Engine Controls - Self-Diagnostics - Altima: Other Nissan Altima L31

FREEZE-FRAME DATA

Note. 1st trip freeze-frame data values can only be displayed with Nissan's CONSULT, and are not displayed on generic scan tool.

ECM records operating conditions such as fuel system status, calculated load value, engine coolant temperature, short term fuel trim, long term fuel trim, engine speed, vehicle speed and absolute pressure. Freeze-frame data is a "snapshot" of these operating conditions present when a fault is detected. When a fault is detected for the first time, ECM stores the first trip DTC, along with first trip freeze-frame data. Only one set of freeze-frame data can be stored in ECM (either first trip freeze-frame data or freeze-frame data). There is no priority for first trip freeze frame data. It is updated each time a different first trip DTC is stored. If a fault is detected for the second time, first trip freeze-frame data is replaced with freeze-frame data.

Freeze-frame data is updated in order of priority. See FREEZE FRAME PRIORITY IDENTIFICATION table. If a priority 1 fault (misfire or fuel injection system malfunction) is detected in another trip when priority 2 freeze-frame data is already stored in ECM, priority 2 freeze-frame data will be replaced by priority 1 freeze-frame data.

Note. Only one 1st trip DTC and one freeze-frame data "snapshot" can be stored in ECM. If using a generic scan tool, 1st trip DTC freeze-frame information may not be accessible. Use CONSULT-II to retrieve 1st trip DTC freeze-frame information.

FREEZE FRAME PRIORITY IDENTIFICATION

Using MIL

Malfunction Indicator Light (MIL) can be used for DTC retrieval and front Heated Oxygen Sensor (HO2S) monitoring. (Scheme 74) When ignition is turned on with engine off, MIL should illuminate. This is a bulb check. If MIL does not illuminate, repair MIL circuit. See appropriate INSTRUMENT PANELS article in ACCESSORIES & EQUIPMENT. Or, see DTC P0650: MIL (CIRCUIT) under DIAGNOSTIC TESTS. When engine is started, MIL should go off. If MIL remains on, ECM has detected a malfunction. If MIL is flashing when engine is running, ECM may be in diagnostic test mode II.

Scheme 74

Using CONSULT-II

1. If ignition is on, turn ignition off and wait at least 10 seconds. Turn ignition on. If DTC is A/T related, go to next step. If DTC is not A/T related, go to step 3 .
2. Turn CONSULT-II on and press A/T. Press SELF-DIAG RESULTS. Press ERASE. DTC in TCM is now cleared. Press BACK twice.
3. Press ENGINE. Press SELF-DIAG RESULTS. Press ERASE. DTC in ECM is now cleared.

1. Enter diagnostic test mode II. See ENTERING DIAGNOSTIC TEST MODE II (SELF-DIAGNOSTIC RESULTS MODE)under RETRIEVING DIAGNOSTIC TROUBLE CODES USING MIL.
2. Fully depress accelerator pedal and hold for more than 10 seconds. Fully release accelerator pedal. To confirm DTCs are cleared, ensure DTC 0000 is set.

FAIL-SAFE MODES

ECM enters a fail-safe mode if certain malfunctions are detected due to an open or short circuit. When ECM enters fail-safe mode, MIL illuminates. Refer to all diagnostic tests that apply for description and testing of circuit affected.

ECM (DTCs Not Accessible)

Maximum engine speed is 3000 RPM. Fuel injection operates in simultaneous mode. Ignition timing is fixed. Fuel pump relay remains on when engine is running and off when engine stalls. Cooling fans operate at high speed when engine is running. If ECM fail-safe mode is confirmed, replace ECM.

Checking SRT Code Status (Using CONSULT-II)

Select SRT STATUS in DTC CONFIRMATION mode with CONSULT-II. For items whose SRT codes are set, CMPLT is displayed. For items whose SRT codes are not set, INCMP is displayed.

Setting SRT Codes (Using CONSULT-II)

Perform DTC CONFIRMATION TEST under corresponding DTC test under DIAGNOSTIC TESTS. If more than on SRT item needs to be set, perform DTC confirmation tests in order of priority. See SRT PRIORITY table.

SRT PRIORITY

Work Support Mode

This mode can be used for the following functions

1. FUEL PRESSURE RELEASE Use to release fuel pressure. Fuel pump will stop by touching START during engine idling. Crank a few times after engine stalls.
2. IDLE AIR VOL LEARN Use to perform idle air volume learning.
3. SELF-LEARNING CONT Use to clear the coefficient of self-learning control value. Air/fuel mixture ratio returns to the original coefficient.
4. EVAP SYSTEM CLOSE Use when testing EVAP system for leaks. This will open vacuum cut valve by-pass valve and close EVAP canister vent control valve in order to seal EVAP system under the following conditions: Ignition switch on. Engine not running. Ambient temperature is above 32°F (0°C). No vacuum and no high pressure in EVAP system. Fuel tank temperature is more than 32°F (0°C). Within 10 minutes after starting EVAP SYSTEM CLOSE. When trying to execute EVAP SYSTEM CLOSE when above conditions are not met, CONSULT-II will discontinue it and display appropriate instruction. NOTE: When starting engine, CONSULT-II may display BATTERY VOLTAGE IS LOW. Charge battery, even if using charged battery.
5. TARGET IDLE RPM ADJ Use when setting target idle speed. This function is usually unnecessary.
6. TARGET IGNITION TIMING ADJ Use when adjusting target ignition timing. After adjustment, verify target ignition timing with a timing light. This function is usually unnecessary.

Self-Diagnostic Results Mode

For DTC and 1st trip DTC descriptions, see DIAGNOSTIC TROUBLE CODE DEFINITIONS . Freeze frame data and 1st trip freeze frame data show a snapshot of the following items at the moment a malfunction is detected.

