engine coolant temperature sensor for damage. see scheme 14 If the connector is in good condition, go to next step. If the connector is damaged, repair or replace it and go to step 14.
4. Connect scan tool to the data link connector. Turn the ignition on. Set the scan tool to the data reading mode for item 21, Engine Coolant Temperature Sensor. The engine coolant temperature and temperature shown with the scan tool should approximately match. Turn the ignition switch off. If the sensor is operating properly, it can be assumed that this malfunction is intermittent. If the sensor is malfunctioning, replace the ECM or PCM and go to step 14.
5. Check connector B-11 at engine coolant temperature sensor for damage. If the connector is in good condition, go to next step. If the connector is damaged, repair or replace it and go to step 14.
6. Disconnect the connector B-11 and measure at the harness side. Turn the ignition on. Measure the voltage between terminal 1 and ground. Voltage should be between 4.5-4.9 volts. Turn the ignition off. If the voltage is normal, go to step 8, otherwise go to next step.
7. Check connector C-60 at ECM (M/T) or connector C-54 at PCM (A/T) for damage. see scheme 15or see scheme 33. If the connector is in good condition, replace the ECM or PCM and go to step 14. If the connector is damaged, repair or replace it and go to step 14.
8. Disconnect the connector B-11 and measure at the harness side. Check for the continuity between terminal 2 and ground. The resistance should be less than 2 ohm. If the continuity is normal, go to step 11, otherwise go to next step.
9. Check connector C-60 at ECM (M/T) or connector C-54 at PCM (A/T) for damage. If the connector is in good condition, go to next step. If the connector is damaged, repair or replace it and go to step 14.
10. Check for harness damage between engine coolant temperature sensor connector B-11, terminal 2 and ECM connector C-60, terminal 92 (M/T) or PCM connector C-54, terminal 57 (A/T). see scheme 14, see scheme 15 or see scheme 33. If the harness wire is in good condition, replace the ECM or PCM and go to step 14. If the harness wire is damaged, repair it and go to step 14.
11. Disconnect the engine coolant temperature sensor connector B-11. Remove the engine coolant temperature sensor. With the temperature sensing portion of engine coolant temperature sensor immersed in hot water, check resistance. Apply 3M(tm) AAD part number 8731 or equivalent on the screw section of the engine coolant temperature sensor. Install the engine coolant temperature sensor, and tighten to the specified torque. If the resistance is at the standard value, go to next step. If the resistance is off, replace the engine coolant temperature sensor and go to step 14.
12. Check connector C-60 at ECM (M/T) or connector C-54 at PCM (A/T) for damage. see scheme 15or see scheme 33. If the connector is in good condition, go to next step. If the connector is damaged, repair or replace it and go to step 14.
13. Check for harness damage between engine coolant temperature sensor connector B-11, terminal 1 and ECM connector C-60, terminal 83 (M/T) or PCM connector C-54, terminal 44 (A/T). see scheme 14, see scheme 15 or see scheme 33. If the harness wire is in good condition, replace the ECM or PCM and go to step 14. If the harness wire is damaged, repair it and go to step 14.
14. Carry out a test drive with the drive cycle pattern. Check for diagnostic trouble codes. If DTC P0116 is output, retry the troubleshooting. If the DTC is absent, the inspection is complete.

1. Check Conditions - 2 seconds or more have passed since the starting sequence was completed.
2. Judgement Criteria - Engine coolant temperature sensor output voltage has continued to be 0.1 volt or lower (corresponding to a coolant temperature of 284°F (140°C) or higher) for 2 seconds.

1. Connect Scan Tool (MB991502) to the data link connector. Turn the ignition on. Set the scan tool to data reading mode for item 21, Engine Coolant Temperature Sensor. The engine coolant temperature and temperature shown with the scan tool should approximately match. Turn the ignition off. If the sensor is operating properly, it can be assumed that this malfunction is intermittent, refer to «INTERMITTENT DIAGNOSTIC TROUBLE CODES»(ref-156203-S19689263182003072200000). If the sensor is malfunctioning, go to next step.
2. Check connector B-11 at the engine coolant temperature sensor for damage. see scheme 14 If the connector is in good condition, go to next step. If the connector is damaged, repair or replace it and go to step 6.
3. Check for short circuit to ground between engine coolant temperature sensor connector B-11 and ECM connector C-60 (M/T) or PCM connector C-54 (A/T). see scheme 14, see scheme 15 or see scheme 33. If the harness wire is in good condition, go to next step. If the harness wire is damaged, repair it and go to step 6.
4. Check connector C-60 at ECM (M/T) or connector C-54 at PCM (A/T) for damage. see scheme 15or see scheme 33. If the connector is in good condition, go to next step. If the connector is damaged, repair or replace it and go to step 6.
5. Disconnect the engine coolant temperature sensor connector B-11. Remove the engine coolant temperature sensor. With the temperature sensing portion of engine coolant temperature sensor immersed in hot water, check resistance. Apply 3M(tm) AAD part number 8731 or equivalent on the screw section of the engine coolant temperature sensor. Install the engine coolant temperature sensor, and tighten to the specified torque. If the resistance is the specified value, replace the ECU or PCM and go to next step. If the resistance is off, replace the engine coolant temperature sensor and go to next step.
6. Carry out a test drive with the drive cycle pattern (OBD-II). Check the diagnostic trouble codes. If DTC P0117 is output, retry the troubleshooting. If the DTC is absent, the inspection is complete.

1. Check Conditions - 2 seconds or more have passed since the starting sequence was completed.
2. Judgement Criteria - Engine coolant temperature sensor output voltage has continued to be 4.6 volts or higher (corresponding to a coolant temperature of -113°F (-45°C) or lower) for 2 seconds.

1. Connect Scan Tool (MB991502) to the data link connector. Turn the ignition on. Set the scan tool to data reading mode for item 21, Engine Coolant Temperature Sensor. The engine coolant temperature and temperature shown with the scan tool should approximately match. Turn the ignition off. If the sensor is operating properly, it can be assumed that this malfunction is intermittent, refer to «INTERMITTENT DIAGNOSTIC TROUBLE CODES»(ref-156203-S19689263182003072200000). If the sensor is malfunctioning, go to next step.
2. Check connector B-11 at the engine coolant temperature sensor for damage. see scheme 14 If the connector is in good condition, go to next step. If the connector is damaged, repair or replace it and go to step 11.
3. Disconnect the connector B-11 and measure at the harness side. Turn the ignition on. Measure the voltage between terminal 1 and ground. Voltage should be between 4.5-4.9 volts. Turn the ignition off. If the voltage is normal, go to step 7, otherwise go to next step.
4. Do not disconnect the ECM connector C-60 (M/T) or PCM connector C-54 (A/T). Disconnect the engine coolant temperature sensor connector B-11. Turn the ignition on. Measure the voltage between terminal 83 (M/T) or 44 (A/T) and ground by backprobing. see scheme 15or see scheme 33. Voltage should be 4.5-4.9 volts. Turn the ignition off. If the voltage is normal, go to next step. If the voltage is abnormal, go to step 6.
5. Check connector C-60 at ECM (M/T) or connector C-54 at PCM (A/T) for damage. If the connector is in good condition, repair harness wire between engine coolant temperature sensor connector B-11 and ECM connector C-54 (M/T) or PCM connector C-60 (A/T) (because of open circuit) and go to step 11. If the connector is damaged, repair or replace it and go to step 11.
6. Check connector C-60 at ECM (M/T) or connector C-54 at PCM (A/T) for damage. see scheme 15or see scheme 33. If the connector is in good condition, replace the ECM or PCM and go to step 11. If the connector is damaged, repair or replace it and go to step 11.
7. Disconnect the connector B-11 and measure at the harness side. Check for continuity between terminal 2 and ground. The resistance should be less than 2 ohm. If the continuity is normal, go to step 10, otherwise go to next step.
8. Check connector C-60 at ECM (M/T) or connector C-54 at PCM (A/T) for damage. If the connector is in good condition, go to next step. If the connector is damaged, repair or replace it and go to step 11.
9. Check for open circuit between engine coolant sensor connector B-11, terminal 2 and ECM connector C-60, terminal 92 (M/T) or PCM connector C-54, terminal 57 (A/T). see scheme 14, see scheme 15 or see scheme 33. If the harness wire is in good condition, replace the ECM or PCM and go to step 11. If the harness wire is damaged, repair it and go to step 11.
10. Disconnect the engine coolant temperature sensor connector B-11. Remove the engine coolant temperature sensor. With the temperature sensing portion of engine coolant temperature sensor immersed in hot water, check resistance. Apply 3M(tm) AAD part number 8731 or equivalent on the screw section of the engine coolant temperature sensor. Install the engine coolant temperature sensor, and tighten to the specified torque. If the resistance is at the standard value, replace the ECU or PCM and go to next step. If the resistance is off, replace the engine coolant temperature sensor and go to next step.
11. Carry out a test drive with the drive cycle pattern (OBD-II). Check the diagnostic trouble codes. If DTC P0118 is output, retry the troubleshooting. If the DTC is absent, the inspection is complete.

1. Check Conditions - 2 seconds or more have passed since the starting sequence was completed. Engine speed is higher than 2000 RPM. Volumetric efficiency is higher than 60%.
2. Judgement Criteria - Throttle position sensor output voltage has continued to be 0.8 volt or lower for 2 seconds.
3. Check Conditions - 2 seconds or more have passed since the starting sequence was completed. Engine speed is lower than 3000 RPM. Volumetric efficiency is lower than 30%.
4. Judgement Criteria - Throttle position sensor output voltage has continued to be 4.6 volts or higher for 2 seconds.

1. Connect Scan Tool (MB991502) to the data link connector. Turn the ignition on. Set the scan tool to data reading mode for item 14, Throttle Position Sensor. With the throttle valve in the idle position, voltage should be between 0.335-0.935 volt. With the throttle valve in the full-open position, voltage should be between 4.39-5.29 volts. Turn the ignition off. If the sensor is operating properly, it can be assumed that this malfunction is intermittent, refer to «INTERMITTENT DIAGNOSTIC TROUBLE CODES»(ref-156203-S19689263182003072200000). If the sensor is malfunctioning, go to next step.
2. Check connector B-07 at throttle position sensor for damage. see scheme 35 If the connector is in good condition, go to next step. If the connector is damaged, repair or replace it and go to step 14.
3. Disconnect the connector B-07. Measure the resistance between throttle position sensor side connector terminal 1 and 4. Measure resistance between the throttle position sensor side connector terminal 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 normal, go to next step. If the resistance is off, replace the throttle position sensor and go to step 14.
4. Disconnect the connector B-07 and measure at the harness side. Turn the ignition on. Measure the voltage between terminal 4 and ground. Voltage should be between 4.8-5.2 volts. Turn the ignition off. If the voltage is normal, go to step 7, otherwise go to next step.
5. Check connector C-60 at ECM (M/T) or connector C-54 at PCM (A/T) for damage. see scheme 15or see scheme 33. If the connector is in good condition, go to next step. If the connector is damaged, repair or replace it and go to step 14.
6. Check for harness damage between throttle position sensor connector B-07, terminal 3 and ECM connector C-60, terminal 81 (M/T) or PCM connector C-54, terminal 46 (A/T). see scheme 15, see scheme 33 or see scheme 35. If the harness wire is in good condition, replace the ECM or PCM and go to step 14. If the harness wire is damaged, repair it and go to step 14.
7. Check the continuity at throttle position sensor harness side connector B-07. Disconnect the connector B-07 and measure at the harness side. Measure the continuity between terminal 1 and ground. The resistance should be less than 2 ohm. If the continuity is normal, go to step 10, otherwise go to next step.
8. Check connector C-60 at ECM (M/T) or connector C-54 at PCM (A/T) for damage. see scheme 15or see scheme 33. If the connector is in good condition, go to next step. If the connector is damaged, repair or replace it and go to step 14.
9. Check for open circuit and harness damage between throttle position sensor connector B-07, terminal 2 and ECM connector C-60, terminal 92 (M/T) or PCM connector C-54, terminal 57 (A/T). see scheme 15, see scheme 33 or see scheme 35. If the harness wire is in good condition, replace the ECM or PCM and go to step 14. If the harness wire is damaged, repair it and go to step 14.
10. Check connector C-60 at ECM (M/T) or connector C-54, C-57 at PCM (A/T) for damage. see scheme 15or see scheme 33. If the connector is in good condition, go to next step. If the connector is damaged, repair or replace it and go to step 14.
11. Check for harness damage between throttle position sensor connector B-07, terminal 1 and ECM connector C-60, terminal 84 (M/T) or PCM connector C-57, terminal 78 (A/T). see scheme 15, see scheme 33 or see scheme 35. If the harness wire is in good condition, go to next step. If the harness wire is damaged, repair it and go to step 14.
12. Check the maladjusted throttle position sensor. If the output voltage is normal, go to next step. If the output voltage is off, adjust the it and go to step 14.
13. Connect scan tool to the data link connector. Turn the ignition on. Set the scan tool to data reading mode for item 14, Throttle Position Sensor. With the throttle valve in the idle position, voltage should be between 0.335-0.935 volt. With the throttle valve in the full-open position, voltage should be between 4.39-5.29 volts. Turn the ignition off. If the sensor is operating properly, it can be assumed that this malfunction is intermittent, refer to «INTERMITTENT DIAGNOSTIC TROUBLE CODES»(ref-156203-S19689263182003072200000). If the sensor is malfunctioning, replace the ECM or PCM and go to next step.
14. Carry out a test drive with the drive cycle pattern (OBD-II). Check the diagnostic trouble codes. If DTC P0121 is output, retry the troubleshooting. If the DTC is absent, the inspection is complete.

1. Check Conditions - 2 seconds or more have passed since the starting sequence was completed.
2. Judgement Criteria - Throttle position sensor output voltage has continued to be 0.2 volt or lower for 2 seconds.

1. Connect Scan Tool (MB991502) to the data link connector. Turn the ignition on. Set the scan tool to data reading mode for item 14, Throttle Position Sensor. With the throttle valve in the idle position, voltage should be between 0.335-0.935 volt. With the throttle valve in the full-open position, voltage should be between 4.39-5.29 volts. Turn the ignition off. If the sensor is operating properly, it can be assumed that this malfunction is intermittent, refer to «INTERMITTENT DIAGNOSTIC TROUBLE CODES»(ref-156203-S19689263182003072200000). If the sensor is malfunctioning, go to next step.
2. Check connector B-07 at throttle position sensor for damage. see scheme 35 If the connector is in good condition, go to next step. If the connector is damaged, repair or replace it and go to step 11.
3. Disconnect the connector B-07 and measure at the harness side. Turn the ignition on. Measure the voltage between terminal 4 and ground. Voltage should be between 4.8-5.2 volts. Turn the ignition off. If the voltage is normal, go to step 6, otherwise go to next step.
4. Check connector C-60 at ECM (M/T) or connector C-54 at PCM (A/T) for damage. see scheme 15or see scheme 33. If the connector is in good condition, go to next step. If the connector is damaged, repair or replace it and go to step 11.
5. Check for open circuit and short circuit to ground between throttle position sensor connector B-07, terminal 3 and ECM connector C-60, terminal 81 (M/T) or PCM connector C-54, terminal 46 (A/T). see scheme 15, see scheme 33 or see scheme 35. If the harness wire is in good condition, replace the ECM or PCM and go to step 11. If the harness wire is damaged, repair it and go to step 11.
6. Disconnect the connector B-07. Measure the resistance between throttle position sensor side connector terminal 1 and 4. Measure the resistance between the throttle position sensor side connector terminal 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 normal, go to next step. If the resistance is off, replace the throttle position sensor and go to step 11.
7. Check connector C-60 at ECM (M/T) or connector C-54, C-57 at PCM (A/T) for damage. see scheme 15or see scheme 33. If the connector is in good condition, go to next step. If the connector is damaged, repair or replace it and go to step 11.
8. Check for open circuit and short circuit to ground between throttle position sensor connector B-07, terminal 1 and ECM connector C-60, terminal 84 (M/T) or PCM connector C-57, terminal 78 (A/T). see scheme 15, see scheme 33 or see scheme 35. If the harness wire is in good condition, go to next step. If the harness wire is damaged, repair it and go to step 11.
9. Check for short circuit to ground between throttle position sensor connector and auto-cruise control-ECU. If the harness wire is in good condition, go to next step. If the harness wire is damaged, repair it and go to step 11.
10. Connect scan tool to the data link connector. Turn the ignition on. Set the scan tool to data reading mode for item 14, Throttle Position Sensor. With the throttle valve in the idle position, voltage should be between 0.335-0.935 volt. With the throttle valve in the full-open position, voltage should be between 4.39-5.29 volts. Turn the ignition off. If the sensor is operating properly, it can be assumed that this malfunction is intermittent, refer to «INTERMITTENT DIAGNOSTIC TROUBLE CODES»(ref-156203-S19689263182003072200000). If the sensor is malfunctioning, replace the ECM or PCM and go to next step.
11. Carry out a test drive with the drive cycle pattern (OBD-II). Check the diagnostic trouble codes. If DTC P0122 is output, retry the troubleshooting. If the DTC is absent, the inspection is complete.

1. Check Conditions 2 seconds or more have passed since the starting sequence was completed. Engine speed is lower than 1000 RPM. Volumetric efficiency is lower than 60%.
2. Judgement Criteria TPS output voltage has continued to be 2 volts or higher for 2 seconds.

1. Connect Scan Tool (MB991502) to the data link connector. Turn the ignition on. Set the scan tool to data reading mode for item 14, Throttle Position Sensor. With the throttle valve in the idle position, voltage should be between 0.335-0.935 volt. With the throttle valve in the full-open position, voltage should be between 4.39-5.29 volts. Turn the ignition off. If the sensor is operating properly, it can be assumed that the malfunction is intermittent, refer to «INTERMITTENT DIAGNOSTIC TROUBLE CODES»(ref-156203-S19689263182003072200000). If the sensor is malfunctioning, go to next step.
2. Check connector B-07 at throttle position sensor for damage. see scheme 35 If the connector is in good condition, go to next step. If the connector is damaged, repair or replace it and go to step 8.
3. Disconnect the connector B-07 and measure at the harness side. Measure the continuity between terminal 1 and ground. The resistance should be less than 2 ohm. If the continuity is normal, go to step 6, otherwise go to next step.
4. Check connector C-60 at ECM (M/T) or connector C-54 at PCM (A/T) for damage. see scheme 15or see scheme 33. If the connector is in good condition, go to next step. If the connector is damaged, repair or replace it and go to step 8.
5. Check for open circuit and harness damage between throttle position sensor connector B-07, terminal 2 and ECM connector C-60, terminal 92 (M/T) or PCM connector C-54, terminal 57 (A/T). see scheme 15, see scheme 33 or see scheme 35. If the harness wire is in good condition, replace the ECM or PCM and go to step 8. If the harness wire is damaged, repair it and go to step 8.
6. Disconnect the connector B-07. Measure the resistance between throttle position sensor side connector terminal 1 and 4. Measure the resistance between the throttle position sensor side connector terminal 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 normal, go to next step. If the resistance is abnormal, replace the throttle position sensor and go to step 8.
7. Connect scan tool to the data link connector. Turn the ignition on. Set the scan tool to data reading mode for item 14, Throttle Position Sensor. With the throttle valve in the idle position, voltage should be between 0.335-0.935 volt. With the throttle valve in the full-open position, voltage should be between 4.39-5.29 volts. Turn the ignition off. If the sensor is operating properly, it can be assumed that this malfunction is intermittent, refer to «INTERMITTENT DIAGNOSTIC TROUBLE CODES»(ref-156203-S19689263182003072200000). If the sensor is malfunctioning, replace the ECM or PCM and go to step 8.
8. Carry out a test drive with the drive cycle pattern (OBD-II). Check the diagnostic trouble codes. If DTC P0123 is output, retry the troubleshooting. If the DTC is absent, the inspection is complete.

1. Check Conditions, Judgement Criteria - Engine coolant temperature drops below 104°F (40°C). Then the engine coolant temperature has remained below 104°F (40°C) for 5 minutes.
2. Check Conditions, Judgement Criteria - About 60-300 seconds have passed for the engine coolant temperature to rise about 45°F (7°C) after starting sequence was completed. However, time is not counted when fuel is shut off.

1. Connect Scan Tool (MB991502) to the data link connector. Turn the ignition on. Set the scan tool to data reading mode for item 21, Engine Coolant Temperature Sensor. The engine coolant temperature and temperature shown with the scan tool should approximately match. Turn the ignition off. If the sensor is operating properly, it can be assumed that this malfunction is intermittent, refer to «INTERMITTENT DIAGNOSTIC TROUBLE CODES»(ref-156203-S19689263182003072200000). If the sensor is malfunctioning, go to next step.
2. Do not disconnect the connector B-11. Turn the ignition on. Measure the voltage between terminal 1 and ground by backprobing. Turn the ignition off. If the voltage is normal, go to next step, otherwise go to step 5.
3. Check connector B-11 at the engine coolant temperature sensor for damage. see scheme 14 If the connector is in good condition, go to next step. If the connector is damaged, repair or replace it and go to step 14.
4. Connect scan tool to the data link connector. Turn the ignition on. Set the scan tool to data reading mode for item 21, Engine Coolant Temperature Sensor. The engine coolant temperature and temperature shown with the scan tool should approximately match. Turn the ignition off. If the sensor is operating properly, it can be assumed that this malfunction is intermittent. If the sensor is malfunctioning, replace the ECM or PCM and go to step 14.
5. Check connector B-11 at engine coolant temperature sensor for damage. If the connector is in good condition, go to next step. If the connector is damaged, repair or replace it and go to step 14.
6. Disconnect the connector B-11 and measure at the harness side. see scheme 14 Turn the ignition on. Measure the voltage between terminal 1 and ground. Voltage should be between 4.5-4.9 volts. Turn the ignition off. If the voltage is normal, go to step 8, otherwise go to next step.
7. Check connector C-60 at ECM (M/T) or connector C-54 at PCM (A/T) for damage. see scheme 15or see scheme 33. If the connector is in good condition, replace the ECM or PCM and go to step see scheme 14. If the connector is damaged, repair or replace it and go to step see scheme 14.
8. Disconnect the connector B-11 and measure at the harness side. Check for continuity between terminal 2 and ground. Resistance should be less than 2 ohm. If the continuity is normal, go to step 11. If the continuity is abnormal, go to next step.
9. Check connector C-60 at ECM (M/T) or connector C-54 at PCM (A/T) for damage. see scheme 15or see scheme 33. If the connector is in good condition, go to next step. If the connector is damaged, repair or replace it and go to step see scheme 14.
10. Check for harness damage between engine coolant temperature sensor connector B-11, terminal 2 and ECM connector C-60, terminal 92 (M/T) or PCM connector C-54, terminal 57 (A/T). see scheme 14, see scheme 15 or see scheme 33. If the harness wire is in good condition, replace the ECM or PCM and go to step see scheme 14. If the harness wire is damaged, repair it and go to step see scheme 14.
11. Disconnect the engine coolant temperature sensor connector B-11. Remove the engine coolant temperature sensor. With the temperature sensing portion of engine coolant temperature sensor immersed in hot water, check resistance. Apply 3M(tm) AAD part number 8731 or equivalent on the screw section of the engine coolant temperature sensor. Install the engine coolant temperature sensor, and tighten to the specified torque. If the resistance is at the standard value, go to next step. If the resistance is off, replace the engine coolant temperature sensor, and go to step see scheme 14.
12. Check connector C-60 at ECM (M/T) or connector C-54 at PCM (A/T) for damage. see scheme 15or see scheme 33. If the connector is in good condition, go to next step. If the connector is damaged, repair or replace it and go to step see scheme 14.
13. Check for harness damage between engine coolant temperature sensor connector B-11, terminal 1 and ECM connector C-60, terminal 83 (M/T) or PCM connector C-54, terminal 44 (A/T). see scheme 14, see scheme 15 or see scheme 33. If the harness wire is in good condition, replace the ECM or PCM and go to next step. If the harness wire is damaged, repair it and go to next step.
14. Carry out a test drive with the drive cycle pattern (OBD-II). Check the diagnostic trouble codes. If DTC P0125 is output, retry the troubleshooting. If the DTC is absent, the inspection is complete.

1. Check Conditions - Engine coolant temperature is between 14°F (-10°C) and 171°F (77°C) when the engine is started. The engine coolant temperature - intake air temperature is 9°F (5°C) or less when the engine is started. The intake air temperature when the engine is started - intake air temperature is 9°F (5°C) or less. The volume air flow sensors output frequency is in the low frequency (50-100 Hz or less) state for 300 seconds or less.
2. Judgement Criteria - The time for the engine coolant temperature to rise to 171°F (77°C) is longer than approximately 11 to 22 minutes.

Check cooling system. If problem exists, repair cooling system. If problem does not exist, replace ECM/PCM. Check that DTC P0128 does not reset.

1. Check Conditions - 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 lower. Engine coolant temperature is higher than 169°F (76°C). Engine speed is higher than 1,200 RPM. Volumetric efficiency is higher than 25%. Monitoring time: 7 seconds.
2. Judgement Criteria - Input voltage supplied to the ECM (M/T) or PCM (A/T) interface circuit is higher than 4.5 volts when 5 volts is applied to the heated oxygen sensor (front) output line via a resistor. Only one monitor per drive cycle.

