Engine Controls - Self-Diagnostics: Other Mazda Tribute I

MALFUNCTION INDICATOR LIGHT

The Malfunction Indicator Light (MIL) is in the instrument cluster and labeled CHECK ENGINE. Power is available for the MIL when ignition is on or in the START position. After engine start, MIL will remain illuminated for approximately 4 seconds as a bulb test. If the MIL does not illuminate as a bulb check, bulb is damaged or MIL circuit is open. The MIL will turn on or flash when the Powertrain Control Module (PCM) detects an emission related component or system fault.

If the PCM has identified an emission related system fault, MIL will remain on after bulb check. PCM will store a corresponding Diagnostic Trouble Code (DTC). If the PCM does not send a control message to the instrument cluster, the MIL will illuminate. If MIL blinks at a steady rate, a severe misfire condition may exist. If MIL blinks erratically, an intermittent open or short may be present in MIL circuit.

In most instances the MIL is illuminated after 2 consecutive drive cycles with the malfunction present. When the MIL is illuminated, 3 consecutive drive cycles without a malfunction are necessary to turn off MIL. The stored DTC is erased after 40 engine warm-up cycles after the MIL is turned off. For diagnosis of MIL, see MALFUNCTION INDICATOR LIGHT in SYSTEM TESTS .

Communication Error

When starting a diagnostic test or accessing Parameter Identification (PIDs) data, it is possible to receive a communication error from the scan tool. A communication error may be caused by operator error, vehicle wiring malfunction, connector problem, PCM malfunction, or other vehicle control modules. The scan tool may display a 2 digit number identifying a communication error code. The scan tool may also display a 2 digit code to a normal (valid) request (these codes require no action). If the scan tool displays an error code, check scan tool connections and verify proper entry of vehicle data. Follow equipment manufacturers instructions to remedy an error code.

Freeze Frame Data

Freeze frame data is technical data which indicates engine's condition at time of first malfunction. This data will remain in memory even if another emission-related DTC is stored, with the exception of misfire or fuel system DTCs. Once freeze frame data for misfire or fuel system DTC is stored, it will overwrite any previous data after which freeze frame data will not be overwritten again.

Pass Codes

SYSTEM PASS indicates no DTCs were stored and scan tool communication is okay. System pass indicates all monitored hardware is functioning within normal operating limits.

Visual Check

Perform the following, and make all necessary repairs before performing VEHICLE PREPARATION

1. Inspect air cleaner and inlet ducts.
2. Check all engine vacuum hoses for damage, bends, leaks, cracks, kinks or improper routing.
3. Inspect system wiring harness for proper connections, bent or broken terminals, corrosion, loose wires and proper routing.
4. Check Powertrain Control Module (PCM), sensors and actuators for physical damage.
5. Check engine coolant for proper level and mixture.
6. Check transaxle fluid level and quality.

Vehicle Preparation

Apply parking brake. Place shift lever into Park or Neutral for manual transaxle. Block drive wheels. Turn all electrical loads off. Start engine and run until normal operating temperature is reached. Go to QUICK TEST under SELF-DIAGNOSTIC SYSTEM.

CLEARING CODES

Note. DO NOT disconnect vehicle battery to clear DTCs.

OBD-II DRIVE CYCLE

The OBD-II drive cycle purpose is to execute OBD-II monitors and identify any concerns with the OBD system. DTC P1000 will be erased of all OBD-II monitors that have completed during OBD-II drive cycle. Obey all traffic laws during execution of OBD-II drive cycle. Use scan tool to observe status of each OBD-II monitor at completion of OBD-II drive cycle.

OBD-II Drive Cycle Recommendations

Most OBD-II monitors will complete more readily driving with a "steady throttle" during acceleration or cruise modes. Smooth throttle operation will minimize the time required for monitor completion. Fuel tank level should be 1/2 to 3/4, with 3/4 being the optimum desired level. The evaporative monitor may only operate during the first 30 minutes of engine operation. When executing the evaporative monitor, stay in part throttle and drive steadily to avoid fuel slosh.

Connect scan tool to vehicle. Verify the following PIDs

1. IAT PID 40-100°F (4-38°C)
2. FLI PID 50-75 percent.
3. ECT PID minimum of 170°F (77°C)

Without returning to key off, using scan tool, clear all DTCs. DTC P1000 will remain. Using scan tool, view status of OBD-II monitors. Proceed to

OBD-II DRIVE CYCLE PROCEDURE

if necessary or proceed to identified monitor drive cycle. See

MONITOR REPAIR VERIFICATION DRIVE CYCLES

OBD-II Drive Cycle Procedure

Note. Once drive cycle is started, engine must not be turned off.

1. Start engine and drive vehicle. Drive vehicle in stop and go traffic for at least 20 minutes with at least 4 idle periods. Drive vehicle on an expressway for 10-15 minutes. Access and monitor IAT PID during expressway drive. Heavy accelerations, sudden accelerations or wide open throttle applications are not recommended.
2. If IAT PID is less than 40°F (4°C) at any time during expressway drive, the Evaporative Emission Monitor will not complete. Access On-Board System Readiness menu to check completion status. Rerun Continuous Memory self-test to check DTC P1000 status. If Evaporative Emission Monitor is the only monitor not showing completion and DTC P1000 has been cleared, OBD-II drive cycle has been completed.

Comprehensive Component Monitor Repair Verification Drive Cycle

1. Ensure Vehicle Preparation has been performed. See «VEHICLE PREPARATION»(ref-150940-S32810755592003012100000) . On M/T vehicles, accelerate 0-50 MPH, then stop vehicle. Go to next step. On A/T vehicles, from a stop, in overdrive, moderately accelerate to 50 MPH and cruise for at least 15 seconds. Stop vehicle and repeat without overdrive to 40 MPH and cruise for at least 30 seconds. While at 40 MPH, activate overdrive and accelerate to 50 MPH and cruise for at least 15 seconds. Stop vehicle for at least 20 seconds, then repeat this procedure 3 more times. After repeating this procedure 3 times, stop vehicle. Go to next step.
2. Accelerate to 65 MPH. Without applying brakes, decelerate at closed throttle until vehicle reaches 40 MPH. Repeat this procedure 3 more times. After repeating this procedure 3 times, verify no DTCs are set with the exception of DTC P1000.

EGR Monitor Repair Verification Drive Cycle

Ensure Vehicle Preparation has been performed. See VEHICLE PREPARATION . From a stop, using 1/2 to 3/4 throttle, accelerate to 45 MPH. Repeat this procedure 3 more times. After repeating this procedure 3 times, verify no DTCs are set with the exception of DTC P1000.

HO2S Monitor Repair Verification Drive Cycle

Ensure Vehicle Preparation has been performed. See VEHICLE PREPARATION . Cruise vehicle at 40 MPH for at least 5 minutes. Verify no DTCs are set with the exception of DTC P1000.

Fuel Or Misfire Monitor Repair Verification Drive Cycle

Ensure Vehicle Preparation has been performed. See VEHICLE PREPARATION . Accelerate on an expressway to 65 MPH. Coast down with foot off accelerator pedal (no brakes) from 65 MPH to 40 MPH. Repeat this procedure 3 more times. After repeating this procedure 3 times, verify no DTCs are set with the exception of DTC P1000.

EVAP Running Loss System Repair Verification Drive Cycle

Note. If ambient temperature is 40-100°F (4-38°C) or altitude is more than 8000 feet (2438 meters), EVAP monitor will not run. FLI PID must be 15-85 percent.

Ensure Vehicle Preparation has been performed. See VEHICLE PREPARATION . Cruise at 45-65 MPH for 10 minutes while avoiding sharp turns and hills. To initiate EVAP monitor, EVAPPDC PID must increase to at least 75 percent (canister purge vent open). At this time, EVAPCV PID will display 100 percent (canister vent solenoid closed to seal the system). Monitor will begin to run. Continue to drive with a steady throttle and light steering until EVAPCV displays zero percent (canister vent solenoid open). Stop vehicle. Using scan tool, view EVAP monitor for completion. Repeat procedure if EVAP monitor is not complete. If EVAP monitor is complete, verify no DTCs are set with exception of DTC P1000.

Catalyst Monitor Repair Verification Drive Cycle

Ensure Vehicle Preparation has been performed. See VEHICLE PREPARATION . Drive vehicle in stop and go traffic. Include 5 different constant cruise speeds from 25-45 MPH over a 10 minute period. Verify no DTCs are set with exception of DTC P1000.

Note. Following procedure is designed to execute and complete Evaporative Emission Repair Verification Drive Cycle and to clear DTC P1000, Inspection Maintenance (I/M) readiness code. When ambient air temperature is below 40°F (4.4°C) or above 100°F (37.8°C), or altitude is above 8000 feet, EVAP monitor will not run. If DTC P1000 must be cleared in these conditions, PCM must detect them once (twice on some applications) before EVAP monitor can be bypassed and DTC P1000 cleared. EVAP bypassing procedure is described in following drive cycle.

Evaporative Emission Repair Verification Drive Cycle

1. Drive Cycle Recommendations Most OBD II monitors will complete more readily using a steady foot driving style during cruise or acceleration modes. Operating throttle in a smooth fashion will minimize time necessary for monitor completion.
2. Fuel tank level should be between one-half and three-quarters full with three-quarters full being most desirable.
3. EVAP monitor can only operate during first 30 minutes of engine operation. When executing procedure for this monitor, stay in part throttle mode and drive in a smooth fashion to minimize fuel slosh.
4. Drive Cycle Preparation Install scan tool. Turn ignition on, engine off. Cycle ignition off, then on. Select appropriate vehicle and engine qualifier. Clear all diagnostic trouble codes (DTCs) and carry out PCM reset.
5. Begin to monitor ECT, EVAPDC, FLI (if available) and TP MODE PIDs. Select DIAGNOSTIC DATA LINK. Select PCM. Select PID/DATA MONITOR AND RECORD. Press TRIGGER to select each PID, then press START.
6. Start engine without returning key to OFF position.
7. Preparation For Monitor Entry Idle vehicle for 15 seconds. Drive at 40 MPH until ECT is at least 170°F (76.7°C).
8. If IAT is not above 40°F (4.4°C) and below 100°F (37.8°C), continue with following steps but note that EVAP Monitor Bypass portion of drive cycle (step 13) will be required to bypass EVAP monitor and clear DTC P1000.
9. Cruise at 40 MPH for 60 seconds.
10. Cruise at 45-65 MPH for 10 minutes.
11. Bring vehicle to a stop. Idle with transaxle in DRIVE (for automatic transaxle) or NEUTRAL (for manual transaxle) for two minutes.
12. Pending Code Check & EVAP Monitor Bypass Check Using scan tool, check for pending codes. Conduct normal repair procedures for any pending code concerns. Rerun any incomplete monitor.
13. EVAP Monitor Bypass Park vehicle for a minimum of 8 hours. Repeat steps 5 - 12 .

SUMMARY

If no diagnostic trouble code is present but driveability problem still exists, proceed to TROUBLE SHOOTING - NO CODES article for symptom diagnosis or intermittent diagnostic procedures.

Condition

DTC P0102 indicates Mass Airflow/Intake Air Temperature (MAF/IAT) signal is less then 0.23 volts during normal engine operation or KOER self-test.

DTC P0103 indicates MAF/IAT signal is more than 4.60 volts sometime during normal engine operation or KOER self-test.

DTC P1100 indicates MAF/IAT signal is less then 0.23 volt during KOEO self-test or more than 4.6 volts during the last 40 warm-up cycles.

DTC P1101 indicates MAF/IAT signal is more than 0.27 volt during KOEO self-test or signal is not between 0.46-2.44 volts during KOER self-test.

MAF/IAT sensor measures amount of engine incoming air. Sensor outputs an analog voltage signal to PCM. PCM uses signal to calculate required fuel injector pulse width. Input is also used to determine transaxle electronic pressure control, shift and torque converter clutch control.

Possible Causes

Possible causes are

1. Damaged MAF/IAT sensor (P0102, P0103 or P1101).
2. Blocked MAF/IAT sensor screen (P0103).
3. MAF/IAT sensor disconnected (P0102).
4. Contaminated MAF/IAT sensor (P1101).
5. MAF/IAT sensor partially connected (P1101).
6. Open PWR GND circuit (P0102 or P1101).
7. Open MAF/IAT RTN circuit (P0102 or P1101).
8. Open VPWR circuit (P0102).
9. MAF/IAT SIG circuit shorted to VPWR (P0103).
10. MAF/IAT SIG circuit shorted to ground (P0102).
11. MAF/IAT SIG circuit open (P0102).
12. Sensor connector or harness with poor continuity (P1100).
13. Sensor with internal intermittent open or short (P1100).
14. Damaged PCM (P0102, P0103 or P1101).
15. Intake air leak near MAF/IAT sensor (P0102).
16. TP sensor system, possible closed throttle indication (P0102).

Scheme 50

1. Perform «QUICK TEST»(ref-150940-S17451707022002112700000) under SELF-DIAGNOSTIC SYSTEM. If DTCs were detected, proceed as follows: KOER DTC P1101, go to next step. KOEO DTC P1101, go to step 4. DTC P1100, go to step 12. DTC P0102, go to step 3. DTC P0103, go to step 14.
2. DTC P1101: Check For MAF/IAT Sensor Continuous Memory DTCs Using scan tool, clear DTC. See «CLEARING CODES»(ref-150940-S31080003522002112700000) under SELF-DIAGNOSTIC SYSTEM. Drive vehicle for 6-10 minutes. Retrieve Continuous memory DTCs. If no Continuous Memory DTCs are present with KOER DTC P1101, turn ignition off and go to step 4. If any Continuous Memory DTCs are present with KOER DTC P1101, proceed as follows: For Continuous Memory DTC P0102, go to next step. For Continuous Memory DTC P0103, go to step 14. All other Continuous Memory DTCs, service DTCs as necessary. See «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(ref-150940-S42582837182002112700000).
3. DTC P0102: Low MAF Sensor Signal Input To PCM Check for broken or loose air outlet tube clamps at throttle body and air cleaner assembly. Check for holes and cracks in air outlet tube. Check for worn gaskets between MAF sensor and air cleaner. Repair as necessary. If no problems are detected, start engine and allow to idle. Check for DTCs. If KOER DTC P0505 is present, go to «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(ref-150940-S42582837182002112700000). On A/T models, if engine stalls or cannot maintain idle speed, go to step 6. If KOER DTC P0505 is not present and engine idles okay, increase engine speed to 1500 RPM for 5 seconds, then return to idle. Using scan tool, select MAF V PID from PID/DATA MONITOR & RECORD menu. If MAF V PID voltage is less than.23 volt, turn ignition off and go to step 5. If MAF V PID voltage is.23 volt or more, go to next step. NOTE: DTC P1101 can be generated by a low charged battery or poor garage ventilation system. Repair as necessary and rerun KOEO self-test.
4. DTC P1101: Check For MAF/IAT Sensor Signal Out Of Self-Test Range Ensure MAF/IAT sensor 6-pin harness connector is connected. Repair as necessary. With KOER, access MAF/IAT V PID. If MAF/IAT V PID value is 0.46-2.44 volts, problem is intermittent. See «INTERMITTENT DIAGNOSTICS»(ref-150940-S12957637142002112700000). If MAF/IAT V PID value is not as specified, go to next step.
5. Check VPWR Voltage To MAF/IAT Sensor Turn ignition off. Disconnect MAF/IAT sensor 6-pin harness connector. With KOEO, measure voltage between ground and MAF/IAT sensor 6-pin harness connector VPWR terminal (White/Red wire). (Scheme 51) If more than 10.5 volts is present, go to next step. If voltage reading is 10.5 volts or less, repair open in White/Red wire between MAF/IAT sensor 6-pin harness connector VPWR terminal and PCM 104-pin harness connector terminal No. 71. See «WIRING DIAGRAMS»(ref-134975) article. After repair, go to step 17.
6. Check MAF/IAT Circuit Short To PWR GND Or MAF/IAT RTN Circuit Disconnect PCM 104-pin harness connector. Disconnect scan tool from DLC. Using DVOM, measure resistance between MAF/IAT sensor 6-pin harness connector MAF terminal (Blue/Red wire) and PWR GND terminal (Black wire). (Scheme 51) Measure resistance between MAF terminal (Blue/Red wire) and MAF RTN terminal (Tan/Light Blue wire) at MAF/IAT 6-pin harness connector. If resistance reading is more than 10,000 ohms, go to next step. If resistance reading is not as specified, repair short in affected circuit. See «WIRING DIAGRAMS»(ref-134975) article. After repair, go to step 17.
7. Check MAF/IAT RTN Circuit For Short To PWR GND Circuit Measure resistance between MAF/IAT sensor 6-pin harness connector MAF RTN terminal (Tan/Light Blue wire) and PWR GND terminal (Black wire). If resistance is more than 10,000 ohms, go to next step. If resistance is 10,000 ohms or less, repair short in affected circuit. After repair, go to step 17.
8. Check MAF/IAT Circuit Voltage Cycling Integrity Reconnect PCM 104-pin harness connector and reconnect scan tool to DLC. With KOEO, access MAF/IAT V PID and record reading. Connect fused jumper wire between MAF/IAT 6-pin harness connector MAF RTN terminal (Tan/Light Blue wire) and PWR GND terminal (Black wire). (Scheme 51) Connect another fused jumper wire between MAF/IAT 6-pin harness connector MAF terminal (Light Blue/Red wire) and VPWR terminal (White/Red wire). Compare MAF/IAT V PID voltage readings. If MAF/IAT V PID voltage reading changes from less than.23 volt to more than 4.5 volts, replace MAF/IAT sensor. After repair, go to step 17. If MAF/IAT V PID voltage reading does not change as specified, proceed as follows: If DTC P0102 is only DTC present, go to next step. If DTC P1101 is present without DTC P0102, go to step 10.
9. Check MAF/IAT Circuit For Open Turn ignition off. Disconnect PCM 104-pin harness connector. Connect Breakout Box (49-UN01-130) to PCM harness connector only. (Scheme 50) Using DVOM, measure resistance between MAF/IAT sensor 6-pin harness connector MAF terminal (Light Blue/Red wire) and breakout box terminal No. 88. If resistance is less than 5.0 ohms, go to next step. If resistance is 5.0 ohms or more, repair open in Light Blue/Red wire between MAF/IAT sensor 6-pin harness connector MAF terminal and PCM 104-pin harness connector terminal No. 88. See «WIRING DIAGRAMS»(ref-134975) article. After repair, go to step 17.
10. Check PWR GND Circuit For Open Turn ignition off. Disconnect PCM 104-pin harness connector. Connect Breakout Box (49-UN01-130) to PCM harness connector only. (Scheme 50) Disconnect scan tool from DLC. Using DVOM, measure resistance between ground and MAF/IAT sensor 6-pin harness connector PWR GND terminal (Black wire). If resistance is less than 10,000 ohms, go to next step. If resistance is 10,000 ohms or more, repair open in Black wire between MAF/IAT sensor 6-pin harness connector PWR GND terminal and PCM 104-pin harness connector terminal No. 103. After repair, go to step 17.
11. Check MAF/IAT RTN Circuit For Open Measure resistance between MAF/IAT sensor 6-pin harness connector MAF RTN terminal (Tan/Light Blue wire) and PCM 104-pin harness connector terminal No 36. If resistance is less than 5.0 ohms, replace PCM. After repair, go to step 17. If resistance is 5.0 ohms or more, repair open in Tan/Light Blue wire between MAF/IAT sensor 6-pin harness connector MAF RTN terminal and PCM 104-pin harness connector terminal No 36. After repair, go to step 17.
12. DTC P1100: Check MAF/IAT Circuit For Intermittent Voltage To PCM Start engine and allow it to idle. If idle is not at least 700 RPM and stable, see appropriate symptom under «SYMPTOM DIAGNOSIS»(ref-134968-S36579230062002022100000) in TROUBLE SHOOTING - NO CODES article. Increase engine speed to 1500 RPM for 5 seconds, then return to idle. Using scan tool, access MAF/IAT V PID. While observing MAF/IAT V PID, lightly tap on MAF/IAT sensor and wiggle sensor 6-pin harness connector to simulate road shock. If MAF/IAT V PID reading changes to less than.23 volt (minimum) or to more than 4.6 volts (maximum), inspect MAF/IAT sensor 6-pin harness connector. Repair connector as necessary. If connector is okay, replace MAF/IAT sensor. After repair, go to step 17. If MAF/IAT V PID reading does not change as specified, go to next step.
13. Check MAF/IAT Circuit For Intermittent Opens Or Shorts Turn ignition on, engine off. Using scan tool, access MAF/IAT V PID. While observing MAF/IAT V PID, wiggle small sections of wiring harness starting at MAF/IAT sensor 6-pin harness connector working toward PCM 104-pin harness connector. If MAF/IAT V PID reading changes to less than.23 volt (minimum) or to more than 4.6 volts (maximum), repair wiring harness as necessary. After repair, go to step 17. If MAF/IAT V PID reading does not change as specified, problem is intermittent. See «INTERMITTENT DIAGNOSTICS»(ref-150940-S12957637142002112700000). NOTE: DTC P0103 can be generated by foreign material blocking MAF/IAT sensor screen, causing airflow restriction. If contaminants are found, ensure air induction system is okay. Repair if necessary. After repair, recheck for DTCs.
14. DTC P0103: Check MAF/IAT Sensor Signal High Input To PCM Start engine and allow to idle. If KOER DTC P0505 is present, go to «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(ref-150940-S42582837182002112700000). Increase engine speed to 1500 RPM for 5 seconds then return to idle. Using scan tool, access MAF/IAT V PID. MAF/IAT V PID reading should be more than 4.60 volts. Record MAF/IAT V PID reading. Turn ignition off. Disconnect MAF/IAT sensor 6-pin harness connector. Connect a fused jumper wire between MAF/IAT sensor 6-pin harness connector PWR GND terminal (Black wire) and MAF RTN terminal (Tan/Light Blue wire). (Scheme 51) Start engine and allow to idle. Access MAF/IAT V PID. If MAF/IAT V PID reading does not drop from previous MAF/IAT V PID reading to less than.23 volt, turn ignition off, remove fused jumper wire and go to next step. If MAF/IAT V PID reading drops from previous MAF/IAT V PID reading to less than.23 volt, turn ignition off. Remove fused jumper wire and replace MAF/IAT sensor. After repair, go to step 17.
15. Check MAF/IAT Circuit For Short To PWR Disconnect PCM 104-pin harness connector. Connect breakout box to PCM harness connector only. Turn ignition on, engine off. Measure voltage between breakout box terminal No. 88 (MAF) and terminals No. 51, 77 and 103 (PWR GND). If voltage reading is less than 1.0 volt, go to next step. If voltage reading is 1.0 volt or more, repair MAF circuit short to VPWR circuit. After repair, go to step 17.
16. Check MAF/IAT Circuit For Short To VREF Circuit Turn ignition off. Measure resistance between breakout box terminals No. 88 (MAF) and No. 90 (VREF). If resistance reading is more than 10,000 ohms and idle concern is not present, replace PCM. After repair, go to next step. If problem was not detected and an idle concern is still present, disregard DTC P0102 at this time. Go to next step.
17. Verify Trouble Shooting Of DTCs Is Completed Reconnect all disconnected connectors. Using scan tool, clear DTCs from PCM memory. See «CLEARING CODES»(ref-150940-S31080003522002112700000) under SELF-DIAGNOSTIC SYSTEM. Perform PCM Quick Test. See «QUICK TEST»(ref-150940-S17451707022002112700000) under SELF-DIAGNOSTIC SYSTEM. If same DTC is present, replace PCM. After repair, repeat PCM Quick Test. If any other DTC is present, go to appropriate DTC inspection. See «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(ref-150940-S42582837182002112700000). If no other DTCs are present, testing is complete.

Scheme 51

Scheme 52

Detection Condition

DTC P0112 indicates Mass Airflow/Intake Air Temperature (MAF/IAT) sensor is less than self-test minimum of 0.2 volt or 250°F (121°C).

DTC P0113 indicates MAF/IAT sensor is more than the self-test maximum of 4.6 volts or -58°F (-50°C).

DTC P0117 indicates Engine Cooling Temperature (ECT) sensor is less than self-test minimum of 0.2 volt or 250°F (121°C).

DTC P0118 indicates ECT sensor is more than self-test maximum of 4.6 volts or -58°F (-50°C).

DTC P0125 indicates ECT sensor has not achieved the required temperature level to enter closed loop operating conditions within a specified amount of time after engine start.

DTC P1112 indicates MAF/IAT sensor signal was intermittent during Comprehensive Component Monitor.

DTC P1116 indicates ECT sensor signal is out of self-test range (0.3-3.7 volts).

DTC P1117 indicates ECT circuit was intermittently open or shorted while engine was running.

DTC P1285 indicates an engine overheat condition was sensed by Cylinder Head Temperature (CHT) sensor.

DTC P1288 indicates CHT sensor is out of self-test range (engine not at operating temperature).

DTC P1289 and P1290 indicates CHT sensor circuit malfunction (open or short).

DTC P1299 indicates an engine overheat condition was detected by CHT sensor and a Failure Mode Effects Management (FMEM) strategy (fail safe cooling) was activated to cool engine.

Engine must be at normal operating temperature to pass KOEO self-test and KOER self-test. Ambient temperature must be more than 50°F (10°C) to receive acceptable input from MAF/IAT sensor. MAF/IAT, ECT and CHT sensors are thermistor type (passive) sensors. PCM uses IAT input as a correction factor in calculation of fuel, spark and MAF. PCM also uses ECT and CHT sensors as inputs. On all sensors, resistance changes with temperature. Resistance decreases with temperature increase, and increases with temperature decrease.

Possible causes are

1. Overheating condition (P1116).
2. Damaged harness (P1112 or P1117).
3. Improper harness connection (P0112, P0113, P0117, P0118, P1289 or P1290).
4. Grounded circuit in harness (P0112 or P0117).
5. Damaged PCM (P0112, P1112, P0113, P1116, P0117, P1117, P0118, P1288, P1289 or P1290).
6. Damaged ECT sensor (P1116, P0117, P1117 or P0118).
7. Damaged CHT sensor (P1285, P1288, P1289 or P1290).
8. Damaged MAF/IAT sensor (P0112, P1112 or P1113).
9. Basic engine concerns (P1285 or P1299).
10. Engine cooling concerns (P1285 or P1299).
11. Insufficient warm-up time (P0125).
12. Low engine coolant level (P0125, P1116, P1117, P1285, P1288 or P1299).
13. Poor thermostat operation (P1116).
14. Leaky or stuck open thermostat (P0125).
15. Damaged harness connector (P1112, P1116, P1117 or P1288).
16. Open in ECT harness (P0118).
17. Grounded circuit in CHT harness (P1289 or P1290).
18. Open circuit in CHT harness (P1289 or P1290).
19. Short to power (P0113 or P0118).
20. Open in MAF/IAT harness (P0113).
21. CHT sensor concerns (P1285).