1. FUEL SYS-B1 Or FUEL SYS-B2 Fuel injection system status for bank 1 or bank 2. One of the following modes is displayed: MODE 2: Open loop due to detected system malfunction. MODE 3: Open loop due to driving conditions (power enrichment, deceleration enrichment). MODE 4: Closed loop - using oxygen sensor(s) as feedback for fuel control. MODE 5: Open loop - has not yet satisfied condition to go into closed loop.
2. CAL/LD VALUE [%] Calculated load value.
3. COOLANT TEMP [°C] or [°F] Engine coolant temperature.
4. S-FUEL TRIM-B1 Or S-FUEL TRIM-B2 [%] Short-term fuel trim (indicates dynamic or instantaneous feedback compensation to base fuel schedule) for bank 1 or bank 2.
5. L-FUEL TRIM-B1 Or L-FUEL TRIM-B2 [%] Long-term fuel trim (indicates much more gradual feedback compensation to the base fuel schedule than short-term fuel trim).
6. ENGINE SPEED [rpm] Engine speed.
7. VHCL SPEED [km/h] or [mph] Vehicle speed.
8. B/FUEL SCHDL [msec] Base fuel schedule.
9. INT/A TEMP SE [°C] or [°F] Intake air temperature.

Data Monitor Mode

For DATA MONITOR mode descriptions, see DATA MONITOR MODE DESCRIPTIONS table.

DATA MONITOR MODE DESCRIPTIONS

Data Monitor (SPEC) Mode

For DATA MONITOR (SPEC) mode descriptions, see DATA MONITOR (SPEC) MODE DESCRIPTIONS table.

DATA MONITOR (SPEC) MODE DESCRIPTIONS

Mode 2: Freeze Frame Data

This mode gains access to emission-related data value information stored by ECM during the freeze frame portion of self-diagnostic mode during engine operation.

Mode 4: Clearing Codes

This mode can clear all emission related diagnostic information for DTCs. These include

1. Clear number of DTCs (MODE 1).
2. Clear DTCs (MODE 3).
3. Clear DTC for freeze-frame data (MODE 1).
4. Clear freeze-frame data (MODE 2).
5. Reset status of system monitoring test (MODE 1).
6. Clear on-board monitoring results (MODE 6 and 7).

Mode 6: On-Board Tests

This mode accesses the results of on-board diagnostic monitoring tests of specific components and systems that are not continuously monitored.

Mode 7: On-Board Tests

This mode enables the off-board test drive to obtain test results for emission-related powertrain components and systems that are continuously monitored during normal driving conditions.

Procedure

1. Ensure accelerator pedal is fully released.
2. Turn ignition on and wait at least 2 seconds.
3. Turn ignition off and wait at least 10 seconds.
4. Turn ignition on and wait at least 2 seconds.
5. Turn ignition off and wait at least 10 seconds.

Learning Procedure

Ensure accelerator pedal is fully released. Turn ignition on. Turn ignition off and wait at least 10 seconds. Make sure that throttle valve moves during 10-second period by listening for operating sound.

NISSAN VEHICLE IMMOBILIZER SYSTEM

Nissan Vehicle Immobilizer System (NVIS) must be initialized after Engine Control Module (ECM) has been replaced. See appropriate IMMOBILIZER SYSTEMS article in ACCESSORIES & EQUIPMENT.

With CONSULT-II

1. Preform «ACCELERATOR PEDAL RELEASED POSITION LEARNING»(ref-135505-S15468391922002101400000) .
2. Perform «THROTTLE VALVE CLOSED POSITION LEARNING»(ref-135505-S20463220872002101400000) . Start engine and warm to normal operating temperature.
3. Ensure all conditions under «PRE-CONDITIONING»(ref-135505-S08426373072002101400000) are met. Select IDLE AIR VOL LEARN in WORK SUPPORT mode with CONSULT-II. Press START and wait 20 seconds.
4. Ensure CMPLT is displayed. If INCMP is displayed, go to step 6 .
5. Quickly increase engine speed 2 or 3 times. Ensure idle speed is 650-750 RPM (A/T in Park or Neutral position) or 650-750 RPM (M/T) and ignition timing is 10-20° BTDC with transmission in Park or Neutral.
6. If INCMP is displayed, proceed as follows: Ensure throttle valve is fully closed. Check PCV valve operation. Ensure no vacuum leaks exist. If problem is found, repair as necessary. If problem is not found, It may be helpful to perform TROUBLE DIAGNOSIS - SPECIFICATION VALUE. See «TROUBLE SHOOTING -- NO CODES»(ref-135811) article. If engine stalls or idle speed fluctuates, repair cause of condition and repeat procedure.

Without CONSULT-II

Note. It is better to count the time accurately with a clock.

Note. It is impossible to switch the diagnostic mode when an accelerator pedal position sensor circuit has a malfunction.

1. Preform «ACCELERATOR PEDAL RELEASED POSITION LEARNING»(ref-135505-S15468391922002101400000).
2. Perform «THROTTLE VALVE CLOSED POSITION LEARNING»(ref-135505-S20463220872002101400000). Start engine and warm to normal operating temperature.
3. Ensure all conditions under «PRE-CONDITIONING»(ref-135505-S08426373072002101400000) are met. Turn ignition off and wait at least 10 seconds. Ensure accelerator pedal is fully released.
4. Turn ignition on and wait 3 seconds. Fully depress and fully release accelerator pedal quickly 5 times within 5 seconds. (Scheme 75)
5. Wait 7 seconds, then fully depress accelerator pedal and hold for approximately 20 seconds until MIL stops blinking and turns on.
6. Fully release accelerator pedal within 3 seconds after MIL turns on. Start engine and let it idle. Wait 20 seconds. Quickly depress and release accelerator pedal 2 or 3 times.
7. Ensure idle speed is 650-750 RPM (A/T in Park or Neutral position) or 650-750 RPM (M/T) and ignition timing is 10-20° BTDC with transmission in Park or Neutral. If idle speed and ignition timing are not as specified, result will be incomplete. Go to next step.
8. Proceed as follows: Ensure throttle valve is fully closed. Check PCV valve operation. Ensure no vacuum leaks exist. If problem is found, repair as necessary. If problem is not found, It may be helpful to perform TROUBLE DIAGNOSIS - SPECIFICATION VALUE. See «TROUBLE SHOOTING -- NO CODES»(ref-135811) article. If engine stalls or idle speed fluctuates, repair cause of condition and repeat procedure.