1. Connect Scan Tool (MB991502) to the data link connector. Start the engine and run at idle. Set the scan tool to data reading mode for item 11, Heated Oxygen Sensor (front). Warm up the engine. When the engine is revved, the output voltage should be 0.6-1.0 volt. When the engine is idling, the output voltage should repeat 0.4 volt and 0.6 volt to 1.0 volt alternately. Turn the ignition off. If the sensor is operating properly, it can be assumed that this malfunction is intermittent, refer to «INTERMITTENT DIAGNOSTIC TROUBLE CODES»(ref-156203-S19689263182003072200000). If the sensor is malfunctioning, go to next step.
2. Do not disconnect the connector B-17. Start the engine and run at idle. Measure the voltage between terminal 4 and ground by backprobing. Warm up the engine. When the engine is 2500 RPM, the output voltage should repeat 0.0-0.8 volt alternately. Turn the ignition off. If the voltage is normal, go to next step, otherwise go to step 7.
3. Check the sensor output voltage at ECM connector C-60 (M/T) or PCM connector C-57 (A/T) by backprobing. see scheme 15or see scheme 33. Do not disconnect the connector C-60 (M/T) or C-57 (A/T). Start the engine and run at idle. Measure the voltage between terminal 76 (M/T) or 71 (A/T) and ground by backprobing. Warm up the engine. When the engine is 2,500 RPM, the output voltage should repeat 0.0-0.8 volt alternately. Turn the ignition off. If the voltage is normal, go to next step, otherwise go to step 6.
4. Check connector B-17 at heated oxygen sensor (front) and connector C-60 at ECM (M/T) or connector C-57 at PCM (A/T) for damage. see scheme 15or see scheme 33. If the connector is in good condition, go to next step. If the connector is damaged, repair or replace it and go to step 15.
5. Connect scan tool to the data link connector. Start the engine and run at idle. Set the scan tool to data reading mode for item 11, Heated Oxygen Sensor (front). Warm up the engine. When the engine is revved, the output voltage should be 0.6-1.0 volt. When the engine is idling, the output voltage should repeat 0.4-0.6 volt to 1.0 volt alternately. Turn the ignition off. If the sensor is operating properly, it can be assumed that this malfunction is intermittent. If the sensor is malfunctioning, replace the ECM or PCM and go to step 15.
6. Check connector B-17 at heated oxygen sensor (front) and connector C-60 at ECM (M/T) or connector C-57 at PCM (A/T) for damage. see scheme 15or see scheme 33. If the connector is in good condition, repair harness wire between heated oxygen sensor (front) connector B-17, terminal 4 and ECM connector C-60, terminal 76 (M/T) or PCM connector C-57, terminal 71 (A/T - because of open circuit or harness damage) and go to step 15. If the connector is damaged, repair or replace it and go to step 15.
7. Check connector B-17 at heated oxygen sensor (front) for damage. If the connector is in good condition, go to next step. If the connector is damaged, repair or replace it and go to step 15.
8. Disconnect the connector B-17 and measure at the harness side. Check the continuity between terminal 2 and ground. The resistance should be less than 2 ohm. If the continuity is normal, go to step 11, otherwise go to next step.
9. Check connector C-60 at ECM (M/T) or connector C-54 at PCM (A/T) for damage. see scheme 15or see scheme 33. If the connector is in good condition, go to next step. If the connector is damaged, repair or replace it and go to step 15.
10. Check for open circuit and harness damage between heated oxygen sensor (front) connector B-17, terminal 2 and ECM connector C-60, terminal 92 (M/T) or PCM connector C-54, terminal 57 (A/T). see scheme 15or see scheme 33. If the harness wire is in good condition, replace the ECM or PCM and go to step 15. If the harness wire is damaged, repair it and go to step 15.
11. Check connector C-60 at ECM (M/T) or connector C-57 at PCM (A/T) for damage. If the connector is in good condition, go to next step. If the connector is damaged, repair or replace it and go to step 15.
12. Check for harness damage between heated oxygen sensor (front) connector B-17, terminal 2 and ECM connector C-60, terminal 92 (M/T) or PCM connector C-54, terminal 57 (A/T). If the harness wire is in good condition, go to next step. If the harness wire is damaged, repair it and go to step 15.
13. Check for short circuit to ground and harness damage between heated oxygen sensor (front) connector B-17, terminal 4 and ECM connector C-60, terminal 76 (M/T) or PCM connector C-57, terminal 71 (A/T). see scheme 15or see scheme 33. If the harness wire is in good condition, go to next step. If the harness wire is damaged, repair it and go to step 15.
14. Disconnect the heated oxygen sensor (front) connector B-17 and connect test harness Special Tool, MD998464, to the connector on the heated oxygen sensor (front) side. Warm up the engine until engine coolant temperature reaches 176°F (80°C) or higher. Use the jumper wires to connect terminal 1 (red clip) to the positive battery terminal and terminal 3 (blue clip) to the negative battery terminal. Connect a digital volt meter between terminal 2 (black clip) and terminal 4 (white clip). While repeatedly revving the engine, measure the heated oxygen sensor (front) output voltage. If the voltage is at the standard value, replace the ECM or PCM and go to next step. If the voltage is off, replace the heated oxygen sensor (front) and go to next step.
15. Carry out a test drive with the drive cycle pattern (OBD-II). Check the diagnostic trouble codes. If DTC P0132 is output, retry the troubleshooting. If the DTC is absent, the inspection is complete.

1. Check Conditions - Engine coolant temperature is higher than 140°F (60°C). Engine speed is between 1500-3000 RPM (M/T) or 1200-3000 RPM (A/T). Volumetric efficiency is between 21-60% (M/T) or 30-60% (A/T). Under the closed loop air/fuel control. Throttle valve is open. Short-term fuel trim is higher than -25% and lower than +25%. More than 2 seconds have elapsed after the aforementioned conditions have been met. Monitoring time: 10 seconds x 7 times.
2. Judgement Criteria - The heated oxygen sensor (front) sends "lean" and "rich" signals alternately 8 times or less for 10 seconds.

Note. If the sensor switching frequency is lower than the Judgement Criteria due to the MUT-II OBD-II test Mode - HO2S Test Results, it is assumed that the heated oxygen sensor has deteriorated. If it is higher, 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.

1. Connect Scan Tool (MB991502) to the data link connector. Start the engine and run at idle. Set the scan tool to data reading mode for item 11, Heated Oxygen Sensor (front). Warm up the engine, 2,500 RPM. Output voltage repeats 0.4 volt or less and 0.6-1.0 volt, 10 times or more within 10 seconds. Turn the ignition off. If the sensor is operating properly, it can be assumed that the malfunction is intermittent, refer to «INTERMITTENT DIAGNOSTIC TROUBLE CODES»(ref-156203-S19689263182003072200000) . If the sensor is malfunctioning, replace the heated oxygen sensor (front) and go to next step.
2. Carry out a test drive with the drive cycle pattern (OBD-II). See «HEATED OXYGEN SENSOR MONITOR»(ref-156203-S12720465482003072200000) . Check the diagnostic trouble codes. If DTC P0133 is output, retry the troubleshooting. If the DTC is absent, the inspection is complete.

1. Check Area - 30 seconds or more have passed since the starting sequence was completed. Engine coolant temperature is higher than 169°F (76°C). Engine speed is higher than 1,200 RPM. Volumetric efficiency is higher than 30%. Throttle position sensor output voltage is lower than 4.3 volts. Except while fuel is being shut off. Monitoring time: 30 seconds.
2. Judgement Criteria - Heated oxygen sensor (front) output voltage does not get across 0.5 volt within about 30 seconds.

1. Connect Scan Tool (MB991502) to the data link connector. Start the engine and run at idle. Set the scan tool to data reading mode for item 59, Heated Oxygen Sensor (rear). Warm up the engine. When the engine is revved, the output voltage should repeat 0.0-0.6 volt to 1.0 volt alternately. Turn the ignition off. If the sensor is operating properly, go to next step. If the sensor is malfunctioning, refer to «DTC P0137: HEATED OXYGEN SENSOR CIRCUIT LOW VOLTAGE (SENSOR 2)»(ref-156203-S10763327702003071100000), «P0138: HEATED OXYGEN SENSOR CIRCUIT HIGH VOLTAGE (SENSOR 2)»(ref-156203-S04662390062003071100000) and «P0139: HEATED OXYGEN SENSOR CIRCUIT SLOW RESPONSE (SENSOR 2)»(ref-156203-S06249972842003071100000).
2. Check for any exhaust leaks. If there are any abnormalities, make repairs and go to step 12. If the system is functioning properly, go to next step.
3. Check the intake system for vacuum leaks. If there are any abnormalities, repair and go to step 12. If the system is airtight, go to next step.
4. Check connector B-17 at the heated oxygen sensor (front) for damage. If the connector is in good condition, go to next step. If the connector is damaged, repair or replace it and go to step 12.
5. Disconnect the heated oxygen sensor (front) connector B-17 and connect test harness Special Tool, MD998464 to the connector on the heated oxygen sensor (front) side. Warm up the engine until engine coolant reaches 176°F (80°C) or higher. CAUTION: Be very careful when connecting the jumper wires; incorrect connection can damage the heated oxygen sensor (front). Use the jumper wires to connect terminal 1 (red clip) to the positive battery terminal and terminal 3 (blue clip) to the negative battery terminal. Connect a digital volt meter between terminal 2 (black clip) and terminal 4 (white clip). While repeatedly revving the engine, measure the heated oxygen sensor (front) output voltage. If the voltage is at the standard value, go to next step. If the voltage is out of range, replace the heated oxygen sensor (front) and go to step 12.
6. Check connector B-01, B-02, B-05, B-06 at injector for damage. see scheme 16 If the connector is in good condition, go to next step. If the connector is damaged, repair or replace it and go to step 12.
7. Disconnect each injector connector. Measure the resistance between injector side connector terminal 1 and 2. If the resistance is at the standard value, go to next step. If the resistance is off, replace the injector and go to step 12.
8. Check connector C-60, C-49 at ECM (M/T) or connector C-57, C-50 at PCM (A/T) for damage. see scheme 15or see scheme 33. If the connector is in good condition, go to next step. If the connector is damaged, repair or replace it and go to step 12.
9. Check for harness damage between heated oxygen sensor (front) connector B-17, terminal 4 and ECM connector C-60, terminal 76 (M/T) or PCM connector C-57, terminal 71 (A/T). see scheme 15or see scheme 33. If the harness wire is in good condition, go to next step. If the harness wire is damaged, repair it and go to step 12.
10. Check for harness damage between injector connector B-01, B-02, B-05, B-06 and ECM connector C-49 (M/T) or PCM connector C-50 (A/T). see scheme 15, see scheme 16 or see scheme 33. Check the harness wire between injector connector B-01, terminal 2 and ECM connector C-49, terminal 1 (M/T) or PCM connector C-50, terminal 1 (A/T) when checking No. 1 cylinder. Check the harness wire between injector connector B-02, terminal 2 and ECM connector C-49, terminal 14 (M/T) or PCM connector C-50, terminal 9 (A/T) when checking No. 2 cylinder. Check the harness wire between injector connector B-05, terminal 2 and ECM connector C-49, terminal 2 (M/T) or PCM connector C-50, terminal 24 (A/T) when checking No. 3 cylinder. Check the harness wire between injector connector B-06, terminal 2 and ECM connector C-49, terminal 15 (M/T) or PCM connector C-50, terminal 2 (A/T) when checking No. 4 cylinder. If the harness wire is in good condition, go to next step. If the harness wire is damaged, repair it and go to step 12.
11. Check the fuel pressure. If the fuel pressure is normal, replace the ECM or PCM and go to next step. If the fuel pressure is abnormal, rectify the fault and go to next step.
12. Carry out a test drive with the drive cycle pattern (OBD-II). Check the diagnostic trouble codes. If DTC P0134 is output, retry the troubleshooting. If the DTC is absent, the inspection is complete.

1. Check Conditions - 60 seconds have elapsed from the start of the previous monitoring. Engine coolant temperature is higher than 68°F (20°C). While the heated oxygen sensor (front) heater is on. Battery positive voltage is between 11-16 volts.
2. Judgement Criteria - Heater current of the heated oxygen sensor (front) heater has continued to be lower than 0.16 ampere or higher than 7.5 ampere for 4 seconds.

1. Check connector B-17 at the heated oxygen sensor (front) for damage. If the connector is in good condition, go to next step. If the connector is damaged, repair or replace it and go to step 12.
2. Disconnect heated oxygen sensor (front) connector B-113 and connect test harness Special Tool, MD998464, to the connector on the heated oxygen sensor (front) sensor side. Measure the resistance between heated oxygen sensor connector terminal 1 (red clip) and terminal 3 (blue clip). If the resistance is normal, go to next step. If the resistance is abnormal, replace the heated oxygen sensor (front) and go to step 12.
3. Disconnect the connector B-17 and measure at the harness side. Turn the ignition on. Measure the voltage between terminal 1 and ground. Voltage should be battery positive voltage. Turn the ignition off. If the voltage is normal, go to step 5, otherwise go to next step.
4. Check connector A-18X at the MFI relay for damage. see scheme 31 If the connector is in good condition, repair harness wire between MFI relay connector A-18X, terminal 4 and heated oxygen sensor (front) connector B-17, terminal 1 (because of open circuit or short circuit to ground) and go to step 12. If the connector is damaged, repair or replace it and go to step 12.
5. Check the power supply voltage at ECM connector C-56 (M/T) or PCM connector C-50 (A/T) by backprobing. see scheme 15or see scheme 33. Do not disconnect the connector C-56 (M/T) or C-50 (A/T). Turn the ignition on. Measure the voltage between terminal 60 (M/T) or 3 (A/T) and ground by backprobing. Voltage should be battery positive voltage. Turn the ignition off. If the voltage is normal, go to step 8, otherwise go to next step.
6. Check connector C-56 at ECM (M/T) or connector C-50 at PCM (A/T) for damage. If the connector is in good condition, go to next step. If the connector is damaged, repair or replace it and go to step 12.
7. Check for open circuit and short circuit to ground between heated oxygen sensor (front) connector B-17, terminal 3 and ECM connector C-56, terminal 60 (M/T) or PCM connector C-50, terminal 3 (A/T). see scheme 15or see scheme 33. If the harness wire is in good condition, replace the ECM or PCM and go to step 12. If the harness wire is damaged, repair it and go to step 12.
8. Check connector C-56 at ECM (M/T) or connector C-50 at PCM (A/T) for damage. see scheme 15or see scheme 33. If the connector is in good condition, go to next step. If the connector is damaged, repair or replace it and go to step 12.
9. Check for harness damage between MFI relay connector A-18X, terminal 4 and heated oxygen sensor (front) connector B-17, terminal 1. see scheme 31 If the harness wire is in good condition, go to next step. If the harness wire is damaged, repair it and go to step 12.
10. Check for harness damage between heated oxygen sensor (front) connector B-17, terminal 3 and ECM connector C-56, terminal 60 (M/T) or PCM connector C-50, terminal 3 (A/T). see scheme 15or see scheme 33. If the harness wire is in good condition, go to next step. If the harness wire is damaged, repair it and go to step 12.
11. Carry out a test drive with the drive cycle pattern. Check for diagnostic trouble codes. If DTC P0135 is output, replace the ECM or PCM and go to next step. If the DTC is absent, it can be assumed that the malfunction is intermittent, refer to «INTERMITTENT DIAGNOSTIC TROUBLE CODES»(ref-156203-S19689263182003072200000).
12. Carry out a test drive with the drive cycle pattern (OBD-II). Check for diagnostic trouble codes. If DTC P0135 is output, retry the troubleshooting. If the DTC is absent, the inspection is complete.

1. Check Conditions - 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 lower. Engine coolant temperature is higher than 169°F (76°C). Engine speed is higher than 1,200 RPM. Volumetric efficiency is higher than 25%. 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 volt or more. After the ignition is turned on, the changes in the output voltage of the heated oxygen sensor (rear) are lower than 0.078 volt. Monitoring time: 10 seconds.
2. Judgement Criteria - Making the air/fuel ratio 15% richer for 10 seconds does not result in raising the heated oxygen sensor (rear) output voltage beyond 0.15 volt. Only one monitor per drive cycle.

1. Connect Scan Tool (MB991502) to the data link connector. Start the engine and run at idle. Set the scan tool to data reading mode for item 59, Heated Oxygen Sensor (rear). Warm up the engine. When the engine is revved, the output voltage should repeat 0.0-0.6 volt to 1.0 volt alternately. Turn the ignition off. If the sensor is operating properly, it can be assumed that the malfunction is intermittent, refer to «INTERMITTENT DIAGNOSTIC TROUBLE CODES»(ref-156203-S19689263182003072200000). If the sensor is malfunctioning, go to next step.
2. Disconnect the heated oxygen sensor (rear) connector C-23 and connect test harness Special Tool, (MB991658), to the connector on the heated oxygen sensor (front) side. see scheme 20 Warm up the engine until engine coolant reaches 176°F (80°C) or higher. CAUTION: Be very careful when connecting the jumper wires; incorrect connection can damage the rear heated oxygen sensor. Use the jumper wires to connect terminal 5 to the positive battery terminal and terminal 6 to the negative battery terminal. Connect a digital volt meter between terminal 3 and terminal 4. While repeatedly revving the engine, measure the heated oxygen sensor (rear) output voltage. If the voltage is at the standard value, go to next step. If the voltage is out of range, replace the heated oxygen sensor (rear) and go to step 5.
3. Check connector C-23 at heated oxygen sensor (rear) and connector C-60 at ECM (M/T) or connector C-57 at PCM (A/T) for damage. see scheme 15, see scheme 20 or see scheme 33. If the connector is in good condition, go to next step. If the connector is damaged, repair or replace it and go to step 5.
4. Check for short circuit to ground between heated oxygen sensor (rear) connector C-23, terminal 1 and ECM connector C-60, terminal 75 (M/T) or PCM connector C-57, terminal 73 (A/T). see scheme 15, see scheme 20 or see scheme 33. If the harness wire is in good condition, replace the ECM or PCM and go to next step. If the harness wire is damaged, repair it and go to next step.
5. Carry out a test drive with the drive cycle pattern (OBD-II). Check the diagnostic trouble codes. If DTC P0137 is output, retry the troubleshooting. If the DTC is absent, the inspection is complete.

1. Check Conditions - 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 higher than 169°F (76°C). Engine speed is higher than 1,200 RPM. Volumetric efficiency is higher than 25%. Monitoring time: 7 seconds.
2. Judgement Criteria - Input voltage supplied to the ECM (M/T) or PCM (A/T) interface circuit is higher than 4.5 volts when 5 volts are applied to the heated oxygen sensor (rear) output line via a resistor. Only one monitor during one drive cycle.

1. Connect Scan Tool (MB991502) to the data link connector. Start the engine and run at idle. Set the scan tool to data reading mode for item 59, Heated Oxygen Sensor (rear). Warm up the engine. When the engine is revved, the output voltage should repeat 0.0-0.6 volt to 1.0 volt alternately. Turn the ignition off. If the sensor is operating properly, it can be assumed that this malfunction is intermittent, refer to «INTERMITTENT DIAGNOSTIC TROUBLE CODES»(ref-156203-S19689263182003072200000). If the sensor is malfunctioning, go to next step.
2. Check the sensor output voltage at heated oxygen sensor (rear) connector C-11 by backprobing. Do not disconnect the connector C-23. Start the engine and run at idle. Measure the voltage between terminal 3 and ground by backprobing. Warm up the engine. When the engine is revved, the output voltage should repeat 0.0-0.6 volt to 1.0 volt alternately. Turn the ignition off. If the voltage is normal, go to next step. If the voltage is abnormal, go to step 7.
3. Check the sensor output voltage at ECM connector C-60 (M/T) or PCM connector C-57 (A/T) by backprobing. see scheme 15or see scheme 33. Do not disconnect the connector C-60 (M/T) or C-57 (A/T). Start the engine and run at idle. Measure the voltage between terminal 75 (M/T) or 73 (A/T) and ground by backprobing. Warm up the engine. When the engine is 2,500 RPM, the output voltage should repeat 0.0-0.6 volt to 1.0 volt alternately. Turn the ignition off. If the voltage is normal, go to next step. If the voltage is abnormal, go to step 6.
4. Check connector C-23 at heated oxygen sensor (rear) and connector C-60 at ECM (M/T) or connector C-57 at PCM (A/T) for damage. see scheme 15, see scheme 20 or see scheme 33. If the connector is in good condition, go to next step. If the connector is damaged, repair or replace it and go to step 14.
5. Connect scan tool to the data link connector. Start the engine and run at idle. Set the scan tool to data reading mode for item 59, Heated Oxygen Sensor (rear). Warm up the engine. When the engine is revved, the output voltage should repeat 0.0-0.6 volt to 1.0 volt alternately. Turn the ignition off. If the sensor is operating properly, it can be assumed that this malfunction is intermittent, refer to «INTERMITTENT DIAGNOSTIC TROUBLE CODES»(ref-156203-S19689263182003072200000). If the sensor is malfunctioning, replace the ECM or PCM and go to step 14.
6. Check connector C-23 at heated oxygen sensor (rear) and connector C-60 at ECM (M/T) or connector C-57 at PCM (A/T) for damage. see scheme 15, see scheme 20 or see scheme 33. If the connector is in good condition, repair harness wire between heated oxygen sensor (rear) connector C-23, terminal 1 and ECM connector C-60, terminal 75 (M/T) or PCM connector C-57, terminal 73 (A/T) (because of open circuit or harness damage) and go to step 14. If the connector is damaged, repair or replace it and go to step 14.
7. Check connector C-23 at heated oxygen sensor (rear) for damage. see scheme 20 If the connector is in good condition, go to next step. If the connector is damaged, repair or replace it and go to step 14.
8. Check the continuity at heated oxygen sensor (rear) harness side connector C-23. Disconnect the connector C-23 and measure the harness side. Check for continuity between terminal 4 and ground. The resistance should be less than 2 ohm. If the continuity is normal, go to step 11, otherwise go to next step.
9. Check connector C-60 at ECM (M/T) or connector C-54 at PCM (A/T) for damage. see scheme 15or see scheme 33. If the connector is in good condition, go to next step. If the connector is damaged, repair or replace it and go to step 14.
10. Check for open circuit and harness damage between heated oxygen sensor (rear) connector C-23, terminal 2 and ECM connector C-60, terminal 92 (M/T) or PCM connector C-54, terminal 57 (A/T). see scheme 15, see scheme 20 or see scheme 33. If the harness wire is in good condition, replace the ECM or PCM and go to step 14. If the harness wire is damaged, repair it and go to step 14.
11. Check connector C-60 at ECM (M/T) or connector C-57 at PCM (A/T) for damage. see scheme 15or see scheme 33. If the connector is in good condition, go to next step. If the connector is damaged, repair or replace it and go to step 14.
12. Check for harness damage between heated oxygen sensor (rear) connector C-23, terminal 4 and ECM connector C-60, terminal 92 (M/T) or PCM connector C-54, terminal 57 (A/T). see scheme 15, see scheme 20 or see scheme 33. If the harness wire is in good condition, go to next step. If the harness wire is damaged, repair it and go to step 14.
13. Disconnect the heated oxygen sensor (rear) connector C-23 and connect test harness Special Tool, (MB991658), to the connector on the heated oxygen sensor (front) side. Warm up the engine until the engine coolant reaches 176°F (80°C) or higher. CAUTION: Be very careful when connecting the jumper wires; incorrect connection can damage the heated oxygen sensor (rear). Use the jumper wires to connect terminal 5 to the positive battery terminal and terminal 4 to the negative battery terminal. Connect a digital volt meter between terminal 3 and terminal 4. While repeatedly revving the engine, measure the heated oxygen sensor (rear) output voltage. If the voltage is at the standard value, replace the ECM or PCM and go to next step. If the voltage is out of range, replace the heated oxygen sensor (rear) and go to next step.
14. Carry out a test drive with the drive cycle pattern (OBD-II). Check the diagnostic trouble codes. If DTC P0138 is output, retry the troubleshooting. If the DTC is absent, the inspection is complete.

1. Check Conditions - Engine coolant temperature is higher than 169°F (76°C). The heated oxygen sensor (front) is active. The cumulative volume air flow sensor output frequency is higher than 4000 Hz. Repeat the following 3 or more times: Drive, Stop.
2. Drive - Engine speed is higher than 1,500 RPM. Volumetric efficiency is higher than 40%. Vehicle speed is higher than 18.7 mph (30 km/h). A total of more than 10 seconds have elapsed with the aforementioned conditions, and more than 2 seconds have elapsed with the fuel shut off.
3. Stop - Vehicle speed is lower than 0.9 mph (1.5 km/h).
4. Judgement Criteria - Change in the output voltage of the heated oxygen sensor (rear) is lower than 0.078 volt. NOTE: Monitoring stops after fuel has been shut off for more than 38 seconds.

1. Connect Scan Tool (MB991502) to the data link connector. Start the engine and run at idle. Set the scan tool to data reading mode for item 59, Heated Oxygen Sensor (rear). Warm up the engine. When the engine is revved, the output voltage should repeat 0.0-0.6 to 1.0 volt alternately. Turn the ignition off. If the sensor is operating properly, it can be assumed that this malfunction is intermittent, refer to «INTERMITTENT DIAGNOSTIC TROUBLE CODES»(ref-156203-S19689263182003072200000) . If the sensor is malfunctioning, replace the heated oxygen sensor (rear) and go to next step.
2. Carry out a test drive with the drive cycle pattern (OBD-II). See «HEATED OXYGEN SENSOR MONITOR»(ref-156203-S12720465482003072200000) . Check the diagnostic trouble codes. If DTC P0139 is output, retry the troubleshooting. If the DTC is absent, the inspection is complete.

1. Check Conditions - 60 seconds have elapsed from the start of the previous monitoring. Engine coolant temperature is higher than 68°F (20°C). While the heated oxygen sensor (rear) heater is on. Battery positive voltage is between 11-16 volts.
2. Judgement Criteria - Heater current of the heated oxygen sensor (rear) heater has continued to be lower than 0.16 ampere or higher than 5.0 ampere for 4 seconds.

1. Check connector C-23 at the heated oxygen sensor (rear) for damage. see scheme 20 If the connector is in good condition, go to next step. If the connector is damaged, repair or replace it and go to step 12.
2. Disconnect the heated oxygen sensor (rear) connector C-23 and connect test harness Special Tool, (MB991658), to the connector on the heated oxygen (rear) sensor side. Measure the resistance between heated oxygen sensor connector terminals No. 5 and 6. If the resistance is normal, go to next step. If the resistance is abnormal, replace the heated oxygen sensor (rear) and go to step 12.
3. Disconnect the connector C-23 and measure at the harness side. see scheme 20 Turn the ignition on. Measure the voltage between terminal 3 and ground. Voltage should be battery positive voltage. Turn the ignition off. If the voltage is normal, go to step 5, otherwise go to next step.
4. Check harness connector A-18X at the MFI relay for damage. see scheme 20and see scheme 31. If the connector is in good condition, repair harness wire between MFI relay connector A-18X, terminal 4 and heated oxygen sensor (rear) connector C-23, terminal 5 (because of open circuit or short circuit to ground) and go to step 12. If the connector is damaged, repair or replace it and go to step 12.
5. Check the power supply voltage at ECM connector C-56 (M/T) or PCM connector C-50 (A/T) by backprobing. see scheme 15or see scheme 33. Do not disconnect the connector C-56 (M/T) or C-50 (A/T). Turn the ignition on. Measure the voltage between terminal 54 (M/T) or 26 (A/T) and ground by backprobing. Voltage should be battery positive voltage. Turn the ignition off. If the voltage is normal, go to step 8, otherwise go to next step.
6. Check connector C-56 at ECM (M/T) or connector C-50 at PCM (A/T) for damage. see scheme 15or see scheme 33. If the connector is in good condition, go to next step. If the connector is damaged, repair or replace it and go to step 12.
7. Check for open circuit and short circuit to ground between heated oxygen sensor (rear) connector C-23, terminal 6 and ECM connector C-56, terminal 54 (M/T) or PCM connector C-50, terminal 26 (A/T). see scheme 15, see scheme 20 or see scheme 33. If the harness wire is in good condition, replace the ECM or PCM and go to step 12. If the harness wire is damaged, repair it and go to step 12.
8. Check connector C-56 at ECM (M/T) or connector C-50 at PCM (A/T) for damage. see scheme 15or see scheme 33. If the connector is in good condition, go to next step. If the connector is damaged, repair or replace it and go to step 12.
9. Check for harness damage between MFI relay connector A-18X, terminal 4 and heated oxygen sensor (rear) connector C-23, terminal 5. see scheme 20and see scheme 31. If the harness wire is in good condition, go to next step. If the harness wire is damaged, repair it and go to step 12.
10. Check for harness damage between heated oxygen sensor (rear) connector C-23, terminal 6 and ECM connector C-56, terminal 54 (M/T) or PCM connector C-50, terminal 26 (A/T). see scheme 15, see scheme 20 or see scheme 33. If the harness wire is in good condition, go to next step. If the harness wire is damaged, repair it and go to step 12.
11. Check the trouble symptoms. Carry out a test drive with the drive cycle pattern. Check diagnostic trouble codes. If DTC P0141 is output, replace the ECM or PCM and go to next step. If the DTC is absent, it can be assumed that the malfunction is intermittent, refer to «INTERMITTENT DIAGNOSTIC TROUBLE CODES»(ref-156203-S19689263182003072200000).
12. Carry out a test drive with the drive cycle pattern (OBD-II). Check the diagnostic trouble codes. If DTC P0141 is output, retry the troubleshooting. If the DTC is absent, the inspection is complete.