Scheme 53

Scheme 54

1. Perform «QUICK TEST»(ref-150940-S17451707022002112700000) under SELF-DIAGNOSTIC SYSTEM. If any DTCs are present, proceed as follows: For DTC P1116 or P1288, go to next step. For DTC 1285 (if not a cooling system malfunction), go to step 4. For KOEO or KOER DTC P0113 or P0118, go to step 6. For DTC P1289 or P1290, go to step 10. For KOEO or KOER DTC P0112 or P0117, go to step 11. For Continuous Memory (without KOEO and KOER DTCs) DTC P0112, P0113, P0117, P0118, P1112, P1117, P1289 or P1290, go to step 14. For DTC P0125, go to step 16. For DTC P1299, go to step 17.
2. DTC P1116 Or DTC P1288: Check Operation Of ECT/CHT Sensor Start engine and run at 2000 RPM until engine temperature becomes stabilized. If vehicle does not start, go to step 4. If vehicle stalls, refer to «SYMPTOM DIAGNOSIS»(ref-134968-S36579230062002022100000) in TROUBLE SHOOTING - NO CODES article. Ensure upper radiator hose is hot and pressurized. Run KOEO self-test. See «KOEO & KOER SELF-TEST»(ref-150940-S38670547312002112700000). If DTC P1116 or P1288 is present, go to next step. If DTC P1116 or P1288 is not present, engine temperature was not stabilized. Repair any other DTCs and repeat «QUICK TEST»(ref-150940-S17451707022002112700000) under SELF-DIAGNOSTIC SYSTEM.
3. Check VREF Circuit Voltage At TP Sensor Turn ignition off. Disconnect TP sensor 3-pin harness connector. With KOEO, measure voltage between TP sensor 6-pin harness connector VREF terminal (Brown/White wire) and SIG RTN terminal (Orange wire). If voltage reading is 4.0-6.0 volts, go to next step. If voltage reading is not as specified, reconnect disconnected connectors and go to «VEHICLE REFERENCE VOLTAGE»(ref-150940-S23619745912002112700000) testing under «SYSTEM TESTS»(ref-150940-S42556424782002112700000).
4. Check Resistance Of Temperature Sensor With Engine Off Turn ignition off. Reconnect TP sensor 3-pin harness connector. Disconnect ECT and CHT sensor harness connectors. Measure resistance between ECT/CHT sensor harness connector ECT/CHT terminal (Light Green/Red wire) and SIG RTN terminal (Orange wire). (Scheme 53)or (Scheme 54). See «ECT & MAF/IAT SENSOR SPECIFICATIONS»(ref-150940-S40297423322002120900000) or «CHT SENSOR SPECIFICATIONS»(ref-150940-S40918980622002120900000) table. If resistance reading is within specification, for ECT/CHT sensor with a No Start: Do not service DTCs P1116 or P1288 at this time. Go to «SYMPTOM DIAGNOSIS»(ref-134968-S36579230062002022100000) in TROUBLE SHOOTING - NO CODES article. For symptoms of cooling fan concerns, overheating and lack of heat: Do not service DTCs P1116 or P1288 at this time. Repair other DTC. If no other DTC is present, go to appropriate COOLING SYSTEMS article in ENGINES. For all other DTCs, go to next step. If resistance reading is not within specification, replace ECT/CHT sensor. After repair, go to step 18. NOTE: Ensure engine is at operating temperature before taking ECT/CHT readings. ECT & MAF/IAT SENSOR SPECIFICATIONS (1) Temperature °F (°C) Volts (2) Ohms 50 (10) 3.51 58,750 68 (20) 3.07 27,300 86 (30) 2.60 24,270 104 (40) 2.13 16,150 122 (50) 1.70 10,970 140 (60) 1.33 7700 158 (70) 1.02 5370 176 (80) 0.78 3840 194 (90) 0.60 2800 212 (100) 0.46 2070 230 (110) 0.35 1550 248 (120) 0.27 1180 (1) Values may differ by as much as 15 percent. (2) Measure resistance between sensor terminals. CHT SENSOR SPECIFICATIONS Temperature °F (°C) Volts (1) Ohms -40 (-40) 4.89 965,808 -22 (-30) 4.81 513,019 -4 (-20) 4.67 283,664 14 (-10) 4.45 162,584 32 (0) 4.14 96,255 50 (10) 3.73 59,175 68 (20) 3.26 37,387 86 (30) 2.74 24,215 104 (40) 2.23 16,043 122 (50) 1.76 10,850 140 (60) 1.36 7487 158 (70) 1.04 5268 176 (80) (2) 0.79 Or 3.99 3775 185 (85) (2) 0.69 Or 3.86 3215 194 (90) (2) 0.60 Or 3.71 2750 203 (95) (2) 0.53 Or 3.56 2361 212 (100) (2) 0.46 Or 3.41 2034 230 (110) 3.07 1523 248 (120) 2.74 1155 266 (130) 2.41 887 284 (140) 2.10 689 302 (150) 1.81 542 320 (160) 1.55 430 338 (170) 1.33 345 356 (180) 1.13 279 374 (190) 0.96 228 392 (200) 0.82 188 410 (210) 0.70 155 428 (220) 0.60 130 446 (230) 0.51 109 464 (240) 0.44 92 482 (250) 0.35 78 500 (260) 0.33 67 (1) Measure resistance between cylinder head temperature sensor terminals. (2) At this temperature, there is a voltage overlap zone where it is possible to have either a cold end (low voltage) or hot end (high voltage) reading at the same temperature. Either voltage specification listed is correct.
5. Check Resistance Of Temperature Sensor With Engine Running Disconnect suspect temperature sensor. Run engine at 2000 RPM for 2 minutes. Measure resistance between ECT/CHT or IAT sensor terminal and SIG RTN terminal at temperature sensor harness connector. (Scheme 53), (Scheme 54) or (Scheme 51). See «ECT & MAF/IAT SENSOR SPECIFICATIONS»(ref-150940-S40297423322002120900000) or «CHT SENSOR SPECIFICATIONS»(ref-150940-S40918980622002120900000) table. If resistance reading is within specification, replace PCM. After repair, go to step 18. If resistance reading is not within specification, Replace suspect ECT/CHT or IAT sensor. After repair, go to step 18.
6. DTC P0113 Or DTC P0118: Check Voltage Between VREF and SIG RTN Turn ignition off. Disconnect TP sensor 3-pin harness connector. Turn ignition on, engine off. Measure voltage between TP sensor 3-pin harness connector VREF terminal (Brown/White wire) and SIG RTN terminal (Orange wire). If voltage reading is 4.0-6.0 volts, go to next step. If voltage reading is not as specified, reconnect disconnected connectors and go to «VEHICLE REFERENCE VOLTAGE»(ref-150940-S23619745912002112700000) testing under «SYSTEM TESTS»(ref-150940-S42556424782002112700000).
7. Simulate Opposite Signal To PCM Turn ignition off. Disconnect suspect temperature sensor. Connect fused jumper wire between suspect ECT/CHT sensor (Light Green/Red wire) or IAT sensor (Pink/Black wire) harness connector terminal and SIG RTN terminal (Orange wire) at temperature sensor harness connector. Turn ignition on, engine off. If scan tool communication concern is present, disconnect fused jumper wire immediately and go to step 9. Access ECT/CHT V or IAT V PID. If ECT/CHT V or IAT V PID reading is less than 0.2 volt, remove fused jumper wire and replace suspect sensor. After repair, go to step 18. If voltage reading is not as specified, remove fused jumper wire and go to next step.
8. Check Temperature Sensor Signal & SIG RTN Circuits For Open In Harness Turn ignition off. Disconnect PCM 104-pin harness connector. Disconnect suspect temperature sensor. Connect Breakout Box (49-UN01-130) to PCM harness connector only. (Scheme 50) Measure resistance between ECT/CHT sensor (Light Green/Red wire) or IAT sensor (Pink/Black wire) harness connector terminal and breakout box terminal No. 38 (ECT/CHT sensor) or terminal No. 39 (IAT sensor). Measure resistance of Orange wire between SIG RTN harness connector terminal of temperature sensor and breakout box terminal No. 91. If resistance is less than 5.0 ohms, replace PCM. After repair, go to step 18. If resistance reading is 5.0 ohms or more, repair open in suspect circuit. After repair, go to step 18.
9. Check Temperature Sensor Signal & SIG RTN Circuits For Open In Harness Measure resistance between SIG RTN circuit (Orange wire) at appropriate temperature sensor harness connector terminal and breakout box terminal No. 90 (VREF). (Scheme 53), (Scheme 54) or (Scheme 51). If resistance reading is more than 10,000 ohms, replace PCM. After repair, go to step 18. If resistance reading is 10,000 ohms or less, repair short in VREF circuit. See «WIRING DIAGRAMS»(ref-134975) article. After repair, go to step 18.
10. DTC P1289 Or DTC P1290: Check Voltage Of CHT PID Turn ignition on, engine off. Access CHT V PID. If CHT V PID reading is less than 0.2 volt, go to next step. If CHT V PID reading is 0.2 volt or more, go to step 7.
11. DTC P0112 Or DTC P0117: Simulate Opposite Signal To PCM Turn ignition off. Disconnect suspect temperature sensor harness connector. Turn ignition on, engine off. Access ECT V or IAT V PID. If ECT V or IAT V PID reading is 4.6 volts or less, go to next step. If ECT V or IAT V PID reading is more than 4.6 volts, replace suspect temperature sensor. After repair, go to step 18.
12. Check VREF Circuit Voltage To TP Sensor Turn ignition off. Disconnect TP sensor. Turn ignition on, engine off. Measure voltage between VREF (Brown/White wire) and SIG RTN (Gray/Red wire) at TP sensor harness connector. (Scheme 55) If voltage is 4.0-6.0 volts, there is sufficient VREF voltage. Reconnect TP sensor. Go to next step. If voltage is not 4.0-6.0 volts, reconnect all electrical connections. Go to «VEHICLE REFERENCE VOLTAGE»(ref-150940-S23619745912002112700000) testing under «SYSTEM TESTS»(ref-150940-S42556424782002112700000).
13. Check Signal Circuit For Short To Ground Turn ignition off. Disconnect suspect temperature sensor. Disconnect PCM 104-pin harness connector. Connect Breakout Box (49-UN01-130) to PCM harness connector only. (Scheme 50) Measure resistance between breakout box terminal No. 38 (ECT/CHT sensor ) or terminal No. 39 (IAT sensor) and terminal No. 24 (PWR GND). (Scheme 53), (Scheme 54) or (Scheme 51). Record reading. Measure resistance between breakout box terminal No. 38 (ECT/CHT sensor) or terminal No. 39 (IAT sensor) and terminal No. 91 (SIG RTN). Record reading. If each resistance reading is more than 10,000 ohms, replace faulty PCM. After repair, go to step 18. If each resistance reading is 10,000 ohms or less, repair short circuit. See «WIRING DIAGRAMS»(ref-134975) article. After repair, go to step 18.
14. DTCs P0112, P1112, P0113 P0117, P1117, P0118, P1289 Or P1290: Intermittent Check Turn ignition on, engine off, Monitor ECT V PID, CHT V PID or IAT V PID. While observing PID, tap on suspect sensor to simulate road shock and wiggle sensor connector. If any large change in temperature reading is not present, go to next step. If any large change in temperature reading is present, disconnect sensor harness connector and inspect. If sensor harness connector is okay, replace suspect sensor. After repair, go to step 18.
15. Check Engine Wiring Harness Turn ignition on, engine off. While observing ECT V PID, CHT V PID or IAT V PID, grasp harness close to suspect sensor. Wiggle, shake and bend harness back to PCM. If any large change in temperature reading is not present, go to step 18. If any large change in temperature reading is present, isolate and repair fault as necessary. After repair, go to step 18. For Continuous Memory DTCs P1112 and P1117, perform «COMPREHENSIVE COMPONENT MONITOR REPAIR VERIFICATION DRIVE CYCLE»(ref-150940-S10090757572002112700000) under MONITOR REPAIR VERIFICATION DRIVE CYCLES.
16. DTC P0125 Indicates Excessive Time To Enter Closed Loop Fuel Control Check engine coolant level. If coolant level is okay, go to appropriate COOLING SYSTEMS article in ENGINES and repair cooling system malfunction as necessary. If coolant level is not okay, fill to proper level. After repair, go to step 18. For Continuous Memory DTCs P1112 and P1117, perform «COMPREHENSIVE COMPONENT MONITOR REPAIR VERIFICATION DRIVE CYCLE»(ref-150940-S10090757572002112700000) under MONITOR REPAIR VERIFICATION DRIVE CYCLES.
17. DTC P1299 Indicates An Engine Overheat Condition Occurred Check engine coolant level. If coolant level is okay, go to appropriate COOLING SYSTEMS article in ENGINES and repair cooling system malfunction as necessary. If coolant level is not okay, repair cooling system leak.
18. Verify Trouble Shooting Of DTCs Completed Reconnect all disconnected connectors. Clear DTCs from PCM memory using scan tool. See «CLEARING CODES»(ref-150940-S31080003522002112700000) under SELF-DIAGNOSTIC SYSTEM. Perform «QUICK TEST»(ref-150940-S17451707022002112700000) under SELF-DIAGNOSTIC SYSTEM. If same DTC is present, replace PCM. After repair repeat «QUICK TEST»(ref-150940-S17451707022002112700000) under SELF-DIAGNOSTIC SYSTEM. If no other DTCs are present, trouble shooting is complete.

DTC P0121 indicates a non-closed throttle position at idle.

DTC P0122 indicates Throttle Position (TP) sensor signal is less than self-test minimum of 0.17 volts (3.42 percent).

DTC P0123 indicates TP sensor signal is more than self-test maximum value of 4.65 volts (93 percent).

DTC P1120 indicates TP sensor signal is between 0.17-0.49 volts (3.42 and 9.85 percent).

DTC P1121 indicates TP sensor signal is inconsistent with Mass Airflow (MAF) sensor.

DTC P1124 indicates TP sensor rotational setting and signal are not in the self-test range of 0.66-1.17 volts (13.27-23.52 percent).

DTC P1125 indicates TP sensor signal went less than 0.49 volts or more than 4.65 volts during the last 80 warm-up cycles.

TP sensor is a linear type sensor. The PCM determines 4 throttle operating conditions from the TP sensor signal; closed throttle (idle or deceleration), part throttle (cruise or moderate acceleration), wide open throttle (maximum acceleration or de-choke on crank) and throttle angle rate.

Possible causes are

1. Binding or bent throttle linkage (P0121 or P1124).
2. TP sensor not seated properly or tightened down (P0122, P0123, P1121 or P1124).
3. Throttle plate less than closed throttle position (P1124).
4. Throttle place/screw misadjusted (P1124).
5. Damaged TP sensor (P0121, P0122, P0123, P1121 or P1124).
6. Damaged PCM (P0122, P0123 or P1124).
7. Air leak between Mass Airflow/Intake Air Temperature (MAF/IAT) sensor and throttle body (P1121).
8. Damaged MAF sensor (P1121).
9. TP sensor loose pins (P1120).
10. Intermittent open or short in TP sensor (P1125).
11. Frayed wire (P1120).
12. Corrosion on TP sensor, PCM or harness connectors (P1120).
13. VREF harness opens or shorts to TP sensor (P0122 or P1120).
14. Open TP SIG circuit or TP circuit open to PCM (P0121 or P0122).
15. Open SIG RTN harness circuit (P0121 or P0123).
16. TP circuit short to ground (P0122).
17. TP circuit short to power (P0123).
18. VREF short to power (P0123).
19. VREF short to SIG RTN (P1120).
20. Poor continuity through TP sensor connectors or harness (P1125).

Scheme 55

1. If QUICK TEST was not performed, go to «QUICK TEST»(ref-150940-S17451707022002112700000) under SELF-DIAGNOSTIC SYSTEM. If QUICK TEST was performed: For KOEO and KOER DTC P1124, go to next step. For DTC P1120, go to step 4. For DTC P0123, go to step 9. For Continuous Memory DTC P1124, go to step 9. For DTC P0122, go to step 13. For DTC P1121, go to step 17. For DTC P1125, go to step 21. For DTC P0121, go to step 23.
2. Check For DTC P1400 In KOEO Or KOER Self-Test If KOEO or KOER DTC P1400 is set with P1124, go to «DTC P1400 OR P1401: DIFFERENTIAL PRESSURE FEEDBACK SENSOR - MALFUNCTION»(ref-150940-S14915085912002112700000). If KOEO or KOER DTC P1400 is not set with P1124, go to next step.
3. Check For Stuck Throttle Plate Or Linkage Visually inspect throttle linkage and throttle plate for binding or sticking. Verify throttle plate and linkage is at closed throttle position. If throttle moves freely and returns to closed throttle position, go to step 9. If throttle does not move freely and does not return to closed throttle position, repair or replace as necessary. After repair, go to step 25.
4. DTC P1120: Check TP Circuit For Frayed Wires Or Corrosion On Connectors Visually inspect TP sensor harness connector terminals for corrosion. Visually inspect wire harness between TP sensor 3-pin harness connector and PCM 104-pin harness connector for insulation fraying and corrosion. If connector and harness are okay, go to next step. If connector and harness are not okay, repair as necessary. After repair, go to step 25.
5. Check For Stuck TP Sensor Turn ignition on, engine off. Access TP V PID. Slowly move throttle from closed throttle position to Wide Open Throttle (WOT) position and observe TP V PID. If TP V PID voltage reading is less than 0.49 volt, go to next step. If TP V PID voltage reading is 0.49 volt or more, go to step 21.
6. Check VREF & SIG RTN Circuit To TP Sensor Turn ignition off. Disconnect TP sensor. Turn ignition on, engine off. Measure voltage between 3-pin harness connector VREF terminal (Brown/White wire) and SIG RTN terminal (Orange wire). (Scheme 55) If voltage is 4.0-6.0 volts, go to next step. If voltage is not as specified, reconnect all electrical connections. Go to «VEHICLE REFERENCE VOLTAGE»(ref-150940-S23619745912002112700000) testing under «SYSTEM TESTS»(ref-150940-S42556424782002112700000).
7. Check TP Circuit Resistance Turn ignition off. Disconnect PCM 104-pin harness connector. Connect Breakout Box (49-UN01-130) to PCM harness connector only. (Scheme 50) Measure resistance of Gray/White wire between TP sensor 3-pin harness connector and breakout box terminal No. 89. (Scheme 55) If resistance reading is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open in Gray/White wire between TP sensor 3-pin harness connector terminal and PCM 104-pin harness connector terminal No. 38. After repair, go to step 25.
8. Check TP Sensor Signal To PCM Connect PCM to breakout box. Reconnect TP sensor 3-pin harness connector. Start engine and idle for 2 minutes. Access TP V PID. While observing TP V PID, slowly open throttle. If TP V PID reading is 0.17-0.49 volt at any time, replace faulty TP sensor. After repair, go to step 25. If TP V PID reading is not 0.17-0.49 volt at any time, rerun KOEO and KOER test. If DTC P1120 is still present, go to step 21.
9. DTC P0123 Or DTC P0124: Attempt To Generate The Opposite Throttle Position Angle (Voltage) PID Reading An intermittent may cause DTC P0123. If DTC P0123 is still set after performing steps 9 through 12, go to step 21. If DTC P0123 is not set after performing steps 9 through 12, turn ignition off. Disconnect TP sensor 3-pin harness connector. Turn ignition on, engine off. Access TP V PID. Observe voltage. If TP V PID reading is less than 0.17 volt, go to next step. If TP V PID reading is 0.17 volt or more, go to step 12.
10. Check SIG RTN Circuit For Open Turn ignition off.Disconnect PCM 104-pin harness connector. Disconnect breakout box from PCM. Measure resistance of SIG RTN circuit (Orange wire) between TP sensor 3-pin harness connector and breakout box terminal No. 91. (Scheme 55) If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open in Orange wire between TP sensor 3-pin harness connector terminal and PCM 104-pin harness connector terminal No. 91. See «WIRING DIAGRAMS»(ref-134975) article. After repair, go to step 25.
11. Check VREF & SIG RTN Circuits To TP Sensor Turn ignition on, engine off. Measure voltage between TP sensor 3-pin harness connector VREF terminal (Brown/White wire) and SIG RTN terminal (Orange wire). (Scheme 55) If voltage reading is 4.0-6.0 volts, replace faulty TP sensor. After repair, go to step 25. If voltage is not 4.0-6.0 volts, reconnect all electrical connections. Go to «VEHICLE REFERENCE VOLTAGE»(ref-150940-S23619745912002112700000) under «SYSTEM TESTS»(ref-150940-S42556424782002112700000).
12. Check TP Circuit For Shorts To VREF Or VPWR In Harness Turn ignition off. Disconnect PCM 104-pin harness connector. Connect Breakout Box (49-UN01-130) to PCM harness connector only. (Scheme 50) Measure resistance between breakout box terminal No. 89 (TP) and terminal No. 71 or 97 (VPWR). Record reading. Measure resistance between breakout box terminals No. 89 (TP) and 90 (VREF). Record reading. If either resistance measurement is more than 10,000 ohms, replace faulty PCM. After repair, go to step 25. If either resistance measurement is 10,000 ohms or less, repair short circuit in harness. See «WIRING DIAGRAMS»(ref-134975) article. After repair, go to step 25.
13. DTC P0122: Attempt To Generate Opposite Throttle Position Angle (Voltage) PID Reading An intermittent fault may cause Continuous Memory DTC P0122. If DTC P0122 is still set after performing steps 13 through 16, go to step 21. Disconnect TP sensor 3-pin harness connector. Connect fused jumper wire between TP sensor 3-pin harness connector VREF terminal (Brown/White wire) and TP terminal (Gray/White wire). (Scheme 55) Turn ignition on, engine off. Access TP V PID. If a scan tool communication concerns are present, remove jumper wire. Go to step 16. If TP V PID reading is more than 4.65 volts, replace faulty TP sensor. After repair, go to step 25. If TP V PID reading is 4.65 volts or less, remove fused jumper wire. Go to next step.
14. Check VREF & SIG RTN Circuits To TP Sensor Turn ignition on, engine off. Measure voltage between TP sensor 3-pin harness connector VREF terminal (Brown/White wire) and SIG RTN terminal (Orange wire). (Scheme 55) If voltage is 4.0-6.0 volts, go to next step. If voltage is not as specified, reconnect all electrical connections. Go to «VEHICLE REFERENCE VOLTAGE»(ref-150940-S23619745912002112700000) testing under «SYSTEM TESTS»(ref-150940-S42556424782002112700000).
15. Check For Open TP Circuit Between PCM & TP Sensor Turn ignition off. Disconnect PCM 104-pin harness connector. Connect Breakout Box (49-UN01-130) to PCM harness connector only. (Scheme 50) Measure resistance of TP circuit (Gray/White wire) between TP sensor 3-pin harness connector terminal and breakout box terminal No. 89. (Scheme 55) If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open in TP circuit (Gray/White wire) between TP sensor 3-pin harness connector terminal and PCM 104-pin harness connector terminal No. 89. See «WIRING DIAGRAMS»(ref-134975) article. After repair, go to step 25.
16. Check TP Circuit For Shorts To SIG RTN Or PWR GND In Harness Disconnect scan tool. Measure resistance between breakout box terminal No. 89 (TP) and terminals No. 51 and 103 (PWR GND). Record reading. Measure resistance between breakout box terminals No. 89 (TP) and 91 (SIG RTN). Record reading. If either resistance measurement is more than 10,000 ohms, replace faulty PCM. After repair, go to step 25. If either resistance measurement is 10,000 ohms or less, repair short circuit in harness. See «WIRING DIAGRAMS»(ref-134975) article. After repair, go to step 25.
17. DTC P1121: TP Sensor & MAF Sensor Rationality Check Attempt to start engine. If engine runs, go to next step. If engine does not run, check for major leaks and cracks between MAF/IAT sensor and throttle body. Repair as necessary. If no discrepancies are found, go to «NO START»(ref-150940-S40223251252002120300000) testing under «SYSTEM TESTS»(ref-150940-S42556424782002112700000).
18. Check Mechanical Operation Of TP Sensor Turn ignition on, engine off. Acces TP V PID. Slowly open throttle from closed throttle position to Wide Open Throttle (WOT) position. While observing TP V PID, slowly open throttle. If TP V PID reading changes between 0.49 and 4.65 volts, go to next step. If TP V PID reading does not change as specified, replace faulty TP sensor. After repair, go to step 25.
19. Check TP Sensor Signal High Versus Engine Load While Driving Drive vehicle exercising throttle. Observe TP V and LOAD PIDs. Record readings. If TP V PID reading is 2.44 volts or less and LOAD PID reading is 30 percent or more, go to next step. If TP V PID is more than 2.44 volts and LOAD PID is less than 30 percent, check for air leaks between MAF/IAT sensor and throttle body while engine is running. If air leaks are present (including air noise sounds), repair as necessary. If air leaks or noises are not present, replace faulty TP sensor. After repair, go to step 25.
20. Check TP Sensor Signal Low Versus Engine Load While Driving Drive vehicle exercising throttle near higher gears (preferably overdrive). Observe TP V and LOAD PIDs. Record readings. If TP V PID reading is not less than 0.24 volt and LOAD PID is not more than 55 percent, fault is unable to be duplicated at this time. Go to step 25. If TP V PID is less than 0.24 volt and LOAD PID is more than 55 percent, verify TP sensor is securely attached to throttle body. Repair as necessary. If Continuous Memory DTC P1121 is not set, replace faulty MAF/IAT sensor. After repair, go to step 25.
21. Check For TP Circuit Intermittent Voltage Input Start engine and idle. Increase engine speed to 1500 RPM for 5 seconds. Access TP V PID. Observe TP V PID while lightly tapping on TP sensor and wiggling harness to simulate road shock. If voltage did not change to less than a minimum of 0.49 volt or more than a maximum of 4.65 volts, go to next step. If voltage changed to less than a minimum of 0.49 volt or more than a maximum of 4.65 volts, inspect TP sensor 3-pin harness connector. If connector is okay, replace faulty TP sensor. After repair, go to step 25.
22. Check TP Sensor Harness For Intermittent Opens & Shorts Access and observe TP V PID. Turn ignition on, engine off. Grasp harness nearest to TP sensor connector. Shake and bend a small section of wiring harness following harness to dash panel. Shake and bend harness from dash panel to PCM. If voltage did not change to less than a minimum of 0.49 volt or more than a maximum of 4.65 volts, fault is unable to be duplicated at this time. Go to step 25. If voltage changed to less than a minimum of 0.49 volt or more than a maximum of 4.65 volts, isolate fault in harness and repair as necessary. See «WIRING DIAGRAMS»(ref-134975) article. After repair, go to step 25.
23. Attempt To Re-Create DTC Or Driveability Symptom If KOER self-test terminates when placing transaxle in Drive or Reverse, go to step next step. Attempt to drive vehicle while still in KOER self-test. Turn igniton off. Wait 15 seconds. Start engine again. Activate KOER self-test. If DTC P0121 is still set or if KOER self-test fails to terminate, go to next step. If DTC P0121 is not set or if KOER self-test terminates, verify symptom is no longer present. Go to step 25.
24. Check TP Or SIG RTN Circuits For Open In Harness Turn ignition off. Disconnect PCM 104-pin harness connector and TP sensor 3-pin harness connector. Connect Breakout Box (49-UN01-130) to PCM harness connector only. (Scheme 50) Measure resistance of TP circuit (Gray/White wire) between breakout box terminal No. 89 and TP sensor 3-pin harness connector terminal. Record reading. Measure resistance of SIG RTN circuit (Orange wire) between breakout box terminal No. 91 and TP sensor 3-pin harness connector terminal. (Scheme 55) Record reading. If either resistance mesurement is less than 5 ohms, replace faulty TP sensor. After repair, go to step 25. If either resistance measurement is 5 ohms or more, repair open circuit. See «WIRING DIAGRAMS»(ref-134975) article. After repair, go to next step.
25. Verify Trouble shooting Of DTCs Completed Reconnect all disconnected connectors. Clear DTCs from PCM memory using scan tool. Perform «QUICK TEST»(ref-150940-S17451707022002112700000) under SELF-DIAGNOSTIC SYSTEM. If same DTC is present, replace faulty PCM. Repeat «QUICK TEST»(ref-150940-S17451707022002112700000) under SELF-DIAGNOSTIC SYSTEM. If same DTC is not present, go to applicable procedure for other DTCs. See «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(ref-150940-S42582837182002112700000). If no DTCs are set, procedure is complete.

DTC P0131 indicates HO2S-11 (front Bank 1 on 3.0L or front on 2.0L) has generated a negative voltage.

DTC P0151 indicates HO2S-21 (front Bank 2) has generated a negative voltage.

HO2S detects oxygen in the exhaust and produces a variable voltage according to the amount of oxygen detected. A high concentration of oxygen in the exhaust causes HO2S to produce a low voltage signal (less than 0.4 volts). A low concentration of oxygen in the exhaust causes HO2S to produce a high voltage signal (more than 0.6 volts). HO2S provides feedback to PCM indicating air/fuel ratio in order to achieve near stoichiometric air/fuel ratio during closed loop engine operation.

Possible causes are

1. Contaminated HO2S.
2. Crossed HO2S signal wiring or signal return wiring.

DTC P0133 indicates frequency and amplitude response rate of HO2S-11 (front Bank 1 on 3.0L or front 2.0L) is below calibrated limit.

DTC P0153 indicates frequency and amplitude response rate of HO2S-21 (front left 3.0L) is below calibrated limit.

Possible causes are

1. Contaminated HO2S.
2. Exhaust leaks.
3. Shorted or open wires.
4. Improper fueling.
5. Mass Airflow/Intake Air Temperature (MAF/IAT) sensor.
6. Deteriorating HO2S.
7. Intake air leaks.

DTC P0135 indicates HO2S-11 heater circuit (front Bank 1 on 3.0L or front on 2.0L) is open, shorted to ground, shorted to VPWR or has low or high current draw.

DTC P0141 indicates HO2S-12 heater circuit (rear) is open, shorted to ground, shorted to VPWR or has low or high current draw.

DTC P0155 indicates HO2S-21 heater circuit (front Bank 2 on 3.0L) is open, shorted to ground, shorted to VPWR or has low or high current draw.

DTC P0161 indicates HO2S-22 heater circuit (rear) is open, shorted to ground, shorted to VPWR or has low or high current draw.

HO2S heater heats HO2S sensor to temperatures of 1400°F (760°C). VPWR circuit supplies voltage to heater with PCM completing circuit ground when proper conditions are present.

Possible causes are

1. Shorts to VPWR in harness or HO2S.
2. Water in connectors (contamination).
3. Open VPWR circuit.
4. Open ground circuit.
5. Low battery voltage.
6. Corrosion or poor mating materials and wiring.
7. Damaged HO2S heater.
8. Damaged PCM.

DTC P0136 indicates output voltage of HO2S-12 (rear) fails to meet calibrated limits (bank 1).

DTC P0156 indicates output voltage of HO2S-22 (rear) fails to meet calibrated limits (bank 2).

DTC P1137 and DTC P1138 indicate HO2S-12 (rear) is forced rich and lean by PCM. The test fails if PCM does not detect a rich signal (P1137) or lean signal (P1138) during KOER self-test (Bank 1).

DTC P1157 and DTC P1158 indicate HO2S-22 (rear) is forced rich and lean by PCM. The test fails if PCM does not detect a rich signal (P1157) or lean signal (P1158) during KOER self-test (Bank 2).

HO2S detects oxygen in the exhaust and produces a variable voltage according to the amount of oxygen detected. A high concentration of oxygen in the exhaust causes HO2S to produce a low voltage signal (less than 0.4 volts). A low concentration of oxygen in the exhaust causes HO2S to produce a high voltage signal (more than 0.6 volts). HO2S provides feedback to PCM indicating air/fuel ratio in order to achieve near stoichiometric air/fuel ratio during closed loop engine operation.