Scheme 75

SUMMARY

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

FUSE BLOCK

Fuse block is located under left side of instrument panel. To identify components on fuse block (Scheme 76)

Scheme 76

INTELLIGENT POWER DISTRIBUTION MODULE

Intelligent Power Distribution Module (IDPM) is located on right side of engine compartment. (Scheme 77)

Scheme 77

Scheme 78

Scheme 79

Scheme 80

ENGINE COMPARTMENT HARNESS CONNECTOR IDENTIFICATION

Scheme 81

ENGINE CONTROL HARNESS CONNECTOR IDENTIFICATION (4-CYL.)

Scheme 82

ENGINE CONTROL HARNESS CONNECTOR IDENTIFICATION (V6)

Scheme 83

MAIN HARNESS CONNECTOR IDENTIFICATION

Possible Causes

Malfunction is detected when there is a gap between angle of target and phase control angle degree. Possible causes are

1. Defective Crankshaft Position (CKP) sensor (POS).
2. Defective Camshaft Position (CMP) sensor (PHASE).
3. Debris accumulated on signal pick-up portion of camshaft.
4. IVT control solenoid valve circuit open or shorted (V6 only).
5. Defective IVT control solenoid valve (V6 only).

Fail-Safe Mode

When this malfunction is detected, ECM enters fail-safe mode. MIL will illuminate, and ECM will not energize IVT control solenoid valve.

Malfunction is detected when

1. A high voltage from MAF sensor is sent to ECM under light load driving condition.
2. A low voltage from MAF sensor is sent to ECM under heavy load driving condition.

Possible causes are

1. MAF sensor circuit open or shorted.
2. Defective MAF sensor.
3. Intake air leaks (malfunction "B" only).

Possible Cause

Malfunction is detected when an excessively low or high voltage from AP sensor is sent to the microcomputer. Possible cause is

1. Faulty ECM.

Malfunction is detected when an excessively low or high voltage from IAT sensor is sent to ECM. Possible causes are

1. IAT sensor circuit open or shorted.
2. Defective IAT sensor.

Malfunction is detected when an excessively low or high voltage from ECT sensor is sent to ECM. Possible causes are

1. ECT sensor circuit open or shorted.
2. Defective ECT sensor.

When this malfunction is detected, ECM enters fail safe mode. MIL illuminates and ECM determines that ECT is fixed at 104°F (40°C) when ignition is first turned on, then increases based on engine run time. After 4 minutes, ECM determines that ECT is fixed at 176°F (80°C). Cooling fan operates while engine is running.

Malfunction is detected when voltage sent to ECM from ECT sensor is not practical, even when some time has passed since starting engine. Or, engine coolant temperature is insufficient for closed loop fuel control. Possible causes are

1. ECT sensor circuit open or shorted.
2. Defective ECT sensor.
3. Defective thermostat.

Malfunction is detected when rationally incorrect voltage from IAT sensor is sent to ECM, compared with voltage from ECT sensor. Possible causes are

1. IAT sensor circuit open or shorted.
2. Defective IAT sensor.

Malfunction is detected when engine coolant temperature has not risen enough to open thermostat even though engine has run long enough. Possible causes are

1. Thermostat stuck open.
2. Leakage from sealing portion of thermostat.
3. Defective ECT sensor.

Malfunction is detected when an excessively high voltage from HO2S1 is sent to ECM. Possible causes are

1. HO2S1 circuit open or shorted.
2. Defective HO2S1.

Malfunction is detected when HO2S1 response time is too long. Possible causes are

1. HO2S1 circuit open or shorted.
2. Defective HO2S1.
3. Defective HO2S1 heater.
4. Fuel pressure incorrect.
5. Defective injectors.
6. Intake air leaks.
7. Exhaust leaks.
8. Defective PCV valve.
9. Defective Mass Airflow (MAF) sensor.

Note. Before proceeding, ensure ambient temperature is more than 14°F (-10°C) and battery voltage is more than 11 volts at idle.

Malfunction is detected when the voltage from HO2S1 is constantly about .3 volt. Possible causes are

1. HO2S1 signal circuit open or shorted.
2. Defective HO2S1.

Note. Before proceeding, ensure battery voltage is more than 11 volts at idle.

Malfunction is detected when an excessively high voltage from HO2S2 is sent to ECM. Possible causes are

1. HO2S2 circuit open or shorted.
2. Defective HO2S2.

Malfunction is detected when HO2S2 response time is too long. Possible causes are

1. HO2S2 circuit open or shorted.
2. Defective HO2S2.
3. Fuel pressure.
4. Injectors.
5. Intake air leaks.

Malfunction is detected when mixture ratio compensation amount is too large (mixture is too lean or too rich). Possible causes are

1. Defective HO2S1.
2. Defective injectors.
3. Exhaust leaks.
4. Fuel pressure incorrect.
5. Defective Mass Airflow (MAF) sensor.
6. Lack of fuel (DTC P0171 or DTC P0174 only).
7. Intake air leaks (DTC P0171 or DTC P0174 only).
8. Incorrect PCV hose connection (DTC P0171 or DTC P0174 only).

DTC P0181 will set when a rationally incorrect voltage from FTT sensor is sent to ECM, compared with voltage signals from engine coolant temperature sensor and intake air temperature sensor. DTC P0182 will set when an excessively low voltage from FTT sensor is sent to ECM. DTC P0183 will set when an excessively high voltage from FTT sensor is sent to ECM. Possible causes are

1. FTT sensor circuit open or shorted.
2. Defective FTT sensor.

Malfunction is detected when engine coolant temperature is excessively high under normal engine speed. Possible causes are

1. Cooling fan circuit open or shorted.
2. Defective cooling fan.
3. Defective thermostat.
4. Improper ignition timing.
5. Defective Engine Coolant Temperature (ECT) sensor.
6. Blocked radiator.
7. Blocked front end.
8. Improper mixture ratio of coolant.
9. Damaged bumper.