DTC Set Conditions)

1. Check Conditions - Engine coolant temperature is lower than approximately 212°F (100°C) when the engine is started. Intake air temperature is lower than 140°F (60°C) when the engine is started. Under the closed loop air/fuel ratio control. Engine coolant temperature is higher than 171°F (77°C). Volume air flow sensor output frequency is 88 Hz or more.
2. Judgement Criteria - Long-term fuel trim has continued to be higher than +12.5% for 5 seconds OR Short-term fuel trim has continued to be higher than +10.0% for 5 seconds.
3. Check Conditions - Engine coolant temperature is lower than approximately 212°F (100°C) when the engine is started. Intake air temperature is lower than 140°F (60°C) when the engine is started. Under the closed loop air/fuel ratio control. Engine coolant temperature is higher than 171°F (77°C). Volume air flow sensor output frequency is 88 Hz or less.
4. Judgement Criteria - Long-term fuel trim has continued to be higher than +12.5% for 5 seconds OR Short-term fuel trim has continued to be higher than +15.0% for 5 seconds.
5. Check Conditions - Engine coolant temperature is lower than approximately 212°F (100°C) when the engine is started. Intake air temperature is higher than 140°F (60°C) when the engine is started. Under the closed loop air/fuel ratio control. Engine coolant temperature is higher than 171°F (77°C). Volume air flow sensor output frequency is 88 Hz or more.
6. Judgement Criteria - Long-term fuel trim has continued to be higher than +12.5% for 5 seconds OR Short-term fuel trim has continued to be higher than +20.0% for 5 seconds.
7. Check Conditions - Engine coolant temperature is lower than approximately 212°F (100°C) when the engine is started. Intake air temperature is higher than 140°F (60°C) when the engine is started. Under the closed loop air/fuel ratio control. Engine coolant temperature is higher than 171°F (77°C). Volume air flow sensor output frequency is 88 Hz or less.
8. Judgement Criteria - Long-term fuel trim has continued to be higher than +12.5% for 5 seconds OR Short-term fuel trim has continued to be higher than +25.0% for 5 seconds.
9. Check Conditions - Engine coolant temperature is higher than 171°F (77°C). Under the closed loop air/fuel ratio control.
10. Judgement Criteria - Long-term fuel trim has continued to be +12.5% for 5 seconds OR Short-term fuel trim has continued to be +25.0% for 5 seconds.

1. Check for exhaust leaks. If there are abnormalities, repair and go to step 14. If the system is sound, go to next step.
2. Check the intake system for vacuum leaks. If there are any abnormalities, repair and go to step 14. If the system is sound, go to next step.
3. Connect Scan Tool (MB991502) to the data link connector. Start the engine and run at idle. Set the scan tool to data reading mode for item 12, Volume Air Flow Sensor. Warm up the engine to normal operating temperature: 176-205°F (80-96°C). When idling, between 12 and 38 Hz (between 1.7 and 4.2 grams/second). When 2500 RPM, between 55 and 95 Hz (between 7.9 and 12.1 grams/second). Turn the ignition off. If the sensor is operating properly, go to next step. If the sensor is malfunctioning, refer to «DTC P0101: VOLUME AIR FLOW (VAF) CIRCUIT RANGE/PERFORMANCE PROBLEM»(ref-156203-S13324973892003071000000) and «P0102: VOLUME AIR FLOW (VAF) CIRCUIT LOW INPUT»(ref-156203-S30594041082003071000000).
4. Turn the ignition on. Set Scan Tool (MB991502) to data reading mode for item 13, Intake Air Temperature Sensor. The intake air temperature and temperature shown with the scan tool should approximately match. Turn the ignition off. If the sensor is operating properly, go to next step. If the sensor is malfunctioning, refer to «DTC P0111: INTAKE AIR TEMPERATURE CIRCUIT RANGE/PERFORMANCE PROBLEM»(ref-156203-S20901221762003071000000), «P0112: INTAKE AIR TEMPERATURE CIRCUIT LOW INPUT»(ref-156203-S11092762822003071000000) and «P0113: INTAKE AIR TEMPERATURE CIRCUIT HIGH INPUT»(ref-156203-S00007730892003071000000).
5. Turn the ignition on. Set scan tool to data reading mode for item 21, Engine Coolant Temperature Sensor. The engine coolant temperature and temperature shown with the scan tool should approximately match. Turn the ignition off. If the sensor is operating properly, go to next step. If the sensor is malfunctioning, refer to «DTC P0116: ENGINE COOLANT TEMPERATURE CIRCUIT RANGE/PERFORMANCE PROBLEM»(ref-156203-S10486595472003071000000), «P0117: ENGINE COOLANT TEMPERATURE CIRCUIT LOW INPUT»(ref-156203-S17016383112003071000000) and «P0118: ENGINE COOLANT TEMPERATURE CIRCUIT HIGH INPUT»(ref-156203-S15418319652003071000000).
6. Turn the ignition on. Set scan tool to data reading mode for item 25, Barometric Pressure Sensor. Turn the ignition off. If the sensor is operating properly, go to next step. If the sensor is malfunctioning, refer to «DTC P0106: BAROMETRIC PRESSURE CIRCUIT RANGE/PERFORMANCE PROBLEM»(ref-156203-S22953494942003071000000), «P0107: BAROMETRIC PRESSURE CIRCUIT LOW INPUT»(ref-156203-S04353885502003071000000) and «P0108: BAROMETRIC PRESSURE CIRCUIT HIGH INPUT»(ref-156203-S06622446682003071000000).
7. Check connector B-01, B-02, B-05, B-06 at injector for damage. If the connector is in good condition, go to next step. If the connector is damaged, repair or replace it and go to step 14.
8. Disconnect each injector connector. Measure the resistance between injector side connector terminals No. 1 and 2. If the resistance is standard value, go to next step. If the resistance is abnormal, replace the injector and go to step 14.
9. Check connector C-49 at ECM (M/T) or connector C-50 at PCM (A/T) for damage. see scheme 15or see scheme 33. If the connector is in good condition, go to next step. If the connector is damaged, repair or replace it and go to step 14.
10. Check for harness damage between injector connector and ECM connector (M/T) or PCM connector (A/T). Check the harness wire between injector connector B-01, terminal 2 and ECM connector C-49, terminal 1 (M/T) or PCM connector C-50, terminal 1 (A/T) when checking No. 1 cylinder. Check the harness wire between injector connector B-02, terminal 2 and ECM connector C-49, terminal 14 (M/T) or PCM connector C-50, terminal 9 (A/T) when checking No. 2 cylinder. Check the harness wire between injector connector B-05, terminal 2 and ECM connector C-49, terminal 2 (M/T) or PCM connector C-50, terminal 24 (A/T) when checking No. 3 cylinder. Check the harness wire between injector connector B-06, terminal 2 and ECM connector C-49, terminal 15 (M/T) or PCM connector C-50, terminal 2 (A/T) when checking No. 4 cylinder. If the harness wire is in good condition, go to next step. If the harness wire is damaged, repair it and go to step 14.
11. Check the fuel pressure. If the fuel pressure is normal, go to next step. If the fuel pressure is abnormal, rectify the fault and go to step 14.
12. Check for entry of foreign matter (water, kerosene, etc.) into the fuel. If there are any abnormalities, replace the fuel and go to step 14, otherwise go to next step.
13. Replace the injector. Carry out a test drive with the drive cycle pattern. Check the diagnostic trouble codes. If DTC P0171 is output, replace the ECM or PCM and go to next step. If the DTC is absent, the inspection is complete.
14. Carry out a test drive with the drive cycle pattern (OBD-II). See «FUEL TRIM MONITOR»(ref-156203-S16866559612003072200000). Check the diagnostic trouble codes. If DTC P0171 is output, retry the troubleshooting. If the DTC is absent, the inspection is complete.

1. Check Conditions - Under the closed loop air/fuel ratio control. Engine coolant temperature is higher than 171°F (77°C). Volume air flow sensor output frequency is 88 Hz or more.
2. Judgement Criteria - Long-term fuel trim has continued to be lower than -12.5% for 5 seconds OR Short-term fuel trim has continued to be lower than -6.0% for 5 seconds.
3. Check Conditions - Under the closed loop air/fuel ratio control. Engine coolant temperature is higher than 171°F (77°C). Volume air flow sensor output frequency is 88 Hz or less.
4. Judgement Criteria - Long-term fuel trim has continued to be lower than -12.5% for 5 seconds OR Short-term fuel trim has continued to be lower than -11.0% for 5 seconds.
5. Check Conditions - Engine coolant temperature is higher than 171°F (77°C). Under the closed loop air/fuel ratio control.
6. Judgement Criteria - Long-term fuel trim has continued to be -12.5% for 5 seconds OR Short-term fuel trim has continued to be -25.0% for 5 seconds.

1. Connect Scan Tool (MB991502) to the data link connector. Start the engine and run at idle. Set the scan tool to data reading mode for item 12, Volume Air Flow Sensor. Warm up the engine to normal operating temperature: 176-205°F (80-96°C). When idling, between 12 and 38 Hz (between 1.7 and 4.2 grams/second). When 2,500 RPM, between 55 and 95 Hz (between 7.9 and 12.1 grams/second). Turn the ignition off. If the sensor is operating properly, go to next step. If the sensor is malfunctioning, refer to «DTC P0101: VOLUME AIR FLOW (VAF) CIRCUIT RANGE/PERFORMANCE PROBLEM»(ref-156203-S13324973892003071000000) and «P0102: VOLUME AIR FLOW (VAF) CIRCUIT LOW INPUT»(ref-156203-S30594041082003071000000) .
2. Turn the ignition on. Set scan tool to data reading mode for item 13, Intake Air Temperature Sensor. The intake air temperature and temperature shown with the scan tool should approximately match. Turn the ignition off. If the sensor is operating properly, go to next step. If the sensor is malfunctioning, refer to «DTC P0111: INTAKE AIR TEMPERATURE CIRCUIT RANGE/PERFORMANCE PROBLEM»(ref-156203-S20901221762003071000000) , «P0112: INTAKE AIR TEMPERATURE CIRCUIT LOW INPUT»(ref-156203-S11092762822003071000000) and «P0113: INTAKE AIR TEMPERATURE CIRCUIT HIGH INPUT»(ref-156203-S00007730892003071000000) .
3. Turn the ignition on. Set scan tool to data reading mode for item 21, Engine Coolant Temperature Sensor. The engine coolant temperature and temperature shown with the scan tool should approximately match. Turn the ignition off. If the sensor is operating properly, go to next step. If the sensor is malfunctioning, refer to «DTC P0116: ENGINE COOLANT TEMPERATURE CIRCUIT RANGE/PERFORMANCE PROBLEM»(ref-156203-S10486595472003071000000) , «P0117: ENGINE COOLANT TEMPERATURE CIRCUIT LOW INPUT»(ref-156203-S17016383112003071000000) and «P0118: ENGINE COOLANT TEMPERATURE CIRCUIT HIGH INPUT»(ref-156203-S15418319652003071000000) .
4. Turn the ignition on. Set scan tool to data reading mode for item 25, Barometric Pressure Sensor. Turn the ignition off. If the sensor is operating properly, go to next step. If the sensor is malfunctioning, refer to «DTC P0106: BAROMETRIC PRESSURE CIRCUIT RANGE/PERFORMANCE PROBLEM»(ref-156203-S22953494942003071000000) , «P0107: BAROMETRIC PRESSURE CIRCUIT LOW INPUT»(ref-156203-S04353885502003071000000) and «P0108: BAROMETRIC PRESSURE CIRCUIT HIGH INPUT»(ref-156203-S06622446682003071000000) .
5. Disconnect each injector. Measure the resistance between injector side connector terminal 1 and 2. If the resistance is at the standard value, go to next step. If the resistance is out of range, replace the injector and go to step 8 .
6. Check the fuel pressure. If the fuel pressure is normal, go to next step. If the fuel pressure is abnormal, rectify and go to step 8 .
7. Replace the injector. Carry out a test drive with the drive cycle pattern. Check the diagnostic trouble codes. If DTC P0172 is output, replace the ECM or PCM and go to next step. If the DTC is absent, the inspection is complete.
8. Carry out a test drive with the drive cycle pattern (OBD-II). See «FUEL TRIM MONITOR»(ref-156203-S16866559612003072200000) . Check the diagnostic trouble codes. If DTC P0172 is output, retry the troubleshooting. If the DTC is absent, the inspection is complete.

1. The Engine Coolant Temperature - Intake air temperature is 9°F (5°C) or less when the engine is started. The engine coolant temperature is between -14-97°F (10-36°C) when the engine is started. Engine coolant temperature sensor is higher than 140°F (60°C). Maximum vehicle speed is higher than 17 mph (30 km/h) after the starting sequence has been completed.
2. The Fuel Temperature - Engine coolant temperature is 27°F (15°C) or more when the engine is started.

1. Connect Scan Tool (MB991502) to the data link connector. Turn the ignition on. Set the scan tool to data reading mode for item 4A, Fuel Temperature Sensor. Approximately the same as the outside temperature when the engine is cooled. Turn the ignition off. If the sensor is operating properly, it can be assumed that this malfunction is intermittent, refer to «INTERMITTENT DIAGNOSTIC TROUBLE CODES»(ref-156203-S19689263182003072200000). If the sensor is malfunctioning, go to next step.
2. Check connector D-17 at the fuel temperature sensor for damage. see scheme 18 If the connector is in good condition, go to next step. If the connector is damaged, repair or replace it and go to step 12.
3. Check the fuel temperature sensor. Disconnect the fuel temperature sensor connector D-17. see scheme 18 Measure the resistance between terminal 1 and 3 of the fuel temperature sensor. If the resistance is at the standard value, go to next step. If the resistance is off, replace the fuel temperature sensor and go to step 12.
4. Disconnect the connector D-17 and measure at the harness side. Check for the continuity between terminal 1 and ground. The resistance should be less than 2 ohm. If the continuity is normal, go to next step. If the continuity is abnormal, repair harness wire between fuel temperature sensor connector D-17, terminal 1 and ground (because of open circuit or harness damage) and go to step 12.
5. Disconnect the connector D-17 and measure at the harness side. see scheme 18 Turn the ignition on. Measure the voltage between terminal 3 and ground. Voltage should be between 4.5-4.9 volts. Turn the ignition off. If the voltage is normal, go to next step, otherwise go to step 10.
6. Check the sensor supply voltage at ECM connector C-60 (M/T) or PCM connector C-54 (A/T) by backprobing. see scheme 15or see scheme 33. Do not disconnect the ECM connector C-60 (M/T) or PCM connector C-54 (A/T). Turn the ignition on. Measure the voltage between terminal 77 (M/T) or terminal 51 (A/T) and ground by backprobing. When fuel temperature is 32°F (0°C), voltage should be 2.7-3.1 volts. When fuel temperature is 68°F (20°C), voltage should be 2.1-2.5 volts. When fuel temperature is 104°F (40°C), voltage should be 1.6-2.0 volts. When fuel temperature is 176°F (80°C), voltage should be 0.8-1.2 volts. Turn the ignition off. If the voltage is normal, go to next step, otherwise go to step 8.
7. Check connector C-60 at ECM (M/T) or connector C-54 at PCM (A/T) for damage. see scheme 15or see scheme 33. If the connector is in good condition, check connector C-90 and C-28 at intermediate connector for damage, and repair or replace as required. If intermediate connectors are in good condition, repair harness wire between fuel gauge unit connector D-17, terminal 3 and ECM connector C-60, terminal 77 (M/T) or PCM connector C-54, terminal 51 (A/T) (because of open circuit) and go to step 12. If the connector is damaged, repair or replace it and go to step 12.
8. Check connector C-60 at ECM (M/T) or connector C-54 at PCM (A/T) for damage. If the connector is in good condition, go to next step. If the connector is damaged, repair or replace it and go to step 12.
9. Check for short circuit to ground between fuel gauge unit connector D-17, terminal 3 and ECM connector C-54, terminal 77 (M/T) or PCM connector C-60, terminal 51 (A/T). see scheme 15, see scheme 18 or see scheme 33. If the harness wire is in good condition, replace the ECM or PCM and go to step 12. If the harness wire is damaged, repair it and go to step 12.
10. Check connector C-60 at ECM (M/T) or connector C-54 at PCM (A/T) for damage. see scheme 15or see scheme 33. If the connector is in good condition, go to next step. If the connector is damaged, repair or replace it and go to step 12.
11. Check for harness damage between fuel temperature sensor connector D-17, terminal 3 and ECM connector C-60, terminal 77 (M/T) or PCM connector C-54, terminal 51 (A/T). see scheme 15, see scheme 18 or see scheme 33. If the harness wire is in good condition, replace the ECM or PCM and go to next step. If the harness wire is damaged, repair it and go to next step.
12. Carry out a test drive with the drive cycle pattern (OBD-II). Check the diagnostic trouble codes. If DTC P0181 is output, retry the troubleshooting. If the DTC is absent, the inspection is complete.

1. Check Conditions - 2 seconds or more have passed since the starting sequence was completed.
2. Judgement Criteria - Fuel temperature sensor output voltage has continued to be 0.1 volt or lower for 2 seconds.

1. Connect Scan Tool (MB991502) to the data link connector. Turn the ignition on. Set the scan tool to data reading mode for item 4A, Fuel Temperature Sensor. Approximately the same as the outside temperature when the engine is cooled. Turn the ignition off. If the sensor is operating properly, it can be assumed that the malfunction is intermittent, refer to «INTERMITTENT DIAGNOSTIC TROUBLE CODES»(ref-156203-S19689263182003072200000). If the sensor is malfunctioning, go to next step.
2. Disconnect the fuel temperature sensor connector D-17. see scheme 18 Measure the resistance between terminal 1 and 3 of the fuel temperature sensor. If the resistance is at the standard value, go to next step. If the resistance is off, replace the fuel temperature sensor and go to step 5.
3. Check connector D-17 at the fuel temperature sensor and connector C-60 at ECM (M/T) or connector C-54 at PCM (A/T) for damage. see scheme 15, see scheme 18 or see scheme 33. If the connector is in good condition, go to next step. If the connector is damaged, repair or replace it and go to step 5.
4. Check for short circuit to ground between fuel temperature sensor connector D-17 and ECM connector C-60 (M/T) or PCM connector C-54 (A/T). see scheme 15, see scheme 18 or see scheme 33. Check harness after checking intermediate connector C-90 and C-28. see scheme 26 If intermediate connector is damaged, repair or replace it and go to next step. If the harness wire is in good condition, replace the ECM or PCM and go to next step. If the harness wire is damaged, repair it and go to next step.
5. Carry out a test drive with the drive cycle pattern (OBD-II). Check the diagnostic trouble codes. If DTC P0182 is output, retry the troubleshooting. If the DTC is absent, the inspection is complete.

1. Check Conditions - 2 seconds or more have passed since the starting sequence was completed.
2. Judgement Criteria - Fuel temperature sensor output voltage has continued to be 4.6 volts or higher for 2 seconds.

1. Connect Scan Tool (MB991502) to the data link connector. Turn the ignition on. Set the scan tool to data reading mode for item 4A, Fuel Temperature Sensor. Approximately the same as the outside temperature when the engine is cooled. Turn the ignition off. If the sensor is operating properly, it can be assumed that this malfunction is intermittent, refer to «INTERMITTENT DIAGNOSTIC TROUBLE CODES»(ref-156203-S19689263182003072200000). If the sensor is malfunctioning, go to next step.
2. Check connector D-17 at the fuel temperature sensor for damage. see scheme 18 If the connector is in good condition, go to next step. If the connector is damaged, repair or replace it and go to step 11.
3. Disconnect the fuel temperature sensor connector D-17. Measure the resistance between terminal 1 and 3 of the fuel temperature sensor. If the resistance is at the standard value, go to next step. If the resistance is out of range, replace the fuel temperature sensor and go to step 11.
4. Disconnect the connector D-17 and measure at the harness side. see scheme 18 Turn the ignition on. Measure the voltage between terminal 3 and ground. Voltage should be between 4.5-4.9 volts. Turn the ignition off. If the voltage is normal, go to step 8, otherwise go to next step.
5. Check the sensor supply voltage at ECM connector C-60 (M/T) or PCM connector C-54 (A/T) by backprobing. see scheme 15or see scheme 33. Do not disconnect the ECM connector C-60 (M/T) or PCM connector C-54 (A/T). Disconnect the fuel temperature sensor connector D-17. Turn the ignition on. Measure the voltage between terminal 77 (M/T) or 51 (A/T) and ground by backprobing. Voltage should be between 4.5-4.9 volts. Turn the ignition off. If the voltage is normal, go to next step, otherwise, go to step 7.
6. Check connector C-60 at ECM (M/T) or connector C-54 at PCM (A/T) for damage. If the connector is in good condition, check connector C-28 and C-90 at intermediate connector for damage, and repair and replace as required. If intermediate connector is in good condition, repair harness wire between fuel temperature sensor connector D-17, terminal 3 and ECM connector C-60, terminal 77 (M/T) or PCM connector C-54, terminal 51 (A/T) (because of open circuit) and go to step 11. If the connector is damaged, repair or replace it and go to step 11.
7. Check connector C-60 at ECM (M/T) or connector C-54 at PCM (A/T) for damage. see scheme 15or see scheme 33. If the connector is in good condition, replace the ECM or PCM and go to step 11. If the connector is damaged, repair or replace it and go to step 11.
8. Check the continuity at fuel temperature sensor harness side connector D-17. see scheme 18 Disconnect the connector D-17 and measure at the harness side. Check for continuity between terminal 1 and ground. The resistance should be less than 2 ohm. If the continuity is normal, go to next step. If the continuity is abnormal, repair harness wire between fuel temperature sensor connector D-17, terminal 1 and ground (because of open circuit or harness damage) and go to step 11.
9. Check connector C-60 at ECM (M/T) or connector C-54 at PCM (A/T) for damage. see scheme 15or see scheme 33. If the connector is in good condition, go to next step. If the connector is damaged, repair or replace it and go to step 11.
10. Check for open circuit and harness damage between fuel temperature sensor connector D-17 and ECM connector C-60 (M/T) or PCM connector C-54. see scheme 15, see scheme 18 or see scheme 33. Check harness after checking intermediate connector C-90 and C-28. see scheme 26 If intermediate connector is damaged, repair or replace it and proceed to next step. If the harness wire is in good condition, replace the ECM or PCM and go to next step. If the harness wire is damaged, repair it and go to next step.
11. Carry out a test drive with the drive cycle pattern (OBD-II). Check the diagnostic trouble codes. If DTC P0183 is output, retry the troubleshooting. If the DTC is absent, the inspection is complete.

1. Engine speed is lower than 1000 RPM. Throttle position sensor output voltage is lower than 1.16 volts.
2. Injector coil surge voltage (battery positive voltage +2V) has not been detected for 2 seconds.

1. Connect Scan Tool (MB991502) to the data link connector. Start the engine and run at idle. Set the scan tool to actuator testing mode for item 01, 02, 03, 04 Injectors. Warm up the engine to normal operating temperature: 176-205°F (80-96°C). Check for unstable idling or engine stalling. Turn the ignition off. If the actuator is operating properly, it can be assumed that this malfunction is intermittent, refer to «INTERMITTENT DIAGNOSTIC TROUBLE CODES»(ref-156203-S19689263182003072200000). If the actuator is malfunctioning, go to next step.
2. Check the connector at each injector for damage. see scheme 16 Check the connector B-01 when checking No. 1 cylinder. Check the connector B-02 when checking No. 2 cylinder. Check the connector B-05 when checking No. 3 cylinder. Check the connector B-06 when checking No. 4 cylinder. If the connector is in good condition, go to next step. If the connector is damaged, repair or replace it and go to step 10.
3. Disconnect the injector connector B-01 (No. 1 cylinder) or B-02 (No. 2 cylinder) or B-05 (No. 3 cylinder) or B-06 (No. 4 cylinder). see scheme 16 Measure the resistance between injector side connector terminal 1 and 2. If the resistance is at the standard value, go to next step. If the resistance is off, replace the injector and go to step 10.
4. Disconnect connector B-01 (No. 1 cylinder) or B-02 (No. 2 cylinder) or B-05 (No. 3 cylinder) or B-06 (No. 4 cylinder) and measure at the harness side. Turn the ignition on. Measure the voltage between terminal 1 and ground. Voltage should be battery positive voltage. Turn the ignition off. If the voltage is normal, go to step 6, otherwise, go to next step.
5. Check connector A-18X at MFI relay for damage. see scheme 31 If the connector is in good condition, repair harness wire between MFI relay connector and injector connector (because of open circuit or short to ground). Repair harness wire between MFI relay connector A-18X, terminal 4 and injector connector B-01, terminal 1 when checking No. 1 cylinder. Repair harness wire between MFI relay connector A-18X, terminal 4 and injector connector B-02, terminal 1 when checking No. 2 cylinder. Repair harness wire between MFI relay connector A-18X, terminal 4 and injector connector B-05, terminal 1 when checking No. 3 cylinder. Repair harness wire between MFI relay connector A-18X, terminal 4 and injector connector B-06, terminal 1 when checking No. 4 cylinder. when finished, go to step 10. If the connector is damaged, repair or replace it.
6. Check for harness damage between MFI relay connector and injector connector. see scheme 16and see scheme 31. Check the harness wire between MFI relay connector A-18X, terminal 4 and injector connector B-01, terminal 1 when checking No. 1 cylinder. Check the harness wire between MFI relay connector A-18X, terminal 4 and injector connector B-02, terminal 1 when checking No. 2 cylinder. Check the harness wire between MFI relay connector A-18X, terminal 4 and injector connector B-05, terminal 1 when checking No. 3 cylinder. Check the harness wire between MFI relay connector A-18X, terminal 4 and injector connector B-06, terminal 1 when checking No. 4 cylinder. If the harness wire is in good condition, go to next step. If the harness wire is damaged, repair it and go to step 10.
7. Check connector C-49 at ECM (M/T) or connector C-50 at PCM (A/T) for damage. see scheme 15or see scheme 33. If the connector is in good condition, go to next step. If the connector is damaged, repair or replace it and go to step 10.
8. Check for open circuit and short circuit to ground and harness damage between injector connector and ECM connector (M/T) or PCM connector (A/T). see scheme 15, see scheme 16 or see scheme 33. Check the harness wire between injector connector B-01, terminal 2 and ECM connector C-49, terminal 1 (M/T) or PCM connector C-50, terminal 1 (A/T) when checking No. 1 cylinder. Check the harness wire between injector connector B-02, terminal 2 and ECM connector C-49, terminal 14 (M/T) or PCM connector C-50, terminal 9 (A/T) when checking No. 2 cylinder. Check the harness wire between injector connector B-05, terminal 2 and ECM connector C-49, terminal 2 (M/T) or PCM connector C-50, terminal 24 (A/T) when checking No. 3 cylinder. Check the harness wire between injector connector B-06, terminal 2 and ECM connector C-49, terminal 15 (M/T) or PCM connector C-50, terminal 2 (A/T) when checking No. 4 cylinder. If the harness wire is in good condition, go to next step. If the harness wire is damaged, repair it and go to step 10.
9. Disconnect the injector connector B-01 (No. 1 cylinder) or B-02 (No. 2 cylinder) or B-05 (No. 3 cylinder) or B-06 (No. 4 cylinder) and connect the test harness Special Tool MB991348 in between. (All terminals should be connected.) Connect the oscilloscope probe to the injector side connector terminal 2. When measuring with the ECM or PCM side connector, connect an oscilloscope probe to each of the following terminals: ECM terminal 1 or PCM terminal 1 when checking No. 1 cylinder. ECM terminal 14 or PCM terminal 9 when checking No. 2 cylinder. ECM terminal 2 or PCM terminal 24 when checking No. 3 cylinder. ECM terminal 15 or PCM terminal 2 when checking No. 4 cylinder. Start the engine and run at idle. Measure the waveform. The waveform should show a normal pattern similar to the illustration. Turn the ignition off. If the waveform is normal, it can be assumed that this malfunction is intermittent. If the waveform is abnormal, replace the ECM or PCM and go to next step.
10. Carry out a test drive with the drive cycle pattern (OBD-II). Check the diagnostic trouble codes. If the DTC P0201, P0202, P0203 or P0204 is output, retry the troubleshooting. If none of the DTC's are present, the inspection is complete.