Possible causes are

1. Pinched, shorted or corroded wiring or connector pins.
2. Crossed sensor wires.
3. Exhaust leaks.
4. Contaminated or damaged sensor.

DTC P0171 indicates air/fuel ratio is too lean (Bank 1).

DTC P0174 indicates air/fuel ratio is too lean (Bank 2).

Fuel control system uses fuel trim tables stored in PCM to compensate for variances in fuel system components from wear and aging. The fuel trim strategy learns deviations during closed-loop engine operation. Fuel trim has 2 means of adapting; a long term fuel trim and a short term fuel trim. Inputs from Engine Coolant Temperature (ECT), Cylinder Head Temperature (CHT) and Mass Airflow/Intake Air Temperature (MAF/IAT) sensors are required to activate fuel trim adjustments. The HO2S detects presence of oxygen in exhaust and provides PCM with feedback identifying air/fuel ratio. A fuel trim factor is added to fuel injector pulse width calculation according to long and short term fuel trims. Long term fuel trim values at their rich or lean limits indicate a fuel system malfunction.

Possible causes are

1. Low fuel pressure or running out of fuel.
2. Excessive fuel pressure.
3. Leaking fuel injector(s).
4. Leaking fuel pressure regulator.
5. Vapor recovery system.
6. Contaminated fuel injector(s).
7. Air leaks after MAF/IAT sensor.
8. Vacuum leaks.
9. Restricted air intake.
10. PCV system.
11. Improperly seated engine oil dipstick.
12. Leaking EGR gasket.
13. Stuck EGR valve.
14. Leaking EGR diaphragm or EGR vacuum regulator.
15. Engine oil overfill.
16. Engine cam timing.
17. Cylinder compression.
18. Exhaust leaks before or near HO2S(s).

DTC P0172 indicates air/fuel ratio is too rich (Bank 1).

DTC P0175 indicates air/fuel ratio is too rich (Bank 2).

Fuel control system uses fuel trim tables stored in PCM to compensate for variances in fuel system components from wear and aging. The fuel trim strategy learns deviations during closed-loop engine operation. Fuel trim has 2 means of adapting; a long term fuel trim and a short term fuel trim. Inputs from Engine Coolant Temperature (ECT), Cylinder Head Temperature (CHT) and Mass Airflow/Intake Air Temperature (MAF/IAT) sensors are required to activate fuel trim adjustments. The HO2S detects presence of oxygen in exhaust and provides PCM with feedback identifying air/fuel ratio. A fuel trim factor is added to fuel injector pulse width calculation according to long and short term fuel trims. Long term fuel trim values at their rich or lean limits indicate a fuel system malfunction.

Possible causes are

1. Low fuel pressure or running out of fuel.
2. Excessive fuel pressure.
3. Leaking fuel injector(s).
4. Leaking fuel pressure regulator.
5. Vapor recovery system.
6. Contaminated fuel injector(s).
7. Air leaks after MAF/IAT sensor.
8. Vacuum leaks.
9. Restricted air intake.
10. PCV system.
11. Improperly seated engine oil dipstick.
12. Leaking EGR gasket.
13. Stuck EGR valve.
14. Leaking EGR diaphragm or EGR vacuum regulator.
15. Engine oil overfill.
16. Engine cam timing.
17. Cylinder compression.
18. Exhaust leaks before or near HO2S(s).

DTC P0201-P0206 indicates fuel injector does not operate electrically even though the harness assembly and fuel injectors test satisfactorily. DTC number indicates cylinder number. Fuel injectors are electrically operated solenoids. Injectors open and close a constant number of times per crankshaft revolution. Amount of fuel is controlled by adjusting injector pulse width. Injectors are normally closed and opened by 12-volt VPWR from PCM power relay. PCM controls PCM power relay ground. Possibly caused by faulty fuel injector driver inside PCM.

Scheme 56

1. If QUICK TEST was not performed, go to «QUICK TEST»(ref-150940-S17451707022002112700000) under SELF-DIAGNOSTIC SYSTEM. If QUICK TEST was performed, go to next step.
2. Check Injector Fault PIDS Access INJ1F-INJ6F PIDs using scan tool. If an injector fault is present, go to next step. If an injector fault is not present, go to step 6. NOTE: Next step measures resistance of suspect fuel injector at breakout box terminals. Resistance measurement includes vehicle wiring harness and fuel injector.
3. Check Fuel Injector(s) & Harness Resistance This erases Continuous Memory DTCs. Disconnect PCM 104-pin harness connector. Connect Breakout Box (49-UN01-130) to PCM harness connector only. (Scheme 50) Use injector fault PID to determine fuel injector circuit(s) requiring testing. Measure resistance of fuel injector between suspect INJ circuit terminal and VPWR terminal No. 71 of breakout box. (Scheme 56) If resistance reading is 11-18 ohms, replace PCM. After repair, go to step 6. If resistance reading is not as specified, go to next step.
4. Check Fuel Injector Harness Resistance Disconnect fuel injector harness connector at suspect fuel injector. Measure resistance of VPWR circuit between breakout box terminal No. 71 and fuel injector harness connector terminal. (Scheme 56) Measure resistance of INJ circuit between appropriate breakout box terminal and fuel injector harness connector terminal. If each resistance reading is less than 5 ohms, go to next step. If each resistance reading is 5 ohms or more, repair open circuit. After repair, go to step 6.
5. Check Fuel Injector Harness Circuit For Short To Power & Ground Measure resistance between suspect INJ circuit terminal and VPWR terminal No. 71 of breakout box. Measure resistance between suspect INJ circuit terminal and PWR GND terminal No. 103 of breakout box. If each resistance reading is more than 10,000 ohms, replace PCM. Repeat «QUICK TEST»(ref-150940-S17451707022002112700000) under SELF-DIAGNOSTIC SYSTEM. After repair, go to next step. If resistance reading is 10,000 ohms or less, repair short circuit. See «WIRING DIAGRAMS»(ref-134975) article. After repair, go to next step.
6. Verify Trouble Shooting Of DTCs Completed Reconnect all disconnected connectors. Clear DTCs from PCM memory using scan tool. Perform «QUICK TEST»(ref-150940-S17451707022002112700000) under SELF-DIAGNOSTIC SYSTEM. If same DTC is present, replace faulty PCM. Repeat «QUICK TEST»(ref-150940-S17451707022002112700000) under SELF-DIAGNOSTIC SYSTEM. If same DTC is not present, go to applicable procedure for other DTCs. See «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(ref-150940-S42582837182002112700000). If no DTCs are set, procedure is complete.

Detection Conditions

DTC P0230 indicates excessive current draw is detected (with Fuel Pump (FP) output command ON) on FP circuit or voltage is not detected (FP output command OFF) on FP circuit (PCM expects to detect VPWR voltage coming through fuel pump relay coil to FP circuit).

DTC P0231 indicates PCM did not detect B+ voltage on Fuel Pump Module (FPM) circuit when fuel pump was commanded ON.

DTC P0232 indicates PCM detected FPM circuit voltage was high when fuel pump was commanded OFF.

DTC 1641 indicates a fault with Fuel Pump Driver Module (FPDM). No possible cause is identified.

Fuel Pump Driver Module (FPDM) modulates voltage to fuel pump to achieve proper fuel pressure. Voltage for fuel pump is supplied by power relay or FPDM power supply relay.

Possible Cause

Possible causes are

DTC P0230

1. Open or shorted fuel pump circuit.
2. Damaged fuel pump relay.
3. Damaged PCM.
4. Open VPWR circuit to fuel pump relay.

DTC P0231

1. Open in B+ circuit to fuel pump relay.
2. Fuel pump relay contacts open.
3. Open in FP PWR circuit between fuel pump relay and connection to FPM circuit.
4. Damaged fuel pump relay.
5. Damaged PCM (engine will start).

DTC P0232 (No Start)

1. Inertia Fuel Shutoff (IFS) switch not reset or electrically open.
2. Open circuit between fuel pump and FPM circuit connection to FP PWR circuit.
3. Poor fuel pump ground.
4. Fuel pump electrically open.

DTC P0232 (Engine Starts)

1. Fuel pump secondary circuit short to power.
2. Fuel pump relay contacts always closed.
3. Open in FPM circuit between PCM connection to FP PWR circuit.
4. Damaged PCM.

Scheme 57

Scheme 58

Scheme 59

1. If QUICK TEST was not performed, go to «QUICK TEST»(ref-150940-S17451707022002112700000) under SELF-DIAGNOSTIC SYSTEM. If QUICK TEST was performed: For DTC P0230, go to next step. For DTC P0231, go to step 18. For KOEO DTC P0232, go to step 9. For Continuous Memory DTC P0230, go to step 21. For Continuous Memory DTC P0231, go to step 22. For Continuous Memory DTC P0232, go to step 23.
2. Check For VPWR To Fuel Pump Relay Disconnect fuel pump relay. Turn ignition on, engine off. Measure VPWR circuit voltage at fuel pump relay 5-pin connector in battery junction box. (Scheme 57) Turn ignition off. If voltage reading was more than 10.5 volts, go to next step. If voltage reading was not as specified, repair open in VPWR circuit (Red wire) between PCM power relay and fuel pump relay 5-pin connector terminal No. 2 in battery junction box. See «WIRING DIAGRAMS»(ref-134975) article. After repair, go to step 24.
3. Check Fuel Pump Relay Measure resistance between fuel pump relay terminals No. 1 and 2. Resistance reading should be 40-120 ohms. Measure resistance between fuel pump relay terminals No. 3 and 5. Resistance reading should be more than 10,000 ohms. Check for continuity between fuel pump relay terminals No. 3 and 4. There should be continuity. If all resistance checks are as specified, go to next step. If any resistance checks are not as specified, replace fuel pump relay. After repair, go to step 24.
4. Check FP Circuit For Short To Power In Harness Disconnect PCM 104-pin harness connector. Connect Breakout Box (49-UN01-130) to PCM harness connector only. (Scheme 50) Turn ignition on, engine off. Measure voltage between ground and breakout box terminal No. 54 (2.0L) or terminal No. 80 (3.0L). Turn ignition off. If voltage was less than 1.0 volt, go to next step. If voltage was not as specified, repair short to power in Blue/Orange wire between PCM 104-pin harness connector terminal No. 54 (2.0L) or terminal No. 80 (3.0L) and fuel pump relay 5-pin connector terminal No. 1 in battery junction box. (Scheme 57) See «WIRING DIAGRAMS»(ref-134975) article. After repair, go to step 24.
5. Check FP Circuit For Short To Ground In Harness Disconnect scan tool from DLC. Measure resistance between ground and breakout box terminal No. 54 (2.0L) or terminal No. 80 (3.0L). If all resistance readings are more than 10,000 ohms, go to next step. If all resistance readings are not as specified, repair short in Blue/Orange wire between PCM 104-pin harness connector terminal No. 54 (2.0L) or terminal No. 80 (3.0L) and fuel pump relay 5-pin connector terminal No. 1 in battery junction box. (Scheme 57) After repair, go to step 24.
6. Check FP For Open Circuit Measure resistance of FP circuit between breakout box terminal No. 54 (2.0L) or terminal No. 80 (3.0L) and fuel pump relay 5-pin connector terminal No. 1 in battery junction box. If resistance reading is less than 5 ohms and DTC P0231 or P0232 is present with P0230, go to next step. If resistance reading is less than 5 ohms and DTC P0231 or P0232 is not present with P0230, replace PCM. After repair, go to step 24. If resistance reading is not as specified, repair open in Blue/Orange wire between PCM 104-pin harness connector terminal No. 54 (2.0L) or terminal No. 80 (3.0L) and fuel pump relay 5-pin connector terminal No. 1 in battery junction box. After repair, go to step 24.
7. Check Fuel Pump Primary Circuit Inside The PCM Remove breakout box. Reconnect PCM. Reconnect fuel pump relay. Reconnect scan tool to DLC. Turn ignition on, engine off. Access FPF PID on scan tool. If FPF PID is not YES, go to next step. If FPF PID is YES, Turn ignition off. Replace PCM. After repair, go to step 24. NOTE: During next step, scan tool must be connected to a reliable power source that is powered with ignition in START position (e.g., directly to vehicle battery). Also verify that vehicle battery is fully charged.
8. Check The Fuel Pump Primary Circuit Inside PCM While Cranking Engine While observing FPF PID, crank engine. If FPF PID is YES during cranking, turn ignition off. Replace PCM. After repair, go to step 24. If FPF PID is not YES, turn ignition off. Fuel pump primary circuit is okay in harness and PCM. If DTC P0231 is present, go to step 18. If DTC P0232 is present, go to next step.
9. Check Engine Start If engine starts, go to next step. If engine does not start, go to step 14.
10. Verify That Fuel Pump Is Off Turn ignition on, engine off. Wait 5 seconds. Listen for motor noise from fuel pump (it may be necessary to listen near fuel tank). If fuel pump is off, turn ignition off and go to step 12. If fuel pump is on, turn ignition off and go to next step.
11. Check For Fuel Pump Relay Always Closed Disconnect fuel pump relay from battery junction box. Turn ignition on, engine off. If fuel pump is off, turn ignition off. Replace fuel pump relay. After repair, go to step 24. If fuel pump is on, turn ignition off. Repair short to power in fuel pump PWR/FPM circuit. See «WIRING DIAGRAMS»(ref-134975) article. After repair, go to step 24.
12. Check For Open Fuel Pump Monitor Circuit Disconnect PCM 104-pin harness connector. Connect Breakout Box (49-UN01-130) to PCM harness connector only. (Scheme 50) Disconnect fuel pump relay from battery junction box. Measure resistance of FP PWR circuit between breakout box terminal No. 40 and fuel pump relay 5-pin connector terminal No. 5 (Dark Green/ Yellow wire). If resistance reading is less than 5 ohms, go to next step. If resistance reading is not as specified, repair open in Dark Green/Yellow wire between fuel pump relay 5-pin connector terminal No. 5 and PCM 104-pin harness connector terminal No. 40. After repair, go to step 24.
13. Check Fuel Pump Monitor Circuit In PCM Remove breakout box. Reconnect PCM 104-pin harness connector and fuel pump relay. Turn ignition on, engine off. Access FPM PID on scan tool. If FPM PID is OFF, fuel pump module circuit is okay in harness and PCM. Disregard DTC P0232 at this time. Go to step 24. If FPM PID is not OFF, replace PCM. After repair, go to step 24.
14. Check Inertia Fuel Shutoff Switch Locate and disconnect Inertia Fuel Shutoff (IFS) switch 3-pin harness connector after verifying switch is reset. Measure resistance between IFS switch terminals No. 1 and 2. (Scheme 58) If resistance reading is less than 5 ohms, go to next step. If resistance reading is not as specified, replace IFS switch. After repair, go to step 24.
15. Check For Open FP PWR Circuit Between IFS Switch & Fuel Pump Relay Disconnect fuel pump relay from battery junction box. Measure resistance of FP PWR circuit (Dark Green/Yellow wire) between fuel pump relay 5-pin connector terminal No. 5 and IFS switch 3-pin harness connector terminal No. 1. (Scheme 57)and (Scheme 58). If resistance reading is less than 5 ohms, reconnect fuel pump relay. Go to next step. If resistance reading is not as specified, repair open in Dark Green/Yellow wire between fuel pump relay 5-pin connector terminal No. 5 and IFS switch 3-pin harness connector terminal No. 1. See «WIRING DIAGRAMS»(ref-134975) article. After repair, go to step 24.
16. Check For Open FP GND Circuit & FP PWR Circuit (Between IFS Switch & Fuel Pump) Disconnect fuel pump tank unit 4-pin harness connector. Measure resistance of FP GND circuit between ground and fuel tank unit 4-pin harness connector terminal No. 3 (Black wire). Measure resistance of FP PWR circuit (Pink/Black wire) between IFS switch 3-pin harness connector terminal No. 2 and fuel tank unit 4-pin harness connector terminal No. 1. (Scheme 59) If resistance reading is less than 5 ohms, go to next step. If resistance reading is not as specified, repair open in Pink/Black wire between IFS switch 3-pin harness connector terminal No. 2 and fuel tank unit 4-pin harness connector terminal No. 1. See «WIRING DIAGRAMS»(ref-134975) article. After repair, go to step 24.
17. Check Internal Resistance Of Fuel Pump Measure internal resistance of fuel pump between fuel tank unit connector FP PWR terminal No. 1 and ground terminal No. 3. If resistance reading is less than 10 ohms, all fuel pump circuits are okay. Verify test step results. If all test steps are okay, reconnect all disconnected connectors. Disregard DTC P0232 at this time. Go to step 24. If resistance reading is not as specified, replace fuel pump. After repair, go to step 24.
18. Check Engine Start If KOEO DTC P0230 is also present and has not been diagnosed, go to step 21 (to check primary fuel pump circuits first). If engine starts, go to step 12. If engine does not start, go to next step.
19. Check B+ Voltage To Fuel Pump Relay Disconnect fuel pump relay located in battery junction box. Measure B+ circuit voltage at fuel pump relay 5-pin connector terminal No. 3 (Orange wire). (Scheme 57) If voltage reading is more than 10.5 volts, go to next step. If voltage reading is not as specified, check for burned No. 6 fuse (20-amp) in battery junction box. If fuse is okay, repair open circuit between positive battery terminal and fuel pump relay 5-pin connector terminal No. 3 (Orange wire). See «WIRING DIAGRAMS»(ref-134975) article. If fuse/fuse link is burned, check B+ and FP PWR circuits for short to ground before replacing. After repair, go to step 24.
20. Check For Open FP PWR Circuit Between Fuel Pump Relay & Ground Point 2 Measure resistance of FP PWR circuit between fuel pump relay 5-pin connector terminal No. 5 and negative battery terminal. If resistance reading is less than 10 ohms, replace fuel pump relay. After repair, go to step 24. If resistance reading is not as specified, repair open circuit. See «WIRING DIAGRAMS»(ref-134975) article. After repair, go to step 24. NOTE: During following step, FPF PID will read YES when an open is detected because PCM will not detect VPWR voltage on PCM terminal No. 54 (2.0L) or terminal No. 80 (3.0L).
21. Continuous Memory DTC P0230: Check Fuel Pump Primary Circuits With scan tool connected. Turn ignition on, engine off. Wait 5 seconds. Access FPF PID. FPF PID will be NO, indicating that PCM detects VPWR voltage through fuel pump relay coil and FP circuit to PCM. Observe FPF PID for an indication of a fault while performing following: Shake, wiggle, bend Fuel Pump (FP) circuit between the PCM and fuel pump relay. Shake, wiggle, bend VPWR circuit between PCM power relay and fuel pump relay. Lightly tap fuel pump relay to simulate road shock. Inspect PCM and fuel pump relay connectors for corrosion or damaged pins. If a fault is indicated, isolate fault and repair as necessary. See «WIRING DIAGRAMS»(ref-134975) article. After repair, go to step 24. If fault is not indicated, problem is intermittent. Refer to «INTERMITTENT»(ref-150940-S23445146842002120200000) testing under «SYSTEM TESTS»(ref-150940-S42556424782002112700000).
22. Continuous Memory DTC P0231: Check Harness Circuits Disconnect PCM 104-pin harness connector. Connect Breakout Box (49-UN01-130) between PCM harness connector and PCM. (Scheme 50) Install fused jumper wire between breakout box terminal No. 51 and terminal No. 54 (2.0L) or terminal No. 80 (3.0L). Connect DVOM between breakout box terminals No. 40 and No 51. Turn ignition on, engine off. Fuel pump will turn on and voltage will be more than 10.0 volts. Observe voltage for an indication of a fault while performing following: Shake, wiggle, bend B+ circuit to fuel pump relay. Lightly tap fuel pump relay to simulate road shock. Shake, wiggle bend FP PWR circuit between fuel pump relay and FPM splice. Turn ignition off. Inspect fuel pump relay connector for corrosion, damaged pins, etc. If a fault is indicated, isolate fault and repair as necessary. See «WIRING DIAGRAMS»(ref-134975) article. If a fault is not indicated, problem is intermittent. Refer to «INTERMITTENT»(ref-150940-S23445146842002120200000) testing under «SYSTEM TESTS»(ref-150940-S42556424782002112700000).
23. Continuous Memory DTC P0232: Check Fuel Pump Secondary Circuits If Continuous Memory DTC P0230 is also present, go to step 21. Turn ignition on, engine off. Access FPM PID on Scan tool. Observe FPM PID for an indication of a fault while performing following (FPM PID will turn ON when an open or short to power is detected): Shake, wiggle, bend FP PWR circuit (Dark Green/Yellow wire) between fuel pump relay FP PWR terminal No. 5 and fuel tank unit 3-pin harness connector terminal No. 2. Shake, wiggle, bend fuel pump ground circuit from fuel tank unit to ground. Lightly tap fuel pump to simulate road shock. Shake, wiggle, bend FPM circuit between PCM and the splice to FP PWR circuit. Lightly tap Inertia Fuel Shutoff (IFS) switch to simulate road shock. Lightly tap fuel pump relay to simulate road shock. If fault is indicated/found, isolate fault and repair as necessary. See «WIRING DIAGRAMS»(ref-134975) article. After repair, go to next step. If fault is not found, problem is intermittent. Refer to «INTERMITTENT»(ref-150940-S23445146842002120200000) testing under «SYSTEM TESTS»(ref-150940-S42556424782002112700000).
24. Verify Trouble Shooting Of DTCs Completed Reconnect all disconnected connectors. Clear DTCs from PCM memory using scan tool. Perform «QUICK TEST»(ref-150940-S17451707022002112700000) under SELF-DIAGNOSTIC SYSTEM. If same DTC is present, replace faulty PCM. Repeat «QUICK TEST»(ref-150940-S17451707022002112700000) under SELF-DIAGNOSTIC SYSTEM. If same DTC is not present, go to applicable procedure for other DTCs. See «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(ref-150940-S42582837182002112700000). If no DTCs are set, procedure is complete.

DTC P0300 indicates multiple cylinders are misfiring or PCM cannot identify which cylinder is misfiring.

DTCs P0301-P0306 indicates random misfire detected or identified cylinder misfire is detected. DTC number indicates cylinder number.

Possible causes are

1. Ignition system.
2. Fuel injectors.
3. Fuel pressure.
4. Evaporative emission system.
5. Base engine.
6. Low fuel or running out of fuel.
7. Camshaft Position (CMP) sensor.
8. Stuck open EGR valve.
9. Blocked EGR passages.

DTC P0320 indicates 2 successive erratic Profile Ignition Pickup (PIP) pulses occurred resulting in possible engine miss or stall.

Crankshaft Position (CKP) sensor is mounted on engine block adjacent to a pulse wheel located on crankshaft. CKP sensor monitors crankshaft mounted pulse wheel. Pulse wheel has 35 teeth spaced 10 degrees apart with one empty space. CKP sensor indicates crankshaft position and speed information to PCM by monitoring pulse wheel. CKP sensor identifies piston travel by monitoring the missing tooth in order to synchronize ignition system and provide a way of tracking angular position of crankshaft relative to a fixed reference for CKP sensor configuration. PCM also uses CKP sensor signal to determine if a misfire has occurred by measuring rapid deceleration between pulse wheel teeth.

Possible causes are

1. Loose wires or connectors.
2. Arcing secondary ignition components.
3. On-board transmitter (2-way radio).
4. CKP sensor.

Scheme 60

1. If QUICK TEST was not performed, go to «QUICK TEST»(ref-150940-S17451707022002112700000) under SELF-DIAGNOSTIC SYSTEM. If QUICK TEST was performed, go to next step.
2. DTC P0320: Erratic Ignition Check for following: Loose wires/connectors. Arcing secondary ignition components (coil, wires, plugs). 2-way radio. Verify all 2-way radio installations regarding routing of antenna and power leads. Carefully follow manufacturer's installation instructions. If any of these faults are present, repair as necessary. After repair, go to step 25. If these possible causes are not present and condition is intermittent, refer to «INTERMITTENT»(ref-150940-S23445146842002120200000) testing under «SYSTEM TESTS»(ref-150940-S42556424782002112700000). If condition is not intermittent, go to next step.
3. Check CKP(+)/CKP(-) Continuity Disconnect CKP sensor harness connector and PCM 104-pin harness connector. Connect Breakout Box (49-UN01-130) to PCM harness connector only. (Scheme 50) Measure resistance of CKP(+) circuit between breakout box terminal No. 21 and CKP sensor harness connector (Black/Pink wire). (Scheme 60) Measure resistance of CKP(-) circuit between breakout box terminal No. 22 and CKP sensor harness connector (Gray/Yellow wire). If each resistance reading is more than 5 ohms, repair open circuit. See «WIRING DIAGRAMS»(ref-134975) article. If resistance reading is not as specified, go to next step.
4. Check For CKP(+) Bias Voltage Fault Remove breakout box. Reconnect PCM 104-pin harness connector. Turn ignition on, engine off. Measure voltage between CKP(+) terminal (Black/Pink wire) at CKP harness connector and negative battery terminal. Turn ignition off. If voltage reading is 1.0-2.0 volts, go to next step. If voltage reading is not as specified, go to step 17.
5. Check For CKP(-) Bias Voltage Fault Turn ignition on, engine off. Measure voltage between CKP(-) terminal (Gray/Yellow wire) at CKP sensor harness connector and negative battery terminal. Turn ignition off. If voltage reading is 1.0-2.0 volts, go to step 9. If voltage reading is not as specified, go to next step.
6. Determine If Bias High Or Bias Low Fault If bias voltage reading for CKP(-) circuit is less than one volt (bias low fault), go to next step. If bias voltage reading is more than 2.0 volts (bias high), go to step 8.
7. Check For CKP(-) Short To Ground In Harness Disconnect PCM 104-pin harness connector. Connect Breakout Box (49-UN01-130) to PCM harness connector only. (Scheme 50) Measure resistance of CKP(-) circuit between breakout box terminal No. 22 and negative battery terminal. If resistance reading is more than 10,000 ohms, replace PCM. After repair, go to step 25. If resistance reading is not as specified, repair short in Gray/Yellow wire between PCM 104-pin harness connector and CKP sensor harness connector. See «WIRING DIAGRAMS»(ref-134975) article. After repair, go to step 25.
8. Check For CKP(-) Short To Power In Harness Disconnect PCM 104-pin harness connector. Connect Breakout Box (49-UN01-130) to PCM harness connector only. (Scheme 50) Turn ignition on, engine off. Measure voltage of CKP(-) circuit between breakout box terminal No. 22 and negative battery terminal. If voltage reading is less than 0.5 volt, replace PCM. After repair, go to step 25. If voltage reading is not less than 0.5 volt repair short to power in Gray/Yellow wire between PCM 104-pin harness connector terminal No. 22 and CKP sensor harness connector. See «WIRING DIAGRAMS»(ref-134975) article. After repair, go to step 25.
9. Check CKP Sensor Amplitude At PCM Disconnect PCM 104-pin harness connector. Connect Breakout Box (49-UN01-130) to PCM harness connector only. (Scheme 50) Measure voltage between breakout box terminal No. 21 (CKP+) and terminal No. 22 (CKP-) while cranking engine. If settled AC voltage reading was more than 0.4 volt, go to next step. If settled AC voltage reading was not as specified, go to step 11.
10. Check CKP(+) Circuit For Short To Ground At Sensor Measure resistance of CKP(+) circuit between breakout box terminal No. 21 and negative battery terminal. If resistance reading is more than 10,000 ohms, go to step 20. If resistance reading is not as specified, go to step 15.
11. Check CKP Circuit Resistance For Amplitude Fault Measure resistance between breakout box terminal No. 21 (CKP+) and terminal No. 22 (CKP-). If resistance reading is 300-800 ohms, go to step 14. If resistance reading is not as specified, go to next step.
12. Determine If Resistance High Or Resistance Low Fault If resistance reading between CKP(+) and CKP(-) was less than 300 ohms, go to next step. If resistance reading was not as specified, replace CKP sensor. After repair, go to step 25.
13. Check CKP(+) For Short To CKP(-) Disconnect CKP sensor. Measure resistance between CKP(+) and CKP(-) at CKP sensor harness connector. If resistance reading is less than 5 ohms, repair short. See «WIRING DIAGRAMS»(ref-134975) article. After repair, go to step 25. If resistance reading is not as specified, go to next step.
14. Check CKP Sensor & Pulse Wheel Visually inspect pulse wheel and CKP sensor for damage. If CKP sensor and pulse wheel are okay, replace CKP sensor. If CKP sensor or pulse wheel are damaged, repair or replace damaged parts. After repair, go to step 25.
15. Check For Open Or Short In PCM Disconnect CKP sensor harness connector. Remove Breakout Box. Reconnect PCM 104-pin harness connector to PCM. Measure resistance between CKP(+) and CKP(-) at CKP harness connector. If resistance reading is 16,000-24,000 ohms, go to next step. If resistance reading is not as specified, replace PCM. After repair, go to step 25.
16. Check CKP(+) For Short To CKP(-) Disconnect PCM 104-pin harness connector. Connect Breakout Box (49-UN01-130) to PCM harness connector only. (Scheme 50) Measure resistance between CKP(+) and CKP(-) at CKP sensor harness connector. If resistance reading is more than 1000 ohms, replace CKP sensor. After repair, go to step 25. If resistance reading is less than 1000 ohms, repair short circuit. See «WIRING DIAGRAMS»(ref-134975) article. After repair, go to step 25.
17. Determine If Bias Voltage High Or Bias Voltage Low Fault If bias voltage was measured less than one volt, go to next step. If bias voltage was measured more than one volt, go to step 19.
18. Check CKP(+) Circuit For Short To Ground In Harness Disconnect PCM 104-pin harness connector. Connect Breakout Box (49-UN01-130) to PCM harness connector only. (Scheme 50) Measure resistance between breakout box terminal No. 21 (CKP+) and negative battery terminal. If resistance reading is more than 10,000 ohms, replace PCM. After repair, go to step 25. If resistance reading is 10,000 ohms or less, repair short in Black/Pink wire between PCM 104-pin harness connector terminal No. 21 and CKP sensor harness connector. See «WIRING DIAGRAMS»(ref-134975) article. After repair, go to step 25.
19. Check CKP(+) Circuit For Short To Power In Harness Disconnect PCM 104-pin harness connector. Connect Breakout Box (49-UN01-130) to PCM harness connector only. (Scheme 50) Turn ignition on, engine off. Measure voltage between breakout box terminal No. 21 (CKP+) and negative battery terminal. If voltage reading is less than 0.5 volts, replace PCM. After repair, go to step 25. If voltage reading is more than 5.0 volts, repair short to power on Pink/Black wire between PCM 104-pin harness connector terminal No. 21 and CKP sensor harness connector. See «WIRING DIAGRAMS»(ref-134975) article. After repair, go to step 25.
20. Visual Inspection Of Ignition System Visually inspect engine compartment to make sure all coils and spark plug wires are secured properly. Examine all wiring harnesses and connectors for damaged, burned or overheated insulation and loose or broken connections. Ensure battery is fully charged. Verify all accessories are off. If no problem is indicated, go to next step. If a problem is indicated, repair as necessary. After repair, go to step 25.
21. DTC P0301 - P0306: Misfire On Specific Cylinder Are DTCS P0301-P0306 present, go to «DTC P0300, P0301, P0302, P0303, P0304, P0305 OR P0306»(ref-150940-S14824013182002112700000). If DTCs P0301-P0306 are not present, go to next step.
22. Check For Spark At All Cylinders Disable inertia fuel shutoff switch. Check for spark at each cylinder while cranking engine. If bluish white spark is consistent between all cylinders, turn ignition off. Go to next step. If bluish white spark is not consistent between all cylinders, turn ignition off. Inspect plug wires (2.0L). Measure resistance of spark plug wires and replace them if more than 7000 ohms per foot. After repair, go to step 25.
23. Check Spark Plugs Remove and inspect plugs for damage, wear, carbon deposits and proper plug gap. If plugs are okay, go to next step. If spark plugs are not okay, clean spark plugs or regap. Replace if necessary. After repair, go to step 25.
24. Check Spark Plug Resistance Measure spark plug resistance. If resistance reading is 2000-20,000 ohms, fault is intermittent. Refer to «INTERMITTENT»(ref-150940-S23445146842002120200000) testing under «SYSTEM TESTS»(ref-150940-S42556424782002112700000). If resistance reading is not as specified, go to next step.
25. Verify Trouble Shooting Of DTCs Completed Perform «QUICK TEST»(ref-150940-S17451707022002112700000) under SELF-DIAGNOSTIC SYSTEM. If any DTC is present, go to applicable procedure for other DTCs. See «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(ref-150940-S42582837182002112700000). If no DTCs are set, trouble shooting is complete.