Cooling Fan Low Speed Circuit

1. Turn ignition off. Disconnect Intelligent Power Distribution Module (IPDM) connectors E118 and E123. (Scheme 77)and (Scheme 79). Measure voltage between ground and IPDM harness connector E118 terminal No. 16 (Green wire). Also, measure voltage between ground and IPDM harness connector E123 terminal No. 9 (White/Blue wire). If battery voltage exists, go to step 3. If battery voltage does not exist, go to next step.
2. Check the following: Check fusible links "k" and "l" (both 40-amp) located in fuse and fusible link box, next to battery. Check for poor connection at Super Multiple Junction (SMJ) connector E130 terminals 5C (Green wire) and 4C (White/Blue wire). see scheme 18 SMJ connector E130 is located in right rear of engine compartment. (Scheme 80) Check for open or short between IPDM and battery. Repair as necessary.
3. Disconnect cooling fan motor harness connectors. (Scheme 84) Check continuity of the following: Blue/Black wire between cooling fan motor No. 1 harness connector terminal No. 1 and IPDM harness connector E118 terminal No. 7. Red/White wire between cooling fan motor No. 2 harness connector terminal No. 1 and IPDM harness connector E123 terminal No. 13. Black wire between body ground and cooling fan motor No. 1 harness connector terminal No. 4. Black wire between body ground and cooling fan motor No. 2 harness connector terminal No. 4. Also, check circuits for short to ground and short to voltage. If problem is found, repair as necessary. If problem is not found, go to next step.
4. Using jumper wires, apply battery voltage to cooling fan motors as shown in illustration. (Scheme 85) If cooling fan motors operate as specified, go to next step. If cooling fan motors do not operate as specified, replace faulty cooling fan motor.
5. Attempt to duplicate intermittent problem. See «INTERMITTENTS»(ref-135811-S09892990442002022500000) in TROUBLE SHOOTING - NO CODES article. If problem is found, repair as necessary. If problem is not found, replace IPDM.

Scheme 84

Scheme 85

Cooling Fan High Speed Circuit

1. Turn ignition off. Disconnect Intelligent Power Distribution Module (IPDM) connectors E118 and E123. (Scheme 77)and (Scheme 79). Disconnect cooling fan motor harness connectors. (Scheme 84) Check continuity of the following: Red/Yellow wire between cooling fan motor No. 1 harness connector terminal No. 2 and IPDM harness connector E119 terminal No. 5. Red wire between cooling fan motor No. 1 harness connector terminal No. 3 and IPDM harness connector E123 terminal No. 15. Yellow wire between cooling fan motor No. 2 harness connector terminal No. 2 and IPDM harness connector E118 terminal No. 10. Blue wire between cooling fan motor No. 2 harness connector terminal No. 3 and IPDM harness connector E123 terminal No. 12. Black wire between body ground and IPDM harness connector E123 terminal No. 14. Also, check circuits for short to ground and short to voltage. If problem is found, repair as necessary. If problem is not found, go to next step.
2. Using jumper wires, apply battery voltage to cooling fan motors as shown in illustration. (Scheme 85) If cooling fan motors operate as specified, go to next step. If cooling fan motors do not operate as specified, replace faulty cooling fan motor.
3. Attempt to duplicate intermittent problem. See «INTERMITTENTS»(ref-135811-S09892990442002022500000) in TROUBLE SHOOTING - NO CODES article. If problem is found, repair as necessary. If problem is not found, replace IPDM.

DTC P0221 will set when rationally incorrect voltage is sent to ECM from TP sensor No. 1 and TP sensor No. 2. DTC P0222 will set when an excessively low voltage is sent to ECM from TP sensor No. 1. DTC P0223 will set when an excessively high voltage is sent to ECM from TP sensor No. 1. Possible causes are

1. TP sensor No. 1 or 2 circuit open or shorted.
2. Defective electric throttle control actuator.

When malfunction is detected, ECM enters fail-safe mode and MIL illuminates. ECM controls the electric throttle control actuator in regulating the throttle opening in order for the idle position to be within +10 degrees. ECM regulates an opening speed of about 5 seconds to an opening of 10 degrees. Therefore, acceleration will be poor.

DTC P0226 will set when rationally incorrect voltage is sent to ECM from APP sensor No. 1 and APP sensor No. 2. DTC P0227 will set when an excessively low voltage from APP sensor No. 1 is sent to ECM. DTC P0228 will set when an excessively high voltage from APP sensor No. 1 is sent to ECM. Possible causes are

1. APP sensor No. 1 or 2 circuit open or shorted.
2. Defective APP sensor.

When malfunction is detected, ECM enters fail-safe mode and MIL illuminates. ECM controls the electric throttle control actuator in regulating the throttle opening in order for the idle position to be within +10 degrees. ECM regulates an opening speed of about 5 seconds to an opening of 10 degrees. Therefore, acceleration will be poor.

Malfunction is detected when one cylinder misfires or multiple cylinders misfire. Possible causes are

1. Improper spark plug.
2. Insufficient compression.
3. Incorrect fuel pressure.
4. Injector circuit is open or shorted.
5. Defective fuel injectors.
6. Intake air leak.
7. Ignition secondary circuit is open or shorted.
8. Lack of fuel.
9. Defective drive plate or flywheel.
10. Defective front HO2S.

Malfunction is detected when ECM receives an excessively low or high voltage from knock sensor. Possible causes are

1. Knock sensor circuit open or shorted.
2. Defective knock sensor.

Malfunction is detected when

1. CKP sensor signal is not detected by ECM during first few seconds of engine cranking.
2. Proper pulse signal from CKP sensor is not sent to ECM while engine is running.
3. CKP sensor signal is not normal during engine running.

Possible causes are

1. CKP sensor circuit open or shorted.
2. Defective CKP sensor.
3. Defective signal plate.

Malfunction is detected when

1. Cylinder No. signal is not sent to ECM for the first few seconds during engine cranking.
2. Cylinder No. signal is not sent to ECM during engine running.
3. Cylinder No. signal is not in the normal pattern during engine running.

Possible causes are

1. CMP sensor (PHASE) circuit is open or shorted.
2. Defective CMP sensor (PHASE).
3. Defective intake camshaft.
4. Defective starter motor.
5. Faulty starting system circuit.
6. Dead (weak) battery.

Malfunction is detected when switching frequency of HO2S2 increases to a specified value, indicating that 3-way catalyst is not operating properly. Possible causes are

1. Defective 3-way catalyst (exhaust manifold).
2. Exhaust leak.
3. Intake air leaks.
4. Defective injectors.
5. Defective spark plugs.
6. Incorrect ignition timing.