1. Check Conditions - Engine speed is between 500-6000 RPM. Engine coolant temperature is higher than 14°F (-10°C). Intake air temperature is higher than 14°F (-10°C). Barometric pressure is higher than 11 psi (76 kPa). Adaptive learning is complete for the vane which generates a crankshaft position signal. While the engine is running, excluding gear shifting, deceleration, sudden acceleration/deceleration and A/C compressor switching. The throttle deviation is -0.059V/10 ms to +0.059V/10 ms.
2. Judgement Criteria - Misfire has occurred more frequently than allowed during the last 200 revolutions (when the catalyst temperature is higher 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.)

Diagnostic Procedures

1. Connect Scan Tool (MB991502) to the data link connector. Start the engine and run at idle. Set the scan tool to data reading mode for 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 off. If the sensor is operating properly, go to next step. If the sensor is malfunctioning, refer to «DTC P0335: CRANKSHAFT POSITION SENSOR CIRCUIT»(ref-156203-S01155963192003071400000).
2. Start the engine and run at idle. Set scan tool to data reading mode for item 81, Long-Term Fuel Compensation (trim). The fuel trim should be between -12.5 and +12.5 when the load is 2,500 RPM (during closed loop) after the engine is warmed. Turn the ignition off. If the specification is normal, go to next step, otherwise, refer to «DTC P0171: SYSTEM TOO LEAN»(ref-156203-S15078368052003071100000) or «DTC P0172: SYSTEM TOO RICH»(ref-156203-S12088912062003071400000).
3. Start the engine and run at idle. Set the scan tool to data reading mode for item 82, Short-Term Fuel Compensation (trim). The fuel trim should be between -25 to +25 when the load is 2,500 RPM (during closed loop) after the engine is warmed. Turn the ignition off. If the specification is normal, go to next step, otherwise, refer to «DTC P0171: SYSTEM TOO LEAN»(ref-156203-S15078368052003071100000) or «DTC P0172: SYSTEM TOO RICH»(ref-156203-S12088912062003071400000).
4. 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 the plug sparked, go to step 7, otherwise, go to next step.
5. Check the spark plugs. Be sure that the plugs are not burned, or otherwise damaged. If cleaning is required, clean using a plug cleaner or wire brush, etc. Check the plug gap using a plug gap gauge, and adjust if not within the standard value. If the spark plugs are in good condition, go to next step, otherwise, replace faulty plug(s) and go to step 13.
6. Check the spark plug cable cap and coating for cracks. Measure the resistance. If the resistance is normal, examine the ignition circuit system for abnormalities, otherwise, replace the faulty spark plug cable and go to step 13.
7. Disconnect the injector connector and measure the resistance between each injector side connector terminal 1 and 2. If the resistance is correct, go to next step, otherwise, replace the faulty injector and go to step 13.
8. Check connector B-01, B-02, B-05, B-06 at injector for damage. see scheme 16 If the connector is in good condition, go to next step, otherwise, repair or replace the faulty injector and go to step 13.
9. Check connector C-49 at ECM (M/T) or connector C-50 at PCM (A/T) for damage. see scheme 15or see scheme 33. If the connector is in good condition, go to next step, otherwise, repair or replace it and go to step 13.
10. Check for harness damage between injector connector and ECM connector (M/T) or PCM connector (A/T). see scheme 15, see scheme 16 or see scheme 33. Check the harness wire between injector connector B-01, terminal 2 and ECM connector C-49, terminal 1 (M/T) or PCM connector C-50, terminal 1 (A/T) when checking No. 1 cylinder. Check the harness wire between injector connector B-02, terminal 2 and ECM connector C-49, terminal 14 (M/T) or PCM connector C-50, terminal 9 (A/T) when checking No. 2 cylinder. Check the harness wire between injector connector B-05, terminal 2 and ECM connector C-49, terminal 2 (M/T) or PCM connector C-50, terminal 24 (A/T) when checking No. 3 cylinder. Check the harness wire between injector connector B-06, terminal 2 and ECM connector C-49, terminal 15 (M/T) or PCM connector C-50, terminal 2 (A/T) when checking No. 4 cylinder. If the harness wire is in good condition, go to next step, otherwise, repair it and go to step 13.
11. Check for skipped timing belt teeth, compression and EGR valve operation. If there are any abnormalities, rectify and go to step 13, otherwise, go to next step.
12. Replace the injector. Carry out a test drive with the drive cycle pattern. Check diagnostic trouble codes. If DTC P0300 is output, replace the ECM or PCM and go to next step, otherwise, the inspection is complete.
13. Carry out a test drive with the drive cycle pattern (OBD-II). Check the diagnostic trouble codes. If DTC P0300 is output, retry the troubleshooting. If the DTC is absent, the inspection is complete.

1. Engine speed is between 500-6000 RPM. Engine coolant temperature is higher than 14°F (-10°C). Intake air temperature is higher than 14°F (-10°C). Barometric pressure is between 11-15 psi (76-106 kPa). Adaptive learning is complete for the vane which generates a crankshaft position signal. While the engine is running, excluding gear shifting, deceleration, sudden acceleration/deceleration and A/C compressor switching. The throttle deviation is -0.059V/10 ms to +0.059V/10 ms.
2. Misfire has occurred more frequently than allowed during the last 200 revolutions (when the catalyst temperature is higher 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.

1. Check that the spark plugs are not burned or otherwise damaged. If cleaning is required, clean using a plug cleaner or wire brush, etc. Check the plug gap using a plug gap gauge, and adjust if not within the standard value. If the spark plugs are in good condition, go to next step, otherwise, replace the spark plug(s) and go to step 9.
2. Check the spark plug cable cap and coating for cracks. Measure the resistance. If the resistance is normal, go to next step, otherwise, replace the spark plug cable and go to step 9.
3. Disconnect the injector connector B-01 (No. 1 cylinder), B-02 (No. 2 cylinder), B-05 (No. 3 cylinder), B-06 (No. 4 cylinder). see scheme 16 Measure the resistance between injector side connector terminal 1 and 2. If the resistance is at the standard value, go to next step, otherwise, replace the injector and go to step 9.
4. Check connector at injector for damage. see scheme 16 Check the connector B-01 when checking No. 1 cylinder. Check the connector B-02 when checking No. 2 cylinder. Check the connector B-05 when checking No. 3 cylinder. Check the connector B-06 when checking No. 4 cylinder. If the connector is in good condition, go to next step, otherwise, repair or replace the injector and go to step 9.
5. Check connector C-49 at ECM (M/T) or connector C-50 at PCM (A/T) for damage. see scheme 15or see scheme 33. If the connector is in good condition, go to next step, otherwise, repair or replace it and go to step 9.
6. Check for harness damage between injector connector and ECM connector (M/T) or PCM connector (A/T). see scheme 15, see scheme 16 or see scheme 33. Check the harness wire between injector connector B-01, terminal 2 and ECM connector C-49, terminal 1 (M/T) or PCM connector C-50, terminal 1 (A/T) when checking No. 1 cylinder. Check the harness wire between injector connector B-02, terminal 2 and ECM connector C-49, terminal 14 (M/T) or PCM connector C-50, terminal 9 (A/T) when checking No. 2 cylinder. Check the harness wire between injector connector B-05, terminal 2 and ECM connector C-49, terminal 2 (M/T) or PCM connector C-50, terminal 24 (A/T) when checking No. 3 cylinder. Check the harness wire between injector connector B-06, terminal 2 and ECM connector C-49, terminal 15 (M/T) or PCM connector C-50, terminal 2 (A/T) when checking No. 4 cylinder. If the harness wire is in good condition, go to next step, otherwise, repair it and go to step 9.
7. Check the compression. If there are any abnormalities, rectify and go to step 9, otherwise, go to next step.
8. Replace the injector. Carry out a test drive with the drive cycle pattern. Check the diagnostic trouble codes. If DTC P0301, P0302, P0303 or P0304 is output, replace the ECM or PCM and go to step 9. If the DTC's are absent, the inspection is complete.
9. Carry out a test drive with the drive cycle pattern (OBD-II). Check the diagnostic trouble codes. If DTC P0301, P0302, P0303 or P0304 is output, retry the troubleshooting. If the DTC's are absent, the inspection is complete.

1. Check Conditions - 2 seconds or more have passed since the starting sequence was completed. Engine speed is higher than 2500 RPM.
2. Judgement Criteria - Knock sensor output voltage (knock sensor peak voltage in each 1/2 turn of the crankshaft) has not changed more than 0.06 volt in the last consecutive 200 periods.

1. Check connector B-35 at the knock sensor for damage. see scheme 29 If the connector is in good condition, go to next step, otherwise, repair or replace it and go to step 6.
2. Disconnect the connector B-35 and measure at the harness side. see scheme 29 Check for continuity between terminal 2 and ground. The resistance should be less than 2 ohm. If the continuity is normal, go to next step. If the continuity is off, repair harness wire between knock sensor connector B-35, terminal 2 and ground (because of open circuit or harness damage) and go to step 6.
3. Check connector C-60 at ECM (M/T) or connector C-57 at PCM (A/T) for damage. see scheme 15or see scheme 33. If the connector is in good condition, go to next step, otherwise, repair or replace it and go to step 6.
4. Check for open circuit and short circuit to ground and harness damage between knock sensor connector B-35, terminal 1 and ECM connector C-60, terminal 78 (M/T) or PCM connector C-57, terminal 90 (A/T). see scheme 15, see scheme 29 or see scheme 33. If the harness wire is in good condition, go to next step, otherwise, repair it and go to step 6.
5. Replace the knock sensor and carry out a test drive. Check the diagnostic trouble codes. If DTC P0325 is output, replace the ECM or PCM and go to next step, otherwise, the inspection is complete.
6. Connect scan tool to the data link connector. Turn the ignition on. Set the scan tool to data reading mode for item 44, Ignition Coils and Ignition Power Transistor. Ignition timing with the knock sensor connector disconnected should retard more than the ignition timing with the knock sensor connector connected. Turn the ignition off. If the ignition timing changes normally, the inspection is complete, otherwise, retry the troubleshooting.

1. Check Conditions - Engine is being cranked.
2. Judgement Criteria - Crankshaft position sensor output voltage has not changed (no pulse signal is input) for 2 seconds.
3. Check Conditions, Judgement Criteria - Normal signal pattern has not been input for cylinder identification from the crankshaft position sensor signal and camshaft position sensor signal for 2 seconds.

1. Connect Scan Tool (MB991502) to the data link connector. Start the engine and run at idle. Set the scan tool to data reading mode for item 22, Crankshaft Position Sensor. The tachometer and engine speed indicated on the scan tool should match. Turn the ignition off. If the sensor is operating properly, it can be assumed that this malfunction is intermittent, refer to «INTERMITTENT DIAGNOSTIC TROUBLE CODES»(ref-156203-S19689263182003072200000). If the sensor is malfunctioning, go to next step.
2. Do not disconnect the crankshaft position sensor connector B-20. Connect an oscilloscope probe to terminal 2 of the crankshaft position sensor by backprobing. see scheme 12 Connect the oscilloscope probe to terminal 89 (M/T) or terminal 45 (A/T) by backprobing when measuring with the ECM or PCM connector. Start the engine and run at idle. Check the waveform. The waveform should show a pattern similar to the illustration. Turn the ignition off. If the waveform is normal, go to next step, otherwise, go to step 5.
3. Check connector B-20 at the crankshaft position sensor for damage. see scheme 12 If the connector is in good condition, go to next step, otherwise, repair or replace it and go to step 21.
4. Connect scan tool to the data link connector. Turn the ignition on. Set the scan tool to data reading mode for item 22, Crankshaft Position Sensor. The tachometer and engine speed indicated on the scan tool should match. Turn the ignition off. If the sensor is operating properly, it can be assumed that this malfunction is intermittent, refer to «INTERMITTENT DIAGNOSTIC TROUBLE CODES»(ref-156203-S19689263182003072200000). If the sensor is malfunctioning, replace the ECM or PCM and go to step 21.
5. Check connector B-20 at the crankshaft position sensor for damage. see scheme 12 If the connector is in good condition, go to next step, otherwise, repair or replace it and go to step 21.
6. Disconnect the connector B-20 and measure at the harness side. see scheme 12 Turn the ignition on. Measure the voltage between terminal 2 and ground. Voltage should be 4.8-5.2 volts. Turn the ignition off. If the voltage is normal, go to step 11, otherwise, go to next step.
7. Check the sensor supply voltage at ECM connector C-60 (M/T) or PCM connector C-54 (A/T) by backprobing. see scheme 15or see scheme 33. Do not disconnect the ECM connector C-60 (M/T) or PCM connector C-54 (A/T). Disconnect the crankshaft position sensor connector B-20. Turn the ignition on. Measure the voltage between terminal 89 (M/T) or 45 (A/T) and ground by backprobing. Voltage should be 4.8-5.2 volts. Turn the ignition off. If the voltage is normal, go to next step, otherwise, go to step 9.
8. Check connector C-60 at ECM (M/T) or connector C-54 at PCM (A/T) for damage. see scheme 15or see scheme 33. If the connector is in good condition, repair open circuit between crankshaft position sensor connector B-20, terminal 3 and ECM connector C-60, terminal 89 (M/T) or PCM connector C-54, terminal 45 (A/T) and go to step 21. If the connector is damaged, repair or replace it and go to step 21.
9. Check connector C-60 at ECM (M/T) or connector C-54 at PCM (A/T) for damage. see scheme 15or see scheme 33. If the connector is in good condition, go to next step, otherwise, repair or replace it and go to step 21.
10. Check for short circuit to ground between crankshaft position sensor connector B-20, terminal 3 and ECM connector C-60, terminal 89 (M/T) or PCM connector C-54, terminal 45 (A/T). see scheme 12, see scheme 15 or see scheme 33. If the harness wire is in good condition, replace the ECM or PCM and go to step 21. If the harness wire is damaged, repair it and go to step 21.
11. Disconnect the connector B-20 and measure at the harness side. see scheme 12 Turn the ignition on. Measure the voltage between terminal 3 and ground. Voltage should be battery positive voltage. Turn the ignition off. If the voltage is normal, go to step 13, otherwise, go to next step.
12. Check connector A-18X at MFI relay for damage. see scheme 31 If the connector is in good condition, repair harness wire between MFI relay connector A-18X, terminal 4 and crankshaft position sensor connector B-20, terminal 3 (because of open circuit or short circuit to ground) and go to step 21. If the connector is damaged, repair or replace it and go to step 21.
13. Disconnect the connector B-20 and measure at the harness side. see scheme 12 Check for continuity between terminal 1 and ground. The resistance should be less than 2 ohm. If the continuity is normal, go to step 16, otherwise, go to next step.
14. Check connector C-53 at ECM (M/T) or connector C-50 at PCM (A/T) for damage. see scheme 15or see scheme 33. If the connector is in good condition, go to next step, otherwise, repair or replace it and go to step 21.
15. Check for open circuit and harness damage between crankshaft position sensor connector B-20, terminal 1 and ECM connector C-53, terminal 40 (M/T) or PCM connector C-50, terminal 16 (A/T). see scheme 12, see scheme 15 or see scheme 33. If the harness wire is in good condition, replace the ECM or PCM and go to step 21. If the harness wire is damaged, repair it and go to step 21.
16. Check connector A-18X at the MFI relay for damage. see scheme 31 If the harness connector is in good condition, go to next step, otherwise, repair or replace it and go to step 21.
17. Check connector C-60 at ECM (M/T) or connector C-54 at PCM (A/T) for damage. see scheme 15or see scheme 33. If the connector is in good condition, go to next step, otherwise, repair or replace it and go to step 21.
18. Check for harness damage between MFI relay connector A-18X, terminal 4 and crankshaft position sensor connector B-20, terminal 3. see scheme 12and see scheme 31. If the harness wire is in good condition, go to next step, otherwise, repair it and go to step 21.
19. Check for harness damage between crankshaft position sensor connector B-20, terminal 2 and ECM connector C-60, terminal 89 (M/T) or PCM connector C-54, terminal 45 (A/T). see scheme 12, see scheme 15 or see scheme 33. If the harness wire is in good condition, go to next step, otherwise, repair it and go to step 21.
20. Check the crankshaft position sensor vane. If the vane is in good condition, replace the crankshaft position sensor and go to next step. If the vane is damaged, repair it and go to next step.
21. Carry out a test drive with the drive cycle pattern (OBD-II). Check the diagnostic trouble codes. If DTC P0335 is output, retry the troubleshooting. If the DTC is absent, the inspection is complete.

1. Check Conditions - Engine speed is higher than 50 RPM.
2. Judgement Criteria - Camshaft position sensor output voltage has not changed (no pulse signal is input) for 2 seconds.
3. Check Conditions - Engine speed is higher than 50 RPM.
4. Judgement Criteria - Normal signal pattern has not been input for cylinder identification from the crankshaft position sensor signal and camshaft position sensor signal for 2 seconds.

Note. The Camshaft Position Sensor is built into the distributor.

1. Disconnect the camshaft position sensor connector B-09, and connect test harness Special Tool MB991709 in between. (All terminals should be connected.) Connect the oscilloscope probe to the camshaft position sensor side connector terminal 2. When measuring with the ECM or PCM side connector, connect an oscilloscope probe to terminal 88 (M/T) or terminal 56 (A/T). Start the engine and run at idle. Check the waveform. The waveform should show a pattern similar to the illustration. Turn the ignition off. If the waveform is normal, go to next step, otherwise, go to step 4.
2. Check connector B-09 at camshaft position sensor for damage. see scheme 10 If the connector is in good condition, go to next step, otherwise, repair or replace it and go to step 20.
3. Carry out a test drive with the drive cycle pattern. Check the diagnostic trouble codes. If DTC P0340 is output, replace the ECM or PCM and go to step 20. If the DTC is absent, it can be assumed that this malfunction is intermittent, refer to «INTERMITTENT DIAGNOSTIC TROUBLE CODES»(ref-156203-S19689263182003072200000).
4. Check connector B-09 at camshaft position sensor for damage. see scheme 10 If the connector is in good condition, go to next step, otherwise, repair or replace it and go to step 20.
5. Disconnect the connector B-09 and measure at the harness side. see scheme 10 Turn the ignition on. Measure the voltage between terminal 2 and ground. Voltage should be between 4.8 and 5.2 volts. Turn the ignition off. If the voltage is normal, go to step see scheme 10, otherwise, go to next step.
6. Check the sensor supply voltage at ECM connector C-60 (M/T) or PCM connector C-54 (A/T) by backprobing. see scheme 15or see scheme 33. Do not disconnect the ECM connector C-60 (M/T) or PCM connector C-54 (A/T). Disconnect the camshaft position sensor connector B-09. Turn the ignition on. Measure the voltage between terminal 88 (M/T) or 56 (A/T) and ground by backprobing. Voltage should be between 4.8 and 5.2 volts. Turn the ignition off. If the voltage is normal, go to next step, otherwise, go to step 8.
7. Check connector C-60 at ECM (M/T) or connector C-54 at PCM (A/T) for damage. see scheme 15or see scheme 33. If the connector is in good condition, repair harness wire between camshaft position sensor connector B-09, terminal 2 and ECM connector C-60, terminal 88 (M/T) or PCM connector C-54, terminal 56 (A/T) (because of open circuit) and go to step 20. If the connector is damaged, repair or replace it and go to step 20.
8. Check connector C-60 at ECM (M/T) or connector C-54 at PCM (A/T) for damage. see scheme 15or see scheme 33. If the connector is in good condition, go to next step, otherwise, repair or replace it and go to step 20.
9. Check for short circuit to ground between camshaft position sensor connector B-09, terminal 2 and ECM connector C-60, terminal 88 (M/T) or PCM connector C-54, terminal 56 (A/T). see scheme 10, see scheme 15 or see scheme 33. If the harness wire is in good condition, replace the ECM or PCM and go to step 20. If the harness wire is damaged, repair it and go to step 20.
10. Disconnect the connector B-09 and measure at the harness side. see scheme 10 Turn the ignition on. Measure the voltage between terminal 3 and ground. Voltage should be battery positive voltage. Turn the ignition off. If the voltage is normal, go to step 20, otherwise, go to next step.
11. Check connector A-18X at MFI relay for damage. see scheme 31 If the connector is in good condition, repair harness wire between MFI relay connector A-18X, terminal 4 and camshaft position sensor connector B-09, terminal 3 (because of open circuit or short circuit to ground) and go to step 20. If the connector is damaged, repair or replace it and go to step 20.
12. Disconnect the connector B-09 and measure at the harness side. Check the continuity between terminal 1 and ground. The resistance should be less than 2 ohm. If the continuity is normal, go to step 15, otherwise, go to next step.
13. Check connector C-53 at ECM (M/T) or connector C-50 at PCM (A/T) for damage. see scheme 15or see scheme 33. If the connector is in good condition, go to next step, otherwise, repair or replace it and go to step 20.
14. Check for open circuit and harness damage between camshaft position sensor connector B-09 terminal 1 and ECM connector C-53, terminal 40 (M/T) or PCM connector C-50, terminal 16 (A/T). see scheme 10, see scheme 15 or see scheme 33. If the harness wire is in good condition, replace the ECM or PCM and go to step 20, otherwise, repair it and go to step 20.
15. Check connector A-18X at the MFI relay for damage. see scheme 31 If the connector is in good condition, go to next step, otherwise, repair or replace it and go to step 20.
16. Check connector C-60 at ECM (M/T) or connector C-54 at PCM (A/T) for damage. see scheme 15or see scheme 33. If the connector is in good condition, go to next step, otherwise, repair or replace it and go to step 20.
17. Check for harness damage between MFI relay connector A-18X, terminal 4 and camshaft position sensor connector B-09, terminal 3. see scheme 10and see scheme 31. If the harness wire is in good condition, go to next step, otherwise, repair it and go to step 20.
18. Check for harness damage between camshaft position sensor connector B-09 terminal 2 and ECM connector C-60, terminal 88 (M/T) or PCM connector C-54, terminal 56 (A/T). see scheme 10, see scheme 15 or see scheme 33. If the harness wire is in good condition, go to next step, otherwise, repair it and go to step 20.
19. Check the camshaft position sensor vane. If the vane is in good condition, replace the camshaft position sensor and go to next step. If the vane is damaged, repair it and go to next step.
20. Carry out a test drive with the drive cycle pattern (OBD-II). Check the diagnostic trouble codes. If DTC P0340 is output, retry the troubleshooting. If the DTC is absent, the inspection is complete.

1. Check Conditions - At least 20 seconds have passed since the last monitor was complete. Engine coolant temperature is higher than 169°F (76°C). Engine speed is at between 1000-1800 RPM (M/T) or 880-1800 RPM (A/T). Intake air temperature is higher than 32°F (0°C). Barometric pressure is higher than 11 psi (76 kPa). Vehicle speed is 0.9 mph (1.5 km/h - M/T) or 18.7 mph (30 km/h - A/T) or more. At least 90 seconds have passed since manifold differential pressure sensor output voltage fluctuated 1.5 volt or more. The throttle valve is closed. Volumetric efficiency is lower than 15% (M/T) or 25% (A/T). While fuel is being shut off (M/T). 20 seconds have elapsed from the start of the previous monitoring. Monitoring time: 2 seconds x 3 times.
2. Judgement Criteria - When intake manifold pressure fluctuation width is lower than 0.37 psi (2.6 kPa). When the EGR solenoid is turned ON.

1. Check the EGR system. See «EXHAUST GAS RECIRCULATION (EGR)»(ref-135493-S13375233772002022200000) under EMISSION SYSTEMS & SUB-SYSTEMS in SYSTEM & COMPONENT TESTING article. If a problem exists, repair and go to step 3 . If the EGR system is functioning properly, go to next step.
2. Connect scan tool to the data link connector. Start the engine and run at idle. Set the scan tool to data reading mode for item 95, Manifold Differential Pressure Sensor. Warm up the engine to normal operating temperature: 176-205°F (80-96°C). The pressure should be between 65-78 kPa when idling. Turn the ignition off. If the sensor is operating properly, clean the EGR valve and EGR passage and go to next step. If the sensor is malfunctioning, refer to DTC P1400.
3. Carry out a test drive with the drive cycle pattern (OBD-II). See «EGR MONITOR»(ref-156203-S02723894162003072200000) . Check the diagnostic trouble codes. If DTC P0401 is output, retry the troubleshooting. If the DTC is absent, the inspection is complete.

1. Check Conditions - Engine is being cranked. Battery positive voltage is between 10-16 volts.
2. Judgement Criteria - The EGR solenoid coil surge voltage (battery positive voltage plus 2 volts) is not detected for 0.2 second. Only one monitor per drive cycle.
3. Check Conditions - Battery positive voltage is between 10-16 volts. ON duty cycle of the EGR solenoid is between 10-90%. ON duty cycle of the evaporative emission purge solenoid is 0%. Evaporative emission ventilation solenoid is OFF. More than 1 second has elapsed after the above mentioned conditions have been met.
4. Judgement Criteria - The EGR solenoid coil surge voltage (battery positive voltage plus 2 volts) is not detected for 1 second.