DTC P0325 indicates Knock Sensor (KS) malfunction.

DTC P0326 indicates knock sensor has detected vibrations (voltage generated is based on this vibration) relative with engine speed that is outside a calibrated level.

A tuned accelerometer on engine that converts engine vibration to an electrical signal. PCM uses this signal to determine presence of engine knock and retard ignition timing as necessary.

Possible causes are

1. Knock Sensor (KS) circuit short to ground.
2. Knock sensor circuit short to power.
3. Open knock sensor circuit.
4. Damaged knock sensor.
5. Damaged PCM.

DTC P0340 indicates Camshaft Position (CMP) sensor circuit failure.

CMP sensor is a magnetic transducer. CMP sensor detects position of camshaft and identifies when piston No. 1 is on compression stroke. A signal is sent to PCM. PCM uses signal to synchronize firing of fuel injectors.

Possible causes are

1. CMP sensor circuit open.
2. CMP sensor circuit shorted to ground.
3. CMP sensor circuit shorted to power.
4. SIG RTN circuit open.
5. Damaged CMP sensor.
6. Damaged CMP sensor shielding.
7. Damaged PCM.

DTC P0350 indicates PCM did not receive a valid Ignition Diagnostic Monitor (IDM) pulse signal. This indicates primary side of ignition coil has failed from the ignition module (integrated in PCM) which is caused by an ignition coil primary or secondary circuit malfunction.

Coil packs are in a tower configuration with 2 adjacent coil towers sharing a common coil (called a matched pair). For 4-cylinder applications, matched cylinder pairs are 1/4 and 2/3. For V6 applications matched cylinder pairs are 1/5, 2/6 and 3/4. When ignition coil is fired by PCM, spark is delivered to a matched pair of towers, then onto the respective (paired cylinder) spark plugs. Spark plugs are fired simultaneously and are paired so one fires on the compression stroke, while the other spark plug fires on the exhaust stroke. On the subsequent firing of ignition coil, paired cylinder spark plugs will fire on opposite piston strokes.

Possible causes are

1. Open or short in ignition START/RUN circuit.
2. Open coil driver circuit.
3. Coil driver circuit shorted to ground.
4. Damaged coil.
5. Coil driver circuit shorted to VPWR.

DTC P0351-P0356 indicate PCM did not receive a valid Ignition Diagnostic Monitor (IDM) pulse signal, which indicates primary side of coil has failed from ignition module (integrated in PCM). This is caused by an ignition coil failure. DTC number indicates cylinder number.

Coil packs are in a tower configuration with 2 adjacent coil towers sharing a common coil (called a matched pair). For 4-cylinder applications, matched cylinder pairs are 1/4 and 2/3. For V6 applications matched cylinder pairs are 1/5, 2/6 and 3/4. When ignition coil is fired by PCM, spark is delivered to a matched pair of towers, then onto the respective (paired cylinder) spark plugs. Spark plugs are fired simultaneously and are paired so one fires on the compression stroke, while the other spark plug fires on the exhaust stroke. On the subsequent firing of ignition coil, paired cylinder spark plugs will fire on opposite piston strokes.

Possible causes are

1. Open or short in IGN START/ON (RUN) circuit.
2. Open coil driver circuit in harness.
3. Coil driver circuit shorted to ground in harness.
4. Coil driver circuit shorted to PWR.
5. Damaged ignition coil.
6. Damaged PCM.

Scheme 61

Scheme 62

1. If QUICK TEST was not performed, go to «QUICK TEST»(ref-150940-S17451707022002112700000) under SELF-DIAGNOSTIC SYSTEM. If QUICK TEST was performed, go to next step. NOTE: Electronic ignition engine timing is entirely controlled by the PCM. Electronic ignition timing is NOT adjustable. Do not attempt to check base timing. You will receive false readings.
2. Determine Which Coil Is Not Firing Determine which coil is not firing using information from «IGNITION COIL-TO-CYLINDER CORRELATION (COIL PACK)»(ref-150940-S06818218262002121900000) table. Record cylinder, coil and breakout box terminal from table. If cylinder number, coil driver and PCM pin numbers have been recorded, go to next step. If information has not been recorded, obtain required information. Go to next step. IGNITION COIL-TO-CYLINDER CORRELATION (COIL PACK) Application & Cylinder No. Coil Driver Breakout Box Terminal No. DTC 2.0L 1 1 26 P0351 3 2 52 P0352 4 1 26 P0351 2 2 52 P0352 3.0L 1 1 26 P0351 4 2 52 P0355 2 3 78 P0354 5 4 1 P0352 3 5 27 P0356 6 6 53 P0353
3. Check IGN START/RUN Voltage To Coil Pack Disconnect coil. Turn ignition on, engine off. Measure voltage between ground and IGN START/RUN circuit at ignition coil harness connector. Turn ignition off. If voltage reading is more than 10.0 volts, for 2.0L go to step 6. For 3.0L, go to next step. If voltage reading is not more than 10 volts, check condition of No. 19 STARTER fuse (40-amp) in under-hood battery junction box. If fuse is okay, repair open circuit. If fuse/fuse link is burned, check IGN START/RUN circuit for short to ground. See «WIRING DIAGRAMS»(ref-134975) article. Repair as necessary. After repair, go to step 11.
4. DTC P0351, P0356: Crankshaft Position Sensor Failure If DTC P0351 or DTC P0356 are present, go to next step. If DTC P0351 or P0356 are not present, go to step 6.
5. Check Resistance Of Crankshaft Position Sensor Measure resistance of Crankshaft Position (CKP) sensor. If resistance reading is 290-390 ohms, go to next step. If resistance reading is not as specified, replace CKP sensor. After repair, go to step 13.
6. Check Functionality Of Suspect Coil Driver (CD) Circuit Connect test light between IGN START/RUN and suspect CD circuit at ignition coil harness connector. See «IGNITION COIL-TO-CYLINDER CORRELATION (COIL PACK)»(ref-150940-S06818218262002121900000) table. Disable fuel pump by disabling Inertia Fuel Shutoff (IFS) switch. Observe test light while cranking engine. If test lamp does not blink consistently, go to next step. If test lamp blinks consistently, go to step 11.
7. Check Suspect CD Circuit For Open In Harness Disconnect PCM 104-pin harness connector. Connect Breakout Box (49-UN01-130) to PCM harness connector only. (Scheme 50) Measure resistance of suspect CD circuit between breakout box terminal and ignition coil harness connector. See «IGNITION COIL-TO-CYLINDER CORRELATION (COIL PACK)»(ref-150940-S06818218262002121900000) table. (Scheme 61)and (Scheme 62). If resistance reading is less than 5 ohms, go to next step. If resistance reading is not as specified, repair open circuit. See «WIRING DIAGRAMS»(ref-134975) article. After repair, go to step 13.
8. Check Suspect CD Circuit For Short To VPWR In Harness Turn ignition on, engine off. Measure voltage of suspect CD circuit between ground and breakout box terminal. See «IGNITION COIL-TO-CYLINDER CORRELATION (COIL PACK)»(ref-150940-S06818218262002121900000) table. If voltage reading is less than one volt, go to next step. If voltage reading is not as specified, repair short to power. See «WIRING DIAGRAMS»(ref-134975) article. After repair, go to step 13.
9. Check Suspect CD Circuit For Short To Ground In Harness Disconnect scan tool. Measure resistance of suspect CD circuit between ground and breakout box terminal. See «IGNITION COIL-TO-CYLINDER CORRELATION (COIL PACK)»(ref-150940-S06818218262002121900000) table. If resistance reading is more than 10,000 ohms, go to next step. If resistance reading is not as specified, repair short circuit. See «WIRING DIAGRAMS»(ref-134975) article. After repair, go to step 13.
10. PERFORM INTERMITTENT TEST ON SUSPECT CD CIRCUIT HARNESS Connect DVOM to suspect CD circuit between breakout box terminal and ignition coil harness connector. See «IGNITION COIL-TO-CYLINDER CORRELATION (COIL PACK)»(ref-150940-S06818218262002121900000) table. Wiggle and bend CD harness from PCM 104-pin harness connector to ignition coil harness connector. (Scheme 61)and (Scheme 62). If resistance reading fluctuated during wiggle test, repair intermittent fault in harness. See «WIRING DIAGRAMS»(ref-134975) article. After repair, go to step 13. If resistance reading did not fluctuated during wiggle test, replace PCM. After repair, go to next step to check for damaged coil.
11. Check Suspect Primary Coil For Open Measure resistance of suspect coil between CD and IGN START/RUN circuits at ignition coil connector. (Scheme 61)and (Scheme 62). If resistance reading fluctuated during wiggle test, repair intermittent fault in harness. If resistance reading is less than 5 ohms, go to step 13. If resistance reading is not as specified, replace ignition coil. After repair, go to step 13.
12. Check Suspect Secondary Coil For Open Remove both plug wires from ignition coil of suspect cylinder. Measure resistance of suspected coil driver between terminals. If resistance reading is 10,000-14,500 ohms and DTC P0350 is present, refer to «DTC P0350: IGNITION COIL PRIMARY CIRCUIT - MALFUNCTION»(ref-150940-S25344015032002112700000). If no additional DTCs are present, refer to «INTERMITTENT»(ref-150940-S23445146842002120200000) testing under «SYSTEM TESTS»(ref-150940-S42556424782002112700000). If resistance reading is not as specified, replace ignition coil. After repair, go to step 13.
13. Drive Cycle Reconnect all disconnected connectors. Clear DTCs from PCM memory using scan tool. Perform Fuel or Misfire Monitor Drive Cycle. Refer to «MONITOR REPAIR VERIFICATION DRIVE CYCLES»(ref-150940-S24809892142002112700000). Retrieve pending code. If same DTC is present, replace PCM. After repair, go to next step. If same DTC is not present, go to next step.
14. Verify Trouble Shooting Of DTCs Completed Perform PCM Quick Test. If any DTC is present, go to applicable procedure for other DTCs. See «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(ref-150940-S42582837182002112700000). If no DTCs are set, trouble shooting is complete.

DTC P0401 indicates self-test has detected insufficient EGR flow.

DTC P1408 indicates EGR flow is less than required calibrated limit.

EGR system receives signals from Engine Coolant Temperature (ECT), Intake Air Temperature (IAT), Throttle Position (TP), Mass Airflow (MAF) and Crankshaft Position (CKP) sensors to provide PCM with information on engine operating conditions. Before EGR system is activated, engine must be warm, stable and running at a moderate load and RPM. PCM deactivates EGR during idle, extended wide open throttle or when a failure is detected in an EGR component or EGR required component. EGR Vacuum Regulator (EGRVR) solenoid receives a variable duty cycle signal from PCM. The higher duty cycle, the more vacuum the solenoid diverts to the EGR valve. An increase in vacuum acting on EGR valve diaphragm overcomes a spring and begins to lift EGR valve pintle off its seat, allowing exhaust gas to enter intake manifold. One side of the EGR orifice tube is exposed to exhaust gas backpressure and the other side is exposed to the intake manifold, causing a pressure drop across the orifice whenever there is EGR flow. When EGR valve closes, there is no longer any flow across the metering orifice and pressure on both sides of the orifice is the same. The Differential Pressure Feedback EGR (DPFEGR) measures actual pressure drop across the metering orifice and relays a proportional voltage signal (0-5 volts) to PCM.

Possible causes are

1. Vacuum supply.
2. EGR valve stuck closed.
3. EGR valve leaks vacuum.
4. EGR flow path restricted.
5. EGRVR circuit shorted to power.
6. VREF open to DPF EGR sensor.
7. DPF EGR sensor downstream hose off or plugged.
8. EGRVR circuit open to PCM.
9. VPWR open to EGRVR solenoid.
10. DPF EGR sensor hoses both off.
11. DPF EGR sensor hoses reversed.
12. Damaged EGR orifice tube.
13. Damaged EGRVR solenoid.
14. Damaged PCM.

Scheme 63

Scheme 64

1. If QUICK TEST was not performed, go to «QUICK TEST»(ref-150940-S17451707022002112700000) under SELF-DIAGNOSTIC SYSTEM. If QUICK TEST was performed and Continuous Memory DTC P1406 appears, go to «DTC P1405 OR P1406»(ref-150940-S26437470652002112700000) troubleshooting. If KOER DTC 1408 does not appear with P0401, go to step 12. Otherwise, go to next step. NOTE: Since EGR vacuum hose is disconnected, ignore DTCs during this KOER self-test.
2. Run KOER Self-Test While Monitoring EGR Vacuum Disconnect vacuum hose at EGR valve and connect hose to vacuum gauge. Start engine. Run Self-Test while monitoring vacuum gauge. About 30 seconds into test, EGR flow will be requested for a few seconds. Vacuum at this time should increase more than 1.6 in. Hg (5.4 kPa) to open valve. If vacuum increases to 3.0 in. Hg (10 kPa) or more at any time during KOER self-test, vacuum indicated is sufficient to open EGR valve. Fault is unlikely to be in EGR valve. Go to next step. If vacuum does not increase to specification, vacuum indicated is insufficient to open EGR valve. Go to step 6.
3. Inspect DPFEGR Sensor Pressure Hoses Visually inspect both pressure hoses for reversed connection at DPFEGR sensor or at orifice tube assembly. Inspect both hoses for improper routing. Hoses should not be pinched or have dips where water could settle and freeze. Inspect both hoses for leaks and blockage. Inspect DPFEGR sensor and orifice tube assembly for blockage or damage at pick up tubes. If there is a fault detected, repair vacuum hoses as necessary. After repair, go to step 6.
4. Check DPFEGR Sensor Output By Applying Vacuum With Hand Pump Disconnect pressure hoses at DPFEGR sensor. Connect a hand vacuum pump to downstream connection at sensor (intake manifold side of sensor or the smaller diameter pickup tube). Turn ignition on, engine off. Access DPFEGR PID with a scan tool and record PID value. Apply 8-9 in. Hg (27-30 kPa) vacuum to DPFEGR sensor and hold for a few seconds. Quickly release vacuum. DPFEGR PID voltage reading must be 0.2-1.3 volts with key on and no vacuum applied. DPFEGR PID voltage reading must increase to more than 4.0 volts with vacuum applied. DPFEGR PID voltage reading must drop to less than 1.5 volts in less than 3 seconds when vacuum is released. Turn ignition off. If DPFEGR PID voltage reading indicated a fault in the DPFEGR sensor, replace DPFEGR sensor. After repair, go to next step. If DPFEGR PID voltage reading did not indicate a fault, go to step 6.
5. Check EGR Valve Function By Applying Vacuum With Hand Pump Disconnect vacuum hose at EGR valve and plug hose. Connect hand vacuum pump to EGR valve. Start engine and bring to idle. Access DPFEGR and RPM PIDs with scan tool. Slowly apply 8-10 in. Hg (27-34 kPa) of vacuum to EGR valve and hold it for 10 seconds. If engine wants to stall, increase RPM with throttle to maintain a minimum of 1000 RPM. Look for following: EGR valve starts opening at about 1.6 in. Hg (5.4 kPa) vacuum indicated by increasing DPFEGR PID voltage reading. DPFEGR PID voltage reading increasing until EGR valve is fully open. DPFEGR PID should read 2.5 volts minimum with full vacuum applied. DPFEGR PID voltage reading is steady when vacuum is held. If voltage drops within a few seconds, EGR valve or vacuum source could be leaking. If DPFEGR PID voltage reading indicated that EGR valve is operating as described in this test, restore vehicle to original condition. Go to step 11. If DPFEGR PID voltage reading did not indicate EGR valve is operating properly, remove and inspect EGR valve for signs of contamination, unusual wear, carbon deposits, binding, leaking diaphragm and other damage. If EGR valve is okay, look for an obstructed EGR port in intake manifold or plugged orifice tube assembly. Repair as necessary. After repair, go to step 17.
6. Check Vacuum Source & Vacuum Hoses To & From EGR Vacuum Regulator (EGRVR) Solenoid Inspect vacuum lines between vacuum source and EGRVR solenoid and between EGRVR solenoid and EGR valve for leaks, kinks, disconnects, blockage, routing or any damage. Disconnect vacuum hoses at EGRVR solenoid. Connect EGRVR solenoid vacuum source hose to a vacuum gauge. With engine warm and at idle, take a vacuum reading. If vacuum gauge reading was a minimum of 15 in. Hg (51 kPa) at idle and vacuum lines are okay, restore vehicle to original condition. Go to next step. If vacuum gauge reading was not as specified or vacuum lines were faulty, isolate fault and repair as necessary. After repair, go to step 17.
7. Check VPWR To EGRVR Solenoid Disconnect EGRVR solenoid. Turn ignition on, engine off. Measure voltage of VPWR circuit (White/Red wire) between ground and EGRVR solenoid harness connector. (Scheme 63) If EGRVR solenoid VPWR voltage reading was more than 10.5 volts, go to next step. If EGRVR solenoid VPWR voltage reading was not as specified, repair open in EGRVR solenoid VPWR circuit (White/Red wire) between PCM 104-pin harness connector terminal No. 71 and EGRVR solenoid harness connector. See «WIRING DIAGRAMS»(ref-134975) article. After repair, go to step 17.
8. Measure Resistance Across EGR Vacuum Regulator (EGRVR) Solenoid Measure resistance across EGRVR solenoid. If EGRVR solenoid resistance reading is 26-40 ohms, go to next step. If EGRVR solenoid resistance reading is not as specified, replace EGRVR solenoid. After repair, go to step 17.
9. Check EGRVR Circuit For Short To PWR Disconnect PCM 104-pin harness connector. Connect Breakout Box (49-UN01-130) to PCM harness connector only. (Scheme 50) Turn ignition on, engine off. Measure voltage between ground and breakout box terminal No. 79 (2.0L) or terminal No. 47 (3.0L) (EGRVR). Turn ignition off. If voltage reading was more than one volt, repair EGRVR circuit (Violet wire) for short to PWR between PCM 104-pin harness connector terminal No. 79 (2.0L) or terminal No. 47 (3.0L) and EGRVR solenoid harness connector. See «WIRING DIAGRAMS»(ref-134975) article. After repair, go to step 17. If voltage reading was one volt or less, go to next step.
10. Check EGRVR Circuit For Open In Harness Measure resistance of EGRVR circuit between breakout box terminal No. 79 (2.0L) or terminal No. 47 (3.0L) and EGRVR solenoid harness connector. (Scheme 63) If resistance reading is less than 5 ohms, go to next step. If resistance reading is not as specified, repair open in EGRVR circuit (Violet wire) between PCM 104-pin harness connector terminal No. 79 (2.0L) or terminal No. 47 (3.0L) and EGRVR solenoid harness connector. See «WIRING DIAGRAMS»(ref-134975) article. After repair, go to step 17.
11. Check EGRVR Solenoid Vacuum Output Capacity By Grounding EGRVR Circuit Remove breakout box. Reconnect PCM 104-pin harness connector and EGRVR solenoid harness connector. Disconnect vacuum hose at EGR valve and connect to a vacuum gauge. Start engine. With engine at idle, connect fused jumper wire between ground and PCM 104-pin harness connector terminal No. 79 (2.0L) or terminal No. 47 (3.0L) (EGRVR). If vacuum gauge reading is 4.0 in. Hg (13.5 kPa) or more, replace PCM. After repair, go to step 17. If vacuum gauge reading was not as specified, replace EGRVR solenoid. After repair, go to step 17.
12. Inspect EGR System For An Intermittent Failure Visually inspect EGR system for signs of intermittent failure. If no fault is found, go to next step. If a fault is found, repair fault as necessary. After repair, go to step 17.
13. Inspect DPFEGR Sensor Pressure Hoses Visually inspect both pressure hoses for reversed connection at DPFEGR sensor or at orifice tube assembly. Inspect both hoses for improper routing. Hoses should not be pinched or have dips where water could settle and freeze. Inspect both hoses for improper routing. Hoses should not be pinched or have dips where water could settle or freeze. Inspect both hoses for leaks and blockage. Inspect DPFEGR sensor and orifice tube assembly for blockage or damage at pickup tubes. If no fault is detected, go to next step. If a fault is detected, repair pressure hoses as necessary. After repair, go to step 17.
14. Check DPFEGR Sensor Output By Applying Vacuum With Hand Pump Disconnect pressure hoses at DPFEGR sensor. Connect hand vacuum pump to downstream connection at DPFEGR sensor (intake manifold side of sensor or smaller diameter pickup tube). Turn ignition on, engine off. Access DPFEGR PID with scan tool and record PID value. Apply 8-9 in. Hg (27-30 kPa) vacuum to DPFEGR sensor and hold for a few seconds. Quickly release vacuum. DPFEGR PID voltage reading must be 0.2-1.3 volts with ignition turned on and no vacuum applied. The DPFEGR PID voltage reading must increase to more than 4.0 volts with vacuum applied. DPFEGR PID voltage reading must drop to less than 1.5 volts in less than 3 seconds when vacuum is released. If DPFEGR PID voltage reading does not indicate a fault in DPFEGR sensor, go to next step. If DPFEGR PID voltage reading indicates a fault in DPFEGR sensor, replace DPFEGR sensor. After repair, go to step 17.
15. Check EGR Valve Function By Applying Vacuum With Hand Pump Disconnect vacuum hose at EGR valve and plug hose. (Scheme 64) Connect a hand vacuum pump to EGR valve. Start engine and bring to idle. Access DPFEGR and RPM PIDs with scan tool. Slowly apply 5-10 in. Hg (17-34 kPa) of vacuum to EGR valve and hold it for 10 seconds. If engine wants to stall, increase RPM with throttle to maintain a minimum of 800 RPM. Look for following: EGR valve starts opening at about 91.6 in. Hg (5.4 kPa) vacuum indicated by increasing DPFEGR PID voltage. DPFEGR PID voltage increasing until EGR valve is fully open. DPFEGR PID should read 2.5 volts minimum with full vacuum applied. DPFEGR PID voltage steady when vacuum is held. If voltage drops within a few seconds, EGR valve or vacuum source could be leaking. Turn ignition off. If DPFEGR PID voltage reading indicated that EGR valve is operating as described in this test, go to next step. If DPFEGR PID voltage reading indicated EGR valve was faulty, remove and inspect EGR valve for signs of contamination, unusual wear, carbon deposits, binding, leaking diaphragm and other damage. If EGR valve is okay, look for an obstructed EGR port in intake manifold. Repair as necessary. After repair, go to step 17.
16. Inspect EGR Vacuum Signal Supply For Intermittent Failure Disconnect PCM 104-pin harness connector. Connect Breakout Box (49-UN01-130) to PCM harness connector and PCM. (Scheme 50) Disconnect plugged hose at EGR valve and connect to a vacuum gauge. Start engine. Connect fused jumper between ground and breakout box terminal No. 79 (2.0L) or terminal No. 47 (3.0L) (EGRVR) to activate EGR vacuum regulator solenoid to full ON. At idle, vacuum gauge should read above 4.0 in. Hg (13.5 kPa). Observe vacuum gauge for an indication of a fault while lightly tapping EGRVR solenoid and wiggling EGRVR solenoid connector, vacuum lines and vehicle harness between EGRVR solenoid and PCM. A fault is indicated by a sudden drop in vacuum reading. If a fault was indicated, isolate fault and repair as necessary. After repair, go to next step. If no fault was indicated, unable to duplicate or identify fault at this time. In cold climates, EGR valve may temporarily freeze shut and thaw when engine warms up causing intermittent DTC. Refer to «INTERMITTENT»(ref-150940-S23445146842002120200000) testing under «SYSTEM TESTS»(ref-150940-S42556424782002112700000).
17. Verify Trouble Shooting Of DTCs Completed Reconnect all disconnected connectors. Clear DTCs from PCM memory using scan tool. Perform «QUICK TEST»(ref-150940-S17451707022002112700000) under SELF-DIAGNOSTIC SYSTEM. If same DTC is present, replace faulty PCM. Repeat «QUICK TEST»(ref-150940-S17451707022002112700000) under SELF-DIAGNOSTIC SYSTEM. If same DTC is not present, go to applicable procedure for other DTCs. See «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(ref-150940-S42582837182002112700000). If no DTCs are set, trouble shooting is complete.

DTC P0402 indicates Self-Test has indicated Differential Pressure Feedback EGR (DPFEGR) signal at idle is more than at KOEO by a calibrated amount.

EGR system receives signals from Engine Coolant Temperature (ECT), Intake Air Temperature (IAT), Throttle Position (TP), Mass Airflow (MAF) and Crankshaft Position (CKP) sensors to provide PCM with information on engine operating conditions. Before EGR system is activated, engine must be warm, stable and running at a moderate load and RPM. PCM deactivates EGR during idle, extended wide open throttle or when a failure is detected in an EGR component or EGR required component. EGR Vacuum Regulator (EGRVR) solenoid receives a variable duty cycle signal from PCM. The higher duty cycle, the more vacuum the solenoid diverts to the EGR valve. An increase in vacuum acting on EGR valve diaphragm overcomes a spring and begins to lift EGR valve pintle off its seat, allowing exhaust gas to enter intake manifold. One side of the EGR orifice tube is exposed to exhaust gas backpressure and the other side is exposed to the intake manifold, causing a pressure drop across the orifice whenever there is EGR flow. When EGR valve closes, there is no longer any flow across the metering orifice and pressure on both sides of the orifice is the same. The Differential Pressure Feedback EGR (DPFEGR) measures actual pressure drop across the metering orifice and relays a proportional voltage signal (0-5 volts) to PCM.

Possible causes are

1. EGR valve stuck open.
2. EGRVR circuit shorted to ground.
3. Damaged EGRVR solenoid.
4. Damaged PCM.
5. Plugged EGRVR solenoid vent.
6. Plugged EGR tube.
7. Slow responding DPFEGR sensor.
8. Damaged DPFEGR sensor.
9. Improper vacuum hose connection.
10. Plugged vacuum hoses.

DTC P0420 indicates Bank 1 catalyst system efficiency is below acceptable threshold.

DTC P0430 indicates Bank 2 catalyst system efficiency is below acceptable threshold.

Interior deterioration of catalytic converter is usually caused by abnormal engine operation. Events that produce higher than normal temperatures in the catalyst are particularly suspect (misfires). Incorrect HO2S signal input may cause abnormal temperature increase in the catalyst. Engine Coolant Temperature/Cylinder Head Temperature (ECT/CHT) sensor DTCs may indicate an incorrectly operating thermostat or coolant level is not to proper level, producing higher than normal operating temperatures.