Malfunction is detected when EVAP control system does not operate properly, or there is a leak between intake manifold and EVAP-CSPS. Possible causes are

1. EVAP-CPVCSV stuck closed.
2. Faulty EVAP-CSPS or circuit.
3. Loose, disconnected or improper connection of hoses.
4. Blockage in hoses.
5. Cracked EVAP canister.
6. Faulty EVAP-CPVCSV circuit.
7. Defective Accelerator Pedal Position (APP) sensor.
8. Blocked purge port.
9. Defective EVAP Canister Vent Control Valve (EVAP-CVCV).

Malfunction is detected when EVAP control system has a leak or does not operate properly. Possible causes are

1. Fuel filler cap remains open or fails to close.
2. Incorrect fuel tank vacuum relief valve.
3. Incorrect fuel filler cap.
4. Foreign matter in fuel filler cap.
5. Leak in hose between intake manifold and EVAP-CPVCSV.
6. Foreign matter in EVAP-CVCV.
7. Leak in EVAP canister or fuel tank.
8. Leak or blockage in EVAP purge line.
9. Leak or blockage in hose to EVAP Control System Pressure Sensor (EVAP-CSPS).
10. Defective EVAP-CVCV or circuit.
11. Defective EVAP-CPVCSV or circuit.
12. Defective absolute pressure sensor (3.5L).
13. Defective fuel tank temperature sensor.
14. Missing or damaged EVAP-CVCV "O" ring.
15. Defective EVAP-CSPS.
16. Defective fuel level sensor or circuit.
17. EVAP canister saturated with water.
18. Defective water separator.
19. Defective refueling control valve.
20. Leak in On-Board Refueling Vapor Recovery (ORVR) system.

Malfunction is detected when an excessively low or high voltage is sent to ECM through EVAP-CPVCSV. Possible causes are

1. EVAP-CPVCSV circuit open or shorted.
2. Defective EVAP-CPVCSV.

Malfunction is detected when improper voltage is sent to ECM through EVAP-CVCV. Possible causes are

1. EVAP-CVCV circuit open or shorted.
2. Defective EVAP-CVCV.

Malfunction is detected when an excessively low voltage is sent to ECM from EVAP-CSPS. Possible causes are

1. EVAP-CSPS circuit open or shorted.
2. Defective EVAP-CSPS.

Note. Before proceeding, ensure ambient temperature is more than 41°F (5°C).

Malfunction is detected when an excessively high voltage is sent to ECM from EVAP-CSPS. Possible causes are

1. EVAP-CSPS circuit open or shorted.
2. Defective EVAP-CSPS.
3. Defective EVAP Canister Vent Control Valve (EVAP-CVCV).
4. Defective EVAP canister
5. Defective water separator.
6. Defective hose between EVAP-CVCV and water separator.

Note. Before proceeding, ensure ambient temperature is more than 41°F (5°C).

Malfunction is detected when EVAP control system has a very large leak, or EVAP control system does not operate properly. Possible Causes are

1. Fuel filler cap remains open or fails to close.
2. Incorrect fuel tank vacuum relief valve.
3. Incorrect fuel filler cap.
4. Foreign matter caught in fuel filler cap.
5. Leak in line between intake manifold and EVAP-CPVCSV.
6. Foreign matter caught in EVAP Canister Vent Control Valve (EVAP-CVCV).
7. EVAP canister or fuel tank leaks.
8. Leak or blockage in EVAP purge line.
9. Blockage in EVAP Control System Pressure Sensor (EVAP-CSPS) hose.
10. Defective EVAP-CVCV or circuit.
11. Defective EVAP-CPVCSV or circuit.
12. Defective Fuel Tank Temperature (FTT) sensor.
13. EVAP-CVCV "O" ring missing or damaged.
14. Defective EVAP-CSPS.
15. Defective refueling control valve.
16. Leak in On-Board Refueling Vapor Recovery (ORVR) system.

Malfunction is detected when EVAP control system has a very small leak or does not operate properly. Possible causes are

1. Incorrect fuel tank vacuum relief valve.
2. Incorrect fuel filler cap.
3. Fuel filler cap remains open or fails to close.
4. Foreign matter in fuel filler cap.
5. Leak in hose between intake manifold and EVAP Canister Purge Volume Control Solenoid Valve (EVAP-CPVCSV).
6. Foreign matter in EVAP Canister Vent Control Valve (EVAP-CVCV).
7. Leak in EVAP canister or fuel tank.
8. Leak or blockage in EVAP purge line.
9. Leak or blockage in hose to EVAP Control System Pressure Sensor (EVAP-CSPS).
10. Defective EVAP-CVCV or circuit.
11. Defective EVAP-CPVCSV or circuit.
12. Defective absolute pressure sensor (on 3.5L).
13. Defective fuel tank temperature sensor.
14. Missing or damaged EVAP-CVCV "O" ring.
15. Defective EVAP-CSPS.
16. Defective fuel level sensor or circuit.
17. EVAP canister saturated with water.
18. Defective water separator.
19. Defective refueling control valve.
20. Leak in On-Board Refueling Vapor Recovery (ORVR) system.

Malfunction is detected when ECM receives a varied signal from fuel level sensor while vehicle is parked. Possible causes are

1. Fuel level sensor circuit open or shorted.
2. Defective fuel level sensor.

Malfunction is detected when the output signal of the fuel level sensor does not change within the specified range even though the vehicle has been driven a long distance. Possible causes are

1. Fuel level sensor circuit open or shorted.
2. Defective fuel level sensor.

Malfunction is detected when ECM receives an excessively low or high voltage from fuel level sensor. Possible causes are

1. Fuel level sensor circuit open or shorted.
2. Defective fuel level sensor.

Malfunction is detected when zero MPH signal is sent to ECM even when vehicle is being driven. Possible causes are

1. CAN communication line open or shorted.
2. VSS signal circuit open or shorted.
3. Defective VSS.
4. Defective instrument cluster.

DTC P0506 will set when idle speed is less than target idle speed by 100 RPM or more. DTC P0507 will set when idle speed is more than target idle speed by 200 RPM or more. Possible causes are

1. Defective electric throttle control actuator.
2. Intake air leak.
3. Faulty PCV system (DTC P0507 only).

Note. If target idle speed is not 625-725 RPM (A/T) or 575-675 RPM (M/T), perform idle air volume learning before proceeding. See PROGRAMMING .