1. Connect Scan Tool (MB991502) to the data link connector. Turn the ignition on. Set the scan tool to 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 off. If the solenoid is operating properly, it can be assumed that this malfunction is intermittent, refer to «INTERMITTENT DIAGNOSTIC TROUBLE CODES»(ref-156203-S19689263182003072200000). If the solenoid is malfunctioning, go to next step.
2. Check connector B-31 at the EGR solenoid for damage. see scheme 13 If the connector is in good condition, go to next step, otherwise, repair or replace it and go to step 12.
3. Disconnect the EGR solenoid connector B-31. see scheme 13 Measure the resistance between EGR solenoid side connector terminal 1 and 2. If the resistance is at the standard value, go to next step, otherwise, replace the EGR solenoid and go to step 12.
4. Disconnect the connector B-31 and measure at the harness side. see scheme 13 Turn the ignition on. Measure the voltage between terminal 1 and ground. Voltage should be battery positive voltage. Turn the ignition off. If the voltage is normal, go to step 6, otherwise, go to next step.
5. Check connector A-18X at MFI relay for damage. see scheme 31 If the connector is in good condition, check connector B-13 at intermediate connector for damage, and repair or replace as required. If intermediate connector is in good condition, repair harness wire between MFI relay connector A-18X terminal 4 and EGR solenoid connector B-101 terminal 1 (because of open circuit or short circuit to ground) and go to step 12. If the connector is damaged, repair or replace it and go to step 12.
6. Check the power supply voltage at ECM connector C-49 (M/T) or PCM connector C-50 (A/T) by backprobing. see scheme 15or see scheme 33. Do not disconnect the connector C-49 (M/T) or C-50 (A/T). Turn the ignition on. Measure the voltage between terminal 6 and ground by backprobing. Voltage should be battery positive voltage. Turn the ignition off. If the voltage is normal, go to step 9, otherwise, go to next step.
7. Check connector C-49 at ECM (M/T) or connector C-50 at PCM (A/T) for damage. see scheme 15or see scheme 33. If the connector is in good condition, go to next step, otherwise, repair or replace it and go to step 12.
8. Check for open circuit and short circuit to ground between EGR solenoid connector B-31 terminal 2 and ECM connector C-49, terminal 6 (M/T) or PCM connector C-50, terminal 6 (A/T). see scheme 13, see scheme 15 or see scheme 33. Check harness after checking intermediate connector B-13. If intermediate connector is damaged, repair or replace it and go to step 12. If the harness wire is in good condition, replace the ECM or PCM and go to step 12. If the harness wire is damaged, repair it and go to step 12.
9. Check connector C-49 at ECM (M/T) or connector C-50 at PCM (A/T) for damage. see scheme 15or see scheme 33. If the connector is in good condition, go to next step, otherwise, repair or replace it and go to step 12.
10. Check for harness damage between MFI relay connector A-18X, terminal 4 and EGR solenoid connector B-101, terminal 1. see scheme 31and see scheme 13. Check harness after checking intermediate connector B-13. If intermediate connector is damaged, repair or replace it and go to step 12. If the harness wire is in good condition, go to next step, otherwise, repair it and go to step 12.
11. Check for harness damage between EGR solenoid connector B-31, terminal 2 and ECM connector C-49, terminal 6 (M/T) or PCM connector C-50, terminal 6 (A/T). see scheme 13, see scheme 15 or see scheme 33. Check harness after checking intermediate connector B-13. If intermediate connector is damaged, repair or replace and go to step 12. If the harness wire is in good condition, replace the ECM or PCM and go to step 12. If the harness wire is damaged, repair it and go to step 12.
12. Carry out a test drive with the drive cycle pattern (OBD-II). Check the diagnostic trouble codes. If DTC P0403 is output, retry the troubleshooting. If the DTC is absent, the inspection is complete.

1. Check Conditions - Engine speed is lower than 3000 RPM. Volume air flow sensor output frequency is between 63-169 Hz. Intake air temperature is higher than 14°F (-10°C). Barometric pressure is higher than 11 psi (76 kPa). The throttle valve is open. Under the closed loop air/fuel ratio control. Vehicle speed is 0.93 mph (1.5 km/h) or more. Monitoring time: 10 seconds x 7 times. Short-term fuel trim is between -25 and +25%. The cumulative volume air flow sensor output frequency is higher than 4000 Hz.
2. Judgement Criteria - The heated oxygen sensor (rear) signal frequency divided by heated oxygen sensor (front) signal frequency = 0.75 (Federal emission regulation) or 0.80 (California emission regulation) or more.

1. Check for exhaust leaks. If the system is airtight, go to next step, otherwise, repair it and go to step 7 .
2. Connect scan tool to the data link connector. Start the engine and run at idle. Set the scan tool to data reading mode for item 59, Heated Oxygen Sensor (rear). Warm up the engine. When the engine is revved, the output voltage should repeat 0.0-0.6 volt to 1.0 volt alternately. Turn the ignition off. If the sensor is operating properly, go to next step, otherwise, refer to «DTC P0137: HEATED OXYGEN SENSOR CIRCUIT LOW VOLTAGE (SENSOR 2)»(ref-156203-S10763327702003071100000) , «P0138: HEATED OXYGEN SENSOR CIRCUIT HIGH VOLTAGE (SENSOR 2)»(ref-156203-S04662390062003071100000) and «P0139: HEATED OXYGEN SENSOR CIRCUIT SLOW RESPONSE (SENSOR 2)»(ref-156203-S06249972842003071100000) .
3. Start the engine and run at idle. Set the scan tool to data reading mode for item 11, Heated Oxygen Sensor (front). Warm up the engine. When the engine is revved, the output voltage should be 0.6 to 1.0 volts. Turn the ignition off. If the sensor is operating properly, go to next step, otherwise, refer to «DTC P0132: HEATED OXYGEN SENSOR CIRCUIT HIGH VOLTAGE (SENSOR 1)»(ref-156203-S23305908302003071100000) , «P0133: HEATED OXYGEN SENSOR CIRCUIT SLOW RESPONSE (SENSOR 1)»(ref-156203-S35067188662003071100000) and «P0134: HEATED OXYGEN SENSOR CIRCUIT NO ACTIVITY DETECTED (SENSOR 1)»(ref-156203-S40191112082003071100000) .
4. Start the engine and run at idle. Set the scan tool to data reading mode for item 11, Heated Oxygen Sensor (front). Keep the engine speed at 2000 RPM. 0.0-0.4 volt and 0.6-1.0 volt should alternate 15 times or more within 10 seconds. Turn the ignition off. If the sensor is operating properly, go to next step, otherwise, replace the heated oxygen sensor (front) and go to step 7 .
5. Carry out a test drive with the drive cycle pattern (OBD-II). See «CATALYTIC CONVERTER MONITOR»(ref-156203-S25430044532003072200000) . Check the diagnostic trouble codes. If DTC P0421 is output, replace the catalytic converter and go to next step, otherwise, the inspection is complete.
6. Carry out a test drive with the drive cycle pattern (OBD-II). See «CATALYTIC CONVERTER MONITOR»(ref-156203-S25430044532003072200000) .Check the diagnostic trouble codes. If DTC P0421 is output, replace the ECM or PCM and go to next step, otherwise, the inspection is complete.
7. Carry out a test drive with the drive cycle pattern (OBD-II). See «CATALYTIC CONVERTER MONITOR»(ref-156203-S25430044532003072200000) .Check the diagnostic trouble codes. If DTC P0421 is output, retry the troubleshooting, otherwise, the inspection is complete.

1. Check Conditions - ON duty cycle of the evaporative emission purge solenoid is 0%. 20 seconds have elapsed from the time the duty cycle of the evaporative emission purge solenoid has turned to 0%.
2. Judgement Criteria - The pressure in the fuel tank is 0.29 psi (-2 kPa) or less.

1. Connect Scan Tool (MB991502) to the data link connector. Turn the ignition on. Set the scan tool to actuator test mode for 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. (Scheme 166) Turn the ignition off. If the solenoid is operating properly, go to next step, otherwise, replace the evaporative emission purge solenoid and go to step 4.
2. Turn the ignition on. Set the scan tool to actuator test mode for 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 off. If the solenoid is operating properly, go to next step, otherwise, replace the evaporative emission ventilation solenoid and go to step 4.
3. Check for clogging in the vent hose and air filter. If there are any clogs, rectify and go to next step, otherwise, refer to «DTC P0451: EVAP SYSTEM PRESSURE SENSOR RANGE/PERFORMANCE»(ref-156203-S13310630852003071400000), «P0452: EVAP SYSTEM PRESSURE SENSOR LOW INPUT»(ref-156203-S01609013812003071400000) and «P0453: EVAP SYSTEM PRESSURE SENSOR HIGH INPUT»(ref-156203-S24879518942003071400000).
4. Carry out a test drive with the drive cycle pattern (OBD-II). See «EVAP SYSTEM LEAK MONITOR»(ref-156203-S23802916432003072200000). Read the diagnostic trouble codes. If DTC P0441 is set, retry the troubleshooting, otherwise, the diagnosis is complete.

Remaining fuel amount is 15-40% (fuel level sensor output voltage is 1.4-2.4 volts).

1. 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 is 97°F (36°C) or less when the engine is started.
2. Test Conditions "B": For Test To Run - The fuel temperature is 97°F (36°C) or less. Within 16 minutes of the engine starting. Engine coolant temperature is higher than 140°F (60°C). Power steering pressure switch: "OFF". Barometric pressure is above 11 psi (76 kPa). Volumetric efficiency is between 20-80%. Fuel tank differential pressure sensor output voltage is 1-4 volts. Vehicle speed is 12.4 mph (20 km/h) or more.
3. 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 higher: 0.065 psi (451 Pa). The pressure fluctuation width is higher than 0.094 psi (647 Pa).
4. Judgement Criteria - Internal pressure of the fuel tank has changed more than 0.122 psi (843 Pa) 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 (75-125 seconds).

Remaining fuel amount is 40-75% (fuel level sensor output voltage is 2.4-3.7 volts).

1. 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 is 97°F (36°C) or lower when the engine is started.
2. Test Conditions "B": For Test To Run - The fuel temperature is 97°F (36°C) or less. Barometric pressure is above 11 psi (76 kPa). Volumetric efficiency is between 20-80%. Fuel tank differential pressure sensor output voltage is 1-4 volts.
3. Test Conditions "C": For Test To Stop - 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 higher: 0.047 psi (324 Pa).
4. Judgement Criteria - 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. NOTE: The monitoring time depends on the fuel level and the temperature in the fuel tank (10-14 minutes).

1. Connect Scan Tool (MB991502) to the data link connector. Turn the ignition on. 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. NOTE: If the engine speed does not reach 2000 RPM during the monitor test, adjustment of the Speed Adjusting Screw may be needed. 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 off. If the scan tool displayed "Evap Leak Mon. Completed Test Passed", the evaporative emission system is working properly at this time. Explain to the customer that an improperly tightened fuel cap may have caused the MIL light to turn on and return the vehicle. If the scan tool displayed "Evap Leak Mon. Completed. Test Failed and DTCs Set", a malfunction has been detected during the monitor test, go to next step. If the scan tool displayed "Evap Lead Mon. Discontinued. Retest again from the first", 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 off once and repeat monitoring from step 1.
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. (Scheme 154) Apply pressure on the 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, otherwise, replace the evaporative emission purge solenoid and go to step 18.
3. Check for leaks in the evaporator line hose "A" to hose "C". (Scheme 154) 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, otherwise, replace the damaged hose and go to step 18.
4. Check for leaks in the chamber. Connect a hand vacuum pump to the 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, otherwise, replace the chamber and go to step 18.
5. Connect the scan tool to the data link connector. Disconnect hose "E" from the evaporative emission ventilation solenoid side. (Scheme 155) Connect the hand vacuum pump to the nipple of the evaporative emission ventilation solenoid from which the hoses have been disconnected. Turn the ignition on. Set the scan tool to actuator test mode for item 29, Evaporative Emission Ventilation Solenoid. When the evaporative emission ventilation solenoid is operated, apply pressure on the hand vacuum pump and confirm that air is maintained. Turn the ignition off and disconnect the scan tool. Disconnect the hand vacuum pump, and connect hose "E" to the evaporative emission canister. (Scheme 156) If the evaporative emission ventilation solenoid is in good condition, go to next step, otherwise, replace the evaporative emission ventilation solenoid and go to step 18. (Scheme 157)
6. 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. (Scheme 155) 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 line is in good condition, go to step 17, otherwise, go to next step.
7. Disconnect hose "G" from the evaporative emission canister side, and plug the hose from which the pipes have been disconnected. (Scheme 158) Perform the pressure test again. If the evaporator line is in good condition, go to next step, otherwise, go to step 10.
8. Check for leaks in the evaporator line hose "D" to hose "F". (Scheme 159) Remove the fuel tank. The leakage test with the hand vacuum pump on each hose from hose "D" to hose "F". If the hoses are in good condition, go to next step, otherwise, replace the hose(s), reinstall the fuel tank and go to step 18.
9. 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 evaporative emission canister is in good condition, go to step 18, otherwise, replace the evaporative emission canister, reinstall the fuel tank and go to step 18.
10. Remove the fuel filler neck protector. Disconnect hose "H" at the liquid separator, and then connect a hand vacuum pump to the hose. (Scheme 160) 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 line is in good condition, go to next step, otherwise, replace that hose, reinstall the fuel filler neck protector and go to step 18.
11. 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". (Scheme 161)and (Scheme 162). If the hoses are in good condition, go to next step, otherwise, replace the hose, reinstall the fuel tank, fuel filler neck assembly and go to step 18.
12. Check the check valve "A". (Scheme 163) The valve should only allow air to pass through in one direction. Air should leak from the check valve body when pressure is applied. If the check valve "A" is in good condition, go to next step, otherwise, replace the valve, reinstall the fuel tank and fuel filler neck assembly and go to step 18.
13. Check the check valve "B". (Scheme 164) Valve "B" is bi-directional, but more air flow is allowed in one direction than the other. Blow on both ends to test this. It is normal for air to leak form the check valve body. If check valve "B" is in good condition, go to next step, otherwise, replace the valve, reinstall the fuel tank and fuel filler neck assembly and go to step 18.
14. Check for leaks in the evaporator line hose "N". (Scheme 165) 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, otherwise, replace the hose, reinstall the fuel tank and fuel filler neck assembly, and 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, otherwise, replace the fuel filler neck assembly, reinstall the fuel tank and fuel filler neck assembly and go to step 18.
16. Check for leaks 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, otherwise, replace the fuel tank, reinstall the fuel tank and fuel filler neck assembly and go to step 18.
17. Connect scan tool to the data link connector. Turn the ignition on. 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 the scan tool will change from "NO" to "YES." Turn the ignition off and disconnect the scan tool. If the scan tool showed "Evap Leak Mon. Completed. Test Passed", the evaporative emission system is working properly at this time, go to next step. If the scan tool showed, "Evap Leak Mon. Completed. Test Failed and DTCs Set", replace the ECM (M/T) or PCM (A/T) and go to next step. If the scan tool showed "Evap Lead Mon. discontinued. Retest again from the first", the monitor was discontinued for a certain reason (vehicle speed input from ECM (M/T) or PCM (A/T), engine speed and engine load deviating from specified range). Turn the ignition off once and recheck the evaporative emission system monitor test.
18. Carry out a test drive with the drive cycle pattern (OBD-II). See «EVAP SYSTEM LEAK MONITOR»(ref-156203-S23802916432003072200000).Read the diagnostic trouble codes. If DTC P0442 is set, retry the troubleshooting. If the DTC is absent, the diagnosis is complete.

Scheme 154

Scheme 155

Scheme 156

Scheme 157

Scheme 158

Scheme 159

Scheme 160

Scheme 161

Scheme 162

Scheme 163

Scheme 164

Scheme 165

1. Check Conditions Battery positive voltage is between 10-16 volts.
2. Judgement Criteria The evaporative emission purge solenoid coil surge voltage (battery positive voltage plus 2 volts) is not detected for 0.2 second. Only one monitor per drive cycle.
3. Check Conditions Battery positive voltage is between 10-16 volts. ON duty cycle of the evaporative emission purge solenoid is between 10-90%. ON duty cycle of the EGR solenoid is 0%. Evaporative emission ventilation solenoid is OFF. More than 1 second has elapsed after the above mentioned conditions have been met.
4. Judgement Criteria The evaporative emission purge solenoid coil surge voltage (battery positive voltage plus 2 volts) is not detected for 1 second.

Scheme 166

1. Connect Scan Tool (MB991502) to the data link connector. Turn the ignition on. Set the scan tool to actuator test mode for 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. (Scheme 166) Turn the ignition off. If the solenoid is operating properly, it can be assumed that this malfunction is intermittent, refer to «INTERMITTENT DIAGNOSTIC TROUBLE CODES»(ref-156203-S19689263182003072200000). If the solenoid is malfunctioning, go to next step.
2. Check connector B-33 at the evaporative emission purge solenoid for damage. see scheme 34 If the connector is in good condition, go to next step, otherwise, replace it and go to step 12.
3. Disconnect the evaporative emission purge solenoid connector B-33. see scheme 34 Measure the resistance between evaporative emission purge solenoid side connector terminal 1 and 2. If the resistance is the standard value, go to next step, otherwise, replace the evaporative emission purge solenoid and go to step 12.
4. Disconnect the connector B-33 and measure at the harness side. see scheme 34 Turn the ignition on. Measure the voltage between terminal 2 and ground. Voltage should be battery positive voltage. Turn the ignition off. If the voltage is normal, go to step 6, otherwise, go to next step.
5. Check connector A-18X at MFI relay for damage. see scheme 31 If the connector is in good condition, repair harness wire between MFI relay connector A-18X, terminal 4 and evaporative emission purge solenoid connector B-33, terminal 2 (because of open circuit or short circuit to ground). see scheme 34 go to step 12. If the connector is damaged, repair or replace it and go to step 12.
6. Check the power supply voltage at ECM connector C-49 (M/T) or PCM connector (A/T) C-50 by backprobing. see scheme 15or see scheme 33. Do not disconnect the connector C-49 (M/T) or C-50 (A/T). Turn the ignition on. Measure the voltage between terminal 9 (M/T) or 34 (A/T) and ground by backprobing. Voltage should be battery positive voltage. Turn the ignition off. If the voltage is normal, go to step 9, otherwise, go to next step.
7. Check connector C-49 at ECM (M/T) or connector C-50 at PCM (A/T) for damage. see scheme 15or see scheme 33. If the connector is in good condition, go to next step, otherwise, repair or replace it and go to step 12.
8. Check for open circuit and short circuit to ground between evaporative emission purge solenoid connector B-33, terminal 1 and ECM connector C-49, terminal 9 (M/T) or PCM connector C-50, terminal 34 (A/T). see scheme 15, see scheme 33 or see scheme 34. If the harness wire is in good condition, replace the ECM or PCM and go to step 12. If the harness wire is damaged, repair it and go to step 12.
9. Check connector C-49 at ECM (M/T) or connector C-50 at PCM (A/T) for damage. see scheme 15or see scheme 33. If the connector is in good condition, go to next step, otherwise, repair or replace it and go to step 12.
10. Check for harness damage between MFI relay connector A-18X, terminal 4 and evaporative emission purge solenoid connector B-33, terminal 2. see scheme 31and see scheme 34. If the harness wire is in good condition, go to next step, otherwise, repair it and go to step 12.
11. Check for harness damage between evaporative emission purge solenoid connector B-33, terminal 1 and ECM connector C-49, terminal 9 (M/T) or PCM connector C-50, terminal 34 (A/T). see scheme 15, see scheme 33 or see scheme 34. If the harness wire is in good condition, replace the ECM or PCM and go to next step. If the harness wire is damaged, repair it and go to next step.
12. Carry out a test drive with the drive cycle pattern (OBD-II). Check the diagnostic trouble codes. If DTC P0443 is output, retry the troubleshooting. If the DTC is absent, the inspection is complete.

1. Check Conditions - Battery positive voltage is between 10-16 volts.
2. Judgement Criteria - The evaporative emission ventilation solenoid coil surge voltage (battery positive voltage plus 2 volts) is not detected for 0.2 second. Only one monitor per drive cycle.
3. Check Conditions - Battery positive voltage is between 10-16 volts. ON duty cycle the evaporative emission purge solenoid is 0%. ON duty cycle of the EGR solenoid is 0%. Evaporative emission ventilation solenoid is ON. More than 1 second has elapsed after the above mentioned conditions have been met.
4. Judgement Criteria - The evaporative emission ventilation solenoid coil surge voltage (battery positive voltage plus 2 volts) is not detected for 1 second.

Scheme 167

1. Connect Scan Tool (MB991502) to the data link connector. Turn the ignition on. Set the scan tool to actuator test mode for 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 off. If the solenoid is operating properly, it can be assumed that this malfunction is intermittent, refer to «INTERMITTENT DIAGNOSTIC TROUBLE CODES»(ref-156203-S19689263182003072200000). If the solenoid is malfunctioning, go to next step.
2. Check connector D-10 at the evaporative emission ventilation solenoid for damage. see scheme 13 If the connector is in good condition, go to next step, otherwise, repair or replace it and go to step 12.
3. Check the evaporative emission ventilation solenoid. Disconnect the evaporative emission ventilation solenoid connector D-10. see scheme 13 Measure the resistance between evaporative emission ventilation solenoid side connector terminal 1 and 2. If the resistance is at the standard value, go to next step, otherwise, replace the over vent valve module and go to step 12. (Scheme 167)
4. Check the power supply voltage at evaporative emission ventilation solenoid harness side connector D-10. see scheme 13 Disconnect the connector D-10 and measure at the harness side. Turn the ignition on. Measure the voltage between terminal 2 and ground. Voltage should be battery positive voltage. Turn the ignition off. If the voltage is normal, go to step 6, otherwise, go to next step.
5. Check connector A-18X at MFI relay for damage. see scheme 31 If the connector is in good condition, check connectors D-16, C-90 and C-28 at intermediate connector for damage, and repair or replace as required. see scheme 26 If intermediate connectors are in good condition, repair harness wire between MFI relay connector A-18X, terminal 4 and evaporative emission ventilation solenoid connector D-10, terminal 2 (because of open circuit or short circuit to ground) and go to step 12. If the connector is damaged, repair or replace it and go to step 12.
6. Check the power supply voltage at ECM connector C-56 (M/T) or PCM connector C-50 (A/T) by backprobing. see scheme 15or see scheme 33. Do not disconnect the connector C-56 (M/T) or C-50 (A/T). Turn the ignition on. Measure the voltage between terminal 55 (M/T) or 35 (A/T) and ground by backprobing. Voltage should be battery positive voltage. Turn the ignition off. If the voltage is normal, go to step 9, otherwise, go to next step.
7. Check connector C-56 at ECM (M/T) or connector C-50 at PCM (A/T) for damage. see scheme 15or see scheme 33. If the connector is in good condition, go to next step, otherwise, repair or replace it and go to step 12.
8. Check for open circuit and short circuit to ground between evaporative emission ventilation solenoid connector D-10, terminal 1 and ECM connector C-56, terminal 55 (M/T) or PCM connector C-50, terminal 35 (A/T). see scheme 13, see scheme 15 or see scheme 33. (Check harness after checking intermediate connectors D-16, C-90 and C-28. see scheme 26 If intermediate connectors are damaged, repair or replace them and go to step 12.) If the harness wire is in good condition, replace the ECM or PCM and go to step 12. If the harness wire is damaged, repair it and go to step 12.
9. Check connector C-56 at ECM (M/T) or connector C-50 at PCM (A/T) for damage. see scheme 15or see scheme 33. If the connector is in good condition, go to next step, otherwise, repair or replace it and go to step 12.
10. Check for harness damage between MFI relay connector A-18X, terminal 4 and evaporative emission ventilation solenoid connector D-10, terminal 2. see scheme 31and see scheme 13. (Check harness after checking intermediate connectors D-16, C-90 and C-28. see scheme 26 If intermediate connectors are damaged, repair or replace them and go to step 12.) If the harness wire is in good condition, go to next step, otherwise, repair it and go to step 12.
11. Check for harness damage between evaporative emission ventilation solenoid connector D-10, terminal 1 and ECM connector C-56, terminal 55 (M/T) or PCM connector C-50, terminal 35 (A/T). see scheme 13, see scheme 15 or see scheme 33. (Check harness after checking intermediate connectors D-16, C-90 and C-28. If intermediate connectors are damaged, repair or replace them and go to next step.) see scheme 26 If the harness wire is in good condition, replace the ECM or PCM and go to next step. If the harness wire is damaged, repair it and go to next step.
12. Carry out a test drive with the drive cycle pattern (OBD-II). Check the diagnostic trouble codes. If DTC P0446 is output, retry the troubleshooting. If the DTC is absent, the inspection is complete.

1. Test Conditions: Electrical Noise - Idle switch: ON. Throttle valve is closed. Vehicle speed is 0.93 mph (1.5 km/h) or less.
2. Judgement Criteria - The event that the output voltage from the fuel tank differential pressure sensor changes by 0.2 volt or more (i.e. sudden pressure fluctuation) is counted at least 20 times during one engine idling, and then consecutively eight times during normal driving conditions. NOTE: If the number of sudden pressure fluctuations does not reach twenty during one engine idling, the counter will be reset to zero. If the ignition switch is turned off, it will also be reset to zero. NOTE: The conditions for deviating from idling operation are as follows: Engine speed is higher than 2,500 RPM. Vehicle speed is 9.3 mph (15 km/h) or more. Volumetric efficiency is 55% or more.