Possible causes are

1. Using leaded fuel.
2. Oil contamination.
3. Engine misfire.
4. Damaged HO2S.
5. Malfunctioning ECT/CHT sensor.
6. Downstream HO2S wires improperly connected.
7. Fuel pressure too high.
8. Damaged exhaust system pipe.
9. Damaged exhaust manifold.
10. Damaged muffler/tailpipe assembly.
11. Damaged catalytic converter.
12. Retarded spark timing.

DTC P0442 indicates a leak has been detected as small as 0.04" (1 mm) in EVAP canister purge valve solenoid system. There is less than 2.5 in. H 2 O (0.625 kPa) bleed-up over 15 seconds at 75 percent fuel fill level. Bleed-up and evaluation time vary as a function of fuel fill level. Vapor generation limit is more than 2.5 in. H 2 O (0.625 kPa) over 120 seconds.

DTC P0456 indicates a fuel vapor leak from an opening as small as .020" (.51mm) has been detected by EVAP running loss monitor test.

Possible causes are

1. Aftermarket EVAP hardware (i.e., fuel filler cap) not meeting required specifications.
2. Small holes in fuel vapor hoses/tubes.
3. Canister vent solenoid stays partially open on closed command.
4. Damaged, cross-threaded or loosely installed fuel filler cap.
5. Loose fuel vapor hose/tube connections to EVAP system components.
6. EVAP system component seals leaking such as EVAP canister purge valve, Fuel Tank Pressure (FTP) sensor, canister vent solenoid, fuel vapor control check valve tube assembly or fuel vapor vent valve assembly.

DTC P0443 indicates signal moved outside minimum or maximum allowable calibrated parameters for a specified purge duty cycle by PCM command.

Possible causes are

1. VPWR circuit open.
2. EVAP canister purge valve circuit shorted to ground.
3. Damaged EVAP canister purge valve.
4. EVAP canister purge valve circuit open.
5. EVAP canister purge valve circuit shorted to VPWR.
6. Damaged PCM.

DTC P0451 indicates fuel tank pressure changes more than 14 in. H 2 O in 0.10 seconds (sensor circuit noisy).

DTC P0461 indicates fuel level input noisy.

Fuel Tank Pressure (FTP) sensor measures fuel tank pressure during EVAP monitor test and to control excessive fuel tank pressure by forcing a system purge. Fuel level input indicates fuel level in tank with a hard wire signal input to PCM from fuel pump module.

Possible causes are

1. Intermittent open or short in Fuel Tank Pressure (FTP) sensor circuit (P0451).
2. Intermittent open or short in Fuel Level Input (FLI) circuit (P0461).

DTC P0452 indicates self-test has detected an FTP circuit input less than minimum allowable calibrated parameter. Fuel Tank Pressure (FTP) sensor measures fuel tank pressure during EVAP monitor test and to control excessive fuel tank pressure by forcing a system purge.

Possible causes are

1. Contamination internal to FTP sensor connector.
2. Damaged PCM.
3. FTP circuit shorted to ground or SIG RTN.
4. Damaged FTP sensor.

Scheme 65

1. If QUICK TEST was not performed, go to «QUICK TEST»(ref-150940-S17451707022002112700000) under SELF-DIAGNOSTIC SYSTEM. If QUICK TEST was performed, go to next step.
2. DTC P0452: Check For Fuel Saturation Of FTP Sensor Turn ignition off. Visually check for liquid fuel contamination of FTP sensor 3-pin harness connector. Check for a completely submerged FTP sensor in liquid fuel which can affect correct FTP voltage reading. If FTP sensor and harness connector do not show signs of fuel contamination, go to next step. If FTP sensor and harness connector show signs of fuel contamination, repair FTP sensor 3-pin harness connector as necessary. If FTP sensor is completely submerged in fuel, drain fuel tank to proper level. After repair, go to step 7.
3. Verify FTP SIG Voltage Turn ignition on, engine off. Access FTP V PID with scan tool. If FTP V PID voltage reading is less than 0.22 volt, go to next step. If voltage reading is not as specified, fault is intermittent. Refer to «INTERMITTENT»(ref-150940-S23445146842002120200000) testing under «SYSTEM TESTS»(ref-150940-S42556424782002112700000). NOTE: If a scan tool communication concern exists during next step, remove fused jumper wire immediately and go directly to step 5.
4. Induce Opposite FTP Signal Turn ignition off. Disconnect FTP sensor 3-pin harness connector. Connect a fused jumper wire between VREF (Brown/White wire) and FTP (Red/Pink wire) terminals at FTP sensor 3-pin harness connector. (Scheme 65) Turn ignition on, engine off. Access FTP V PID with scan tool. If FTP V PID value is 4-6 volts, replace FTP sensor. After repair, go to step 7. If FTP V PID value is not as specified, go to next step.
5. Check VREF At FTP Sensor Harness Connector Measure voltage between VREF (Brown/White wire) and SIG RTN (Orange wire) terminals at FTP sensor 3-pin harness connector. If VREF voltage reading is 4-6 volts, go to next step. If VREF voltage reading is not as specified, refer to «VEHICLE REFERENCE VOLTAGE»(ref-150940-S23619745912002112700000) testing under «SYSTEM TESTS»(ref-150940-S42556424782002112700000).
6. Check FTP Circuit For Shorts To SIG RTN & PWR GND Turn ignition off. Disconnect PCM 104-pin harness connector. Connect Breakout Box (49-UN01-130) to PCM harness connector only. (Scheme 50) Disconnect scan tool from DLC. Measure resistance between breakout box terminals No. 62 (FTP) and No. 91 (SIG RTN). Measure the resistance between breakout box terminals No. 62 (FTP) and No. 103 (PWR GND). If each resistance reading is more than 10,000 ohms, replace PCM. After repair, go to next step. If each resistance reading is not more than 10,000 ohms, repair short in harness between FTP circuit (Red/Pink wire) and SIG RTN circuit (Orange wire) or PWR GND circuit (Black wire). See «WIRING DIAGRAMS»(ref-134975) article. After repair, go to next step.
7. Verify Trouble Shooting Of DTCs Completed Reconnect all disconnected connectors. Perform PCM Quick Test. If any DTC is present, go to applicable procedure for other DTCs. See «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(ref-150940-S42582837182002112700000). If no DTCs are set, trouble shooting is complete.

DTC P0453 indicates self-test has detected an FTP circuit input more than the maximum allowable calibrated parameter. Fuel Tank Pressure (FTP) sensor measures fuel tank pressure during EVAP monitor test and to control excessive fuel tank pressure by forcing a system purge.

Possible causes are

1. FTP circuit open.
2. FTP shorted to VREF or VPWR.
3. VREF shorted to VPWR.
4. SIG RTN circuit open.
5. Damaged FTP sensor.
6. Damaged PCM.

DTC P0455 indicates a substantial leak or blockage has been detected in EVAP system when there is -7 in. H 2 O (-1.74 kPa) or less vacuum for 30 seconds evaluation time.

DTC P1443 indicates a substantial leak and no purge flow has been detected in EVAP system when there is -7 in. H 2 O (-1.74 kPa) or less vacuum for 30 seconds evaluation time with less than 0.02 lb/min vapor flow.

Possible causes are

1. Aftermarket EVAP hardware (i.e., fuel filler cap) not meeting required specifications (P0455).
2. Disconnected or cracked fuel EVAP canister tube, EVAP canister purge outlet tube or EVAP return tube (P0455).
3. EVAP canister purge valve stuck closed (P0455).
4. Damaged or missing fuel filler cap (P0455).
5. Insufficient fuel filler cap installation (P0455).
6. Loose fuel vapor hose/tube connections to EVAP system components (P0455).
7. Blockages or restrictions in fuel vapor hoses/tubes (P0455).
8. Fuel vapor control valve tube assembly or fuel vapor vent valve assembly blocked (P0455).
9. Canister Vent (CV) solenoid stuck open (P0455).
10. Mechanically inoperative Fuel Tank Pressure (FTP) sensor (P0455).
11. Pinched, blocked or plugged fuel vapor tubes/hoses except between fuel tank and EVAP canister (P1443).
12. Damaged EVAP canister (P0455 or P1443).
13. Disconnected, cracked or cut fuel vapor tubes/hoses except between fuel tank and EVAP canister (P1443).
14. Damaged EVAP canister purge valve (P1443).

DTC P0457 indicates initial vacuum could not be achieved after a refueling event and purge vapor flow is excessive (gross leak). Fuel filler cap prevents fuel spillage and closes EVAP system to the atmosphere.

Possible cause is a missing or loose fuel filler cap.

DTC P0505 indicates desired RPM could not be reached or controlled during KOEO self-test.

DTC P1504 indicates an electrical load failure on IAC output circuit.

DTC P1507 indicates engine idle speed is less than desired RPM.

Idle Air Control (IAC) valve controls engine speed and provides a dashpot function. IAC valve meters intake air around throttle plate through a bypass within IAC valve assembly and throttle body. PCM determines desired idle speed or bypass air and signals IAC valve through a specified duty cycle. The IAC valve responds by positioning to control amount of bypass air. Possible causes are

1. VPWR to IAC solenoid open (P0505, P1504 or P1507).
2. IAC circuit open (P0505, P1504 or P1507).
3. IAC circuit shorted to PWR (P0505, P1504 or P1507).
4. IAC circuit shorted to GND (P1504).
5. VPWR circuit open (P0505, P1504 or P1507).
6. Air inlet plugged (P0505 or P1507).
7. Air inlet leakage (P1507).
8. Damaged IAC solenoid (P1504 or P1507).
9. Damaged throttle body (P0505 or P1507).
10. Damaged PCM (P0505, P1504 or P1507).

Scheme 66

1. If QUICK TEST was not performed, go to «QUICK TEST»(ref-150940-S17451707022002112700000) under SELF-DIAGNOSTIC SYSTEM. If QUICK TEST was performed, go to next step. NOTE: If EGR DTC P0402 was present during Self-Test, diagnose it first before continuing with next test.
2. DTC P0505, P1504, P1507 Or Starts Only At Part Throttle: Check VPWR To IAC Valve Assembly Disconnect IAC valve. Turn ignition on, engine off. Measure voltage between ground and VPWR terminal (White/Red wire) at IAC valve harness connector. Turn ignition off. If voltage reading was more than 10.5 volts, go to next step. If voltage reading was not as specified, repair open in White/Red wire between PCM 104-pin harness connector terminals No. 71 and 97 and IAC valve harness connector. See «WIRING DIAGRAMS»(ref-134975) article. After repair, go to step 12. NOTE: Due to diode in solenoid, place DVOM positive lead on VPWR terminal and negative lead on IAC terminal.
3. Check IAC Valve Resistance Measure IAC valve assembly resistance. If resistance is 6-13 ohms, go to next step. If resistance reading is not as specified, replace IAC valve assembly. After repair, go to step 12.
4. Check IAC Valve Assembly For An Internal Short To IAC Case Measure resistance from IAC terminal to IAC valve case. (Scheme 66) If resistance reading is more than 10,000 ohms and DTC P1504 is present, go to step 7. For all other DTCs, go to next step. If resistance reading is not as specified, replace IAC valve. After repair, go to step 12.
5. Check Air Inlet For Plugging Inspect entire air intake system for debris, blockage and other damage. Remove and inspect air cleaner element for excessive dirt. If air intake system is okay, restore air inlet system and go to next step. If problem is found in air intake system, repair as necessary. After repair, go to step 12.
6. Check For Vacuum Leaks Start engine. With engine running at idle, listen for vacuum leaks. Inspect entire air intake system from Mass Airflow (MAF) sensor to intake manifold for leaks such as: Cracked or punctured intake air tube. Loose intake air tube at air cleaner housing or throttle body. IAC valve assembly or gasket seal. EGR valve gasket seal. Vacuum supply connector and hose. PCV connectors and hose. Turn ignition off. If no leaks were detected, go to next step. If any leaks were detected, repair as necessary. After repair, go to step 12.
7. Check IAC Circuit Resistance Disconnected PCM and IAC valve harness connectors. Connect Breakout Box (49-UN01-130) to PCM harness connector only. (Scheme 50) Measure resistance of IAC circuit (White/blue wire) between breakout box terminal No. 83 and IAC valve harness connector. Is resistance reading is less than 5.0 ohms, go to next step. If resistance reading is not as specified, repair open in White/Blue wire between PCM 104-pin harness connector terminal No. 83 and IAC valve harness connector. See «WIRING DIAGRAMS»(ref-134975) article. After repair, go to step 12.
8. Check IAC Circuit For Short To PWR Turn ignition on, engine off. Measure voltage between ground and breakout box terminal No. 83 (IAC). Turn ignition off. If voltage reading was less than one volt, go to next step. If voltage reading was not as specified, repair short in White/Blue wire between PCM 104-pin harness connector terminal No. 83 and IAC valve harness connector. After repair, go to step 12.
9. Check IAC Circuit For Short To Ground Disconnect scan tool from DLC. Measure resistance between breakout box terminals No. 83 (IAC) and No. 103 (PWR GND). If resistance reading is more than 10,000 ohms, go to next step. If resistance reading is 10,000 ohms or less, repair short in White/Blue wire between PCM 104-pin harness connector terminal No. 83 and IAC valve harness connector. After repair, go to step 12. NOTE: During following step, if stalling occurs, place a shim under the hard stop screw to maintain idle conditions. NOTE: If closed throttle RPM is significantly higher than normal, ignore next step.
10. Check IAC Signal From PCM Remove Breakout Box. Reconnect PCM and IAC valve harness connectors. Reconnect scan tool. Start engine. Using scan tool, select DIAGNOSTIC DATA LINK. Select PCM Select PID DATA MONITOR AND RECORD. Access IAC and RPM PIDs. With engine at normal operating temperature, all accessories off and at closed throttle, IAC duty cycle must be approximately 22-45 percent. Slowly increase engine speed to 3000 RPM and return to closed throttle. If IAC duty cycle is within specification at closed throttle and duty cycle responded to change in RPM, proceed as follows: For DTCs P1504 and P1507, go to next step. For all other DTCs, turn ignition off. Inspect throttle body for damage. Repair as necessary. If throttle body is okay, replace IAC valve. After repair, go to step 12. If IAC duty cycle is not within specification at closed throttle and duty cycle does not responded to change in RPM, proceed as follows: For DTC P1507, replace IAC valve. For all other DTCs, replace PCM. After repair, go to step 12.
11. Check IAC System For Intermittent Open Or Short Using scan tool, select DIAGNOSTIC DATA LINK. Select PCM. Select PID DATA MONITOR AND RECORD. Access IAC and RPM PIDs. Observe PIDs for an indication of a fault while performing the following at idle: Lightly tap on IAC valve and wiggle harness connector to simulate road shock. Grasp vehicle harness closest to IAC valve. Shake and bend a small section of harness from IAC valve to dash panel and from dash panel to PCM. If IAC and RPM PIDs suddenly change in value indicating a fault, isolate fault and repair as necessary. After repair, go to next step. If IAC and RPM PIDs do not suddenly change in value and idle quality, starting or stalling symptoms currently present, replace IAC valve. After repair, go to next step. For all other concerns, problem is intermittent. Refer to «INTERMITTENT»(ref-150940-S23445146842002120200000) testing under «SYSTEM TESTS»(ref-150940-S42556424782002112700000).
12. Verify Trouble Shooting Of DTCs Completed Reconnect all disconnected connectors. Clear DTCs from PCM memory using scan tool. Perform «QUICK TEST»(ref-150940-S17451707022002112700000) under SELF-DIAGNOSTIC SYSTEM. If same DTC is present, replace faulty PCM. Repeat «QUICK TEST»(ref-150940-S17451707022002112700000) under SELF-DIAGNOSTIC SYSTEM. If same DTC is not present, go to applicable procedure for other DTCs. See «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(ref-150940-S42582837182002112700000). If no DTCs are present, trouble shooting is complete.

DTC P0603 and P1605 indicates PCM has experienced a power interrupt in Keep Alive Power (KAPWR) circuit or an internal memory test failure. However, there are external items that can cause this DTC.

DTC P1633 indicates KAPWR circuit has experienced a power interrupt.

DTC P1639 indicates PCM programmable parameters are corrupted or not programmed correctly.

PCM receives information from a variety of sensor and switch inputs. Based on strategy and calibration stored within the memory chip, PCM generates an appropriate output. The system is designated to minimize emissions and optimize fuel economy and driveability. The software strategy controls basic operation of engine and transaxle, provides OBD-II strategy, controls Malfunction Indicator Light (MIL), communicates through the Data Link Connector (DLC), allows for Flash Electronically Erasable Programmable Read Only Memory (FEEPROM), provides idle air and fuel trim, and controls Failure Mode Effects Management (FMEM).

Possible causes are

1. Battery terminal corrosion or loose connections (P0603 or P1605).
2. Open KAPWR circuit (P1633).
3. KAPWR to PCM interrupt/open (P0603 or P1605).
4. Damaged PCM (P0603, P1605 or P1633).
5. Reprogramming (P0603 or P1605).
6. Intermittent KAPWR circuit (P1633).

DTC P0703 indicates PCM did not receive a BPP input.

DTC P1703 indicates BPP signal was high (KOEO) or BPP signal did not cycle high and low (KOER).

Brake Pedal Position (BPP) switch is used by PCM to disengage transaxle Torque Converter Clutch (TCC) and an input to idle speed control for idle quality. BPP is hard wired to PCM and supplies B+ when vehicle brake pedal is applied.

Possible causes are

1. Open or short in BPP circuit.
2. Open or short in brakelight circuits.
3. Damaged PCM.
4. Malfunction in module(s) connected to BPP circuit.
5. Damaged brake switch.
6. Misadjusted brake switch.

DTC P0704 indicates a malfunction of Clutch Pedal Position (CPP) switch has been detected.

DTC P1709 indicates voltage is high or switch is open when voltage should be low or switch should be closed grounding the circuit.

CPP switch is an input to PCM indicating clutch pedal position. PCM provides a 5-volt reference (VREF) signal to CPP switch. If switch is closed indicating clutch pedal is engaged, output voltage from PCM is grounded through the signal return line to PCM, and there is one volt or less indicating there is a reduced load on the engine. If CPP signal is open (clutch pedal disengaged) input on CPP signal to PCM will be approximately 5 volts indicating there is a load on the engine.

Possible causes are

1. Starter relay disconnected during QUICK TEST.
2. CPP circuit shorted to power.
3. CPP open in SIG RTN circuit.
4. Damaged CPP switch.
5. Damaged PCM.

DTC P1000 indicates OBD-II monitor testing is not complete.

Possible causes are

1. The vehicle is new from the factory and has not completed an OBD-II drive cycle.
2. Battery or PCM has been disconnected.
3. OBD-II monitor failure had occurred before completion of an OBD-II drive cycle.
4. PCM DTCs have been cleared with a scan tool as part of a service process.

DTC P1001 may indicate several failures; unable to access Continuous Memory DTCs, unable to activate KOEO or KOER self-test, scan tool communication problem, DTC displayed by scan tool not listed, or KOER self-test cannot be completed.

Possible causes are

1. Damaged Data Link Connector (DLC).
2. Incorrect self-test procedure.
3. VREF is not in specification.
4. Idle RPM out of specification.
5. Open in DLC harness circuit.
6. Short in DLC circuit or associated modules.
7. Damaged PCM power relay circuit.
8. Damaged PCM.

Scheme 67

1. If QUICK TEST was not performed, go to «QUICK TEST»(ref-150940-S17451707022002112700000) under SELF-DIAGNOSTIC SYSTEM. If QUICK TEST was performed, go to next step.
2. Check For VREF At Throttle Position (TP) Sensor Turn ignition off. Disconnect TP sensor 3-pin harness connector. Turn ignition on, engine off. Measure voltage between VREF (Brown/White wire) and SIG RTN (Orange wire) at TP sensor 3-pin harness connector. (Scheme 55) Turn ignition off. If voltage reading is 4.0-6.0 volts, reconnect TP sensor and go to next step. If voltage reading is not as specified, reconnect TP sensor. Refer to «VEHICLE REFERENCE VOLTAGE»(ref-150940-S23619745912002112700000) testing under «SYSTEM TESTS»(ref-150940-S42556424782002112700000).
3. Ability To Access Continuous Memory DTCs If Continuous Memory DTCs can be accessed, go to next step. If Continuous Memory DTCs cannot be accessed, go to step 7.
4. Ability To Activate KOEO Self-Test If KOEO self-test can be activated, go to next step. If KOEO self-test cannot be activated, go to step 6.
5. Ability To Activate KOER Self-Test If KOER self-test can be activated and are here for DTC P1001 and other KOER DTCs are present, begin diagnosis with first KOER DTC that appears. If DTC is not listed in Diagnostic Trouble Code Definitions table, ensure correct PCM is installed on vehicle. If KOER self-test cannot be activated, go to next step. NOTE: If failures are present in following components or systems, EEC strategy can be prevented from completing KOER self-test or cause PCM to generate a scan tool communication error message: Idle cruise control. EGR system. Fuel control system. Vehicle speed signal circuits. Mass Airflow/Intake Air Temperature (MAF/IAT) sensor circuits. Transaxle range circuits.
6. Retrieve Any Continuous Memory DTCs Turn ignition on, engine off. Retrieve and record Continuous Memory DTCs (MIL and non-MIL). Turn ignition OFF. If Continuous Memory DTCs were not present, go to next step. If any Continuous Memory DTC P1001 and other DTCs are present, begin diagnosis of other DTCs first.
7. Check B+ At Data Link Connector (DLC) Inspect DLC for damage. Repair as necessary. Measure voltage between ground and B+ at DLC terminal No. 16 (Orange/Light Green wire). (Scheme 67) If voltage reading was more than 10.5 volts, go to next step. If voltage reading was not as specified, repair open in Orange/Light Green wire between DLC terminal No. 16 and No. 27 fuse (10-amp) in Central Junction Box. See «WIRING DIAGRAMS»(ref-134975) article. After repair, go to step 16.
8. Check DLC Chassis Ground Resistance Measure resistance between ground and DLC terminal No. 4 (Black/White wire). If resistance reading is less than 5.0 ohms, go to next step. If resistance reading is not as specified, repair open in Black/White wire between DLC terminal No. 4 and negative battery terminal. After repair, go to step 16.
9. Check DLC PWR GND Circuit For Open In Harness Measure resistance between DLC terminal No. 5 (PWR GND) and negative battery terminal. (Scheme 67) If resistance reading is less than 5.0 ohms, go to next step. If resistance reading is not as specified, repair open in Black wire between DLC terminal No. 5 and negative battery terminal. After repair, go to step 16.
10. Check BUS+ For Short To Ground In Harness Disconnect PCM 104-pin harness connector. Connect Breakout Box (49-UN01-130) to PCM harness connector only. (Scheme 50) Measure resistance of BUS+ circuit between ground and breakout box terminal No. 16. If resistance is more than 5.0 ohms, go to next step. If resistance reading is not as specified, repair short circuit. See «WIRING DIAGRAMS»(ref-134975) article. Short can exist in wire harness or associated modules. For further diagnosis, refer to appropriate MODULE COMMUNICATIONS NETWORK article in ACCESSORIES & EQUIPMENT.
11. Check BUS+ Circuit For Short To B+ In Harness Turn ignition on, engine off. Measure voltage between ground and BUS+ circuit at breakout box terminal No. 16. If voltage reading is more than one volt, repair short circuit. Short can exist in wire harness or associated modules. For further diagnosis, refer to appropriate MODULE COMMUNICATIONS NETWORK article in ACCESSORIES & EQUIPMENT. If voltage reading is not as speified, go to next step.
12. Check DLC BUS+ Circuit For Open In Harness Turn ignition off. Measure resistance of BUS+ circuit between breakout box terminal No. 16 and DLC connector terminal No. 2. If resistance reading is more than 5.0 ohms, go to next step. If resistance reading is not as specified, repair open in Tan/Orange wire between DLC terminal No. 2 and PCM 104-pin harness connector terminal No. 16. After repair, go to step 16.
13. Check BUS- For Short To Ground In Harness Turn ignition off. Measure resistance of BUS- circuit between ground and breakout box terminal No. 15. If resistance is more than 5.0 ohms, go to next step. If resistance reading is not as specified, repair short circuit. Short can exist in wire harness or associated modules. For further diagnosis, refer to appropriate MODULE COMMUNICATIONS NETWORK article in ACCESSORIES & EQUIPMENT.
14. Check BUS- Circuit For Short To B+ In Harness Turn ignition on, engine off. Measure voltage of BUS- circuit between ground and breakout box terminal No. 15. If voltage reading is 6.0 volts or less, go to next step. If voltage reading is more than 6.0 volts, repair short circuit. Short can exist in wire harness or associated modules. For further diagnosis, refer to appropriate MODULE COMMUNICATIONS NETWORK article in ACCESSORIES & EQUIPMENT.
15. Check DLC BUS- Circuit For Open In Harness Turn ignition off. Measure resistance of BUS- circuit between breakout box terminal No. 15 and DLC connector terminal No. 10. (Scheme 67) If resistance reading is less than 5.0 ohms, replace PCM. After repair, go to next step. If voltage reading is not as specified, repair open in Pink/Light Blue wire between PCM 104-pin harness connector terminal No. 15 and DLC terminal No. 10. See «WIRING DIAGRAMS»(ref-134975) article. After repair, go to next step.
16. Verify Trouble Shooting Of DTCs Completed Reconnect all disconnected connectors. Clear DTCs from PCM memory using scan tool. Perform «QUICK TEST»(ref-150940-S17451707022002112700000) under SELF-DIAGNOSTIC SYSTEM. If same DTC is present, replace faulty PCM. Repeat «QUICK TEST»(ref-150940-S17451707022002112700000) under SELF-DIAGNOSTIC SYSTEM. If same DTC is not present, go to applicable procedure for other DTCs. See «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(ref-150940-S42582837182002112700000). If no DTCs are present, trouble shooting is complete.

DTC P1127 indicates that the inferred exhaust temperature to determine when HO2S heaters are cycled ON is less than a minimum calibrated value.

Possible causes are

1. Engine not operating long enough prior to performing KOER self-test.
2. Exhaust system too cool.

DTC P1128 indicates during KOER testing the front HO2S signal(s) response for a fuel shift to the correct engine bank was not indicated.

DTC P1129 indicates during KOER testing the rear HO2S signal(s) response for a fuel shift to the correct engine bank was not indicated.

HO2S detects presence of oxygen in exhaust and produces a variable voltage according to the amount of oxygen detected. A high concentration of oxygen in the exhaust produces a low voltage signal (less than 0.4 volt). A low concentration of oxygen in the exhaust produces a high voltage signal (more than 0.6 volt). HO2S provides feedback to PCM indicating air/fuel ratio in order to achieve near stoichiometric air/fuel ratio during closed loop engine operation.

Possible causes are

1. Crossed HO2S harness connectors.
2. Crossed wiring at HO2S harness connectors.
3. Crossed wiring at PCM 104-pin harness connector.
4. Poor terminal connection.

DTC P1130 indicates HO2S-11 (Bank 1) fails to switch due to circuit or fuel at or exceeding a calibrated limit.

DTC P1150 indicates HO2S-21 (Bank 2) fails to switch due to circuit or fuel at or exceeding a calibrated limit.

HO2S detects presence of oxygen in exhaust and produces a variable voltage according to the amount of oxygen detected. A high concentration of oxygen in the exhaust produces a low voltage signal (less than 0.4 volt). A low concentration of oxygen in the exhaust produces a high voltage signal (more than 0.6 volt). HO2S provides feedback to PCM indicating air/fuel ratio in order to achieve near stoichiometric air/fuel ratio during closed loop engine operation.

Possible causes are

1. Excessive fuel pressure.
2. Leaking fuel injector(s).
3. Leaking fuel pressure regulator.
4. Low fuel pressure or running out of fuel.
5. Contaminated fuel injector(s).
6. Air leaks after Mass Airflow (MAF) sensor.
7. Vacuum leaks.
8. PCV system.
9. Improperly seated engine oil dipstick.
10. Leaking gasket.
11. Stuck open EGR valve.
12. Leaking EGR diaphragm.
13. Engine oil overfill.
14. Cam timing.
15. Cylinder compression.
16. Exhaust leaks before or near HO2S.
17. Short to VPWR in harness or HO2S.
18. Water in harness connector.
19. Open or shorted HO2S.
20. Damaged HO2S.
21. Damaged PCM.