Note. Before proceeding, ensure battery voltage is more than 11 volts at idle and ambient temperature is more than 14°F (-10°C).

Malfunction is detected when an excessively low or high voltage from PSP sensor is sent to ECM. Possible causes are

1. PSP sensor circuit open or shorted.
2. Defective PSP sensor.

Malfunction is detected when

1. ECM calculation function is malfunctioning.
2. ECM EEPROM system is malfunctioning.
3. ECM self shut-off system is malfunctioning.

Only possible cause is a faulty ECM.

When malfunction "A" is detected, ECM will enter fail-safe mode. ECM stops electric throttle control actuation, and throttle valve is fixed at about 5 degrees.

Malfunction is detected when

1. An excessively high voltage is sent to ECM through the MIL circuit under the condition that calls for MIL to light up.
2. An excessively low voltage is sent to ECM through the MIL circuit under the condition that calls for MIL not to light up.

Possible causes are

1. MIL circuit open or shorted.
2. Defective instrument cluster (MIL LED).

ECM enters fail-safe mode when both DTC P0650 and another DTC, which calls for MIL to light up, are detected at the same time. When in fail-safe mode, engine speed will not rise more than 2500 RPM due to fuel cut.

Malfunction is detected when ECM back-up RAM system does not function properly. Possible causes are

1. ECM power supply (back-up) circuit is open or shorted.
2. Defective ECM.

Malfunction is detected when voltage from MAF sensor is constantly about one volt when engine is running. Possible causes are

1. MAF sensor circuit open or shorted.
2. Defective MAF sensor.

When this malfunction is detected, ECM enters fail-safe mode. MIL will illuminate, and engine speed will not rise more than 2400 RPM due to fuel cut.

Malfunction is detected when an improper voltage is sent to the ECM through IVTC solenoid valve. Possible causes are

1. IVTC solenoid valve circuit open or shorted.
2. Defective IVTC solenoid valve.

Malfunction is detected when

1. Electric throttle control actuator does not function properly due to the return spring malfunction.
2. Throttle valve opening angle in fail-safe mode is not in specified range.
3. ECM detects the throttle valve is stuck open.

ECM enters fail-safe mode when malfunction is detected.

When malfunction "A" is detected, ECM controls electric throttle actuator by regulating throttle opening around idle position. The engine speed will not rise more than 2000 RPM.

When malfunction "B" is detected, ECM controls electric throttle control actuator by regulating throttle opening to 20 degrees or less.

When malfunction "C" is detected, the following occurs: while vehicle is driving, it slows down gradually by fuel cut. After vehicle stops, engine stalls. The engine can restart Park or Neutral, and engine speed will not exceed 1000 RPM.

Note. Perform the following DTC confirmation tests in order. If a DTC confirmation test has been previously performed, turn ignition off and wait at least 10 seconds before performing next DTC confirmation test.

Malfunction is detected when electric throttle control function does not operate properly. Possible causes are

1. Throttle control motor circuit open or shorted.
2. Defective electric throttle control actuator.

When malfunction is detected, ECM enters fail-safe mode. ECM stops electric throttle control actuator control, and throttle valve is maintained at a fixed opening (about 5 degrees) by the return spring.

DTC P1124 will set when ECM detects throttle control motor relay is stuck on. Possible causes are

1. Throttle control motor relay circuit is shorted.
2. Defective throttle control motor relay.

DTC P1126 will set when ECM detects power supply voltage for throttle control motor is excessively low. Possible causes are

1. Throttle control motor relay circuit is open.
2. Defective throttle control motor relay.

When malfunction is detected, ECM enters fail-safe mode. ECM stops electric throttle control actuator control, and throttle valve is maintained at a fixed opening (about 5 degrees) by the return spring.

Malfunction is detected when ECM detects a short in both circuits between throttle control motor and ECM. Possible causes are

1. Throttle control motor circuit shorted.
2. Defective electric throttle control actuator (throttle control motor).

Malfunction is detected when the maximum and minimum voltage from the sensor are not reached to the specified voltages. Possible causes are

1. Defective HO2S1.
2. Defective HO2S1 heater.
3. Fuel pressure incorrect.
4. Defective injectors.
5. Intake air leaks.

Note. Before proceeding, ensure ambient temperature is more than 14°F (-10°C) and battery voltage is more than 11 volts at idle.

Malfunction is detected when the maximum and minimum voltage from the sensor are beyond the specified voltages. Possible causes are

1. Defective HO2S1.
2. Defective HO2S1 heater.
3. Fuel pressure incorrect.
4. Defective injectors.

Note. Before proceeding, ensure ambient temperature is more than 14°F (-10°C) and battery voltage is more than 11 volts at idle.

Malfunction is detected when the minimum voltage from the sensor is not low enough. Possible causes are

1. HO2S2 circuit open or shorted.
2. Defective HO2S2.
3. Fuel pressure incorrect.
4. Defective injectors.

Malfunction is detected when the minimum voltage from the sensor is not low enough. Possible causes are

1. HO2S2 circuit open or shorted.
2. Defective HO2S2.
3. Fuel pressure incorrect.
4. Defective injectors.
5. Intake air leaks.

Malfunction is detected when fuel injection system on either bank does not operate in closed loop. Possible causes are

1. HO2S1 circuit open or shorted.
2. Defective HO2S1.
3. Defective front HO2S1 heater.

Note. Before proceeding, ensure battery voltage is more than 11 volts at idle. DO NOT raise engine speed above 3600 RPM during DTC confirmation test.

Note. Freeze frame data is not stored in ECM for this self-diagnosis. MIL will not light up for this self-diagnosis.

Malfunction is detected when ECM receives malfunction information from ABS actuator and electric unit. Possible causes are

1. Defective ABS actuator and electric unit.
2. Defective ABS or ABS/TCS related parts.

Note. Freeze frame data is not stored in ECM for this self-diagnosis. MIL will not light up for this self-diagnosis.