1. Connect Scan Tool (MB991502) 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 on. Remove the fuel cap. Set the scan tool to data reading mode for item 73, Fuel Tank Differential Pressure Sensor. The fuel tank pressure should be -1.5 to 1.5 kPa (-285 to 285 in Hg). Connect an evaporative emission system pressure pump to the fuel filler neck, and apply pressure. The scan tool reading should increase. Turn the ignition off and disconnect the scan tool. If the scan tool reading is within the specified value, go to step 28, otherwise, go to next step.
2. Check the output circuit voltage at intermediate connector D-16. see scheme 26 Remove the rear seat cushion. Remove the protector. Disconnect intermediate connector D-16. Use Special Tools (MB991658 and MB991709) to connect terminals 5, 6 and 8 between connectors of the intermediate connector respectively. Turn the ignition on. Remove the fuel cap. Measure the voltage between terminal 5 and ground. Voltage should be between 2.0 and 3.0 volts. Turn the ignition off. If the voltage is normal, go to next step, otherwise, go to step 6.
3. Check the output circuit voltage at ECM connector C-57 (M/T) or PCM connector C-57 (A/T) by backprobing. see scheme 15or see scheme 33. Do not disconnect the ECM connector C-56 (M/T) or PCM connector C-57 (A/T). Turn the ignition on. Remove the fuel cap. Measure the voltage between terminal 61 (M/T) or terminal 92 (A/T) and ground by backprobing. Voltage should be between 2.0-3.0 volts. Turn the ignition off. If the voltage is normal, go to step 27, otherwise, go to next step.
4. Check connectors C-28, C-90, D-16 at intermediate connector and C-56 at ECM (M/T) or C-57 at PCM (A/T) for damage. see scheme 26 If the connectors are in good condition, go to next step, otherwise, repair or replace them and go to step 28.
5. Check the harness wire between ECM connector C-56, terminal 61 (M/T) or PCM connector C-57, terminal 92 (A/T) and intermediate connector D-16, terminal 5 for damage. see scheme 15, see scheme 26 or see scheme 33. If the harness wire is in good condition, go to step 28, otherwise, repair it and go to step 28.
6. Check the 5 volts supply circuit voltage at intermediate connector D-16. Disconnect intermediate connector D-16. see scheme 26 Use Special Tools (MB991658 and MB991709) to connect terminals 5, 6 and 8 between connectors of the intermediate connector respectively. Turn the ignition on. Measure the voltage between terminal 8 and ground. Voltage should be between 4.8-5.2 volts. Turn the ignition off. If the voltage is normal, go to step 11, otherwise, go to next step.
7. Check the 5 volts supply circuit voltage at ECM connector C-60 (M/T) or PCM connector C-54 (A/T) by backprobing. see scheme 15or see scheme 33. Do not disconnect ECM connector C-60 (M/T) or PCM connector C-54 (A/T). Turn the ignition on. Measure the voltage between terminal 81 (M/T) or terminal 46 (A/T) and ground by backprobing. Voltage should be between 4.8-5.2 volts. Turn the ignition off. If the voltage is normal, go to step 9, otherwise, go to next step.
8. Check connector C-60 at ECM (M/T) or C-54 at PCM (A/T) for damage. see scheme 15or see scheme 33. If the connector is in good condition, go to step 27, otherwise, repair or replace it and go to step 28.
9. Check connectors C-28, C-90, D-16 at intermediate connector for damage. see scheme 26 If the connectors are in good condition, go to next step, otherwise, repair or replace it and go to step 28.
10. Check the harness wire between ECM connector C-60, terminal 81 (M/T) or PCM connector C-54, terminal 46 (A/T) and intermediate connector D-16, terminal 8 for damage. see scheme 15or see scheme 33. If the harness wire is in good condition, go to step 28, otherwise, repair it and go to step 28.
11. Check the circuit voltage at intermediate connector D-16. see scheme 26 Disconnect intermediate connector D-16. Use Special Tool (MB991658) to connect terminal 6 between connectors of the intermediate connector. Turn the ignition on. Measure the voltage at the male side connector between terminal 6 and ground. Voltage should be between 4.8-5.2 volts. Turn the ignition off. If the voltage is normal, go to next step, otherwise, go to step 15.
12. Check the ground voltage at ECM connector C-60 (M/T) or PCM connector C-54 (A/T) by backprobing. see scheme 15or see scheme 33. Do not disconnect ECM connector C-60 (M/T) or PCM connector C-54 (A/T). Turn the ignition on. Measure the voltage between terminal 92 (M/T) or terminal 57 (A/T) and ground by backprobing. The voltage should be 0.5 volt or less. Turn the ignition off. If the voltage is normal, go to step 28, otherwise, go to next step.
13. Check connectors C-28, C-90, D-16 at intermediate connector and C-60 at ECM (M/T) or C-54 at PCM (A/T) for damage. see scheme 15, see scheme 26 or see scheme 33. If the connectors are in good condition, go to next step, otherwise, repair or replace them and go to step 28.
14. Check the harness wire between ECM connector C-60, terminal 92 (M/T) or PCM connector C-54, terminal 57 (A/T) and intermediate connector D-16, terminal 6 for damage. see scheme 15, see scheme 26 or see scheme 33. If the harness wire is in good condition, go to step 27, otherwise, repair it and go to step 28.
15. Check the 5 volts supply circuit voltage at fuel tank differential pressure sensor connector D-18. see scheme 17 Remove the center exhaust pipe. Remove the fuel bank assembly, tilt the fuel tank. Disconnect fuel tank differential pressure sensor connector D-18. Use Special Tool (MB991658) to connect terminals 1, 2 and 3 of the disconnected sensor connector and those of the harness side connector respectively. Turn the ignition on. Measure the voltage between terminal 3 and ground. Voltage should be between 4.8-5.2 volts. Turn the ignition off. If the voltage is normal, go to step 18, otherwise, go to next step.
16. Check connectors D-16 at intermediate connector and D-18 at fuel tank differential pressure sensor for damage. see scheme 17and see scheme 26. If the connectors are in good condition, go to next step, otherwise, repair or replace them and go to step 28.
17. Check the harness wire between intermediate connector D-16, terminal 8 and fuel tank differential pressure sensor connector D-18, terminal 3 for damage. see scheme 17and see scheme 26. If the harness wire is in good condition, go to step 28, otherwise, repair it and go to step 28.
18. Disconnect fuel tank differential pressure sensor connector D-18. see scheme 17 Use Special Tool (MB991658) to connect terminal 3 of the disconnected sensor connector and those of the harness side connector respectively. Turn the ignition on. Measure the voltage at the fuel tank differential pressure sensor side connector between terminal 2 and ground. Voltage should be between 4.8-5.2 volts. Turn the ignition off. If the voltage is normal, go to next step, otherwise, replace the fuel tank differential pressure sensor and go to step 28.
19. Check the ground voltage at ECM connector C-60 (M/T) or PCM connector C-54 (A/T) by backprobing. see scheme 15or see scheme 33. Do not disconnect ECM connector C-60 (M/T) or PCM connector C-54 (A/T). Turn the ignition on. Measure the voltage between terminal 92 (M/T) or terminal 57 (A/T) and ground by backprobing. The voltage should be 0.5 volt or less. Turn the ignition off. If the voltage is normal, go to step 28, otherwise, go to next step.
20. Check connectors C-28, C-90, D-16 at intermediate connector and C-60 at ECM (M/T) or C-54 at PCM (A/T) and D-18 at fuel tank differential pressure sensor for damage. see scheme 15, see scheme 17 see scheme 26 or see scheme 33 and. If the connectors are in good condition, go to next step, otherwise, repair or replace them and go to step 28.
21. Check the harness wire between ECM connector C-60, terminal 92 (M/T) or PCM connector C-54, terminal 57 (A/T) and fuel tank differential pressure sensor connector D-18, terminal 2 for damage. see scheme 15, see scheme 17 or see scheme 33. If the harness wire is in good condition, go to next step, otherwise, repair it and go to step 28.
22. Check the ground voltage at ECM connector C-60 (M/T) or PCM connector C-54 (A/T) by backprobing. see scheme 15or see scheme 33. Do not disconnect ECM connector C-60 (M/T) or PCM connector C-54 (A/T). Turn the ignition on. Measure the voltage between terminal 92 (M/T) or terminal 57 (A/T) and ground by backprobing. The voltage should be 0.5 volt or less. Turn the ignition off. If the voltage is normal, go to next step, otherwise, go to step 28.
23. Disconnect fuel tank differential pressure sensor connector D-18. see scheme 17 Use Special Tool (MB991658) to connect terminals 1, 2 and 3 of the disconnected sensor connector and those of the harness side connector respectively. Turn the ignition on. Remove the fuel cap. Measure the voltage between terminal 1 and ground. Voltage should be between 2.0-3.0 volts. Turn the ignition off. If the voltage is normal, go to next step, otherwise, replace the fuel tank differential pressure sensor and go to step 28.
24. Check the output circuit voltage at ECM connector C-56 (M/T) or PCM connector C-57 (A/T) by backprobing. see scheme 15or see scheme 33. Do not disconnect the ECM connector C-56 (M/T) or PCM connector C-57 (A/T). Turn the ignition on. Remove the fuel cap. Measure the voltage between terminal 61 (M/T) or terminal 92 (A/T) and ground by backprobing. Voltage should be between 2.0-3.0 volts. Turn the ignition off. If the voltage is normal, go to step 27, otherwise, go to next step.
25. Check connectors C-28, C-90, D-16 at intermediate connector and C-56 at ECM (M/T) or C-57 at PCM (A/T) and D-18 at fuel tank differential pressure sensor for damage. see scheme 15, see scheme 17, see scheme 26 or see scheme 33. If the connectors are in good condition, go to next step, otherwise, repair or replace them and go to step 28.
26. Check the harness wire between ECM connector C-56, terminal 61 (M/T) or PCM connector C-57, terminal 92 (A/T) and fuel tank differential pressure sensor connector D-18 terminal 1 for damage. see scheme 15, see scheme 17 or see scheme 33. If the harness wire is in good condition, go to step 28, otherwise, repair it and go to step 28.
27. 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 on. Remove the fuel cap. Set the scan tool to data reading mode for item 73, Fuel Tank Differential Pressure Sensor. The fuel tank pressure should be -285 to 285 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 off and disconnect the scan tool. If the scan tool reading is within the specified value, this malfunction is intermittent, refer to «INTERMITTENT DIAGNOSTIC TROUBLE CODES»(ref-156203-S19689263182003072200000). If the scan tool reading is not in line with the specified value, replace the ECM (M/T) or PCM (A/T) and go to next step.
28. Carry out a test drive with the drive cycle pattern (OBD-II). See «EVAP SYSTEM LEAK MONITOR»(ref-156203-S23802916432003072200000). Read the diagnostic trouble codes. If DTC P0451 is set, retry the troubleshooting. If the DTC is absent, the inspection is complete.

1. Test Conditions: For Test To Run - Intake air temperature is higher than 41°F (5°C). Engine speed is 1,600 RPM or more. Volumetric efficiency is between 20-80%.
2. Judgement Criteria - When the evaporative emission purge solenoid is off, the fuel differential pressure sensor output voltage remains 1.0 volt or less for 10 seconds.

1. Connect Scan Tool (MB991502) 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 on. Remove the fuel cap. Set the scan tool to data reading mode for item 73, Fuel Tank Differential Pressure Sensor. The fuel tank pressure should be -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 off and disconnect the scan tool. If the scan tool is reading within the specified value, go to step 28, otherwise, go to next step.
2. Check the output circuit voltage at intermediate connector D-16. see scheme 26 Remove the rear seat cushion. Remove the protector. Disconnect intermediate connector D-16. Use Special Tools (MB991658 and MB991709) to connect terminals 5, 6 and 8 between connectors of the intermediate connector respectively. Turn the ignition on. Remove the fuel cap. Measure the voltage between terminal 5 and ground. Voltage should be between 2.0-3.0 volts. Turn the ignition off. If the voltage is normal, go to next step, otherwise, go to step 6.
3. Check the output circuit voltage at ECM connector C-57 (M/T) or PCM connector C-57 (A/T) by backprobing. see scheme 15or see scheme 33. Do not disconnect the ECM connector C-56 (M/T) or PCM connector C-57 (A/T). Turn the ignition on. Remove the fuel cap. Measure the voltage between terminal 61 (M/T) or terminal 92 (A/T) and ground by backprobing. Voltage should be between 2.0-3.0 volts. Turn the ignition off. If the voltage is normal, go to step 27, otherwise, go to next step.
4. Check connectors C-28, C-90, D-16 at intermediate connector and C-56 at ECM (M/T) or C-57 at PCM (A/T) for damage. see scheme 15, see scheme 26 or see scheme 33. If the connectors are in good condition, go to next step, otherwise, repair or replace them and go to step 28.
5. Check the harness wire between ECM connector C-56, terminal 61 (M/T) or PCM connector C-57, terminal 92 (A/T) and intermediate connector D-16, terminal 5 for damage. see scheme 15, see scheme 26 or see scheme 33. If the harness wire is in good condition, go to step 28, otherwise, repair it and go to step 28.
6. Check the 5 volts supply circuit voltage at intermediate connector D-16. see scheme 26 Disconnect intermediate connector D-16. Use Special Tools (MB991658 and MB991709) to connect terminals 5, 6 and 8 between connectors of the intermediate connector respectively. Turn the ignition on. Measure the voltage between terminal 8 and ground. Voltage should be between 4.8-5.2 volts. Turn the ignition off. If the voltage is normal, go to step 11, otherwise, go to next step.
7. Check the 5 volts supply circuit voltage at ECM connector C-60 (M/T) or PCM connector C-54 (A/T) by backprobing. see scheme 15or see scheme 33. Do not disconnect ECM connector C-60 (M/T) or PCM connector C-54 (A/T). Turn the ignition on. Measure the voltage between terminal 81 (M/T) or terminal 46 (A/T) and ground by backprobing. Voltage should be between 4.8-5.2 volts. Turn the ignition off. If the voltage is normal, go to step 9, otherwise, go to next step.
8. Check connector C-60 at ECM (M/T) or C-54 at PCM (A/T) for damage. see scheme 15or see scheme 33. If the connector is in good condition, go to step 27, otherwise, repair or replace it and go to step 28.
9. Check connectors C-28, C-90, D-16 at intermediate connector for damage. see scheme 26 If the connectors are in good condition, go to next step, otherwise, repair or replace them and go to step 28.
10. Check the harness wire between ECM connector C-60, terminal 81 (M/T) or PCM connector C-54, terminal 46 (A/T) and intermediate connector D-16, terminal 8 for damage. see scheme 15, see scheme 26 or see scheme 33. If the harness wire is in good condition, go to step 28, otherwise, repair it and go to step 28.
11. Check the circuit voltage at intermediate connector D-16. see scheme 26 Disconnect intermediate connector D-16. Use Special Tool (MB991658) to connect terminal 6 between connectors and the intermediate connector. Turn the ignition on. Measure the voltage at the male side connector between terminal 6 and ground. Voltage should be between 4.8-5.2 volts. Turn the ignition off. If the voltage is normal, go to next step, otherwise, go to step 15.
12. Check the ground voltage at ECM connector C-60 (M/T) or PCM connector C-54 (A/T) by backprobing. see scheme 15or see scheme 33. Do not disconnect ECM connector C-60 (M/T) or PCM connector C-54 (A/T). Turn the ignition on. Measure the voltage between terminal 92 (M/T) or terminal 57 (A/T) and ground by backprobing. The voltage should be 0.5 volt or less. Turn the ignition off. If the voltage is normal, go to step 28, otherwise, go to next step.
13. Check connectors C-28, C-90, D-16 at intermediate connector and C-60 at ECM (M/T) or C-54 at PCM (A/T) for damage. see scheme 15, see scheme 26 or see scheme 33. If the connectors are in good condition, go to next step, otherwise, repair or replace them and go to step 28.
14. Check the harness wire between ECM connector C-60, terminal 92 (M/T) or PCM connector C-54, terminal 57 (A/T) and intermediate connector D-16, terminal 6 for damage. see scheme 15, see scheme 26 or see scheme 33. If the harness wire is in good condition, go to step 27, otherwise, repair it and go to step 28.
15. Check the 5 volts supply circuit voltage at fuel tank differential pressure sensor connector D-18. see scheme 17 Remove the center exhaust pipe. Remove the fuel band assembly, tilt the fuel tank. Disconnect fuel tank differential pressure sensor connector D-18. Use Special Tool (MB991658) to connect terminals 1, 2 and 3 of the connected sensor connector and those of the harness side connector respectively. Turn the ignition on. Measure the voltage between terminal 3 and ground. Voltage should be between 4.8-5.2 volts. Turn the ignition off. If the voltage is normal, go to step 18, otherwise, go to next step.
16. Check connectors D-16 at intermediate connector and D-18 at fuel tank differential pressure sensor for damage. see scheme 17and see scheme 26. If the connectors are in good condition, go to next step, otherwise, repair or replace them and go to step 28.
17. Check the harness wire between intermediate connector D-16, terminal 8 and fuel tank differential pressure sensor connector D-18, terminal 3 for damage. If the harness wire is in good condition, go to step 28, otherwise, repair it and go to step 28.
18. Check the ground circuit voltage at fuel tank differential pressure sensor connector D-18. see scheme 17 Disconnect fuel tank differential pressure sensor connector D-18. Use Special Tool (MB991658) to connect terminal 3 of the disconnected sensor connector and those of the harness side connector respectively. Turn the ignition on. Measure the voltage at the fuel tank differential pressure sensor side connector between terminal 2 and ground. Voltage should be between 4.8-5.2 volts. Turn the ignition off. If the voltage is normal, go to next step, otherwise, replace the fuel tank differential pressure sensor and go to step 28.
19. Check the ground voltage at ECM connector C-60 (M/T) or PCM connector C-54 (A/T) by backprobing. see scheme 15or see scheme 33. Do not disconnect ECM connector C-60 (M/T) or PCM connector C-54 (A/T). Turn the ignition on. Measure the voltage between terminal 92 (M/T) or terminal 57 (A/T) and ground by backprobing. The voltage should be 0.5 volt or less. Turn the ignition off. If the voltage is normal, go to step 28, otherwise, go to next step.
20. Check connectors C-28, C-90, D-16 at intermediate connector and C-60 at ECM (M/T) or C-54 at PCM (A/T) and D-18 at fuel tank differential pressure sensor for damage. see scheme 15, see scheme 17 see scheme 26 or see scheme 33. If the connectors are in good condition, go to next step, otherwise, repair or replace them and go to step 28.
21. Check the harness wire between ECM connector C-60, terminal 92 (M/T) or PCM connector C-54, terminal 57 (A/T) and fuel tank differential pressure sensor connector D-18, terminal 2 for damage. see scheme 15, see scheme 17 or see scheme 33. If the harness wire is in good condition, go to next step, otherwise, repair it and go to step 28.
22. Check the ground voltage at ECM connector C-60 (M/T) or PCM connector C-54 (A/T) by backprobing. see scheme 15or see scheme 33. Do not disconnect ECM connector C-60 (M/T) or PCM connector C-54 (A/T). Turn the ignition on. Measure the voltage between terminal 92 (M/T) or terminal 57 (A/T) and ground by backprobing. The voltage should be 0.5 volt or less. Turn the ignition off. If the voltage is normal, go to next step, otherwise, go to step 27.
23. Check the output circuit voltage at fuel tank differential pressure connector D-18. see scheme 17 Disconnect fuel tank differential pressure sensor connector D-18. Use Special Tool (MB991658) to connect terminals 1, 2 and 3 of the disconnected sensor connector and those of the harness side connector respectively. Turn the ignition on. Remove the fuel cap. Measure the voltage between terminal 1 and ground. Voltage should be between 2.0-3.0 volts. Turn the ignition off. If the voltage is normal, go to next step, otherwise, replace the fuel tank differential pressure sensor and go to step 28.
24. Check the output circuit voltage at ECM connector C-56 (M/T) or PCM connector C-57 (A/T) by backprobing. see scheme 15or see scheme 33. Do not disconnect the ECM connector C-56 (M/T) or PCM connector C-57 (A/T). Turn the ignition on. Remove the fuel cap. Measure the voltage between terminal 61 (M/T) or terminal 92 (A/T) and ground by backprobing. Voltage should be between 2.0-3.0 volts. Turn the ignition off. If the voltage is normal, go to step 27, otherwise, go to next step.
25. Check connectors C-28, C-90, D-16 at intermediate connector and C-56 at ECM (M/T) or C-57 at PCM (A/T) and D-18 at fuel tank differential pressure sensor for damage. see scheme 15, see scheme 17, see scheme 26 or see scheme 33. If the connectors are in good condition, go to next step, otherwise, repair or replace it and go to step 28.
26. Check the harness wire between ECM connector C-56, terminal 61 (M/T) or PCM connector C-57, terminal 92 (A/T) and fuel tank differential pressure sensor connector D-18, terminal 1 for damage. see scheme 15, see scheme 17 or see scheme 33. If the harness wire is in good condition, go to step 28, otherwise, repair it and go to step 28.
27. 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 on. Remove the fuel cap. Set the scan tool to data reading mode for item 73, Fuel Tank Differential Pressure Sensor. The fuel tank pressure should be -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 off and disconnect the scan tool. If the scan tool is reading within the specified value, the malfunction is intermittent, refer to «INTERMITTENT DIAGNOSTIC TROUBLE CODES»(ref-156203-S19689263182003072200000). If the scan tool is reading out of range, replace the ECM (M/T) or PCM (A/T) and go to next step.
28. Carry out a test drive with the drive cycle pattern (OBD-II). See «EVAP SYSTEM LEAK MONITOR»(ref-156203-S23802916432003072200000). Read the diagnostic trouble codes. If DTC P0452 is set, retry the troubleshooting. If the DTC is absent, the inspection is complete.

1. Test Conditions: For Test To Run - Intake air temperature is between 41-113°F (5-45°C) or more. Engine speed is 1,600 RPM or more. Volumetric efficiency is between 20-80%.
2. Judgement Criteria - When the evaporative emission purge solenoid valve is activating at 100% ratio, the fuel differential pressure sensor output voltage remains 4.0 volts or more for 10 seconds.

1. Connect Scan Tool (MB991502) 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 on. Remove the fuel cap. Set the scan tool to data reading mode for item 73, Fuel Tank Differential Pressure Sensor. The fuel tank pressure should be -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 off and disconnect the scan tool. If the scan tool reading is within the specified value, go to step 28, otherwise, go to next step.
2. Check the output circuit voltage at intermediate connector D-16. see scheme 26 Remove the rear seat cushion and protector. Disconnect intermediate connector D-16. Use Special Tools (MB991658 and MB991709) to connect terminals 5, 6 and 8 between connectors of the intermediate connector respectively. Turn the ignition on. Remove the fuel cap. Measure the voltage between terminal 5 and ground. Voltage should be between 2.0-3.0 volts. Turn the ignition off. If the voltage is normal, go to next step, otherwise, go to step 6.
3. Check the output circuit voltage at ECM connector C-56 (M/T) or PCM connector C-57 (A/T) by backprobing. see scheme 15or see scheme 33. Do not disconnect the ECM connector C-56 (M/T) or PCM connector C-57 (A/T). Turn the ignition on. Remove the fuel cap. Measure the voltage between terminal 61 (M/T) or terminal 92 (A/T) and ground by backprobing. Voltage should be between 2.0-3.0 volts. Turn the ignition off. If the voltage is normal, go to step 27, otherwise, go to next step.
4. Check connectors C-28, C-90, D-16 at intermediate connector and C-56 at ECM (M/T) or C-57 at PCM (A/T) for damage. see scheme 15, see scheme 26 or see scheme 33. If the connectors are in good condition, go to next step, otherwise, repair or replace them and go to step 28.
5. Check the harness wire between ECM connector C-56, terminal 61 (M/T) or PCM connector C-57, terminal 92 (A/T) and intermediate connector D-16, terminal 5 for damage. see scheme 15, see scheme 26 or see scheme 33. If the harness wire is in good condition, go to step 28, otherwise, repair it and go to step 28.
6. Check the 5 volts supply circuit voltage at intermediate connector D-16. see scheme 26 Disconnect intermediate connector D-16. Use Special Tools (MB991658 and MB991709) to connect terminals 5, 6 and 8 between connectors of the intermediate connector respectively. Turn the ignition on. Measure the voltage between terminal 8 and ground. Voltage should be between 4.8-5.2 volts. Turn the ignition off. If the voltage is normal, go to step 11, otherwise, go to next step.
7. Check the 5 volts supply circuit voltage at ECM connector C-60 (M/T) or PCM connector C-54 (A/T) by backprobing. see scheme 15or see scheme 33. Do not disconnect ECM connector C-60 (M/T) or PCM connector C-54 (A/T). Turn the ignition on. Measure the voltage between terminal 81 (M/T) or terminal 46 (A/T) and ground by backprobing. Voltage should be between 4.8-5.2 volts. Turn the ignition off. If the voltage is normal, go to step 9, otherwise, go to next step.
8. Check connector C-60 at ECM (M/T) or C-54 at PCM (A/T) for damage. see scheme 15or see scheme 33. If the connector is in good condition, go to step 27, otherwise, repair or replace it and go to step 28.
9. Check connectors C-28, C-90, D-16 at intermediate connector for damage. see scheme 26 If the connectors are in good condition, go to next step, otherwise, repair or replace them and go to step 28.
10. Check the harness wire between ECM connector C-60, terminal 81 (M/T) or PCM connector C-54, terminal 46 (A/T) and intermediate connector D-16, terminal 8 for damage. see scheme 15, see scheme 26 or see scheme 33. If the harness wire is in good condition, go to step 28, otherwise, repair it and go to step 28.
11. Check the circuit voltage at intermediate connector D-16. see scheme 26 Disconnect intermediate connector D-16. Use Special Tool (MB991658) to connect terminal 6 between connectors of the intermediate connector. Turn the ignition on. Measure the voltage at the male side connector between terminal 6 and ground. Voltage should be between 4.8-5.2 volts. Turn the ignition off. If the voltage is normal, go to next step, otherwise, go to step 15.
12. Check the ground voltage at ECM connector C-60 (M/T) or PCM connector C-54 (A/T) by backprobing. see scheme 15or see scheme 33. Do not disconnect ECM connector C-60 (M/T) or PCM connector C-54 (A/T). Turn the ignition on. Measure the voltage between terminal 92 (M/T) or terminal 57 (A/T) and ground by backprobing. The voltage should be 0.5 volt or less. Turn the ignition off. If the voltage is normal, go to step 28, otherwise, go to next step.
13. Check connectors C-28, C-90, D-16 at intermediate connector and C-60 at ECM (M/T) or C-54 at PCM (A/T) for damage. see scheme 15, see scheme 26 or see scheme 33. If the connectors are in good condition, go to next step, otherwise, repair or replace them and go to step 28.
14. Check the harness wire between ECM connector C-60, terminal 92 (M/T) or PCM connector C-54, terminal 57 (A/T) and intermediate connector D-16, terminal 6 for damage. If the harness wire is in good condition, go to step 27, otherwise, repair it and go to step 28.
15. Check the 5 volts supply circuit voltage at fuel tank differential pressure sensor connector D-18. see scheme 17 Remove the center exhaust pipe. Remove the fuel band assembly, tilt the fuel tank. Disconnect fuel tank differential pressure sensor connector D-18. Use Special Tool (MB991658) to connect terminals 1, 2 and 3 of the disconnected sensor connector and those of the harness side connector respectively. Turn the ignition on. Measure the voltage between terminal 3 and ground. Voltage should be between 4.8-5.2 volts. Turn the ignition off. If the voltage is normal, go to step 18, otherwise, go to next step.
16. Check connectors D-16 at intermediate connector and D-18 at fuel tank differential pressure sensor for damage. see scheme 26and see scheme 17. If the connectors are in good condition, go to next step, otherwise, repair or replace them and go to step 28.
17. Check the harness wire between intermediate connector D-16, terminal 8 and fuel tank differential pressure sensor connector D-18, terminal 3 for damage. If the harness wire is in good condition, go to step 28, otherwise, repair it and go to step 28.
18. Check the ground circuit voltage at fuel tank differential pressure sensor connector D-18. see scheme 17 Disconnect fuel tank differential pressure sensor connector D-18. Use Special Tool (MB991658) to connect terminal 3 of the disconnected sensor connector and those of the harness side connector respectively. Turn the ignition on. Measure the voltage at the fuel tank differential pressure sensor side connector between terminal 2 and ground. Voltage should be between 4.8-5.2 volts. Turn the ignition off. If the voltage is normal, go to next step, otherwise, replace the fuel tank differential pressure sensor and go to step 28.
19. Check the ground voltage at ECM connector C-60 (M/T) or PCM connector C-54 (A/T) by backprobing. see scheme 15or see scheme 33. Do not disconnect ECM connector C-60 (M/T) or PCM connector C-54 (A/T). Turn the ignition on. Measure the voltage between terminal 92 (M/T) or terminal 57 (A/T) and ground by backprobing. The voltage should be 0.5 volt or less. Turn the ignition off. If the voltage is normal, go to step 28, otherwise, go to next step.
20. Check connectors C-28, C-90, D-16 at intermediate connector and C-60 at ECM (M/T) or C-54 at PCM (A/T) and D-18 at fuel tank differential pressure sensor for damage. see scheme 15, see scheme 17, see scheme 26 or see scheme 33. If the connectors are in good condition, go to next step, otherwise, repair or replace them and go to step 28.
21. Check the harness wire between ECM connector C-60, terminal 92 (M/T) or PCM connector C-54, terminal 57 (A/T) and fuel tank differential pressure sensor connector D-18, terminal 2 for damage. see scheme 15, see scheme 17 or see scheme 33. If the harness wire is in good condition, go to next step, otherwise, repair it and go to step 28.
22. Check the ground voltage at ECM connector C-60 (M/T) or PCM connector C-54 (A/T) by backprobing. see scheme 15or see scheme 33. Do not disconnect ECM connector C-60 (M/T) or PCM connector C-54 (A/T). Turn the ignition on. Measure the voltage between terminal 92 (M/T) or terminal 57 (A/T) and ground by backprobing. The voltage should be 0.5 volt or less. Turn the ignition off. If the voltage is normal, go to next step, otherwise, go to step 27.
23. Check the output circuit voltage at fuel tank differential pressure connector D-18. see scheme 17 Disconnect fuel tank differential pressure sensor connector D-18. Use Special Tool (MB991658) to connect terminals 1, 2 and 3 of the disconnected sensor connector and those of the harness side connector respectively. Turn the ignition on. Remove the fuel cap. Measure the voltage between terminal 1 and ground. Voltage should be between 2.0-3.0 volts. Turn the ignition off. If the voltage is normal, go to next step, otherwise, replace the fuel tank differential pressure sensor and go to step 28.
24. Check the output circuit voltage at ECM connector C-56 (M/T) or PCM connector C-57 (A/T) by backprobing. see scheme 15or see scheme 33. Do not disconnect the ECM connector C-56 (M/T) or PCM connector C-57 (A/T). Turn the ignition on. Remove the fuel cap. Measure the voltage between terminal 61 (M/T) or terminal 92 (A/T) and ground by backprobing. Voltage should be between 2.0-3.0 volts. Turn the ignition off. If the voltage is normal, go to step 27, otherwise, go to next step.
25. Check connectors C-28, C-90, D-16 at intermediate connector and C-56 at ECM (M/T) or C-57 at PCM (A/T) and D-18 at fuel tank differential pressure sensor for damage. see scheme 15, see scheme 17, see scheme 26 or see scheme 33. If the connectors are in good condition, go to next step, otherwise, repair or replace them and go to step 28.
26. Check the harness wire between ECM connector C-56, terminal 61 (M/T) or PCM connector C-57, terminal 92 (A/T) and fuel tank differential pressure sensor connector D-18, terminal 1 for damage. see scheme 15, see scheme 17 or see scheme 33. If the harness wire is in good condition, go to step 28, otherwise, repair it and go to step 28.
27. 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 on. Remove the fuel cap. Set the scan tool to data reading mode for item 73, Fuel Tank Differential Pressure Sensor. The fuel tank pressure should be -1.5-1.5 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 off and disconnect the scan tool. If the scan tool reading is within the specified value, the malfunction is intermittent, refer to «INTERMITTENT DIAGNOSTIC TROUBLE CODES»(ref-156203-S19689263182003072200000). If the scan tool reading is out of range, replace the ECM (M/T) or PCM (A/T) and go to next step.
28. Carry out a test drive with the drive cycle pattern (OBD-II). See «EVAP SYSTEM LEAK MONITOR»(ref-156203-S23802916432003072200000). Read the diagnostic trouble codes. If DTC P0453 is set, retry the troubleshooting. If the DTC is absent, the diagnosis is complete.