Scheme 68

1. If QUICK TEST was not performed, go to «QUICK TEST»(ref-150940-S17451707022002112700000) under SELF-DIAGNOSTIC SYSTEM. If QUICK TEST was performed, go to next step.
2. Verify Related Pending And Stored DTCs If no other DTCs are present during PCM Quick Test, go to next step. If any other DTCs are present during PCM Quick Test, go to appropriate trouble shooting procedures. See «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(ref-150940-S42582837182002112700000).
3. Identify Trigger DTC For FREEZE FRAME DATA If DTC P1130 or P1150 are on FREEZE FRAME DATA, go to next step. If DTC P1130 or P1150 are not on FREEZE FRAME DATA, go to trouble shooting procedure for DTC that triggered FREEZE FRAME DATA. NOTE: It is necessary to address all Continuous Memory Ignition and Misfire DTCs, if received during Continuous Memory testing, before addressing any KOER HO2S DTCs.
4. DTCs P1130 & P1150: Fuel System Not Switching At Fuel Trim (RICH Or LEAN) Check air cleaner element and air cleaner housing for blockage. Check air intake system for leaks and damage. Verify integrity of PCV system. See «POSITIVE CRANKCASE VENTILATION SYSTEM»(ref-150940-S18985781452002120200000) in «SYSTEM TESTS»(ref-150940-S42556424782002112700000). Check for vacuum leaks. If no intake air system leak or blockage concerns are present, go to next step. If any intake air system leak or blockage concerns are present, repair as necessary. After repair, go to step 16.
5. Check HO2S Ability To Generate A Voltage Greater Than 0.5 Volt Inspect HO2S harness for chafing, burned wiring or other damage and repair as necessary. Disconnect suspect HO2S from vehicle harness. Connect DVOM to HO2S SIG RTN or HO2S GND at HO2S 4-pin connector. see scheme 9 Run engine at 2000 RPM for 3 minutes. Run KOER self-test and monitor HO2S voltage. Turn ignition off. If voltage reading was more than 0.5 volt during or at end of Self-Test, go to next step. If voltage reading was not as specified, replace HO2S. After repair, go to step 16.
6. Monitor HO2S (PID) For Proper Switching Start engine. Warm up engine to operating temperature. Using scan, select DIAGNOSTIC DATA LINK. Select PCM. Select PID/DATA MONITOR AND RECORD. Access O2S11 (Front Bank 1) or O2S21 (Front Bank 2) PID and monitor while wiggling, bending and shaking small sections of engine harness from HO2S to PCM. Turn ignition off. If HO2S voltage reading did not stay high (more than 0.45 volt) or low (less than 0.45 volt), go to next step. If HO2S voltage reading stayed high or low, isolate cause of lack of switching and repair as necessary. After repair, go to step 16. WARNING: Fuel system is pressurized when engine is not running. To prevent injury or fire, use caution when working on fuel system. NOTE: During next step, fuel pump will only operate for approximately 8 seconds when Output Test Mode is selected and activated.
7. Check Fuel Pressure Install fuel pressure gauge. Turn ignition on, engine off. Using scan tool, select DIAGNOSTIC DATA LINK. Select PCM. Select ACTIVE COMMAND MODES. Access OUTPUT TEST MODE and run fuel pump to obtain maximum fuel pressure. If fuel pressure is 55-70 psi, go to next step. If fuel pressure is not as specified, refer to «FUEL DELIVERY SYSTEM»(ref-150940-S38917645432002120200000) testing under «SYSTEM TESTS»(ref-150940-S42556424782002112700000).
8. Check Injector Fault PIDs Access INJ1F-INJ6F PIDs. If an injector(s) fault is present, go to next step. If an injector fault is not present, go to step 12. NOTE: Performing following procedure erases Continuous Memory DTCs. NOTE: Use injector fault PID to determine fuel injector circuit(s) requiring testing.
9. Check Fuel Injector(s) & Harness Resistance Disconnect PCM 104-pin harness connector. Connect Breakout Box (49-UN01-130) to PCM harness connector only. (Scheme 50) Measure resistance of suspect fuel injector between suspect INJ circuit breakout box terminal and terminal No. 71 (VPWR). If resistance reading is 11-18 ohms, replace PCM. After repair, go to step 16. If resistance reading is not within specification, go to next step.
10. Check Fuel Injector Harness Resistance Disconnect fuel injector harness connector at suspect fuel injector. Measure resistance of VPWR circuit (Red wire) between breakout box terminal No. 71 and fuel injector harness connector. Measure resistance of INJ circuit between appropriate breakout box terminal and fuel injector harness connector. (Scheme 68) If each resistance reading is less than 5 ohms, go to next step. If each resistance reading is not as specified, repair open circuit. See «WIRING DIAGRAMS»(ref-134975) article. After repair, go to step 16.
11. Check Fuel Injector Harness Circuit For Short To Power & Ground Measure resistance between suspect INJ circuit breakout box terminal and terminal No. 71 (VPWR). Measure resistance between suspect INJ circuit breakout box terminal and terminal No. 103 (PWR GND). If each resistance reading is more than 10,000 ohms, go to next step. If each resistance reading is not as specified, replace fuel injector(s). After repair, go to step 16.
12. Flow Test Fuel Injector(s) Use a fuel injector tester to flow test fuel injectors according to instructions for tester. Flow rate specification is 17 lb/hr (7.8 kg/hr) for 2.0L engines and 22 lb/hr (10.1 kg/hr) for 3.0L engines. If leakage and flow are within specification, go to next step. If leakage and flow are not within specification, replace fuel injector(s). After repair, go to step 16.
13. Inspect Induction System For Air Leaks Inspect following areas for signs of air leaks: Inlet tube(s) from air cleaner to throttle body. Gaskets which seal upper and lower intake manifold. Vacuum hoses and lines for cracks and proper connections. PCV system. If there are no signs of leakage or damage, go to next step. If there are any signs of leaks or damage, repair as necessary. After repair, go to step 16.
14. Check Cylinder Compression Check cylinder compression. Refer to «MECHANICAL INSPECTION»(ref-134958-S31679170122002022100000) under PRELIMINARY INSPECTION & ADJUSTMENTS in BASIC DIAGNOSTIC PROCEDURES article. If cylinder compression readings are within specification, go to next step. If cylinder compression readings are not within specification, repair as necessary. After repair, go to step 16. NOTE: This step requires an observer to monitor PID for proper operation.
15. Test Drive While Monitoring HO2S PID For Proper Switching Using scan tool, select DIAGNOSTIC DATA LINK. Select PCM. Select PID/DATA MONITTOR AND RECORD. Access O2S11 (Front Bank 1) or O2S21 (Front Bank 2) PID. While observer views PID, test drive vehicle under different road conditions in an attempt to simulate original fault. If HO2S appears to switch properly, unable to duplicate problem. Go to next step. If HO2S does not appear to switch properly, replace HO2S. After repair, go to next step.
16. Drive Cycle Reconnect all disconnected connectors. Clear DTCs from PCM memory using scan tool. Perform HO2S Monitor Drive Cycle. Refer to «EVAPORATIVE EMISSION REPAIR VERIFICATION DRIVE CYCLE»(ref-150940-S36910449522003010300000) under MONITOR REPAIR VERIFICATION DRIVE CYCLES. Retrieve pending code. If same DTC present, replace PCM. After repair, go to next step. If same DTC is not present, go to next step.
17. Verify Trouble Shooting Of DTCs Completed Perform «QUICK TEST»(ref-150940-S17451707022002112700000) under SELF-DIAGNOSTIC SYSTEM. If any DTC is present, go to applicable procedure for other DTCs. See «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(ref-150940-S42582837182002112700000). If no DTCs are set, trouble shooting is complete.

DTC P1131 (Bank 1) and DTC P1151 (Bank 2) indicates HO2S is indicating lean at the end of a test trying to correct for over-rich conditions. The test fails when fuel control system no longer detects a switch for a calibrated amount of time.

HO2S detects presence of oxygen in exhaust and produces a variable voltage according to the amount of oxygen detected. A high concentration of oxygen in the exhaust produces a low voltage signal (less than 0.4 volt). A low concentration of oxygen in the exhaust produces a high voltage signal (more than 0.6 volt). HO2S provides feedback to PCM indicating air/fuel ratio in order to achieve near stoichiometric air/fuel ratio during closed loop engine operation.

Possible causes are

1. Excessive fuel pressure.
2. Leaking fuel injector(s).
3. Leaking fuel pressure regulator.
4. Low fuel pressure or running out of fuel.
5. Contaminated fuel injector(s).
6. Air leaks after Mass Airflow (MAF) sensor.
7. Vacuum leaks.
8. PCV system.
9. Improperly seated engine oil dipstick.
10. Leaking gasket.
11. Stuck open EGR valve.
12. Leaking EGR diaphragm.
13. Engine oil overfill.
14. Cam timing.
15. Cylinder compression.
16. Exhaust leaks before or near HO2S.
17. Short to VPWR in harness or HO2S.
18. Water in harness connector.
19. Open or shorted HO2S.
20. Damaged HO2S.
21. Damaged PCM.

DTC P1132 (Bank 1) and P1152 (Bank 2) indicates HO2S is indicating rich at the end of a test trying to correct for over-lean conditions. The test fails when fuel control system no longer detects a switch for a calibrated amount of time.

HO2S detects presence of oxygen in exhaust and produces a variable voltage according to the amount of oxygen detected. A high concentration of oxygen in the exhaust produces a low voltage signal (less than 0.4 volts). A low concentration of oxygen in the exhaust produces a high voltage signal (more than 0.6 volts). HO2S provides feedback to PCM indicating air/fuel ratio in order to achieve near stoichiometric air/fuel ratio during closed loop engine operation.

Possible causes are

1. Excessive fuel pressure.
2. Leaking fuel injector(s).
3. Leaking fuel pressure regulator.
4. Low fuel pressure or running out of fuel.
5. Contaminated fuel injector(s).
6. Air leaks after Mass Airflow (MAF) sensor.
7. Vacuum leaks.
8. PCV system.
9. Improperly seated engine oil dipstick.
10. Leaking gasket.
11. Stuck open EGR valve.
12. Leaking EGR diaphragm.
13. Engine oil overfill.
14. Cam timing.
15. Cylinder compression.
16. Exhaust leaks before or near HO2S.
17. Short to VPWR in harness or HO2S.
18. Water in harness connector.
19. Open or shorted HO2S.
20. Damaged HO2S.
21. Damaged PCM.

DTCs P1244, P1245, or P1246 indicates Generator Load Input (GLI) is not within a calibrated limit for a calibrated amount of time.GLI signal is sent to the PCM from the voltage generator/regulator and is a variable frequency duty cycle. GLI signal is used by the PCM to determine generator load on the engine. As generator load increases, PCM will adjust idle speed accordingly.

Possible causes are

1. GLI circuit problem.
2. Damaged voltage generator/regulator.
3. Damaged PCM.

Scheme 69

1. If QUICK TEST was not performed, go to «QUICK TEST»(ref-150940-S17451707022002112700000) under SELF-DIAGNOSTIC SYSTEM. If QUICK TEST was performed, go to next step.
2. Verify Generator Drive Cycle Check generator drive belt condition and tension. Start engine and verify generator is turning. If everything is okay, go to next step. If everything is not okay, repair or replace parts as necessary. After repair, go to step 11.
3. Verify Charging System Is EEC Controlled Turn ignition off. Disconnect battery cables at battery. Disconnect generator 3-pin harness connector and measure resistance between BATT-SENSE and GEN-COM terminals at generator. If resistance reading is between 950 and 1050 ohms, go to next step. If resistance reading is not as specified, Replace generator/regulator assembly. After repair, go to step 11.
4. Check Battery-Sense Voltage At Battery Reconnect battery cables. Measure voltage at generator/regulator 3-pin harness connector between ground and BATT-SENSE terminal (Black/Yellow wire). If voltage reading of BATT-SENSE circuit is within 0.5 volt of battery voltage, go to next step. If voltage reading is not as specified, Repair Black/Yellow wire between generator/regulator 3-pin harness connector and positive battery terminal. See «WIRING DIAGRAMS»(ref-134975) article. After repair, go to step 11.
5. Check Generator Failure Mode Turn off all electrical loads. Access GFS PID. Start engine and increase engine speed to 2000 RPM. Perform wiggle test. If no failure is indicated, go to next step. If a failure is indicated, repair as necessary. After repair, go to step 11.
6. Check GEN-MON & GEN-COM Circuit For Short To Power Turn ignition off. Disconnect generator 3-pin harness connector. (Scheme 69) Disconnect PCM 104-pin harness connector. Connect Breakout Box (49-UN01-130) to PCM harness connector only. (Scheme 50) Turn ignition on, engine off. Measure voltage between ground and breakout box terminal No. 72 (GEN-COM). Measure voltage between ground and breakout box terminal No. 59 (GEN-MON). Turn ignition off. If each voltage reading is more than 0.5 volt, repair short circuit. See «WIRING DIAGRAMS»(ref-134975) article. After repair, go to step 11.
7. Check GEN-MON & GEN-COM Circuit For Short To Ground Measure resistance between ground and breakout box terminal No. 72 (GEN-COM). Measure resistance between ground and breakout box terminal No. 59 (GEN-MON). If each resistance reading is not more than 10,000 ohms, go to next step. If each resistance reading is more than 10,000 ohms, repair open circuit. After repair, go to step 11.
8. Check GEN-MON & GEN-COM Circuit For Open Measure resistance of GEN-COM circuit between breakout box terminal No. 72 and generator/regulator 3-pin harness connector (Brown/White wire). (Scheme 69) Measure resistance of GEN-MON circuit between breakout box terminal No. 59 and generator/regulator 3-pin harness connector (Gray/Orange). If each resistance reading is less than 5 ohms, go to next step. If each resistance reading is more than 5 ohms, repair open circuit. After repair, go to step 11.
9. Check Generator Monitor Signal Start engine. Access GF PID. If duty cycle is 6-98 percent, go to next step. If duty cycle is not as specified, replace generator/regulator. After repair, go to step 11.
10. Check Generator Communicator Signal Start engine. Access GENFDC PID. Toggle load on and off (headlights). If duty cycle is 0-99 percent, go to next step. If duty cycle is not 0-99 percent, replace generator/regulator. After repair, go to next step.
11. Verify Trouble Shooting Of DTCs Completed Reconnect all disconnected connectors. Clear DTCs from PCM memory using scan tool. Perform «QUICK TEST»(ref-150940-S17451707022002112700000) under SELF-DIAGNOSTIC SYSTEM. If same DTC is present, replace faulty PCM. Repeat «QUICK TEST»(ref-150940-S17451707022002112700000) under SELF-DIAGNOSTIC SYSTEM. If same DTC is not present, go to applicable procedure for other DTCs. See «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(ref-150940-S42582837182002112700000). If no DTCs are present, trouble shooting is complete.

DTC P1260 indicates anti-theft system has determined a theft condition existed and engine is disabled.

Possible causes are

1. Previous theft condition.
2. Anti-theft system failure.

DTC P1270 indicates vehicle has been operated in a manner which caused the engine or vehicle to exceed a calibration limit.

Possible causes are

1. Wheel slippage (water, mud, ice or snow).
2. Excessive engine RPM in neutral.
3. Vehicle driven at a high rate of speed.

DTC P1309 indicates misfire detection monitor is disabled, usually due to input signal generated by Camshaft Position (CMP) sensor. CMP sensor is a magnetic transducer. It detects position of camshaft and identifies when piston No. 1 is on compression stroke. A signal is then sent to PCM and used for synchronizing firing of fuel injectors.

Possible causes are

1. Damaged CMP sensor.
2. Damaged PCM.
3. Engine Coolant Temperature (ECT), Mass Airflow (MAF) and Crankshaft Position (CKP) sensors.

DTC P1400 indicates average voltage of DPFEGR SIG circuit input is less than the minimum of 0.2 volts.

DTC P1401 indicates average voltage of DPFEGR SIG circuit input is more than the maximum of 4.5 volts.

Differential Pressure Feedback EGR (DPFEGR) sensor measures the actual pressure drop across the metering orifice and relays a proportional voltage signal to PCM.

Possible causes are

1. DPFEGR SIG shorted to GND (P1400).
2. DPFEGR SIG open (P1401).
3. DPFEGR SIG shorted to PWR (P1401).
4. VREF shorted to PWR (P1401).
5. VREF shorted to GND (P1400).
6. SIG RTN open (P1401).
7. Damaged DPFEGR sensor (P1400 or P1401).
8. Damaged PCM (P1400 or P1401).

Scheme 70

1. If QUICK TEST was not performed, go to «QUICK TEST»(ref-150940-S17451707022002112700000) under SELF-DIAGNOSTIC SYSTEM. If QUICK TEST was performed and DTC P1400 is present, go to next step. If QUICK TEST was performed and DTC P1401 is present, go to step 6.
2. DTC P1400: Verify Differential Pressure Feedback EGR (DPFEGR) Voltage Turn ignition on, engine off. Using scan tool, select DIAGNOSTIC DATA LINK. Select PCM. Select PID/DATA MONITOR AND RECORD. Access DPFEGR PID. Turn ignition off. If DPFEGR PID voltage reading was less than 0.2 volt, sensor voltage is less than minimum. Go to next step. If DPFEGR PID voltage reading was 0.2 volt or more, problem is intermittent. Go to step 14.
3. Induce Opposite DPFEGR Sensor Voltage Disconnect DPFEGR sensor 3-pin harness connector. (Scheme 70) Turn ignition on, engine off. Using scan tool, select DIAGNOSTIC DATA LINK. Select PCM. Select PID/DATA MONITOR AND RECORD. Access DPFEGR PID. Turn ignition off. If DPFEGR PID value reading is not 4.0-6.0 volts, go to next step. If DPFEGR PID value reading is 4.0-6.0 volts, replace DPFEGR sensor. After repair, go to step 15.
4. Measure VREF Voltage At DPFEGR Sensor Vehicle Harness Connector Turn ignition on, engine off. Measure voltage between VREF and SIG RTN at DPFEGR sensor 3-pin harness connector. Turn ignition off. If VREF voltage reading is between 4.0-6.0 volts, go to next step. If VREF voltage reading is not 4.0-6.0 volts, VREF voltage is out of range. Refer to «VEHICLE REFERENCE VOLTAGE»(ref-150940-S23619745912002112700000) testing under «SYSTEM TESTS»(ref-150940-S42556424782002112700000).
5. Check DPFE Circuit For Shorts To Ground & SIG RTN Disconnect scan tool from DLC. Disconnect PCM 104-pin harness connector. Connect Breakout Box (49-UN01-130) to PCM harness connector only. (Scheme 50) Measure resistance between breakout box terminal No. 65 (DPFEGR SIG) and terminal No. 91 (SIG RTN). Measure resistance between breakout box terminal No. 65 (DPFEGR SIG) and terminal No. 103 (PWR GND). If each resistance reading is more than 10,000 ohms, replace PCM. After repair, go to step 15. If each resistance reading is not more than 10,000 ohms, repair short circuit. See «WIRING DIAGRAMS»(ref-134975) article. After repair, go to step 15.
6. DTC P1401: Verify DPFEGR PID Voltage Turn ignition on, engine off. Access DPFEGR PID with scan tool. Turn ignition off. If DPFEGR PID voltage reading was more than 4.0 volts, sensor voltage is more than acceptable maximum. Go to next step. If sensor voltage reading was 4.0 volts or less, problem is intermittent. Go to step 14.
7. Check DPFEGR SIG For Short To PWR Disconnect DPFEGR sensor harness connector. (Scheme 70) Turn ignition on, engine off. Measure voltage between ground and DPFEGR SIG circuit at DPFEGR sensor 3-pin harness connector. Turn ignition off. If voltage reading was more than 10.5 volts, go to next step. If voltage reading is 10.5 volts or less, go to step 9.
8. Check DPFEGR SIG For Short To PWR In Harness Disconnect scan tool from DLC. Disconnect PCM 104-pin harness connector. Connect Breakout Box (49-UN01-130) to PCM harness connector only. (Scheme 50) Turn ignition on, engine off. Measure voltage between breakout box terminal No. 65 (DPFEGR SIG) and terminal No. 103 (PWR GND). Turn ignition off. If voltage reading is more than 10.5 volts, repair short. See «WIRING DIAGRAMS»(ref-134975) article. After repair, go to step 15. If voltage reading is 10.5 volts or less, replace PCM. After repair, go to step 15. NOTE: If scan tool communication concern exists during next step, remove fused jumper wire immediately and go to step 14.
9. Induce Opposite DPFEGR Sensor Voltage Connect fused jumper wire between sensor DPFEGR SIG (Brown/Light Green) and SIG RTN (Orange wire) circuits at DPFEGR sensor 3-pin harness connector. (Scheme 70) Using scan tool, select DIAGNOSTIC DATA LINK. Select PCM. Select PID/DATA MONITOR AND RECORD. Access DPFEGR PID. Turn ignition OFF. If DPFEGR PID voltage reading was less than 0.05 volt, remove fused jumper wire and go to next step. If DPFEGR PID voltage reading was 0.05 volt or more, go to step 12.
10. Verify That VREF Is In Range Turn ignition on, engine off. Measure voltage between sensor VREF (Brown/White wire) and SIG RTN (Orange wire) at DPFEGR sensor 3-pin harness connector. Turn ignition off. If VREF voltage reading is 4.0-6.0 volts, go to next step. If voltage reading is not as specified, VREF voltage reading is out-of-range. Refer to «VEHICLE REFERENCE VOLTAGE»(ref-150940-S23619745912002112700000) testing under «SYSTEM TESTS»(ref-150940-S42556424782002112700000).
11. Check DPFEGR SIG For Short To VREF In Harness Disconnect scan tool from DLC. Disconnect PCM 104-pin harness connector. Connect Breakout Box (49-UN01-130) to PCM harness connector only. (Scheme 50) Measure resistance between breakout box terminal No. 65 (DPFEGR SIG) and terminal No. 90 (VREF). If resistance reading is more than 10,000 ohms, replace DPFEGR sensor. After repair, go to step 15. If resistance reading is not as specified, repair short. See «WIRING DIAGRAMS»(ref-134975) article. After repair, go to step 15.
12. Check DPFEGR SIG Circuit For Open In Harness Disconnect PCM 104-pin harness connector. Connect Breakout Box (49-UN01-130) to PCM harness connector only. (Scheme 50) Measure resistance between breakout box terminal No. 65 (DPFEGR SIG) and DPFEGR sensor 3-pin harness connector (Brown/Light Green wire). If resistance reading is less than 5.0 ohms, go to next step. If resistance reading is not as specified, repair open in Brown/Light Green wire between PCM 104-pin harness connector terminal No. 65 and DPFEGR sensor 3-pin harness connector. After repair, go to step 15.
13. Check SIG RTN For Open In Harness Measure resistance of DPFEGR SIG RTN circuit between breakout box terminal No. 91 and DPFEGR sensor 3-pin harness connector (Orange wire). If resistance reading is less than 5.0 ohms, replace PCM. After repair, go to step 15. If resistance reading is more than 5.0 ohms, repair open in Orange wire between PCM 104-pin harness connector terminal No. 91 and DPFEGR sensor 3-pin harness connector. After repair, go to step 15.
14. Wiggle Test DPFEGR Sensor & Harness Turn ignition on, engine off. Using scan tool, select DIAGNOSTIC DATA LINK. Select PCM. Select PID/DATA MONITOR AND RECORD. Access DPFEGR PID. Observe DPFEGR PID for an indication of fault while performing following: Lightly tap on DPFEGR sensor. Wiggle DPFEGR sensor connector and vehicle harness between sensor and PCM. A fault is indicated by a sudden change in DPFEGR PID voltage. If a fault is indicated, isolate fault and repair as necessary. After repair, go to next step. If a fault is not indicated, problem is intermittent. Refer to «INTERMITTENT»(ref-150940-S23445146842002120200000) testing under «SYSTEM TESTS»(ref-150940-S42556424782002112700000).
15. Verify Trouble Shooting Of DTCs Completed Reconnect all disconnected connectors. Clear DTCs from PCM memory using scan tool. Perform «QUICK TEST»(ref-150940-S17451707022002112700000) under SELF-DIAGNOSTIC SYSTEM. If same DTC is present, replace faulty PCM. Repeat «QUICK TEST»(ref-150940-S17451707022002112700000) under SELF-DIAGNOSTIC SYSTEM. If same DTC is not present, go to applicable procedure for other DTCs. See «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(ref-150940-S42582837182002112700000). If no DTCs are present, trouble shooting is complete.

DTC P1405 indicates exhaust manifold side (upstream) DPFEGR sensor pressure hose is off or plugged.

DTC P1406 indicates intake manifold side (downstream) DPFEGR sensor pressure hose is off or plugged.

Differential Pressure Feedback (DPFEGR) sensor measures actual pressure drop across the metering orifice and relays a proportional voltage signal to PCM.

Possible causes are

1. Upstream or downstream pressure hose disconnected or improperly connected.
2. Upstream or downstream pressure hose plugged (by ice).
3. Plugged or damaged pressure pickup tubes.
4. Damaged DPFEGR sensor.

DTC P1409 indicates self-test has detected an electrical malfunction in EGRVR circuit. EGR Vacuum Regulator (EGRVR) solenoid receives a variable duty cycle signal from PCM. The higher the duty cycle, the more vacuum the solenoid diverts to EGR valve.

Possible causes are

1. Open EGRVR circuit.
2. Open VPWR circuit to EGRVR solenoid.
3. EGRVR circuit shorted to VPWR.
4. EGRVR circuit shorted to GND.
5. Damaged EGRVR solenoid.
6. Damaged PCM.

DTC P1450 indicates self-test has detected the EVAP system is unable to bleed up fuel tank vacuum. EVAP canister purge valve is normally closed. It controls the flow of vapors (purging) from EVAP canister to intake manifold during various engine operating modes.

Possible causes are

1. Blockages or kinks in EVAP canister tube or EVAP canister purge outlet tube (between fuel tank, EVAP canister purge valve and EVAP canister).
2. Fuel filler cap stuck closed (no vacuum relief).
3. Contaminated fuel vapor elbow on EVAP canister.
4. Restricted EVAP canister.
5. Canister Vent (CV) solenoid stuck open (partially or fully).
6. Plugged CV solenoid filter.
7. EVAP canister purge valve stuck open.
8. VREF circuit open (harness near Fuel Tank Pressure (FTP) sensor or PCM).
9. Damaged FTP sensor.

DTC P1451 indicates self-test has detected a CV solenoid circuit failure. Canister Vent (CV) solenoid seals EVAP canister from atmospheric pressure during the EVAP test monitor. This allows EVAP canister purge valve to obtain the target vacuum in the fuel tank during monitor run.

Possible causes are

1. VPWR circuit open.
2. CV circuit open.
3. CV circuit shorted to PWR GND or CHASSIS GND.
4. CV circuit shorted to VPWR.
5. Damaged CV solenoid.
6. Damaged PCM.

Scheme 71

1. If QUICK TEST was not performed, go to «QUICK TEST»(ref-150940-S17451707022002112700000) under SELF-DIAGNOSTIC SYSTEM. If QUICK TEST was performed, go to next step.
2. DTC P1451: Check VPWR Voltage To Canister Vent Solenoid Turn ignition off. Disconnect CV solenoid. Connect a non-powered test lamp between CV and VPWR circuits at CV solenoid harness connector. Turn ignition on, engine off. Using scan tool, select DIAGNOSTIC DATA LINK. Select PCM. Select PID/DATA MONITOR AND RECORD. Attempt to close and open CV solenoid driver in PCM by accessing OUTPUT TEST MODE. Select ALL OFF mode. Cycle START button ON and OFF, and observe test lamp. If test lamp cycles on and off (light up and turn off), turn ignition off and go to next step. If test lamp is always off, go to step 4. If test lamp is always on, turn ignition off and go to step 8.
3. Check CV Solenoid Resistance Measure CV solenoid resistance. If resistance reading is 45-65 ohms, problem is intermittent. Refer to «INTERMITTENT»(ref-150940-S23445146842002120200000) testing under «SYSTEM TESTS»(ref-150940-S42556424782002112700000). If resistance reading is not as specified, replace damaged CV solenoid.
4. Check For Open VPWR Circuit Between CV Solenoid & Power Relay Measure voltage of VPWR circuit (Light Blue/Orange wire) between CV solenoid harness connector and negative battery terminal. (Scheme 71) If voltage reading is more than 10.5 volts, turn ignition off and go to next step. If voltage reading is not as specified, repair open in Light Blue/Orange wire between PCM power relay and CV solenoid harness connector. See «WIRING DIAGRAMS»(ref-134975) article. After repair, go to step 10.
5. Check VPWR Circuit For Open In Harness Disconnect PCM 104-pin harness connector. Connect Breakout Box (49-UN01-130) to PCM harness connector only. (Scheme 50) Measure resistance of VPWR circuit between breakout box terminal No. 71 (White/Red wire) and CV solenoid harness connector (Light Blue/Orange wire). If resistance reading is less than 5.0 ohms, go to next step. If resistance reading is not as specified, repair open circuit between PCM 104-pin harness connector terminal No. 71 (White/Red wire) and CV solenoid harness connector (Light Blue/Orange wire). After repair, go to step 10.
6. Check CV Circuit For Open In Harness Measure resistance of CV circuit between breakout box terminal No. 67 and CV solenoid harness connector (Violet/White wire). (Scheme 71) If resistance reading is less than 5.0 ohms, replace PCM. After repair, go to next step. If resistance reading is not as specified, repair open in Violet/White wire between PCM 104-pin harness connector terminal No. 67 and CV solenoid harness connector. See «WIRING DIAGRAMS»(ref-134975) article. After repair, go to step 10.
7. Check CV Circuit For Short To VPWR Turn ignition on, engine off. Measure voltage of CV circuit between CV solenoid harness connector and ground. If voltage reading is less than one volt, replace PCM. After repair, go to step 10. If voltage reading is one volt or more, repair short to VPWR in Violet/White wire between PCM 104-pin harness connector terminal No. 67 and CV solenoid harness connector. After repair, go to step 10.
8. Check CV Circuit For Short To PWR GND In Harness Disconnect PCM 104-pin harness connector. Disconnect scan tool from DLC. Measure resistance of CV circuit (Violet/White wire) between CV solenoid harness connector and negative battery terminal. (Scheme 71) If resistance reading is more than 10,000 ohms, go to next step. If resistance reading is not as specified, repair short in Violet/White wire between PCM 104-pin harness connector terminal No. 67 and CV solenoid harness connector. After repair, go to step 10.
9. Check Circuit For Short To Power Reconnect scan tool. Turn ignition on, engine off. Measure voltage of CV circuit (Violet/White wire) between CV solenoid harness connector and ground. Turn ignition off. If voltage reading was less than one volt, replace PCM. After repair, go to next step. If voltage reading was not less than one volt, repair short to VPWR, VREF or ground in Violet/White wire between PCM 104-pin harness connector terminal No. 67 and CV solenoid harness connector. See «WIRING DIAGRAMS»(ref-134975) article. After repair, go to next step.
10. Verify Trouble Shooting Of DTCs Completed Reconnect all disconnected connectors. Clear DTCs from PCM memory using scan tool. Perform «QUICK TEST»(ref-150940-S17451707022002112700000) under SELF-DIAGNOSTIC SYSTEM. If same DTC is present, replace faulty PCM. Repeat «QUICK TEST»(ref-150940-S17451707022002112700000) under SELF-DIAGNOSTIC SYSTEM. If same DTC is not present, go to applicable procedure for other DTCs. See «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(ref-150940-S42582837182002112700000). If no DTCs are present, trouble shooting is complete.