Malfunction is detected when ECM can not receive the information from ABS/TCS control unit continuously. Possible causes are

1. CAN communication line open or shorted.
2. Defective ABS actuator and electric unit.
3. Dead (weak) battery.

Malfunction is detected when engine coolant reaches an abnormally high temperature. Possible causes are

1. Cooling fan circuit open or shorted.
2. Defective cooling fan.
3. Defective radiator hose.
4. Defective radiator.
5. Defective radiator cap.
6. Defective water pump.
7. Defective thermostat.

1. Turn ignition off. Disconnect Intelligent Power Distribution Module (IPDM) connectors E118 and E123. (Scheme 77)and (Scheme 79). Measure voltage between ground and IPDM harness connector E118 terminal No. 16 (Green wire). Also, measure voltage between ground and IPDM harness connector E123 terminal No. 9 (White/Blue wire). If battery voltage exists, go to step 3. If battery voltage does not exist, go to next step.
2. Check the following: Check fusible links "k" and "l" (both 40-amp) located in fuse and fusible link box, next to battery. Check for poor connection at Super Multiple Junction (SMJ) connector E130 terminals 5C (Green wire) and 4C (White/Blue wire). see scheme 18 SMJ connector E130 is located in right rear of engine compartment. (Scheme 80) Check for open or short between IPDM and battery. Repair as necessary.
3. Disconnect cooling fan motor harness connectors. (Scheme 84) Check continuity of the following: Blue/Black wire between cooling fan motor No. 1 harness connector terminal No. 1 and IPDM harness connector E118 terminal No. 7. Red/White wire between cooling fan motor No. 2 harness connector terminal No. 1 and IPDM harness connector E123 terminal No. 13. Black wire between body ground and cooling fan motor No. 1 harness connector terminal No. 4. Black wire between body ground and cooling fan motor No. 2 harness connector terminal No. 4. Also, check circuits for short to ground and short to voltage. If problem is found, repair as necessary. If problem is not found, go to next step.
4. Using jumper wires, apply battery voltage to cooling fan motors as shown in illustration. (Scheme 85) If cooling fan motors operate as specified, go to next step. If cooling fan motors do not operate as specified, replace faulty cooling fan motor.
5. Attempt to duplicate intermittent problem. See «INTERMITTENTS»(ref-135811-S09892990442002022500000) in TROUBLE SHOOTING - NO CODES article. If problem is found, repair as necessary. If problem is not found, replace IPDM.

1. Turn ignition off. Disconnect Intelligent Power Distribution Module (IPDM) connectors E118 and E123. (Scheme 77)and (Scheme 79). Disconnect cooling fan motor harness connectors. (Scheme 84) Check continuity of the following: Red/Yellow wire between cooling fan motor No. 1 harness connector terminal No. 2 and IPDM harness connector E119 terminal No. 5. Red wire between cooling fan motor No. 1 harness connector terminal No. 3 and IPDM harness connector E123 terminal No. 15. Yellow wire between cooling fan motor No. 2 harness connector terminal No. 2 and IPDM harness connector E118 terminal No. 10. Blue wire between cooling fan motor No. 2 harness connector terminal No. 3 and IPDM harness connector E123 terminal No. 12. Black wire between body ground and IPDM harness connector E123 terminal No. 14. Also, check circuits for short to ground and short to voltage. If problem is found, repair as necessary. If problem is not found, go to next step.
2. Using jumper wires, apply battery voltage to cooling fan motors as shown in illustration. (Scheme 85) If cooling fan motors operate as specified, go to next step. If cooling fan motors do not operate as specified, replace faulty cooling fan motor.
3. Attempt to duplicate intermittent problem. See «INTERMITTENTS»(ref-135811-S09892990442002022500000) in TROUBLE SHOOTING - NO CODES article. If problem is found, repair as necessary. If problem is not found, replace IPDM.

Malfunction is detected when an excessively low or high voltage from TP sensor No. 2 is sent to ECM. Possible causes are

1. TP sensor No. 2 circuit open or shorted.
2. Defective TP sensor No. 2 (electric throttle control actuator).

When malfunction is detected, ECM enters fail-safe mode and MIL illuminates. ECM controls electric throttle control actuator in regulating throttle opening in order for idle position to be within plus 10 degrees. Also, ECM regulates an opening speed of about 5 seconds for 10 degrees. Therefore, acceleration will be poor.

Malfunction is detected when closed throttle position learning value is excessively low. Possible cause is

1. Defective TP sensor No. 1 and 2 (electric throttle control actuator).

Malfunction is detected when closed throttle position learning is not performed successfully, repeatedly. Possible cause is

1. Defective TP sensor No. 1 and 2 (electric throttle control actuator).

Malfunction is detected when an excessively low or high voltage from APP sensor No. 2 is sent to ECM. Possible causes are

1. APP sensor No. 2 circuit open or shorted.
2. Defective APP sensor.

When malfunction is detected, ECM enters fail-safe mode and MIL illuminates. ECM controls the electric throttle control actuator in regulating the throttle opening in order for the idle position to be within +10 degrees. ECM regulates an opening speed of about 5 seconds to an opening of 10 degrees. Therefore, acceleration will be poor.

Malfunction is detected when ECM detects an excessively low or high sensor power supply voltage. Possible causes are

1. TP sensor No. 1 and 2 circuit shorted.
2. Accelerator Pedal Position (APP) sensor circuit shorted.
3. Mass Airflow (MAF) sensor circuit shorted.
4. EVAP Control System Pressure Sensor (EVAP-CSPS) circuit shorted.
5. Power Steering Pressure (PSP) sensor circuit shorted.
6. Refrigerant pressure sensor circuit shorted.
7. Defective electric throttle control actuator.
8. Defective APP sensor.
9. Defective MAF sensor.
10. Defective EVAP-CSPS.
11. Defective PSP sensor.
12. Defective refrigerant pressure sensor.
13. Defective ECM pin terminals.

When malfunction is detected, ECM enters fail-safe mode and MIL illuminates. ECM stops electric throttle control actuator control and throttle valve is maintained at a fixed opening (about 5 degrees) by the return spring.