1. 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 is 97°F (36°C) or less when the engine is started.
2. Test Conditions B: For Test To Run - The engine coolant temperature is 136°F (58°C) or more (i.e. the amount of remaining fuel is 15-40%). The engine coolant temperature is 68°F (20°C) or more (i.e. the amount of remaining fuel is 40-80%). Engine speed is 1600 RPM or more. Barometric pressure is above 11 psi (76 kPa). Volumetric efficiency is between 20-80%. The fuel temperature is 97°F (36°C) or less. Fuel tank differential pressure sensor output voltage is 1-4 volts.
3. 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 higher than 0.065 psi (451 Pa) - i.e. the amount of remaining fuel is 15-40%. When the evaporative emission purge solenoid and evaporative emission ventilation solenoid are closed, the pressure rises higher than 0.047 psi (324 Pa) - i.e. the amount of remaining fuel is 40-85%.
4. Judgement Criteria - The fuel tank internal pressure is 0.29 psi (2 kPa) or more after the evaporative emission purge solenoid has been driven when the fuel tank and vapor line have been closed. NOTE: The monitoring time (75-125 seconds) depends on the fuel level and the temperature in the fuel tank.

Scheme 168

1. Connect Scan Tool (MB991502) to the data link connector. Turn the ignition on. 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. (If the engine speed does not reach 2000 RPM during the monitor test, adjustment of the Speed Adjusting Screw may be needed.) 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". If the scan tool shows "Evap Leak Mon. Completed. Test Passed", the evaporative emission system is working properly at this time. Explain to the customer that improperly tightened fuel cap can cause MIL to turn on, and return the vehicle. If the scan tool shows "Evap Leak Mon. Completed. Test Failed and DTCs Set", a malfunction has been detected during the monitor test, go to next step. If the scan tool shows "Evap Lead Mon. discontinued. Retest again from the first", 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 off once and repeat the monitoring from step 1.
2. Using scan tool, check solenoid for clogging of the purge control. Disconnect hoses "A" and "B" from the evaporative emission purge solenoid side. (Scheme 166) Connect the hand vacuum pump to the evaporative emission purge solenoid instead of hose "B". Turn the ignition on. Set the scan tool to actuator test mode for 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 off and disconnect the 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, otherwise, replace the evaporative emission purge solenoid and go to step 27.
3. Check for leaks and clogging in the evaporator line hose "A" to hose "C". (Scheme 154) If the hoses are in good condition, go to next step, otherwise, replace the damaged hose(s) and go to step 27.
4. Check for leaks and clogging in the chamber. The chamber should allow air flow, but restricted. Air leaking from the chamber body is normal. If the chamber is in good condition, go to next step, otherwise, replace the chamber and go to step 27.
5. Connect scan tool to the data link connector. Disconnect hose "E" from the evaporative emission ventilation solenoid side, and connect a hand vacuum pump. (Scheme 159) Turn the ignition on. Set the scan tool to actuator test mode for 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 off and disconnect the 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, otherwise, replace the evaporative emission ventilation solenoid and go to step 27.
6. Pressure test for leaks in the evaporator line from hose "D" to hose "N". (Scheme 159)and (Scheme 165). 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 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. (Scheme 159)and (Scheme 165). If air is maintained, go to step 17, otherwise, go to next step.
7. Pressure test for leaks in the evaporator line from hose "G" to hose "N". (Scheme 158)and (Scheme 165). Disconnect hose "G" from the evaporative emission canister side, and plug the hose. Perform the pressure test again. If air is maintained, go to step 10, otherwise, go to next step.
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". (Scheme 159) If the hoses are in good condition, go to next step, otherwise, replace the damaged hose(s), reinstall the fuel tank and 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, otherwise, replace the evaporative emission canister, reinstall the fuel tank and go to step 27.
10. Check for leaks in the evaporator line from hose "H" to hose "I". (Scheme 160)and (Scheme 168) Remove the fuel tank. Disconnect hose H at the liquid separator side, and then connect a hand vacuum pump to the hose. Plug hose I at the fuel tank side. 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, otherwise, replace the damaged hose(s), reinstall the fuel tank and go to step 27.
11. Check for leaks in the evaporator line hose "G", "J", "K", "L" and hose "M". (Scheme 158)and (Scheme 162). Remove the filler neck assembly. Perform the 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, otherwise, replace the damaged hose(s), reinstall the filler neck assembly and go to step 27.
12. Check the check valve "A". (Scheme 163) The valve should only allow air to pass in one direction, air leaking from the check valve body is normal. If check valve "A" is in good condition, go to next step, otherwise, replace the check valve "A", reinstall the filler neck assembly and go to step 27.
13. Check the check valve "B" (Scheme 164) The valve should allow a greater air volume to pass in one direction than the other, verify this. Air leaking from the check valve body is normal. If check valve "B" is in good condition, go to next step, otherwise, replace check valve "B", reinstall the filler neck assembly and go to step 27.
14. Check for leaks in the evaporator line from hose "N" (Scheme 165) Perform the leakage test with a hand vacuum pump on hose "N". If hose "N" is in good condition, go to next step, otherwise, replace hose "N", reinstall the fuel tank and go to step 27.
15. Check for leaks in the fuel tank. (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. (Scheme 165) 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 the leaking parts, check again for leaks. Reinstall the fuel tank and go to step 27. If the fuel tank is leaking, replace it and go to step 27. If there are no leaks, go to next step.
16. Visually check for cracks in the fuel tank filler neck. If the fuel filler neck assembly is in good condition, reinstall the fuel tank, fuel filler neck assembly and go to step 27. If the fuel filler neck assembly is damaged, replace the fuel tank filler neck assembly, reinstall the fuel tank and go to step 27.
17. Pressure test for clogging in the evaporator line from hose "G" to hose "N". (Scheme 158)and (Scheme 165). Disconnect hose "G" from the evaporative emission canister side, and unplug 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 hose "G" and go to next step, otherwise, go to step 22.
18. Pressure test for clogging in the evaporator line form hose "D" to hose "F". (Scheme 159) 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" and go to next step, otherwise, go to step 20.
19. Connect scan tool to the data link connector. Turn the ignition on. 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. (If the engine speed does not reach 2000 RPM during the monitor test, adjustment of the Speed Adjusting Screw may be needed.) 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 off and disconnect the scan tool. If the scan tool shows "Evap Leak Mon. Completed. Test Passed", the evaporative emission system is working properly at this time, go to step 27. If the scan tool shows "Evap Leak Mon. Completed. Test Failed and DTCs Set", replace the ECM (M/T) or PCM (A/T) and go to step 27. If the scan tool shows "Evap Lead Mon. discontinued. Retest again from the first", the monitor was discontinued for a certain reason (vehicle speed input from ECM (M/T) or PCM (A/T), engine speed and engine load deviating from specified range). Turn the ignition off once and recheck evaporative emission system monitor test.
20. Check for clogging in the evaporator line hose "D" to "F". (Scheme 159) Remove the fuel tank. Perform the clogging test with a hand vacuum pump on each hose from hose "D" to "F". If the hoses are in good condition, go to next step, otherwise, replace the inferior hose, reinstall the fuel tank and 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 pressure on the vacuum pump. When each nipple is unplugged, air should pass through. If the evaporative emission canister is in good condition, reinstall the fuel tank and go to step 27. If the evaporative emission canister is damaged, replace it, reinstall the fuel tank and go to step 27.
22. Check for clogging in the evaporator line from hose "H" to hose "I". (Scheme 160)and (Scheme 167). Remove the fuel tank. Disconnect hose "H" at the liquid separator side, and then connect a hand vacuum pump to the hose. Unplug hose "I" at the fuel tank side. Apply pressure on the vacuum pump, air should pass through hose "I". If the hoses are in good condition, go to next step, otherwise, replace the damaged hose(s), reinstall the fuel tank and go to step 27.
23. Check for clogging in the evaporator line hose "G", "J", "K", "L" and "M". (Scheme 158)and (Scheme 162). Remove the filler neck assembly. Perform 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, otherwise, replace the damaged hose(s), reinstall the filler neck assembly and go to step 27.
24. Check the check valve "A". (Scheme 163) Check valve should only allow air to pass in one direction, verify this. It is normal for air to leak from the check valve body. If check valve "A" is in good condition, go to next step, otherwise, replace check valve "A", reinstall the filler neck assembly and go to step 27.
25. Check the check valve "B". (Scheme 164) Check valve should allow a higher volume of air to pass in one direction than the other, verify this. It is normal for air to leak from the check valve body. If check valve "B" is in good condition, go to next step, otherwise, replace check valve "B", reinstall the filler neck assembly and go to step 27.
26. Check for clogging in the evaporator line from hose "N". (Scheme 165) Perform the clogging test with a hand vacuum pump on hose "N". If hose "N" is in good condition, go to next step, otherwise, replace hose "N", reinstall the fuel tank and go to next step.
27. Carry out a test drive with the drive cycle pattern (OBD-II). See «EVAP SYSTEM LEAK MONITOR»(ref-156203-S23802916432003072200000).Read the diagnostic trouble codes. If DTC P0455 is set, retry the troubleshooting. If the DTC is absent, the inspection is complete.

1. 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%). Intake air temperature is 91°F (33°C) or less when the engine is started. The engine coolant temperature is 91°F (33°C) or less when the engine is started.
2. Test Conditions B: For Test To Run - Barometric pressure is above 11 psi (76 kPa). Volumetric efficiency is between 20-80%. The fuel temperature is 91°F (33°C) or less. Fuel tank differential pressure sensor output voltage is 1-4 volts.
3. Test Conditions C: For Test To Stop - Engine coolant temperature is less than 68°F (20°C). 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 higher: 0.047 psi (324 Pa).
4. Judgement Criteria - Internal pressure of the fuel tank fluctuates 0.177-0.199 psi (1177-1373 Pa) or more in 10 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).

1. Connect Scan Tool (MB991502) to the data link connector. Turn the ignition on. 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. (If the engine speed does not reach 2000 RPM during the monitor test, adjustment of the Speed Adjusting Screw may be needed.) 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 off and disconnect the scan tool. If the scan tool shows "Evap Leak Mon. Completed Test Passed", the evaporative emission system is working properly at this time. Explain to the customer that improperly tightened fuel cap can cause the MIL to turn on, and return the vehicle. If the scan tool shows "Evap Leak Mon. Completed. Test Failed and DTCs Set", a malfunction has been detected during the monitor test, go to next step. If the scan tool shows "Evap Lead Mon. discontinued. Retest again from the first", 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 off once and repeat the monitoring from step 1.
2. Check evaporative emission purge solenoid for leaks. (Scheme 166) 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. (Scheme 154) Apply pressure with 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, otherwise, replace the evaporative emission purge solenoid, and go to step 18.
3. Check for leaks in the evaporator line hose "A" to hose "C". (Scheme 154) Perform the leakage test with the hand vacuum pump on each hose from hose "A" to "C" If the hoses are in good condition, go to next step, otherwise, replace the damaged hose(s) and 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, otherwise, replace the chamber and go to step 18.
5. Connect scan tool to the data link connector. Disconnect the hose "E" from the evaporative emission ventilation solenoid side. (Scheme 159) Connect the hand vacuum pump to the nipple of the evaporative emission ventilation solenoid from which the hoses have been disconnected. Turn the ignition on. Set the scan tool to actuator test mode for 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 off and disconnect the 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, otherwise, replace the evaporative emission ventilation solenoid and go to step 18.
6. Pressure test for evaporator line from hose "D" to hose "N". (Scheme 159)and (Scheme 165). 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 line is in good condition, go to step 17, otherwise, go to next step.
7. Pressure test for evaporator line from hose "G" to hose "N". (Scheme 158)and (Scheme 165). Disconnect hose "G" from the evaporative emission canister side, and plug the hose form which the pipes have been disconnected. Perform the pressure test again. If the evaporator line is in good condition, go to next step, otherwise, go to step 10.
8. Check for leaks in the evaporator line hose "D" to hose "F". (Scheme 159) 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, otherwise, replace the damaged hose(s), reinstall the fuel tank and 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 evaporative emission canister is in good condition, go to step 18, otherwise, replace the evaporative emission canister, reinstall the fuel tank and go to step 18.
10. Check for leaks in the evaporator line from hose "H" and hose "I". (Scheme 160)and (Scheme 168). 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 line is in good condition, go to next step, otherwise, replace that hose, reinstall the fuel filler neck protector and go to step 18.
11. Check for leaks in the evaporator line hose "G", "J", "K", "L" and "M". (Scheme 161)and (Scheme 162). 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, otherwise, replace the hose, reinstall the fuel tank and fuel filler neck assembly and go to step 18.
12. Check the check valve "A". (Scheme 163) The check valve should only allow air to pass in one direction, verify this. It is normal for air to leak from the check valve body. If check valve "A" is in good condition, go to next step, otherwise, replace check valve "A", reinstall the fuel tank and fuel filler neck assembly and go to step 18.
13. Check the check valve "B". (Scheme 164) The check valve should allow a greater volume of air to pass in one direction than the other, verify this. It is normal for air to leak from the check valve body. If check valve "B" is in good condition, go to next step, otherwise, replace check valve "B", reinstall the fuel tank and fuel filler neck assembly and 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, otherwise, replace the hose, reinstall the fuel tank and fuel filler neck assembly and 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, otherwise, replace the fuel filler neck assembly, reinstall the fuel tank and fuel filler neck assembly and go to step 18.
16. Visually check for leaks in the fuel tank. (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. Apply pressure with the evaporative emission system pressure pump. In the pressurized state, check for the leak by applying soap water or the like to each section. If the fuel tank is in good condition, go to next step, otherwise, replace the fuel tank, reinstall the fuel tank and fuel filler neck assembly and go to step 18.
17. Connect scan tool to the data link connector. Turn the ignition on. 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. (If the engine speed does not reach 2000 RPM during the monitor test, adjustment of the Speed Adjusting Screw may be needed.) 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 off and disconnect the scan tool. If the scan tool shows "Evap Leak Mon. Completed. Test Passed", the evaporative emission system is working properly at this time, go to next step. If the scan tool shows "Evap Leak Mon. Completed. Test Failed and DTCs Set", replace the ECM (M/T) or PCM (A/T) and go to next step. If the scan tool shows "Evap Leak Mon. discontinued. Retest again from the first", the monitor was discontinued for a certain reason (vehicle speed input from ECM (M/T) or PCM (A/T), engine speed and engine load deviating from specified range). Turn the ignition off once and recheck the evaporative emission system monitor test.
18. Carry out a test drive with the drive cycle pattern (OBD-II). See «EVAP SYSTEM LEAK MONITOR»(ref-156203-S23802916432003072200000). Read the diagnostic trouble codes. If DTC P0442 is set, retry the troubleshooting. If the DTC is absent, the diagnosis is complete.

Check Conditions, Judgement Criteria - When the fuel consumption calculated from the operation time of the injector amounts to 20 liters, the diversity of the amount of fuel in tank calculated from the fuel level sensor is 2 liter or less.

1. Connect Scan Tool (MB991502) to the data link connector. Turn the ignition on. Set the scan tool to data reading mode for item 4B, Fuel Level Sensor. When the fuel gauge is near "FULL", voltage should be 100-3600 millivolts. When the fuel gauge is near "EMPTY", voltage should be 2700-6200 millivolts. Turn the ignition off. If the sensor is operating properly, it can be assumed that this malfunction is intermittent, refer to «INTERMITTENT DIAGNOSTIC TROUBLE CODES»(ref-156203-S19689263182003072200000). If the sensor is malfunctioning, go to next step.
2. Check connector D-17 at the fuel gauge unit for damage. see scheme 18 If the connector is in good condition, go to next step, otherwise, repair or replace it and go to step 12.
3. Check the continuity at fuel gauge unit harness side connector D-17. see scheme 18. Disconnect the connector D-17 and measure at the harness side. Check for continuity between terminal 1 and ground. The resistance should be less than 2 ohm. If the continuity is normal, go to next step, otherwise, repair harness wire between fuel gauge unit connector D-17, terminal 1 and ground (because of open circuit or harness damage) and go to step 12.
4. Check the sensor supply voltage at fuel gauge unit harness side connector D-17. see scheme 18 Disconnect the connector D-17 and measure at the harness side. Disconnect the combination connector C-41. see scheme 11 Turn the ignition on. Measure the voltage between terminal 2 and ground. Voltage should be battery positive voltage. Turn the ignition off. If the resistance is normal, go to step 9, otherwise, go to next step.
5. Check the sensor supply voltage at ECM connector C-60 (M/T) or PCM connector C-54 (A/T) by backprobing. see scheme 15or see scheme 33. Do not disconnect the ECM connector C-60 (M/T) or PCM connector C-54 (A/T). Disconnect the combination meter connector C-41. Turn the ignition on. Measure the voltage between terminal 74 (M/T) or terminal 60 (A/T) 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 off. If the voltage is normal, go to next step, otherwise, go to step 7.
6. Check connector C-60 at ECM (M/T) or connector C-54 at PCM (A/T) for damage. see scheme 15or see scheme 33.If the connector is in good condition, check connector C-90 and C-28 at intermediate connector for damage, and repair or replace as required. If intermediate connector is in good condition, repair harness wire between fuel gauge unit connector D-17, terminal 2 and ECM connector C-60, terminal 74 (M/T) or PCM connector C-54, terminal 60 (A/T - because of open circuit) and go to step 12. If the connector is damaged, repair or replace it and go to step 12.
7. Check connector C-60 at ECM (M/T) or connector C-54 at PCM (A/T) for damage. see scheme 15or see scheme 33. If the connector is in good condition, go to next step, otherwise, repair or replace it and go to step 12.
8. Check for short circuit to ground between fuel gauge unit connector D-17, terminal 2 and ECM connector C-60, terminal 74 (M/T) or PCM connector C-54, terminal 60 (A/T). see scheme 15, see scheme 18 or see scheme 33. If the harness wire is in good condition, replace the ECM or PCM and go to step 12, otherwise, repair it and go to step 12.
9. Check the fuel gauge unit. If the fuel gauge unit is normal, go to next step, otherwise, replace the fuel gauge unit and go to step 12.
10. Check connector C-60 at ECM (M/T) or connector C-54 at PCM (A/T) for damage. see scheme 15or see scheme 33. If the connector is in good condition, go to next step, otherwise, repair or replace it and go to step 12.
11. Check for harness damage between fuel gauge unit connector D-17, terminal 2 and ECM connector C-60, terminal 74 (M/T) or PCM connector C-54, terminal 60 (A/T). see scheme 15, see scheme 18 or see scheme 33. If the harness wire is in good condition, replace the ECM or PCM and go to next step, otherwise, repair it and go to next step.
12. Carry out a test drive with the drive cycle pattern (OBD-II). Check the diagnostic trouble codes. If DTC P0460 is output, retry the troubleshooting. If the DTC is absent, the inspection is complete.

1. Check Conditions - 2 seconds or more have passed since the starting sequence was completed. Engine speed is between 2000-4000 RPM. Volumetric efficiency is between 48-65%.
2. Judgement Criteria - Vehicle speed sensor output voltage has not changed (no pulse signal is input) for 2 seconds.

1. Connect Scan Tool (MB991502) to the data link connector. Start the engine. Set the scan tool to data reading mode for item 24, Vehicle Speed Sensor. Check that the speedometer and MUT-II display speed match when traveling at a vehicle speed of 25 mph (40 km/h). Turn the ignition off. If the sensor is operating properly, it can be assumed that this malfunction is intermittent, refer to «INTERMITTENT DIAGNOSTIC TROUBLE CODES»(ref-156203-S19689263182003072200000). If the sensor is malfunctioning, go to next step.
2. Check the speed meter. If the speed meter is functioning, go to next step, otherwise, go to step 8.
3. Do not disconnect the ECM connector C-60. Disconnect the combination meter connector and auto-cruise control-ECU connector. Connect the oscilloscope probe to ECM connector C-60, terminal 86 by backprobing. Start the engine. see scheme 15 Check the waveform. The waveform should show a pattern similar to the illustration while the vehicle is being moved. Turn the ignition off. If the waveform is normal, go to next step, otherwise, go to step 6.
4. Check connector C-60 at ECM for damage. see scheme 15 If the connector is in good condition, repair or replace it and go to step 17.
5. Connect scan tool to the data link connector. Start the engine. Set the scan tool to data reading mode for item 24, Vehicle Speed Sensor. Check that the speedometer and MUT-II display speed match when traveling at a vehicle speed of 25 mph (40 km/h). Turn the ignition off. If the sensor is operating properly, it can be assumed that this malfunction is intermittent, refer to «INTERMITTENT DIAGNOSTIC TROUBLE CODES»(ref-156203-S19689263182003072200000). If the sensor is malfunctioning, replace the ECM and go to step 17.
6. Check the sensor supply voltage at ECM connector C-60 by backprobing. see scheme 15 Do not disconnect the ECM connector C-60. Disconnect the vehicle speed sensor connector B-39. see scheme 36 Turn the ignition on. Measure the voltage between terminal 86 and ground by backprobing. Voltage should be between 4.8-5.2 volts. Turn the ignition off. If the voltage is normal, go to step 17, otherwise, replace the ECM and go to step 17.
7. Check connector C-60 at ECM for damage. see scheme 15 If the connector is in good condition, check connector B-36 at intermediate connector for damage, and repair or replace as required. see scheme 36 If intermediate connector is in good condition, repair harness wire between vehicle speed sensor connector B-39, terminal 3 and ECM connector C-60, terminal 86 (because of open circuit) and go to step 17. If the connector is damaged, repair or replace it and go to step 17.
8. Check connector B-39 at vehicle speed sensor for damage. see scheme 36 If the connector is in good condition, go to next step, otherwise, repair or replace it and go to step 17.
9. Check the power supply voltage at vehicle speed sensor harness side connector B-39. see scheme 36 Disconnect the connector B-39 and measure at the harness side. Turn the ignition on. Measure the voltage between terminal 1 and ground. Voltage should be battery positive voltage. Turn the ignition off. If the voltage is normal, go to next step. If the voltage is abnormal, check connectors B-36, C-28, C-78, C-112 and C-111 at intermediate connector for damage, and repair or replace as required. If intermediate connectors are in good condition, repair harness wire between ignition switch connector C-87, terminal 2 and vehicle speed sensor connector B-39, terminal 1 (because of open circuit or short circuit to ground) and go to step 17.
10. Check the continuity at vehicle speed sensor harness side connector B-39. see scheme 36 Disconnect the connector B-39 and measure at the harness side. Check for the continuity between terminal 2 and ground. The resistance should be less than 2 ohm. If the continuity is normal, go to next step. If the continuity is abnormal, check connector B-36 at intermediate connector for damage, and repair or replace as required. If intermediate connector is in good condition, repair harness wire between vehicle speed sensor connector B-39, terminal 2 and ground (because of open circuit or harness damage) and go to step 17.
11. Check the sensor supply voltage at the vehicle speed sensor harness side connector B-39. see scheme 36 Disconnect the vehicle speed sensor connector B-39 and measure at the harness side. Disconnect the combination meter connector and auto-cruise control-ECU connector. Turn the ignition on. Measure the voltage between terminal 3 and ground. Voltage should be between 4.8-5.2 volts. Turn the ignition off. If the voltage is normal, go to next step, otherwise, check connector B-36 at intermediate connector for damage, and repair or replace as required. If intermediate connector is in good condition, repair harness wire between vehicle speed sensor connector B-39, terminal 3 and ECM connector C-60, terminal 86 (because of short circuit to ground or harness damage) and go to step 17.
12. Check the vehicle speed sensor. If the vehicle speed sensor is normal, go to next step, otherwise, replace the vehicle speed sensor and go to step 17.
13. Check connector C-60 at ECM for damage. see scheme 15 If the connector is in good condition, go to next step, otherwise, repair or replace it and go to step 17.
14. Check for harness damage between ignition switch connector C-87, terminal 2 and vehicle speed sensor connector B-39, terminal 1. see scheme 22and see scheme 36. (Check harness after checking intermediate connectors B-36, C-28, C-78, B-112 and C-111. If intermediate connectors are damaged, repair or replace them and go to step 17.) If the harness wire is in good condition, go to next step, otherwise, repair it and go to step 17.
15. Check for harness damage between vehicle speed sensor connector B-39, terminal 3 and ECM connector C-60, terminal 86. see scheme 15and see scheme 36. (Check harness after checking intermediate connector B-36. If intermediate connector is damaged, repair or replace it and go to step 17.) If the harness wire is in good condition, go to next step, otherwise, repair it and go to step 17.
16. Check for harness damage between vehicle speed sensor connector B-39, terminal 2 and ground. see scheme 36 (Check harness after checking intermediate connector B-36. If intermediate connector is damaged, repair or replace it and go to step 17.) If the harness wire is in good condition, check for harness wire between vehicle speed sensor connector B-39, terminal 3 and other system (because of short circuit to ground) and go to next step. If the harness wire is damaged, repair it and go to next step.
17. Connect scan tool to the data link connector. Start the engine. Set the scan tool to data reading mode for item 24, Vehicle Speed Sensor. Check that the speedometer and MUT-II display speed match when traveling at a vehicle speed of 25 mph (40 km/h). Turn the ignition off. If the sensor is operating properly, the inspection is complete. If the sensor is malfunctioning, retry the troubleshooting.

1. Check Conditions - Under the closed loop idle speed control. Engine coolant temperature is more than 171°F (77°C). Battery positive voltage is higher than 10 volts. Power steering pressure switch: "OFF". Volumetric efficiency is lower than 40%. Barometric pressure is higher than 11 psi (76 kPa). Intake air temperature is higher than 14°F (-10°C). 25 seconds have elapsed from the start of the previous monitoring. Target idle air control motor position is more than 100 steps.
2. Judgement Criteria - The actual idle speed is more than 100 RPM lower than the target idle speed for 12 seconds.