DTC P1460 indicates excessive current draw is detected on A/C Clutch Relay (ACCR) circuit when PCM grounds the circuit or voltage is not detected on ACCR circuit when circuit is not grounded by PCM. The Wide Open Throttle Air Conditioning Cut-Off (WAC) output is used by PCM to disengage A/C clutch when A/C operation is desirable. Under normal conditions (A/C off), PCM will ground WAC output which opens normally closed A/C clutch relay. When A/C demand switch is on, and A/C cycling switch and A/C high pressure switch contacts are closed, voltage is supplied to A/C clutch relay and to A/C Control Signal (ACCS) circuit. Voltage on ACCS circuit indicates to PCM A/C is requested. PCM will verify A/C clutch operation is desirable and adjust idle speed as necessary unground WAC output. This closes normally closed WOT A/C clutch relay and allows voltage to A/C clutch.

Possible causes are

1. A/C on during self-test.
2. Open or shorted ACCR circuit.
3. Damaged ACCR.
4. Damaged PCM.
5. Open VPWR circuit to ACCR.

Scheme 72

Scheme 73

1. If QUICK TEST was not performed, go to «QUICK TEST»(ref-150940-S17451707022002112700000) under SELF-DIAGNOSTIC SYSTEM. If QUICK TEST was performed, go to next step. NOTE: If Continuous Memory DTC P1460 is present, Go to step 8. NOTE: For A/C always ON, refer to appropriate SYMPTOM TESTS in MANUAL A/C-HEATER SYSTEMS - TRIBUTE article in AIR-CONDITIONING & HEATING. NOTE: Verify A/C and defrost were off during KOEO/KOER self-tests.
2. KOEO/KOER DTC P1460: Verify ACCS PID Is Off If vehicle is not equipped with A/C, ACCR circuit is not used and DTC 1460 can be ignored. Start engine. A/C and defroster off. Using scan tool, select DIAGNOSTIC DATA LINK. Select PCM. Select PID/DATA MONITOR AND RECORD. Access A/C Control Signal (ACCS) PID. If ACCS PID is off, turn ignition off and go to next step. If ACCS PID is not off, turn ignition off and go to step 2 of DTC P1464: A/C CONTROL SIGNAL MALFUNCTION to check A/C circuits for short to power.
3. Check For VPWR To A/C Clutch Relay Disconnect A/C clutch relay. Turn ignition on, engine off. Measure voltage of VPWR circuit between ground and A/C clutch relay 5-pin harness connector terminal No. 2 (White/Violet wire). (Scheme 72)and (Scheme 73). If voltage reading is more than 10.5 volts, go to next step. If voltage is not as specified, repair open in VPWR circuit. See «WIRING DIAGRAMS»(ref-134975) article. Reconnect A/C clutch relay. Start engine. Turn A/C on, wait 15 seconds. Turn A/C off. Turn ignition off. Go to step 10.
4. Check A/C Clutch Relay Turn ignition off. Refer to terminal numbers molded on A/C clutch relay. Measure resistance between terminals No. 1 and 2. (Scheme 72) Resistance reading should be 40-120 ohms. Measure resistance between A/C clutch relay terminals No. 3 and 5. Resistance reading should be more than 10,000 ohms. If all resistance checks are okay, go to next step. If any resistance checks are not as specified, replace A/C clutch relay. Start engine. Turn A/C on, wait 15 seconds. Turn A/C off. Turn ignition off. Go to step 10.
5. Check A/C Clutch Circuit For Short To Power In Harness Turn ignition off. Disconnect PCM 104-pin harness connector. Connect Breakout Box (49-UN01-130) to PCM harness connector only. (Scheme 50) Turn ignition on, engine off. Measure voltage between ground and breakout box terminal No. 69 (ACCR). Turn ignition off. If voltage reading was less than one volt, go to next step. If voltage reading was not less than one volt, repair short to power. After repair, remove breakout box. Reconnect all components. Start engine. Turn A/C off. Turn ignition off. Go to step 10.
6. Check ACCR Circuit For Short To Ground In Harness Disconnect scan tool from DLC. Measure resistance of ACCR circuit between ground and A/C clutch relay 5-pin harness connector terminal No. 1 (Pink/Yellow wire). (Scheme 72)and (Scheme 73). If resistance reading is more than 10,000 ohms, go to next step. If resistance reading is not more than 10,000 ohms, repair short in Pink/Yellow wire between A/C clutch relay 5-pin harness connector terminal No. 1 and PCM 104-pin harness connector terminal No. 69. See «WIRING DIAGRAMS»(ref-134975) article. After repair, go to step 10.
7. Check ACCR Circuit Continuity Measure resistance of ACCR circuit between breakout box terminal No. 69 and A/C clutch relay 5-pin harness connector terminal No. 1 (Pink/Yellow wire). If resistance reading is less than 5.0 ohms, replace PCM. Reconnect all components. Start engine. Turn A/C on, wait 15 seconds. Turn A/C off. Turn ignition off. After repair, go to step 10. If resistance reading is not less than 5.0 ohms, repair open in Pink/Yellow wire between A/C clutch relay 5-pin harness connector terminal No. 1 and PCM 104-pin harness connector terminal No. 69. Reconnect all components. Start engine. Turn A/C on, wait 15 seconds. Turn A/C off. Turn ignition off. After repair, go to step 10. NOTE: If vehicle is not equipped with A/C, ACCR circuit is not used and P1460 can be ignored.
8. Continuous Memory DTC 1460: Check ACCR Circuit For Intermittent Short To Ground Turn ignition on, engine off. Check ACCR circuit for short to ground while performing following: Shake, wiggle and bend ACCR circuit between PCM and A/C clutch relay. (Scheme 72)and (Scheme 73). Lightly tap on A/C clutch relay (to simulate road shock). NOTE: A/C clutch will click on when a fault is indicated. If no fault is indicated, go to next step. If a fault is indicated, turn ignition off. Repair as necessary. See «WIRING DIAGRAMS»(ref-134975) article. Reconnect all components. Start engine. Turn A/C on, wait 15 seconds. Turn A/C off. Turn ignition off. Go to step 10.
9. Check ACCR Circuit For Intermittent Open Or Short To Power Using scan tool, select DIAGNOSTIC DATA LINK. Select PCM. Select ACTIVE COMMAND MODES. Access OUTPUT TEST MODE. Turn outputs on. Check ACCR circuit for open or short to power while performing following: Shake, wiggle and bend ACCR circuit between PCM and A/C clutch relay. Shake, wiggle and bend VPWR circuit to A/C clutch relay. Lightly tap on A/C clutch relay (to simulate road shock). NOTE: A/C clutch will click off when a fault is indicated. If a fault is indicated, turn ignition off. Repair as necessary. Reconnect all components. Start engine. Turn A/C on, wait 15 seconds. Turn A/C off. Turn ignition off. Go to step 10. If a fault is not indicated, fault is intermittent. Refer to «INTERMITTENT»(ref-150940-S23445146842002120200000) testing under «SYSTEM TESTS»(ref-150940-S42556424782002112700000).
10. Verify Trouble Shooting Of DTCs Completed Reconnect all disconnected connectors. Clear DTCs from PCM memory using scan tool. Perform «QUICK TEST»(ref-150940-S17451707022002112700000) under SELF-DIAGNOSTIC SYSTEM. If same DTC is present, replace faulty PCM. Repeat «QUICK TEST»(ref-150940-S17451707022002112700000) under SELF-DIAGNOSTIC SYSTEM. If same DTC is not present, go to applicable procedure for other DTCs. See «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(ref-150940-S42582837182002112700000). If no DTCs are present, trouble shooting is complete.

DTC P1464 indicates A/C Control Signal (ACCS) input to PCM was high during self-test. When A/C cycling switch opens, PCM will turn off A/C clutch. The A/C cycling switch circuit to PCM provides a voltage signal which indicates when A/C is requested. When A/C demand switch is turned on, both the A/C cycling switch and high pressure contacts of A/C high pressure switch are closed, voltage is supplied to ACCS circuit at PCM. If ACCS signal is not received by PCM, PCM will not allow A/C to operate.

Possible causes are

1. A/C was on during self-test.
2. A/C clutch PWR circuit short to power.
3. Short to power on ACCS circuit.
4. Damaged A/C demand switch.
5. Damaged A/C clutch relay.
6. Damaged PCM.

Scheme 74

1. If QUICK TEST was not performed, go to «QUICK TEST»(ref-150940-S17451707022002112700000) under SELF-DIAGNOSTIC SYSTEM. If QUICK TEST was performed, go to next step. NOTE: Verify that A/C and defrost were OFF during Self-Test. If A/C or defrost were on, turn off and rerun Self-Test.
2. DTC P1464: Check ACCS PID Turn ignition on, engine off. Turn A/C and defrost off. Using scan tool, select DIAGNOSTIC DATA LINK. Select PCM. Select PID/DATA MONITOR AND RECORD. Access ACCS PID. If ACCS PID is on, go to next step. If ACCS PID is not on, ACCS input to PCM is low. Verify test results. Rerun Self-Test where DTC P1464 was received. Go to step 7.
3. ACCS PID On: Disconnect A/C Cycling Switch & Check If ACCS PID Turns Off Turn ignition off. Disconnect A/C Cycling Switch. Turn ignition on, engine off. Access ACCS PID from PID/DATA MONITOR AND RECORD. If ACCS PID is off, verify operation of A/C demand switch. Refer to «SYMPTOM TESTS»(ref-98830-S24754111402001061400000) appropriate SYMPTOM TESTS in MANUAL A/C-HEATER SYSTEMS - TRIBUTE article in AIR-CONDITIONING & HEATING. If okay, repair short to power in A/C demand circuit (Violet wire) to A/C cycling switch. See «WIRING DIAGRAMS»(ref-134975) article. After repair, go to step 7.
4. Check Power To A/C Clutch Circuit For Short To Power Turn ignition off. Disconnect A/C clutch relay. Turn ignition on, engine off. Measure voltage between ground and A/C clutch power circuit at 5-pin harness connector (Violet/White wire). Turn ignition off. If voltage reading was less than one volt, go to next step. If voltage reading was not less than one volt, repair short to power in A/C clutch power circuit (Violet/White wire) between PCM 104-pin harness connector terminal No. 71 and A/C clutch relay 5-pin harness connector terminal No. 2. After repair, go to step 7.
5. Check ACCS Circuit For Short To Power Disconnect PCM 104-pin harness connector. Connect Breakout Box (49-UN01-130) to PCM harness connector only. (Scheme 50) Turn ignition on, engine off. Measure voltage between breakout box terminals No. 41 (ACCS) and No. 103 (PWR GND). Turn ignition off. If voltage reading was less than one volt, go to next step. If voltage reading was not less than one volt, repair short to power in ACCS circuit (Dark Green/Orange wire) between PCM 104-pin harness connector terminal No. 41 and A/C high pressure switch 4-pin harness connector terminal No. 1. (Scheme 74) After repair, go to step 7.
6. Check ACCS Circuit Voltage To PCM With A/C Clutch Relay Connected Reconnect A/C clutch relay. Turn ignition on, engine off. Measure voltage between breakout box terminals No. 41 (ACCS) and No. 103 (PWR GND). Turn ignition off. If voltage reading was less than one volt, replace PCM. After repair, go to next step. If voltage reading was not less than one volt, replace A/C clutch relay. After repair, go to next step.
7. Verify Trouble Shooting Of DTCs Completed Reconnect all disconnected connectors. Clear DTCs from PCM memory using scan tool. Perform «QUICK TEST»(ref-150940-S17451707022002112700000) under SELF-DIAGNOSTIC SYSTEM. If same DTC is present, replace faulty PCM. Repeat «QUICK TEST»(ref-150940-S17451707022002112700000) under SELF-DIAGNOSTIC SYSTEM. If same DTC is not present, go to applicable procedure for other DTCs. See «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(ref-150940-S42582837182002112700000). If no DTCs are present, trouble shooting is complete.

1. DTC P1474 indicates excessive current draw detected on Low Fan Control (LFC) circuit when PCM grounds the circuit or with LFC circuit not grounded by PCM, voltage is not detected on LFC circuit (PCM expects to detect VPWR voltage coming through LFC relay coil to LFC circuit).
2. DTC P1477 indicates excessive current draw detected on Medium Fan Control (MFC) circuit when PCM grounds the circuit or with MFC circuit not grounded by PCM, voltage is not detected on MFC circuit (PCM expects to detect VPWR voltage coming through MFC relay coil to MFC circuit).
3. DTC P1479 indicates excessive current draw detected on High Fan Control (HFC) circuit when PCM grounds the circuit or with HFC circuit not grounded by PCM, voltage is not detected on HFC circuit (PCM expects to detect VPWR voltage coming through HFC relay coil to HFC circuit).

PCM monitors certain parameters such as engine coolant temperature, vehicle speed, A/C on/off status, and A/C pressure to determine engine cooling fan needs. PCM controls fan operation through Low Fan Control (LFC), Medium Fan Control (MFC) and High Fan Control (HFC) outputs.

Possible causes are

1. Open or shorted LFC/MFC/HFC circuit.
2. Open VPWR or IGN START/RUN circuit to low/medium/high speed FC relay.
3. Damaged low/medium/high FC relay.
4. Damaged PCM.

DTC P1506 indicates PCM detected an engine idle speed more than desired RPM. Idle Air Control (IAC) valve controls engine idle speed and provides a dashpot function. IAC valve meters intake air around throttle plate through a bypass within the IAC valve assembly and throttle body. PCM determines desired idle speed or bypass air and signals IAC valve through a specified duty cycle. The IAC valve responds by positioning to control amount of bypass air. PCM monitors engine RPM and increases or decreases IAC duty cycle in order to achieve desired RPM.

Possible causes are

1. Vacuum leak.
2. Damaged IAC valve.
3. Damaged PCM.
4. Damaged throttle body.
5. IAC circuit short to GND.
6. IAC valve stuck open.

DTC P1650 indicates PSP signal to PCM is high during KOEO or PSP signal did not change state during KOER.

DTC P1651 indicates PSP signal is open or shorted. PCM expects PSP signal to change after a calibrated number of speed transitions.

Power Steering Pressure (PSP) monitors hydraulic pressure within power steering system. PSP switch is normally closed, which opens as hydraulic pressure increases. PCM uses input signal from PSP switch to compensate for additional loads on engine by adjusting idle RPM and preventing engine stall during parking maneuvers. It also signals PCM to adjust transaxle Electronic Pressure Control (EPC) during increased engine load.

Possible causes are

1. PSP switch damaged.
2. SIG RTN circuit open or shorted to GND.
3. PSP circuit open or shorted to SIG RTN.
4. PCM damaged.

DTC P1780 indicates TCS was not cycled during KOER self-test. Transaxle Control Switch (TCS) is a momentary contact switch that allows driver to cancel overdrive gear. When TCS is pressed, a signal is sent to PCM which then uses the shift solenoids to disengage/disable overdrive gear operation. At the same time, Transaxle Control Indicator Light (TCIL) is illuminated to notify driver that overdrive gear is canceled. When TCS is pressed again, overdrive gear operation is enabled and TCIL is turned off.

Possible causes are

1. Open or short circuit.
2. Damaged TCS.
3. Damaged PCM.
4. Damaged indicator bulb and/or fuse.

Scheme 75

1. If QUICK TEST was not performed, go to «QUICK TEST»(ref-150940-S17451707022002112700000) under SELF-DIAGNOSTIC SYSTEM. If QUICK TEST was performed, go to next step.
2. Check Test Validity Turn ignition on, engine off. Using scan tool, select DIAGNOSTIC DATA LINK. Select PCM. Select PID/DATA MONITOR AND RECORD. Access the TCS PID. Cycle TCS switch button, then hold it depressed. If TCS PID reading does not switch from ON to OFF and reading does not indicate ON when button is depressed, go to next step. If TCS PID reading switches from ON to OFF, and if reading indicates ON when button is depressed, rerun KOER self-test to cycle TCS.
3. Check Transaxle Control Switch (TCS) Circuit For Voltage Turn ignition off. Disconnect PCM 104-pin harness connector. Connect Breakout Box (49-UN01-130) to PCM harness connector only. (Scheme 50) Turn ignition switch on, engine off. Measure voltage between breakout box terminal No. 29 (TCS) and terminals No. 24 and 103 (PWR GND) while cycling TCS several times. If voltage reading does not cycle, go to next step. If voltage reading cycles, replace PCM. After repair, go to step 7.
4. Check Harness Circuit(s) For Short To Ground Turn ignition off. Disconnect TCS. Measure resistance between breakout box terminal No. 29 (TCS) and terminals No. 24 and 103 (PWR GND). If resistance reading is more than 10,000 ohms, go to next step. If resistance reading is not as specified, repair short circuit. See «WIRING DIAGRAMS»(ref-134975) article. After repair, go to step 7.
5. Check Resistance Of TCS Harness Measure resistance of TCS circuit between I/P fuse panel No. 16 fuse (10-amp) and TCS harness connector (Red/Yellow wire). (Scheme 75) Measure resistance of TCS circuit between breakout box terminal No. 29 and TCS harness connector (Orange/Yellow wire). If each resistance reading is less than 5.0 ohms, go to next step. If each resistance reading is not as specified, repair open circuit. After repair, go to step 7.
6. Check Harness Circuit For Shorts To Power Measure resistance between breakout box terminal No. 29 (TCS) and terminals No. 71 and 97 (VPWR). If resistance reading is less than 10,000 ohms, repair short in harness. After repair, go to next step. If resistance reading is not as specified, replace PCM. After repair, go to next step.
7. Verify Trouble Shooting Of DTCs Completed Reconnect all disconnected connectors. Clear DTCs from PCM memory using scan tool. Perform «QUICK TEST»(ref-150940-S17451707022002112700000) under SELF-DIAGNOSTIC SYSTEM. If same DTC is present, replace faulty PCM. Repeat «QUICK TEST»(ref-150940-S17451707022002112700000) under SELF-DIAGNOSTIC SYSTEM. If same DTC is not present, go to applicable procedure for other DTCs. See «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(ref-150940-S42582837182002112700000). If no DTCs are present, trouble shooting is complete.

SYSTEM TESTS

GENERAL TEST INDEX

VEHICLE REFERENCE VOLTAGE

1. Is Voltage Reference (VREF) More Than 6.0 Volts? Disconnect TP sensor 3-pin harness connector. Turn ignition on, engine off. Measure voltage between TP sensor 3-pin harness connector VREF terminal (Brown/White wire) and SIG RTN terminal (Orange wire). See «WIRING DIAGRAMS»(ref-134975) article. If VREF voltage is more than 6.0 volts, check for VREF short to power. After repair, go to step 16. If VREF voltage is 6.0 volts or less, go to next step.
2. Check Battery Voltage Turn ignition on, engine off. If voltage across battery terminals is more than 10.5 volts, go to next step. If voltage across battery terminals is 10.5 volts or less, check battery condition and repair as necessary.
3. Check SIG RTN Circuit To Sensor Where VREF Check Failed Turn ignition on, engine off. Disconnect sensor where VREF check failed. Measure voltage between positive battery terminal and SIG RTN terminal (Orange wire) at appropriate sensor harness connector. If voltage is more than 10.5 volts and within one volt of battery voltage, go to next step. If voltage is not as specified, SIG RTN/PWR GND fault present. Go to step 11.
4. Check VREF Integrity Through PCM Communication On TP PID Turn ignition on, engine off. Attempt to access TP PID. If TP PID can be accessed, check VREF circuit for opens. Go to step 10. If TP PID cannot be accessed, go to next step.
5. Check For VPWR To IAC Valve Turn ignition off. Disconnect Idle Air Control (IAC) valve solenoid harness connector. Turn ignition on, engine off. Measure voltage between IAC valve solenoid harness connector VPWR terminal (White/Red wire) and negative battery terminal. If voltage reading is more than 10.5 volts, reconnect IAC valve solenoid harness connector and go to next step. If voltage reading is 10.5 volts or less, VPWR is not present. Reconnect IAC valve solenoid harness connector. Go to «PCM POWER RELAY»(ref-150940-S11465752392002112700000) test.
6. Check For Shorted DPFEGR Sensor Turn ignition off. Disconnect Differential Pressure Feedback EGR (DPFEGR) sensor. Turn ignition on, engine off. Measure voltage between TP sensor 3-pin harness connector VREF terminal (Brown/White wire) and SIG RTN terminal (Orange wire). If voltage reading is 4.0-6.0 volts, replace DPFEGR sensor. After repair, rerun «QUICK TEST»(ref-150940-S17451707022002112700000) under SELF-DIAGNOSTIC SYSTEM. If voltage reading is not as specified, go to next step.
7. Check For Shorted FTP Sensor Turn ignition off. Disconnect Fuel Tank Pressure (FTP) sensor. Disconnect DPFEGR sensor. Turn ignition on, engine off. Measure voltage between TP sensor VREF terminal (Brown/White wire) and SIG RTN terminal (Orange wire). If voltage reading is 4.0-6.0 volts, replace FTP sensor and rerun «QUICK TEST»(ref-150940-S17451707022002112700000) under SELF-DIAGNOSTIC SYSTEM. If voltage reading is not as specified, go to next step.
8. Check VPWR To PCM Disconnect FTP sensor harness connector. Disconnect PCM 104-pin harness connector. Connect Breakout Box (49-UN01-130) to PCM harness connector only. (Scheme 50) Turn ignition on, engine off. Measure voltage between breakout box terminals No. 71 (VPWR) and No. 103 (PWR GND). If voltage reading is more than 10.5 volts, go to next step. If voltage reading is 10.5 or less, repair open in VPWR circuit (White/Red wire) between PCM 104-pin harness connector terminal No. 71 and PCM power relay (located in battery junction box). See «WIRING DIAGRAMS»(ref-134975) article. After repair, rerun «QUICK TEST»(ref-150940-S17451707022002112700000) under SELF-DIAGNOSTIC SYSTEM.
9. Check VREF Circuit For Short To Ground Or SIG RTN Turn ignition off. Disconnect scan tool from DLC. Measure resistance between breakout box terminals No. 90 (VREF), No. 103 (PWR GND) and No. 91 (SIG RTN). If each resistance reading is more than 10,000 ohms, replace PCM. Reconnect all disconnected connectors. After repair, rerun «QUICK TEST»(ref-150940-S17451707022002112700000) under SELF-DIAGNOSTIC SYSTEM. If resistance reading is 10,000 ohms or less, repair short to ground in affected circuit. After repair, rerun «QUICK TEST»(ref-150940-S17451707022002112700000) under SELF-DIAGNOSTIC SYSTEM.
10. Check VREF Circuit Resistance To PCM Turn ignition off. Disconnect PCM 104-pin harness connector. Connect Breakout Box (49-UN01-130) to PCM harness connector only. (Scheme 50) Measure resistance between breakout box terminal No. 90 (VREF) and VREF terminal (Brown/White wire) at appropriate sensor harness connector. If resistance reading is less than 5.0 ohms, replace PCM. After repair, rerun «QUICK TEST»(ref-150940-S17451707022002112700000) under SELF-DIAGNOSTIC SYSTEM. If resistance reading is 5.0 ohms or more, repair open in VREF circuit (Brown/White wire) between PCM 104-pin harness connector terminal No. 90 and appropriate sensor. After repair, rerun «QUICK TEST»(ref-150940-S17451707022002112700000) under SELF-DIAGNOSTIC SYSTEM. NOTE: Purpose of this step is to determine if scan tool is able to communicate with PCM.
11. Check SIG RTN/PWR GND Through PCM On TP PID Turn ignition on, engine off. Attempt to access TP PID. If TP PID can be accessed, go to next step. If TP PID cannot be accessed, go to step 14.
12. Are KOEO DTCS Present For Two Or More Sensors/Switches Connected To SIG RTN Circuit? Sensors connected to SIG RTN: Engine Coolant Temperature (ECT) sensor Intake Air Temperature (IAT) sensor Camshaft Position (CMP) sensor Differential Pressure Feedback EGR (DPFEGR) sensor Fuel Tank Pressure (FTP) sensor Clutch Pedal Position (CPP) switch/jumper Transaxle Fluid Temperature (TFT) sensor Turbine Shaft Speed (TSS) sensor Power Steering Pressure (PSP) switch All Heated Oxygen Sensors (HO2Ss) If KOEO DTCs are present for two or more components connected to SIG RTN circuit, go to next step. If KOEO DTC is present for only one component connected to SIG RTN circuit, repair open in SIG RTN circuit to affected component where check failed. After repair, rerun «QUICK TEST»(ref-150940-S17451707022002112700000) under SELF-DIAGNOSTIC SYSTEM.
13. Check SIG RTN Circuit Resistance To PCM Turn ignition off. Disconnect scan tool from DLC. Disconnect PCM 104-pin harness connector. Connect Breakout Box (49-UN01-130) to PCM harness connector only. (Scheme 50) Measure resistance between breakout box terminal No. 91 (SIG RTN) and SIG RTN (Orange wire) circuit at appropriate sensor connector. If resistance reading is less than 5.0 ohms, reconnect sensor harness connector and go to next step. If resistance reading is 5.0 ohms or more, repair open in SIG RTN circuit of appropriate sensor. See «WIRING DIAGRAMS»(ref-134975) article. After repair, rerun «QUICK TEST»(ref-150940-S17451707022002112700000) under SELF-DIAGNOSTIC SYSTEM.
14. Check PCM PWR GND Circuits Turn ignition off. Disconnect scan tool from DLC. Disconnect PCM 104-pin harness connector. Install breakout box, PCM disconnected. Measure resistance between negative battery terminal and breakout box terminals No. 51, 76, 77, and 103 (PWR GND). If each resistance reading is less than 5.0 ohms, go to next step. If resistance reading is 5.0 ohms or more, repair open in appropriate circuit. After repair, rerun «QUICK TEST»(ref-150940-S17451707022002112700000) under SELF-DIAGNOSTIC SYSTEM.
15. Check VREF For Short To Power Turn ignition off. Connect PCM to breakout box. Measure resistance between breakout box terminal No. 91 (SIG RTN) and breakout box terminals No. 51, 76, 77, and 103 (PWR GND). If each resistance reading is less than 5.0 ohms, SIG RTN circuits are okay. Ensure results from previous steps are correct. Rerun «QUICK TEST»(ref-150940-S17451707022002112700000) under SELF-DIAGNOSTIC SYSTEM. If each resistance reading is 5.0 ohms or more, replace PCM. After repair, rerun «QUICK TEST»(ref-150940-S17451707022002112700000) under SELF-DIAGNOSTIC SYSTEM.
16. Check VREF For Short To Power Turn ignition off. Disconnect sensor harness connector where VREF check failed. Disconnect all other sensors connected to VREF circuit (TP, DPFE and FTP sensor). Disconnect PCM 104-pin harness connector. Turn ignition on, engine off. Measure voltage between TP sensor harness connector VREF terminal (Brown/White wire) and negative battery terminal. If voltage reading is less than 5.0 volts, replace PCM. After repair, rerun «QUICK TEST»(ref-150940-S17451707022002112700000) under SELF-DIAGNOSTIC SYSTEM. If voltage reading is 5.0 volts or more, repair short to power in Brown/White wire between TP sensor 3-pin harness connector VREF terminal and PCM 104-pin harness connector terminal No. 90. After repair, rerun «QUICK TEST»(ref-150940-S17451707022002112700000) under SELF-DIAGNOSTIC SYSTEM.

1. Carry Out The Instrument Cluster Warning Lamps And Chime Active Command Using Diagnostic Tool Turn ignition off. Connect scan tool to DLC. Turn ignition on, engine off. Select instrument cluster WARNING LAMPS AND CHIME active command. Trigger ALL LAMPS active command. Observe Malfunction Indicator Lamp (MIL). If MIL is illuminating, refer to «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(ref-150940-S42582837182002112700000) . If MIL is not illuminating, go to next step.
2. Check For Correct Instrument Cluster Operation Disconnect all instrument cluster harness connectors. Check for corrosion and pushed out pins. Reconnect all instrument cluster connectors and make sure they seat correctly. Operate system and verify concern is still present. If concern is still present, replace instrument cluster. Test system for normal operation. If concern is not present, system is operating correctly at this time. Concern may have been caused by a loose or corroded terminal or connector. Clear DTCs and repeat self-test. See «CLEARING CODES»(ref-150940-S31080003522002112700000) and «KOEO & KOER SELF-TEST»(ref-150940-S38670547312002112700000) under SELF-DIAGNOSTIC SYSTEM.