Malfunction is detected when EVAP control system has a leak or does not operate properly. Possible causes are

1. Incorrect fuel tank vacuum relief valve.
2. Incorrect fuel filler cap.
3. Fuel filler cap open or leaking.
4. Foreign matter in fuel filler cap.
5. Leak in hose between intake manifold and EVAP-CPVCSV.
6. Foreign matter in EVAP-CVCV.
7. Leak in EVAP canister or fuel tank.
8. Leak or blockage in EVAP purge line.
9. Leak or blockage in hose to EVAP-CSPS.
10. Defective EVAP-CVCV or circuit.
11. Defective EVAP-CPVCSV or circuit.
12. Defective Fuel Tank Temperature (FTT) sensor or circuit.
13. EVAP-CVCV "O" ring missing or damaged.
14. Defective water separator.
15. EVAP canister saturated with water.
16. Defective EVAP-CSPS.
17. Defective fuel level sensor or circuit.
18. Defective refueling control valve.
19. Leak in On Board Refueling Vapor Recovery (ORVR) system.
20. Foreign matter caught in EVAP-CPVCSV.

Malfunction is detected when canister purge flow is detected when EVAP-CPVCSV is closed. Possible causes are

1. Defective EVAP Control System Pressure Sensor (EVAP-CSPS).
2. EVAP-CPVCSV stuck open.
3. Defective EVAP Canister Vent Control Valve (EVAP-CVCV).
4. Defective EVAP canister.
5. EVAP system hoses misrouted or plugged.

Note. Before proceeding, ensure ambient temperature is more than 41°F (5°C).

Malfunction is detected when EVAP-CVCV remains closed under certain driving conditions. Possible causes are

1. Defective EVAP-CVCV.
2. Faulty EVAP Control System Pressure Sensor (EVAP-CSPS) or circuit.
3. Blockage in hose to EVAP-CVCV.
4. Defective water separator.
5. EVAP canister saturated with water.

Malfunction is detected when EVAP-CVCV remains open under certain driving conditions. Possible causes are

1. Defective EVAP-CVCV.
2. Faulty EVAP Control System Pressure Sensor (EVAP-CSPS) or circuit.
3. Blockage in EVAP-CVCV hose.
4. Defective water separator.
5. EVAP canister saturated with water.
6. Defective vacuum cut valve.

Malfunction is detected when EVAP control system has a very small leak or does not operate properly. Possible causes are

1. Incorrect fuel tank vacuum relief valve.
2. Incorrect fuel filler cap.
3. Fuel filler cap open or leaking.
4. Foreign matter in fuel filler cap.
5. Leak in hose between intake manifold and EVAP-CPVCSV.
6. Foreign matter in EVAP-CVCV.
7. Leak in EVAP canister or fuel tank.
8. Leak or blockage in EVAP purge line.
9. Leak or blockage in hose to EVAP-CSPS.
10. Defective EVAP-CVCV or circuit.
11. Defective EVAP-CPVCSV or circuit.
12. Defective Fuel Tank Temperature (FTT) sensor or circuit.
13. EVAP-CVCV "O" ring missing or damaged.
14. Defective water separator.
15. EVAP canister saturated with water.
16. Defective EVAP-CSPS.
17. Defective fuel level sensor or circuit.
18. Defective refueling control valve.
19. Leak in On Board Refueling Vapor Recovery (ORVR) system.
20. Foreign matter caught in EVAP-CPVCSV.

Malfunction is detected when ECM receives a high voltage from fuel level sensor. Possible cause is

1. Fuel level sensor circuit open or shorted.

Malfunction is detected when ECM receives an improper voltage signal from vacuum cut valve by-pass valve. Possible causes are

1. Vacuum cut valve by-pass valve circuit open or shorted.
2. Defective vacuum cut valve by-pass valve.

Malfunction is detected when vacuum cut valve by-pass valve does not operate properly. Possible causes are

1. Defective vacuum cut valve by-pass valve.
2. Defective vacuum cut valve.
3. Blockage in by-pass hoses.
4. Fault in EVAP Control System Pressure Sensor (EVAP-CSPS) or circuit.
5. Defective EVAP Canister Vent Control Valve (EVAP-CVCV).
6. Blockage in hose between fuel tank and vacuum cut valve.
7. Blockage in hose between EVAP canister and vacuum cut valve.
8. Defective EVAP canister.
9. Blockage in fuel tank purge port.

Malfunction is detected when

1. An excessively high voltage signal from ASCD steering switch is sent to ECM.
2. ECM detects that input signal from ASCD steering switch is out of specified range.
3. ECM detects that ASCD steering switch is stuck on.

Possible causes are

1. ASCD steering switch circuit open or shorted.
2. Defective ASCD steering switch.
3. Defective ECM.

Malfunction is detected when an ON signal from stop lamp switch and ASCD brake switch are sent to ECM at the same time when vehicle speed is more than 19 MPH. Possible causes are

1. Stop lamp switch circuit open or shorted.
2. ASCD brake switch circuit open or shorted.
3. ASCD clutch switch circuit open or shorted.
4. Defective ASCD brake switch.
5. Defective ASCD clutch switch.
6. Defective stop lamp switch.
7. Incorrect stop lamp switch installation.
8. Incorrect ASCD brake switch installation.
9. Incorrect ASCD clutch switch installation.
10. Defective ECM.

Malfunction is detected when ECM detects a difference in values between the 2 vehicle speed signals. Possible causes are

1. CAN communication line open or shorted.
2. Instrument cluster circuit open or shorted.
3. Defective instrument cluster.
4. Defective vehicle speed sensor.
5. Defective TCM.
6. Defective ECM.

Malfunction is detected when PNP switch signal does not change between starting and driving. Possible causes are

1. PNP switch circuit open or shorted.
2. Defective PNP switch.

Malfunction is detected when an excessively low or high voltage signal is sent to ECM through VIAS control solenoid valve. Possible causes are

1. VIAS control solenoid valve circuit open or shorted.
2. Defective VIAS control solenoid valve.

Malfunction is detected when a brake switch signal is not sent to ECM for an extremely long time while the vehicle is driving. Possible causes are

1. Stop lamp switch circuit open or shorted.
2. Defective stop lamp switch.

Malfunction is detected when ECM can not communicate to other control unit, or ECM can not communicate for more than the specified time. Possible cause is

1. CAN communication line is open or shorted.