1. Connect Scan Tool (MB991502) to the data link connector. Turn the ignition on. Set the scan tool to read the DTC. Turn the ignition off. If a diagnostic trouble code other than P0506 is output, follow the appropriate diagnostic procedure. If there are no additional trouble codes present, go to next step.
2. Check the throttle body (throttle valve area). If the throttle valve area is dirty, clean it and go to step 14, otherwise, go to next step.
3. Check connector B-34 at idle air control motor for damage. see scheme 21 If the connector is in good condition, go to next step, otherwise, repair or replace it and go to step 14.
4. Check the idle air control motor coil resistance. Disconnect the idle air control motor connector B-34. see scheme 21 Measure the resistance between idle air control motor connector terminal 2 and either terminal 1 or terminal 3. Measure the resistance between idle air control motor connector terminal 5 and either terminal 4 or terminal 6. If the resistance is normal, go to next step, otherwise, replace the idle air control motor and go to step 14.
5. Check the power supply voltage at idle air control motor harness side connector B-34. see scheme 21 Disconnect the connector B-34 and measure at the harness side. Turn the ignition on. Measure the voltage between terminal 2, 5 and ground. Voltage should be battery positive voltage. Turn the ignition off. If the voltage is normal, go to step 7, otherwise, go to next step.
6. Check connector A-18X at MFI relay for damage. see scheme 31 If the connector is in good condition, repair harness wire between MFI relay connector A-18X, terminal 4 and idle air control motor connector B-34, terminal 2, 5 (because of open circuit or short circuit to ground) and go to step 14. If the connector is damaged, repair or replace it and go to step 14.
7. Check the power supply voltage at ECM connector C-49 (M/T) or PCM connector C-50 (A/T) by backprobing. see scheme 15or see scheme 33. Do not disconnect the connector C-49 (M/T) or C-50 (A/T). Measure the voltage between terminal (4, 5, 17, 18 - M/T) or (14, 15, 28, 29 - A/T) and ground by backprobing. The voltage is 1 volt or lower for approximately 3 seconds, then changes to the battery positive voltage when the ignition switch is turned on. Turn the ignition off. If the voltage is normal, go to step 10, otherwise, go to next step.
8. Check connector C-49 at ECM (M/T) or connector C-50 at PCM (A/T) for damage. see scheme 15or see scheme 33. If the connector is in good condition, go to next step, otherwise, repair or replace it and go to step 14.
9. Check for open circuit and short circuit to ground between idle air control motor connector B-34 and ECM connector C-49 (M/T) or PCM connector C-50 (A/T). see scheme 15, see scheme 21 or see scheme 33: Idle air control motor connector B-34, terminal 1 and ECM connector C-49, terminal 4 (M/T) or PCM connector C-50, terminal 14 (A/T). Idle air control motor connector B-34, terminal 3 and ECM connector C-49, terminal 17 (M/T) or PCM connector C-50, terminal 28 (A/T). Idle air control motor connector B-34, terminal 4 and ECM connector C-49, terminal 5 (M/T) or PCM connector C-50, terminal 15 (A/T). Idle air control motor connector B-34, terminal 6 and ECM connector C-49, terminal 18 (M/T) or PCM connector C-50, terminal 29 (A/T). If the harness wire is in good condition, replace the ECM or PCM and go to step 14, otherwise, repair it and go to step 14.
10. Check connector C-49 at ECM (M/T) or connector C-50 at PCM (A/T) for damage. see scheme 15or see scheme 33. If the connector is in good condition, go to next step, otherwise, repair or replace it and go to step 14.
11. Check the idle air control motor operation using Special Tool (MB991709). Remove the idle air control motor. Connect Special Tool (MB991709) to the idle air control motor (All terminals should be connected). Use the jumper wires to connect terminal 2 of the idle air control motor connector to the positive battery terminal. Check to ensure that the motor operates when terminals 1 and 3 of the idle air control motor connector are respectively connected to the negative battery terminal using a jumper wire. Vibration should be present at each application of voltage to test clip combination. Use jumper wires to connect terminal 5 of the idle air control motor connector to the positive battery terminal. Check to ensure that the motor operates when terminals 4 and 6 of the idle air control motor connector are respectively connected to the negative 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, otherwise, replace the idle air control motor and go to step 14.
12. Check for harness damage between MFI relay connector A-18X, terminal 4 and idle air control motor connector B-34, terminal 2, 5. see scheme 21and see scheme 31. If the harness wire is in good condition, go to next step, otherwise, repair it and go to step 14.
13. Check for harness damage between idle air control motor connector B-34 and ECM connector C-49 (M/T) or PCM connector C-50 (A/T). see scheme 15, see scheme 21 or see scheme 33: Idle air control motor connector B-34, terminal 1 and ECM connector C-49, terminal 4 (M/T) or PCM connector C-50, terminal 14 (A/T). Idle air control motor connector B-34, terminal 3 and ECM connector C-49, terminal 17 (M/T) or PCM connector C-50, terminal 28 (A/T). Idle air control motor connector B-34, terminal 4 and ECM connector C-49, terminal 5 (M/T) or PCM connector C-50, terminal 15 (A/T). Idle air control motor connector B-34, terminal 6 and ECM connector C-49, terminal 18 (M/T) or PCM connector C-50, terminal 29 (A/T). If the harness wire is in good condition, replace the ECM or PCM and go to next step, otherwise, repair it and go to next step.
14. Carry out a test drive with the drive cycle pattern (OBD-II). Check the diagnostic trouble codes. If DTC P0506 is output, retry the troubleshooting, otherwise, the inspection is complete.

1. Check Conditions - Vehicle speed has reached 0.93 mph (1.5 km/h) or more at least once. Under the closed loop idle speed control. Engine coolant temperature is higher than 171°F (77°C). Battery positive voltage is higher than 10 volts. Barometric pressure is higher than 11 psi (76 kPa). Intake air temperature is higher than 14°F (-10°C). 25 seconds have elapsed from the start of the previous monitoring. Target idle air control motor position is 0 steps.
2. Judgement Criteria - Actual idle speed has continued to be higher than the target idle speed by 200 RPM if maximum air temperature during the previous operation was less than 113°F (45°C) or 300 RPM if maximum air temperature during the previous operation was more than 113°F (45°C) or more for 12 seconds.

1. Connect Scan Tool (MB991502) to the data link connector. Turn the ignition on. Set the scan tool to read DTCs. Turn the ignition off. If a DTC other than P0507 is output, refer to the appropriate diagnostic procedure. If no additional DTCs are present, go to next step.
2. Check the intake system for vacuum leaks. If there are any abnormalities, rectify and go to step 14, otherwise, go to next step.
3. Check connector B-34 at idle air control motor for damage. see scheme 21 If the connector is in good condition, go to next step, otherwise, repair or replace it and go to step 14.
4. Check the idle air control motor coil resistance. Disconnect the idle air control motor connector B-34. see scheme 21 Measure the resistance between idle air control motor connector terminal 2 and either terminal 1 or terminal 3. Measure the resistance between idle air control motor connector, terminal 5 and either terminal 4 or terminal 6. If the resistance is normal, go to next step, otherwise, replace the idle air control motor and go to step 14.
5. Check the power supply voltage at idle air control motor harness side connector B-34. see scheme 21 Disconnect the connector B-34 and measure at the harness side. Turn the ignition on. Measure the voltage between terminal 2, 5 and ground. Voltage should be battery positive voltage. Turn the ignition off. If the voltage is normal, go to step 7, otherwise, go to next step.
6. Check connector A-18X at MFI relay for damage. see scheme 31 If the connector is in good condition, repair harness wire between MFI relay connector A-18X, terminal 4 and idle air control motor connector B-34, terminal 2, 5 (because of open circuit or short circuit to ground) and go to step 14. If the connector is damaged, repair or replace it and go to step 14.
7. Check the power supply voltage at ECM connector C-49 (M/T) or PCM connector C-50 (A/T) by backprobing. see scheme 15or see scheme 33. Do not disconnect the connector C-49 (M/T) or C-50 (A/T). Measure the voltage between terminal (4, 5, 17, 18 - M/T) or (14, 15, 28, 29 - A/T) and ground by backprobing. The voltage is 1 volt or lower for approximately 3 seconds, then changes to the battery positive voltage when the ignition is turned on. Turn the ignition off. If the voltage is normal, go to step 10, otherwise, go to next step.
8. Check connector C-49 at ECM (M/T) or connector C-50 at PCM (A/T) for damage. see scheme 15or see scheme 33. If the connector is in good condition, go to next step, otherwise, repair or replace it and go to step 14.
9. Check for open circuit and short circuit to ground between idle air control motor connector B-34 and ECM connector C-49 (M/T) or PCM connector C-50 (A/T). see scheme 15, see scheme 21 or see scheme 33: Idle air control motor connector B-34, terminal 1 and ECM connector C-49, terminal 4 (M/T) or PCM connector C-50, terminal 14 (A/T). Idle air control motor connector B-34, terminal 3 and ECM connector C-49, terminal 17 (M/T) or PCM connector C-50, terminal 28 (A/T). Idle air control motor connector B-34, terminal 4 and ECM connector C-49, terminal 5 (M/T) or PCM connector C-50, terminal 15 (A/T). Idle air control motor connector B-34, terminal 6 and ECM connector C-49, terminal 18 (M/T) or PCM connector C-50, terminal 29 (A/T). If the harness wire is in good condition, replace the ECM or PCM and go to step 14, otherwise, repair it and go to step 14.
10. Check connector C-49 at ECM (M/T) or connector C-50 at PCM (A/T) for damage. see scheme 15or see scheme 33. If the connector is in good condition, go to next step, otherwise, repair or replace it and go to step 14.
11. Check the idle air control motor operation using Special Tool (MB991709). Remove the idle air control motor. Connect Special Tool MB991709 to the idle air control motor (all terminals should be connected). Use the jumper wires to connect terminal 2 of the idle air control motor connector to the positive battery terminal. Check to ensure that the motor operates when terminals 1 and 3 of the idle air control motor connector are respectively connected to the negative battery terminal using a jumper wire. Vibration should be present at each application of voltage to test clip combination. Use jumper wires to connect terminal 5 of the idle air control motor connector to the positive battery terminal. Check to ensure that the motor operates when terminals 4 and 6 of the idle air control motor connector are respectively connected to the negative 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, otherwise, replace the idle air control motor and go to step 14.
12. Check for harness damage between MFI relay connector A-18X, terminal 4 and idle air control motor connector B-34, terminal 2, 5. see scheme 21and see scheme 31. If the harness wire is in good condition, go to next step, otherwise, repair it and go to step 14.
13. Check for harness damage between idle air control motor connector B-34 and ECM connector C-49 (M/T) or PCM connector C-50 (A/T). see scheme 15, see scheme 21 or see scheme 33: Idle air control motor connector B-34, terminal 1 and ECM connector C-49, terminal 4 (M/T) or PCM connector C-50, terminal 14 (A/T). Idle air control motor connector B-34, terminal 3 and ECM connector C-49, terminal 17 (M/T) or PCM connector C-50, terminal 28 (A/T). Idle air control motor connector B-34, terminal 4 and ECM connector C-49, terminal 5 (M/T) or PCM connector C-50, terminal 15 (A/T). Idle air control motor connector B-34, terminal 6 and ECM connector C-49, terminal 18 (M/T) or PCM connector C-50, terminal 29 (A/T). If the harness wire is in good condition, replace the ECM or PCM and go to next step, otherwise, repair it and go to next step.
14. Carry out a test drive with the drive cycle pattern (OBD-II). Check the diagnostic trouble codes. If DTC P0507 is output, retry the troubleshooting. If the DTC is absent, the inspection is complete.

1. Check Conditions - Engine coolant temperature is higher than 86°F (30°C). Drive for 4 seconds or more at 31 mph (50 km/h) or more. Stop the vehicle (vehicle speed is 0.93 mph (1.5 km/h) or less). Repeat 10 times or more.
2. Judgement Criteria - Power steering pressure switch continues to be "ON".

1. Connect Scan Tool (MB991502) to the data link connector. Start the engine and run at idle. Set the scan tool to data reading mode for 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 off. If the sensor is operating properly, it can be assumed that this malfunction is intermittent, refer to «INTERMITTENT DIAGNOSTIC TROUBLE CODES»(ref-156203-S19689263182003072200000). If the sensor is malfunctioning, go to next step.
2. Check the power supply voltage at power steering pressure switch connector B-19 by backprobing. See Do not disconnect the connector B-19. Start the engine and run at idle. Measure the voltage between terminal 1 and ground by backprobing. When steering wheel is stationary, voltage should be battery positive voltage. When steering wheel is turned, voltage should be 1 volt or less. Turn the ignition off. If the voltage is normal, go to next step, otherwise, go to step 5.
3. Check connector B-19 at power steering pressure switch for damage. If the connector is in good condition, go to next step, otherwise, repair or replace it and go to step 14.
4. Connect scan tool to the data link connector. Start the engine and run at idle. Set the scan tool to data reading mode for 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 off. If the sensor is operating properly, it can be assumed that this malfunction is intermittent, refer to «INTERMITTENT DIAGNOSTIC TROUBLE CODES»(ref-156203-S19689263182003072200000). If the sensor is malfunctioning, replace the ECM or PCM and go to step 14.
5. Check connector B-19 at power steering pressure switch for damage. If the connector is in good condition, go to next step, otherwise, repair or replace it and go to step 14.
6. Check the power supply voltage at power steering pressure switch harness side connector B-19. Disconnect the connector B-19 and measure at the harness side. Turn the ignition on. Measure the voltage between terminal 1 and ground. Voltage should be battery positive voltage. Turn the ignition off. If the voltage is normal, go to step 11, otherwise, go to next step.
7. Check the power supply voltage at ECM connector C-53 (M/T) or PCM connector C-54 (A/T) by backprobing. see scheme 15or see scheme 33. Do not disconnect the ECM connector C-53 (M/T) or PCM connector C-54 (A/T). Disconnect the power steering pressure switch connector B-19. Turn the ignition on. Measure the voltage between terminal 37 (M/T) or 52 (A/T) and ground by backprobing. Voltage should be battery positive voltage. Turn the ignition off. If the voltage is normal, go to next step, otherwise, go to step 9.
8. Check connector C-53 at ECM (M/T) or connector C-54 at PCM (A/T) for damage. see scheme 15or see scheme 33. If the connector is in good condition, repair harness wire between power steering pressure switch connector B-19, terminal 1 and ECM connector C-53, terminal 37 (M/T) or PCM connector C-54, terminal 52 (A/T) (because of open circuit) and go to step 14. If the connector is damaged, repair or replace it and go to step 14.
9. Check connector C-53 at ECM (M/T) or connector C-54 at PCM (A/T) for damage. see scheme 15or see scheme 33. If the connector is in good condition, go to next step, otherwise, repair or replace it and go to step 14.
10. Check for short circuit to ground between power steering pressure switch connector B-19, terminal 1 and ECM connector C-53, terminal 37 (M/T) or PCM connector C-54, terminal 52 (A/T). see scheme 15or see scheme 33. If the harness wire is in good condition, replace the ECM or PCM and go to step 14. If the harness wire is damaged, repair it and go to step 14.
11. Replace the power steering pressure switch. Check the trouble symptoms. Check the diagnostic trouble codes. If DTC P0551 is output, go to next step, otherwise, go to step 14.
12. Check connector C-53 at ECM (M/T) or connector C-54 at PCM (A/T) for damage. see scheme 15or see scheme 33. If the connector is in good condition, go to next step, otherwise, repair or replace it and go to step 14.
13. Check for harness damage between power steering pressure switch connector B-19, terminal 1 and ECM connector C-53, terminal 37 (M/T) or PCM connector C-54, terminal 52 (A/T). see scheme 15or see scheme 33. If the harness wire is in good condition, replace the ECM or PCM and go to next step, otherwise, repair it and go to next step.
14. Connect scan tool to the data link connector. Start the engine and run at idle. Set the scan tool to data reading mode for 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 off. If the switch is operating properly, the inspection is complete, otherwise, retry the troubleshooting.

1. Check Conditions - 8 minutes or more have passed since the starting of the engine. Note that this is only if the engine coolant temperature is less than 32°F (0°C) when starting. Engine coolant temperature is higher than 113°F (45°C). Intake air temperature is higher than 32°F (0°C). Volumetric efficiency is between 30-45%.
2. Judgement Criteria - Manifold differential pressure sensor output voltage has continued to be higher than 4.6 volts [corresponding to an absolute pressure of 17 psi (118 kPa) or higher] for 2 seconds OR Manifold differential pressure sensor output voltage has continued to be lower than 0.1 volt (corresponding to an absolute pressure of 0.3 psi (2.4 kPa) or lower) for 2 seconds.
3. Check Conditions - 8 minutes or more have passed since the engine started. Note that this is only if the engine coolant temperature is 32°F (0°C) or more when starting. Engine coolant temperature is higher than 113°F (45°C). Intake air temperature is higher than 41°F (5°C). Volumetric efficiency is lower than 30%.
4. Judgement Criteria - Manifold differential pressure sensor output voltage has continued to be higher than 4.2 volts [corresponding to an absolute pressure of 16 psi (108 kPa) or higher] for 2 seconds.
5. Check Conditions - 8 minutes or more have passed after starting the engine. Note that this is only if the engine coolant temperature is 32°F (0°C) or more when starting. Engine coolant temperature is higher than 113°F (45°C). Intake air temperature is higher than 32°F (0°C). Volumetric efficiency is higher than 70%.
6. Judgement Criteria - Manifold differential pressure sensor output voltage has continued to be lower than 1.8 volts (corresponding to an absolute pressure of 4.6 psi (46 kPa) or lower) for 2 seconds.

1. Connect Scan Tool (MB991502) to the data link connector. Start the engine and run at idle. Set the scan tool to data reading mode for item 95, Manifold Differential Pressure Sensor. While engine is idling, pressure should be between 62 and 76 kPa. Turn the ignition off. If the sensor is operating properly, it can be assumed that this malfunction is intermittent, refer to «INTERMITTENT DIAGNOSTIC TROUBLE CODES»(ref-156203-S19689263182003072200000). If the sensor is malfunctioning, go to next step.
2. Check connector B-04 at manifold differential pressure sensor for damage. see scheme 30 If the connector is in good condition, go to next step, otherwise, repair or replace it and go to step 12.
3. Check the sensor supply voltage at manifold differential pressure sensor harness side connector B-04. see scheme 30 Disconnect the connector B-04 and measure at the harness side. Turn the ignition on. Measure the voltage between terminal 3 and ground. Voltage should be between 4.8-5.2 volts. Turn the ignition off. If the voltage is normal, go to step 6, otherwise, go to next step.
4. Check connector C-60 at ECM (M/T) or connector C-54 at PCM (A/T) for damage. see scheme 15or see scheme 33. If the connector is in good condition, go to next step, otherwise, repair or replace it and go to step 12.
5. Check for open circuit and short circuit to ground between manifold differential pressure sensor connector B-04, terminal 3 and ECM connector C-60, terminal 81 (M/T) or PCM connector C-54, terminal 46 (A/T). see scheme 15, see scheme 30 or see scheme 33. If the harness wire is in good condition, replace the ECM or PCM and go to step 12, otherwise, repair it and go to step 12.
6. Check the continuity at manifold differential pressure sensor harness side connector B-04. see scheme 30 Disconnect the connector B-04 and measure at the harness side. Measure the continuity between terminal 2 and ground. The resistance should be less than 2 ohm. If the continuity is normal, go to step 9, otherwise, go to next step.
7. Check connector C-60 at ECM (M/T) or connector C-54 at PCM (A/T) for damage. see scheme 15or see scheme 33. If the connector is in good condition, go to next step, otherwise, repair or replace it and go to step 12.
8. Check for open circuit and harness damage between manifold differential pressure sensor connector B-04, terminal 2 and ECM connector C-60, terminal 92 (M/T) or PCM connector C-54, terminal 57 (A/T). see scheme 15, see scheme 30 or see scheme 33. If the harness wire is in good condition, replace the ECM or PCM and go to step 12, otherwise, repair it and go to step 12.
9. Check connector C-60 at ECM (M/T) or connector C-54, C-57 at PCM (A/T) for damage. see scheme 15or see scheme 33. If the connector is in good condition, go to next step, otherwise, repair or replace it and go to step 12.
10. Check for harness damage between manifold differential pressure sensor connector B-04, terminal 3 and ECM connector C-60, terminal 81 (M/T) or PCM connector C-54, terminal 46 (A/T). see scheme 15, see scheme 30 or see scheme 33. If the harness wire is in good condition, go to next step, otherwise, repair it and go to step 12.
11. Check for open circuit and short circuit to ground and harness damage between manifold differential pressure sensor connector B-04, terminal 1 and ECM connector C-60, terminal 73 (M/T) or PCM connector C-57, terminal 91 (A/T). see scheme 15, see scheme 30 or see scheme 33. If the harness wire is in good condition, replace the manifold differential pressure sensor and go to next step, otherwise, repair it and go to next step.
12. Carry out a test dive with the drive cycle pattern (OBD-II). Check the diagnostic trouble codes. If DTC P1400 is output, retry the troubleshooting, otherwise, the inspection is complete.

1. Check Conditions - Engine speed is higher than 50 RPM.
2. Judgement Criteria - Input voltage from the generator FR terminal has continued to be approximately battery positive voltage for 20 seconds.

1. Check the voltage at generator intermediate connector B-13 by backprobing. see scheme 24 Do not disconnect the connector B-13. Start the engine and run at idle. Measure the voltage between terminal 3 and ground by backprobing: Engine: warming up Radiator fan: stopped Headlight switch: OFF to ON Rear defogger switch: OFF to ON Stoplight switch: OFF to ON The voltage should drop. Turn the ignition off. If the voltage is normal, go to next step, otherwise, go to step 4.
2. Check connector B-13 at generator intermediate connector for damage. see scheme 24 If the connector is in good condition, go to next step, otherwise, repair or replace it and go to step 11.
3. Carry out a test drive with the drive cycle pattern. Check the diagnostic trouble codes. If DTC P1500 is output, replace the ECM or PCM and go to step 11, otherwise, it can be assumed that this malfunction is intermittent, refer to «INTERMITTENT DIAGNOSTIC TROUBLE CODES»(ref-156203-S19689263182003072200000).
4. Check connector B-13 at generator intermediate connector for damage. see scheme 24 If the connector is in good condition, go to next step, otherwise, repair or replace it and go to step 11.
5. Check connector B-45 at generator connector for damage. see scheme 19 If the connector is in good condition, go to next step, otherwise, repair or replace it and go to step 11.
6. Check the voltage at generator harness side connector B-45. see scheme 19 Disconnect the connector B-45 and measure at the harness side. Turn the ignition on. Measure the voltage between terminal 4 and ground. The voltage should be battery positive voltage. Turn the ignition off. If the voltage is normal, go to step 9, otherwise, go to next step.
7. Check connector C-53 at ECM (M/T) or connector C-54 at PCM (A/T) for damage. see scheme 15or see scheme 33. If the connector is in good condition, go to next step, otherwise, repair or replace it and go to step 11.
8. Check for open circuit and short circuit to ground between generator connector B-45, terminal 4 and ECM connector C-53, terminal 41 (M/T) or PCM connector C-54, terminal 54 (A/T). see scheme 15, see scheme 19 or see scheme 33. If the harness wire is in good condition, replace the ECM or PCM and go to step 11, otherwise, repair it and go to step 11.
9. Check connector C-53 at ECM (M/T) or connector C-54 at PCM (A/T) for damage. see scheme 15or see scheme 33. If the connector is in good condition, go to next step, otherwise, repair or replace it and go to step 11.
10. Check for harness damage between generator connector B-45 terminal 4 and ECM connector C-53, terminal 41 (M/T) or PCM connector C-54, terminal 54 (A/T). see scheme 15, see scheme 19 or see scheme 33. If the harness wire is in good condition, replace the generator and go to next step, otherwise, repair it and go to next step.
11. Carry out a test drive with the drive cycle pattern (OBD-II). Check the diagnostic trouble codes. If DTC P1500 is output, retry the troubleshooting, otherwise, the inspection is complete.

1. Check Conditions - Starting sequence was completed. Battery positive voltage is higher than 10 volts.
2. Judgement Criteria - Battery backup line voltage has continued to be 6 volts or lower for 2 seconds.

1. Connect Scan Tool (MB991502) to the data link connector. Turn the ignition on. Erase the DTCs. Start the engine and run at idle. Read the DTCs. Turn the ignition off. If DTC P1603 is output, go to next step, otherwise, the inspection is complete.
2. Check the backup power supply voltage at ECM connector C-60 (M/T) or PCM connector C-54 (A/T) by backprobing. see scheme 15or see scheme 33. Do not disconnect the ECM connector C-60 (M/T) or PCM connector C-54 (A/T). Measure the voltage between terminal 80 (M/T) or 66 (A/T) and ground by backprobing. Voltage should be battery positive voltage. If the voltage is normal, go to step 5, otherwise, go to next step.
3. Check the backup power supply voltage at ECM harness side connector C-60 (M/T) or PCM harness side connector C-54 (A/T). see scheme 15or see scheme 33. Disconnect the ECM connector C-60 (M/T) or PCM connector C-54 (A/T) and measure at the harness side. Measure the voltage between terminal 80 (M/T) or 66 (A/T) and ground. Voltage should be battery positive voltage. If the voltage is normal, go to next step. If the voltage is abnormal, check connectors C-78, C-89 and C-28 at intermediate connector for damage, and repair or replace as required. see scheme 27 If intermediate connector is in good condition, repair harness wire between battery and ECM connector C-60 (M/T), terminal 80 or PCM connector C-54 (A/T), terminal 66 (because of open circuit or short circuit to ground) and go to step 6.
4. Check connector C-60 at ECM (M/T) or connector C-54 at PCM (A/T) for damage. see scheme 15or see scheme 33. If the harness connector is in good condition, check connectors C-78, C-89 and C-28 at intermediate connector for damage, and repair or replace as required. see scheme 27 If intermediate connector is in good condition, repair harness wire between battery and ECM connector C-60 (M/T), terminal 80 or PCM connector C-54 (A/T), terminal 66 (because of harness damage) and go to step 6. If the harness connector is damaged, repair or replace it and go to step 6.
5. Check connector C-60 at ECM (M/T) or connector C-54 at PCM (A/T) for damage. see scheme 15or see scheme 33. If the harness connector is in good condition, replace the ECM or PCM and go to next step. If the harness connector is damaged, repair or replace it and go to next step.
6. Connect scan tool to the data link connector. Turn the ignition on. Read the DTCs. Turn the ignition off. If DTC P1603 is output, retry the troubleshooting. If the DTC is absent, the inspection is complete.

1. Check Conditions - Ignition switch is on.
2. Judgement Criteria - When the communication error between ECM (M/T) or PCM (A/T) and the immobilizer-ECU continues for 2 seconds or more.

Using scan tool, check for immobilizer system DTCs. If immobilizer system DTC is present, diagnose immobilizer system concern. See appropriate IMMOBILIZER SYSTEMS - ECLIPSE article in ACCESSORIES & EQUIPMENT. If immobilizer system DTC is not present, erase Multiport Fuel Injection (MFI) DTCs and retest system. If DTC P1610 sets again, replace ECM/PCM.