INTERMITTENT

Note. PIDs selected from PID/DATA MONITOR table will display commanded values only. Digital multimeter measurements will display actual values.

Note. Proceed with this step only if a PCM Reset was not done earlier; otherwise, go to step 2 . Eliminating Failure Mode Effects Management (FMEM) will insure reproduction of any PCM related symptom.

1. Perform PCM Reset to clear FMEM Connect scan tool to DLC. Turn ignition on, engine off. Ensure freeze frame data has been recorded before resetting PCM. Complete PCM reset. See «QUICK TEST»(ref-150940-S17451707022002112700000) under SELF-DIAGNOSTIC SYSTEM. If PCM reset is complete, go to next step. If PCM reset is not complete, perform PCM reset. Go to next step.
2. Select PIDs Related To Symptom A list of PIDs is needed for use with scan tool to indicate area of fault. See appropriate PIN/PID CHARTS under PIN VOLTAGE/PID VALUE CHARTS in PIN VOLTAGE/PID VALUE CHARTS article. Highlight each PID related to symptom. After all PIDs related to symptom have been chosen, go to next step.
3. Decision To Verify Symptom Path of symptom verification is optional, but is recommended for several reasons. Some are because: Vehicle is in for repeat repair. No DTC is present. Customer has difficulty describing symptom. If symptom needs to be verified, go to next step. If symptom does not need to be verified, go to step 10 . NOTE: Only MIL codes will trigger freeze frame data.
4. Collect Any Available Data To Aid In Symptom Verification Prepare freeze frame data for use which was recorded earlier from the Diagnostic Index. Continuous Memory DTCs should already be recorded from an earlier test. Access any other available data from customer. If all data has been recorded, go to next step. If all data has not been recorded, gather as much information as possible to aid in isolation of intermittent fault area. Go to next step. NOTE: Vehicle may require some driving to proceed with this test step.
5. Re-Create Symptom Using All Data Concern must be verified by re-creating conditions that originally set DTC. With scan tool, select and monitor same PIDs as displayed in freeze frame along with previous highlighted PIDs from step 2 . Using freeze frame data recorded earlier, re-create conditions described by each freeze frame PID. Pay special attention to ECT/CHT, LOAD, RPM and VSS PIDs. Also, use any available customer data to aid in producing correct conditions for re-creating symptom. When symptom occurs, press trigger to begin recording. If symptom could be reproduced, go to step 10 . If symptom could not be reproduced, go to next step. NOTE: PIDs for outputs represent commanded values only. Circuit measurements with DVOM indicate actual output status. Therefore, in case of a fault, PID and circuit reading on vehicle may not correspond with each other. PIDs for PCM inputs with a mismatch to circuit measurement indicate a possible PCM concern. See appropriate PIN/PID CHARTS under PIN VOLTAGE/PID VALUE CHARTS in PIN VOLTAGE/PID VALUE CHARTS article.
6. Re-create Symptom Using KOEO Road Test Procedure Road test is the last attempt to locate area of concern before physically disturbing vehicle circuits. Intermittent Road Test Procedure is a set of instructions for monitoring PIDs with scan tool or DVOM. This is done under four different conditions: KOEO HOT IDLE 30 MPH 55 MPH Use PID/DATA MONITOR to compare with actual vehicle values. For 30 and 55 MPH procedures, a planned route with passenger is required. Locate corresponding PIN/PID Chart. Refer to appropriate PIN/PID CHARTS under PIN VOLTAGE/PID VALUE CHARTS in PIN VOLTAGE/PID VALUE CHARTS article. Set vehicle up to measure circuits with a scan tool or DVOM. Connect scan tool to DLC. Turn ignition on, engine off. Select and monitor PIDs and also measure circuits shown in PIN/PID Chart. Compare scan tool PIDs and DVOM values to values listed in PIN/PID Chart. If any values are out-of-range, go to step 10 . If values are not out of range, go to next step.
7. Re-Create Symptom Using Hot Idle Road Test Procedure Turn ignition on, engine running and at least 195°F (87°C). Continue to monitor same PIDs and circuits as in previous step at hot idle. If any values are out-of-range, go to step 10 . If values are not out of range, go to next step.
8. Re-Create Symptom Using 30 MPH Slow Cruise Road Test Procedure Drive vehicle on preplanned route. Continue to monitor same PIDs and circuits during slow cruise as in previous step. If any values are out-of-range, go to step 10 . If values are not out of range, go to next step.
9. Re-Create Symptom Using 55 MPH High Cruise Road Test Procedure Continue to drive vehicle on preplanned route. Continue to monitor same PIDs and circuits during high cruise as in previous step. If any values are out-of-range, go to next step. If values are not out of range, it is now necessary to physically disturb selected vehicle circuits in an attempt to re-create intermittent concern. Go to next step.
10. Select Circuits From The PID/DATA Monitor Table Remain in PID selection menu with scan tool. If Intermittent Road Test was used to verify symptom, highlight related PIDs or signals that displayed a mismatch to values listed in appropriate PIN/PID Charts. See appropriate PIN/PID CHARTS under PIN VOLTAGE/PID VALUE CHARTS in PIN VOLTAGE/PID VALUE CHARTS article. Otherwise, highlight only the PIDs from step 2 . Match selected PIDs to the corresponding circuit. There may be more than one circuit to test. If a PID recording was made with scan tool, it may be helpful to replay at this time (refer to scan tool instruction manual for recorder function). Select and proceed to appropriate test: Input Test Used on sensing devices such as temperature, position or oxygen. Output Test Used on output devices such as relays, coils or solenoids. If a test has been chosen: For input test, go to next step. For output test, go to step 15 . If no mismatch has been detected, go to «DTC P1001: DATA LINK CONNECTOR - MALFUNCTION»(ref-150940-S24210192462002112700000) . WARNING: When performing any of the test steps, always be aware of hands, clothing or tools near cooling fans or hot surfaces.
11. KOEO Input Test Procedure For PCM Sensors Select only related PID(s) to monitor with scan tool. If a PID is not available for circuit, use a DVOM. Proceed to area of suspect wiring or component fault. Turn ignition on, engine off. If input is a switch-type component, turn on manually. Monitor PID or DVOM values while tapping on component. Monitor while wiggling sensor harness wire from component to PCM. Look for abrupt changes in values. Compare actual values to KOEO PID values. See appropriate PIN/PID CHARTS under PIN VOLTAGE/PID VALUE CHARTS in PIN VOLTAGE/PID VALUE CHARTS article. If values are fluctuating in and out-of-range, repair as necessary. If no problem is found, go to next step.
12. KOER Input Test Procedure For PCM Sensors Repeat step 11 with ignition on, engine running. If any values are fluctuating in and out-of-range, repair as necessary. If no problem is found, go to next step.
13. KOEO Water Soak Test Procedure For PCM Sensors Turn ignition on, engine off. Continue to monitor PIDs or circuits with scan tool as in step 12 . Proceed to the area of suspect wiring or component fault. If input is a switch-type component, turn on manually. Monitor PID or DVOM values while lightly spraying a water mist on suspect component. Monitor while spraying sensor harness wire from suspect component to PCM. Look for abrupt changes in values. Compare actual values to KOEO PID values. See appropriate PIN/PID CHARTS under PIN VOLTAGE/PID VALUE CHARTS in PIN VOLTAGE/PID VALUE CHARTS article. Are any values fluctuating in and out-of-range, repair as necessary. If no problem is found, go to next step.
14. KOER Water Soak Test Procedure For PCM Sensors With ignition on, engine running, repeat step 13 . If values are fluctuating in and out-of-range, repair as necessary. If no problem is found, go to step 19 . NOTE: Output Test Mode may not control some outputs, such as injectors and ignition coils. To test these output types, go to step 16 . Caution must be used for next steps. Cooling fans or fuel pump may turn on.
15. KOEO Output Test Procedure For PCM Actuators Select related PID(s) to monitor using scan tool. Also, use a DVOM to compare circuit values with scan tool PID values. If PIDs are not available for a particular circuit, look for a DVOM fluctuation to occur when doing any of the following tests. Turn ignition on, engine off. With scan tool, turn all outputs on using OUTPUT TEST MODE. Proceed to area of suspect wiring or component fault. Monitor PID and DVOM values while tapping on component. Monitor while wiggling actuator harness wire from suspect component to PCM. Look for abrupt changes or PID to DVOM value mismatches. Also, compare the actual values to KOEO PID values. See appropriate PIN/PID CHARTS under PIN VOLTAGE/PID VALUE CHARTS in PIN VOLTAGE/PID VALUE CHARTS article. If there is a mismatch or there are any values fluctuating in and out-of-range, repair as necessary. If no problem is found, go to next step.
16. KOER Output Test Procedure For PCM Actuators Turn ignition on, engine running. Proceed to area of suspect wiring or component fault. Monitor PIDs with scan tool (if PIDs are available) using PID monitor function. Compare the DVOM values with scan tool or look for a fluctuation in idle while tapping on suspect component. If a coil has been tapped and is suspect, with ignition off, it may be helpful to remove suspect coil and measure continuity from spark plug terminal to signal terminal while tapping the coil. A large fluctuation in resistance will indicate an intermittent open. Otherwise, monitor while wiggling actuator harness wire from component to PCM. Look for abrupt changes in idle or PID to DVOM value mismatches or fluctuation. Also, compare actual values to HOT IDLE PID values. See appropriate PIN/PID CHARTS under PIN VOLTAGE/PID VALUE CHARTS in PIN VOLTAGE/PID VALUE CHARTS article. If there is an idle fluctuation or DVOM value mismatch or fluctuation, repair as necessary. If no problem is found, go to next step. NOTE: Output Test Mode may not control some outputs, such as injectors. To test these output types, go to step 18 .
17. KOEO Water Soak Test Procedure For PCM Actuators Turn ignition on, engine off. With scan tool, turn all outputs on using Output Test Mode. Proceed to area of suspect wiring or component fault. Monitor PID and DVOM value while spraying a light mist of water on the component. Monitor while spraying actuator harness wire from component to PCM. Look for abrupt changes or PID to DVOM value mismatches. Also, compare actual values to KOEO PID/DATA. See appropriate PIN/PID CHARTS under PIN VOLTAGE/PID VALUE CHARTS in PIN VOLTAGE/PID VALUE CHARTS article. If there is a PID to DVOM value mismatch or fluctuation in and out-of-range according to PIN/PID CHARTS, repair as necessary. If no problem is found, go to next step.
18. KOER Water Soak Test Procedure For PCM Actuators Repeat step 17 with ignition on, engine running. If there is an idle fluctuation, value mismatch or values fluctuating in and out-of-range according to PIN/PID CHARTS, repair as necessary. If no problem is found, go to next step. NOTE: It is possible for an intermittent mechanical concern to cause a good PCM system to react abnormally.
19. Inspect For Intermittent Mechanical Concerns An inspection of mechanical systems relating to the DTC or symptom should have been performed in an earlier section. If not, visually inspect at this time. Look for possibility of wires, vacuum lines or hoses that may short or kink during normal engine operation, such as: Engine rock during acceleration. Components moving during conditions of vibrations (high RPM or rough road). Accelerator or transaxle linkage contact or interference. If a mechanical concern is detected, repair as necessary. If mechanical concern is not found, unable to verify fault.

FUEL DELIVERY SYSTEM

1. Check System Integrity Visually inspect complete fuel delivery system, including fuel lines, connections, relays, damage to fuel tank, fuel pump, fuel pressure regulator, fuel pulse damper and fuel injector areas for leaks, looseness, cracks, kinks, pinching, or abrasion caused by a collision or mishandling. Visually inspect electrical harnesses and connectors for loose pins, corrosion, abrasion, or other damage from collision or mishandling. Verify vehicle has followed maintenance schedule. Verify Inertia Fuel Shutoff (IFS) switch is set. Refer to «SWITCHES»(ref-134970-S42030263742002022100000) under SENSORS & SWITCHES in SYSTEM & COMPONENT TESTING - B2300, B3000, B4000 & TRIBUTE article. Verify battery is fully charged (12.5 volts or more). Verify electrical/fuse integrity. Verify fuel level is sufficient. If any concern has been found, repair as necessary. After repair, rerun «QUICK TEST»(ref-150940-S17451707022002112700000) under SELF-DIAGNOSTIC SYSTEM. If no problem is found, go to next step.
2. Check For Voltage At Fuel Pump Harness Connector Verify Inertia Fuel Shutoff (IFS) switch state. Follow the IFS switch reset procedure. Refer to «SWITCHES»(ref-134970-S42030263742002022100000) under SENSORS & SWITCHES in SYSTEM & COMPONENT TESTING - B2300, B3000, B4000 & TRIBUTE article. Disconnect fuel pump 4-pin harness connector at fuel pump. Turn ignition on, engine off. Connect scan tool. Select DIAGNOSTIC DATA LINK. Select PCM. Select ACTIVE COMMAND MODES. Select OUTPUT TEST MODE. Select FUEL PUMP PID. Press MODE to change to ALL ON MODE. Press START to turn on fuel pump circuit. Connect a DVOM between fuel pump power circuit (Pink/Black wire) and fuel pump ground circuit (Black wire) at fuel pump 4-pin harness connector. See «WIRING DIAGRAMS»(ref-134975) article. If voltage reading is more than 12.5 volts, restore vehicle to original condition and go to next step. If voltage reading is 12.5 volts or less, check for open or short in fuel pump power and ground circuit.
3. Check Fuel Filter For Proper Maintenance Locate and inspect the vehicle maintenance schedule and fuel filter. If fuel filter was serviced according to schedule, go to next step. If fuel filter was not changed according to schedule, replace fuel filter. After repair, go to next step. NOTE: The fuel pump will only operate for approximately 8 seconds when OUTPUT TEST MODE is selected and activated.
4. Check Fuel Pressure Install fuel pressure tester. Release fuel pressure. See «FUEL PRESSURE RELEASE»(ref-134958-S02405930982002022100000) under FUEL SYSTEM in BASIC DIAGNOSTIC PROCEDURES article. Turn ignition on, engine off. Connect scan tool to DLC. Select PCM, ACTIVE COMMAND MODES, OUTPUT TEST MODE and FUEL PUMP PID. Press MODE to change to ALL ON MODE. Press START to run fuel pump. If fuel pressure is 55-70 psi (380-482 kPa), go to next step. If fuel pressure is more than 70 psi (482 kPa), replace fuel pump module. See «FUEL PUMP»(ref-134974-S33611150832002022100000) under FUEL SYSTEM in REMOVAL, OVERHAUL & INSTALLATION article. After repair, return vehicle to original condition and recheck fuel pressure. If fuel pressure is less than 55 psi (380 kPa), go to next step.
5. Check Fuel Injector Flow And Leakage Check injectors for leakage and flow rate using an injector tester. Flow rate specification: 17 lb/hr (7.84 kg/hr) for 2.0L. 22 lb/hr (10.1 kg/hr) for 3.0L. If the flow rate and leakage rate for injectors tested is within specification, ensure there are no other leaks and replace fuel pump module. See «FUEL PUMP»(ref-134974-S33611150832002022100000) under FUEL SYSTEM in REMOVAL, OVERHAUL & INSTALLATION article. If flow rate is not as specified, replace faulty fuel injector. Restore vehicle to original condition and recheck fuel pressure.
6. Check Pulse Damper Diaphragm Start engine and run engine for 10 seconds. Turn ignition off. Wait 10 seconds and then start engine and run engine for 10 seconds. Turn ignition off. Remove vacuum hose from fuel pressure regulator or pulse damper port. Inspect for fuel in vacuum hose at fuel pressure regulator or pulse damper end. If vacuum hose and fuel pressure regulator or pulse damper port are free of fuel, go to next step. If vacuum hose, fuel pressure regulator or pulse damper port have fuel present, replace faulty fuel pressure regulator or pulsation damper.
7. Check Fuel Supply Line For Restriction Release fuel pressure. See «FUEL PRESSURE RELEASE»(ref-134958-S02405930982002022100000) under FUEL SYSTEM in BASIC DIAGNOSTIC PROCEDURES article. Disconnect fuel supply line at fuel rail and fuel pump. Check fuel supply line for restrictions due to blockage, kinking, or pinching. Apply 3-5 psi (21-34 kPa) regulated shop air pressure to fuel supply line. If air flows freely through fuel supply line, replace fuel pump. If air does not flow freely through fuel supply line, repair restriction as necessary. After repair, restore vehicle to original condition and recheck fuel pressure.

Note. This test is intended to diagnose only the PCV valve and related vacuum lines.

POSITIVE CRANKCASE VENTILATION SYSTEM

1. Stuck PCV Valve Check Turn ignition off. Verify PCV valve maintenance schedule has been followed. Verify proper PCV valve part number. Verify clean PCV valve. Shake PCV valve. If PCV valve rattles when shaken, reinstall PCV valve and go to next step. If PCV valve does not rattle when shaken, replace PCV valve.
2. PCV System Check Start engine and bring to normal operating temperature. Disconnect closure (fresh air) hose from remote air cleaner or air inlet tube (tube connecting Mass Airflow/Intake Air Temperature (MAF/IAT) sensor and throttle body). Place a stiff piece of paper over the hose end. Wait one minute. If vacuum holds paper in place, PCV system is okay. Reconnect hose. Refer to «SYMPTOM DIAGNOSIS»(ref-134968-S36579230062002022100000) in TROUBLE SHOOTING - NO CODES article. If vacuum does not hold paper in place, PCV system is leaking/plugged or EVAP system is leaking. If EVAP emission hose is not connected to PCV hose, check for vacuum leaks/obstructions in PCV system (oil cap, PCV valve, hoses, cut grommets or valve cover bolt torque/gasket leaks). Repair as necessary. If EVAP emission hose is connected to PCV hose, go to next step.
3. Evaporative Emission System Check Disconnect EVAP emission hose at connection to PCV hose (if equipped). Cap the connector. Start engine. Again, place a piece of stiff paper over closure (fresh air) hose end. Wait one minute. If vacuum holds paper in place, PCV system is okay. Go to step 4 under Diagnostic Procedures under DTC P0455 or P1443. If vacuum does not hold paper in place, check for vacuum leaks/obstructions in PCV system (oil cap, PCV valve, hoses, cut grommets or valve cover bolt torque/gasket leaks). Repair as necessary.

PCM POWER RELAY

1. Check VPWR Circuit Resistance Disconnect Idle Air Control (IAC) valve harness connector. Disconnect scan tool from DLC. Disconnect PCM power relay (located in battery junction box). Measure resistance of VPWR circuit between IAC valve harness connector terminal (White/Red wire) and PCM Power Relay battery junction box terminal (Red wire). See «WIRING DIAGRAMS»(ref-134975) article. If resistance is less than 5.0 ohms, reconnect IAC valve and go to next step. If resistance reading is 5.0 ohms or more, repair open in VPWR circuit between PCM power relay (Red wire) and IAC valve (White/Red wire). After repair, restore vehicle to original condition and rerun «QUICK TEST»(ref-150940-S17451707022002112700000) under SELF-DIAGNOSTIC SYSTEM.
2. Check B+ And IGN START/RUN Voltage To PCM Power Relay Measure B+ circuit (Red/Light Green wire) voltage at the PCM power relay connector. Turn ignition on, engine off. Measure IGN START/RUN circuit (White/Violet wire) voltage at PCM Power Relay battery junction box terminal. If both voltages are more than 10.5 volts, go to next step. If both voltages are 10.5 volts or less, repair open in B+ (Red/Light Green wire) or IGN START/RUN circuit (White/Violet wire). After repair, restore vehicle to original condition and rerun «QUICK TEST»(ref-150940-S17451707022002112700000) under SELF-DIAGNOSTIC SYSTEM.
3. Check Ground Circuit To Power Relay Measure voltage between B+ circuit (Red/Light Green wire) and ground circuit (Black wire) at PCM Power Relay battery junction box terminal. Turn ignition off. If voltage reading was more than 10.5 volts, replace PCM. After repair, restore vehicle to original condition and rerun «QUICK TEST»(ref-150940-S17451707022002112700000) under SELF-DIAGNOSTIC SYSTEM. If voltage reading was 10.5 volts or less, repair open in ground circuit. After repair, restore vehicle to original condition and rerun «QUICK TEST»(ref-150940-S17451707022002112700000) under SELF-DIAGNOSTIC SYSTEM.

FUEL PRESSURE REGULATOR

1. Check Fuel Pressure Connect fuel pressure gauge. Start engine and run at idle. Disconnect vacuum hose from fuel pressure regulator and plug it. Drive vehicle under heavy acceleration while observing fuel pressure gauge reading. If fuel pressure holds steady within 3 psi (20.6 kPa), go to next step. If fuel pressure does not hold to within 3 psi (20.6 kPa), check fuel vapor valve. If fuel vapor valve is okay, check for clogged fuel filter.
2. Check Fuel Pressure With Vacuum Applied To Regulator Connect vacuum pump to fuel pressure regulator. Apply vacuum to fuel pressure regulator. If fuel line pressure decreases when vacuum is applied, check vacuum hose and vacuum source. Repair as necessary. After repair, go to next step. If fuel pressure does not decrease when vacuum is applied, replace fuel pressure regulator. After repair, go to step 4 .
3. Check Fuel Pressure And Verify Fuel Flow Disconnect the fuel return line from fuel rail. Connect a short hose from fuel rail to a one quart (one liter) measuring container. Turn ignition on, engine off. Connect scan tool to DLC. Select PCM, ACTIVE COMMAND MODES, OUTPUT TEST MODE and FUEL PUMP PID. Press MODE to change to ALL ON MODE. Press START to run fuel pump. Measure fuel line pressure and verify fuel is flowing into container. If fuel pressure is still high, replace fuel pressure regulator. Restore vehicle to original condition. If fuel pressure is not high, inspect fuel return line for blockage or clog. Repair or replace as necessary. After repair, go to next step.
4. Check Regulator For Fuel Leaks Start engine and run at idle for 10 seconds. Turn ignition off for 10 seconds. Start engine and run at idle for 10 seconds. Turn ignition off. Disconnect vacuum hose from pressure regulator. If diaphragm is leaking fuel, replace fuel pressure regulator. Restore vehicle to original condition. If fuel is not leaking from diaphragm, restore vehicle to original condition. Testing is complete.

EGR VALVE

1. Check EGR Valve Function By Applying Vacuum With Hand Pump Disconnect Idle Air Control (IAC) valve harness connector. Remove and plug vacuum supply hose to EGR valve. Start engine and run at idle with transaxle in NEUTRAL. Observe idle speed. Connect hand vacuum pump to EGR valve and slowly apply 5-20 in. Hg of vacuum. If idle speed drops more than 100 RPM with vacuum applied and returns to normal after vacuum is removed, EGR valve is okay. If idle speed does not drop more than 100 RPM with vacuum applied and return to normal after vacuum is removed, replace faulty EGR valve.

DIFFERENTIAL PRESSURE FEEDBACK EGR SENSOR

1. Check DPFEGR Output Connect scan tool to DLC. Warm up engine and run at idle. Access DPFEGR PID and record value for the following: Hot idle specification (0.2-1.3 V). Driving 30 MPH specification (0.2-1.3 V). Driving 55 MPH specification (0.2-4.5 V). If DPFEGR PID values are as specified, DPFEGR sensor is okay. If DPFEGR PID values are not as specified, go to next step.
2. Check DPFEGR Sensor Output By Applying Vacuum With Hand Pump Turn ignition on, engine off. Access DPFEGR PID on scan tool. Disconnect upstream and downstream hoses from DPFEGR sensor. Connect a hand vacuum pump to intake manifold side (downstream side = smaller diameter) of DPFEGR sensor. Apply vacuum and check DPFEGR PID. DPFEGR PID voltage reading must be 0.2-1.3 volts with ignition on and no vacuum applied. DPFEGR PID voltage reading must increase to more than 4.0 volts with vacuum applied. DPFEGR PID must drop to less than 1.5 volts in less than 3 seconds when vacuum is released. If DPFEGR PID voltage reading is as specified, DPFEGR sensor is okay. If DPFEGR PID voltage reading is not as specified, replace DPFEGR sensor.

NO START

Note. This vehicle might have an anti-theft system, which may be activated, causing no start condition. Verify by viewing anti-theft indicator on instrument panel or a DTC P1260 may be present.

1. Check Passive Anti-Theft System Verify if vehicle has anti-theft system. If system is activated, see appropriate DOOR LOCKS & ANTI-THEFT SYSTEMS article in ACCESSORIES & EQUIPMENT. If system is not activated, go to next step.
2. Attempt To Crank Engine Ensure Inertia Fuel Shutoff (IFS) switch is set (button pushed in). Refer to «SWITCHES»(ref-134970-S42030263742002022100000) under SENSORS & SWITCHES in SYSTEM & COMPONENT TESTING - B2300, B3000, B4000 & TRIBUTE article. If engine cranks, go to next step. If engine does not crank, refer to «SYMPTOM DIAGNOSIS»(ref-134968-S36579230062002022100000) in TROUBLE SHOOTING - NO CODES article. NOTE: Purpose of this test step is to identify intermittent No Starts in order to guide technician to proper repair procedure.
3. Identify Type Of No Start If vehicle starts now, problem is intermittent. Refer to «INTERMITTENT»(ref-150940-S23445146842002120200000) in «SYSTEM TESTS»(ref-150940-S42556424782002112700000) . If vehicle does not start now, go to next step.
4. Check For VREF At Throttle Position (TP) Sensor Disconnect TP sensor. Turn ignition on, engine off. Measure voltage between VREF circuit (Brown/White wire) and SIG RTN circuit (Orange wire) at TP sensor harness connector. Turn ignition off. If voltage reading is 4.0-6.0 volts, reconnect TP sensor and go to next step.
5. Check Flash EPROM Power Supply (FEPS) Circuit For Short To Power Turn ignition on, engine off. Measure voltage between DLC terminal No. 13 (Violet wire) and battery negative terminal. Turn ignition off. If voltage reading is more than 9.0 volts, repair short to power in Violet wire between DLC terminal No. 13 and PCM 104-pin harness connector terminal No. 13. After repair, restore vehicle to original condition. Rerun «QUICK TEST»(ref-150940-S17451707022002112700000) under SELF-DIAGNOSTIC SYSTEM. If voltage reading is 9.0 volts or less, go to next step. NOTE: Scan tool must be connected to a reliable power source that is powered with ignition switch in START position (such as directly to vehicle battery). Ensure vehicle battery is fully charged.
6. Check Profile Ignition Pickup (PIP) In The PCM Access PIP PID. While viewing the PIP PID, crank engine. If PIP PID is switching on and off, Turn ignition off. Check ignition coils, spark plugs and spark plug wires. Refer to «IGNITION SCOPE TEST»(ref-150940-S39555094232002120300000) . If ignition coils, spark plugs and spark plug wires are okay, go to next step. If PIP PID is not switching on and off, check Crankshaft Position (CKP) sensor for malfunction. Refer to «DTC P0320: CRANKSHAFT POSITION SENSOR - MALFUNCTION»(ref-150940-S09046396932002112700000) under DIAGNOSTIC TESTS. WARNING: Before servicing or replacing any components in fuel system, release fuel system pressure. Refer to «FUEL PRESSURE RELEASE»(ref-134958-S02405930982002022100000) under FUEL SYSTEM in BASIC DIAGNOSTIC PROCEDURES article.
7. Check Fuel Pressure Install fuel pressure gauge. Turn ignition on, engine off. Using scan tool, select DIAGNOSTIC DATA LINK, PCM, ACTIVE COMMAND MODE, OUTPUT TEST MODE and Fuel Pump PID. Press MODE to change to ALL ON MODE and then press START to run fuel pump. Turn ignition off. If fuel pressure is 55-70 psi, go to next step. If fuel pressure is not as specified, refer to «FUEL DELIVERY SYSTEM»(ref-150940-S38917645432002120200000) testing.
8. Check Fuel Pressure Leakdown Verify fuel pressure reading remains within 5 psi of maximum pressure for one minute after turning off fuel pump. If fuel pressure reading is as specified, restore vehicle to original condition and go to next step. If fuel pressure reading is not as specified, refer to «FUEL DELIVERY SYSTEM»(ref-150940-S38917645432002120200000) testing. NOTE: Check at least two fuel injectors, one on each bank. No start condition can exist only if more than 50 percent of the fuel injectors are without power.
9. Check Fuel Injectors For VPWR Disconnect any two fuel injectors. Turn ignition on, engine off. Measure VPWR circuit (Red wire) voltage at fuel injector harness connector. If voltage reading is more than 10.5 volts, turn ignition off and go to next step. If voltage reading is 10.5 volts or less, repair Red wire between fuel injector harness connector and PCM power relay.
10. Check Fuel Injectors' Ability To Delivery Fuel Connect fuel pressure gauge to Schrader valve connection. Locate and disconnect Inertia Fuel Shutoff (IFS) switch. Cycle ignition switch several times. Monitor fuel pressure gauge while cranking engine for at least five seconds. If fuel pressure reading drops more than 5 psi (34 kPa) while cranking engine, fuel system is okay. Refer to «SYMPTOM DIAGNOSIS»(ref-134968-S36579230062002022100000) in TROUBLE SHOOTING - NO CODES article. If fuel pressure reading does not drop as specified, replace PCM.