Engine Controls - Self-Diagnostics - 3.3: Diagnosis Nissan Quest II

DIAGNOSTIC TESTS

Note. To identify circuits and wire colors referenced in testing, see appropriate wiring diagram in WIRING DIAGRAMS article.

DTC Confirmation Test "A"

Malfunction is detected when MAF sensor voltage is too high when engine is not running.

Turn ignition on. Select DATA MONITOR mode on scan tool. Wait at least 6 seconds. If first trip DTC is detected, go to TEST PROCEDURE . If first trip DTC is not detected, go to DTC CONFIRMATION TEST "B" .

DTC Confirmation Test "B"

Malfunction is detected when MAF sensor voltage is excessively low while engine is running. ECM will enter fail-safe mode, DTC will set and MIL will illuminate.

Turn ignition on. Select DATA MONITOR mode on scan tool. Start engine and at least 5 seconds. If first trip DTC is detected, go to TEST PROCEDURE . If first trip DTC is not detected, go to DTC CONFIRMATION TEST "C" .

DTC Confirmation Test "C"

Malfunction is detected when MAF sensor voltage is high under light-load driving conditions.

Turn ignition on. Select DATA MONITOR mode on scan tool. Start engine and warm to normal operating temperature. Run engine at least 10 seconds at idle speed. If first trip DTC is detected, go to TEST PROCEDURE . If first trip DTC is not detected, go to DTC CONFIRMATION TEST "D" (OVERALL FUNCTION CHECK) .

DTC Confirmation Test "D" (Overall Function Check)

Malfunction is detected when MAF sensor voltage is low under heavy-load driving conditions.

Start engine and warm to normal operating temperature. Select DATA MONITOR mode on scan tool and observe MAF sensor output. Increase engine speed. MAF sensor output should linearly increase as engine speed is increased to 4000 RPM. If MAF sensor output increases as specified, fault is intermittent. See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article. MAF sensor output does not increase as specified, go to TEST PROCEDURE .

Test Procedure

1. If malfunction "A" or "C" was duplicated, go to next step. If malfunction "B" or "D" was duplicated, inspect air intake duct and vacuum hoses for improper connection or leaks. If problem exists, reconnect or repair duct or hose(s) as necessary. If problem does not exist, go to next step.
2. Turn ignition off. Loosen and retighten engine ground bolts. (Scheme 43) Disconnect MAF sensor harness connector located near air cleaner housing. Turn ignition on. Measure voltage between ground and MAF sensor harness connector Black/White wire. If battery voltage exists, go to next step. If battery voltage does not exist, repair open or short circuit. See appropriate wiring diagram in WIRING DIAGRAMS article.
3. Turn ignition off. Disconnect Engine Control Module (ECM) harness connector. see scheme 1 Check continuity of Blue/Orange wire between MAF sensor harness connector and ECM harness connector terminal No. 55. see scheme 2 If continuity exists, go to next step. If continuity does not exist, repair open in Blue/Orange wire.
4. Check for short to ground and short to power in Blue/Orange wire between MAF sensor harness connector and ECM harness connector terminal No. 55. If problem exists, repair Blue/Orange wire as necessary. If problem does not exist, go to next step.
5. Check continuity of White/Blue wire between MAF sensor harness connector and ECM harness connector terminal No. 54. If continuity exists, go to next step. If continuity does not exist, repair open in White/Blue wire.
6. Check for short to ground and short to power in White/Blue wire between MAF sensor harness connector and ECM harness connector terminal No. 54. If problem exists, repair White/Blue wire as necessary. If problem does not exist, go to next step.
7. Reconnect all connectors. Start engine and warm to normal operating temperature. Measure voltage between ground and ECM harness connector terminal No. 54 by backprobing. see scheme 2 See «MASS AIRFLOW SENSOR VOLTAGE»(ref-3202-S08035393612000041900000) table. If voltage is not as specified, go to next step. If voltage is as specified, no problem is indicated at this time. Problem may be intermittent. See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article.
8. Disconnect and reconnect MAF sensor harness connector. Repeat step 7. If voltage is still not as specified, check for dust or foreign material in hot wire air passage of MAF sensor. If air passage is okay, replace mass airflow sensor and retest system.

MASS AIRFLOW SENSOR VOLTAGE

Scheme 43

Malfunction "A" is detected when AP sensor voltage is too high or too low.

Turn ignition on. Select DATA MONITOR mode on scan tool. Wait at least 6 seconds. If first trip DTC is detected, go to TEST PROCEDURE "A" . If first trip DTC is not detected, go to DTC CONFIRMATION TEST "B" .

Malfunction "B" is detected when AP sensor voltage is too high under light-load driving conditions.

Start engine and warm to normal operating temperature. Turn ignition off and wait at least 5 seconds. Turn ignition on. Select DATA MONITOR mode on scan tool. Start engine and let idle. Wait at least 15 seconds. If first trip DTC is detected, go to TEST PROCEDURE "B" . If first trip DTC is not detected, go to DTC CONFIRMATION TEST "C" (OVERALL FUNCTION CHECK) .

DTC Confirmation Test "C" (Overall Function Check)

Malfunction "C" is detected when AP sensor voltage is too low under heavy-load driving conditions.

Turn ignition on. Select DATA MONITOR mode on scan tool and check MAP value. MAP reading should be more than 46 kPa. If MAP value is as specified, fault is intermittent. See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article. MAP value is not as specified, go to TEST PROCEDURE "A" .

Test Procedure "A"

1. Turn ignition off. Loosen and retighten engine ground bolts. (Scheme 43) Disconnect AP sensor harness connector. (Scheme 44) Check AP sensor harness connector for water. If water is present, repair harness connector as necessary. If water is not present, go to next step.
2. Turn ignition on. Measure voltage between ground and AP sensor harness connector Brown wire. If voltage is about 5 volts, go to next step. If voltage is not about 5 volts, repair open or short to ground in Brown wire between AP sensor and ECM or TP sensor. See appropriate wiring diagram in WIRING DIAGRAMS article.
3. Turn ignition off. Check continuity between ground and AP sensor harness connector Blue wire. If continuity exists, go to next step. If continuity does not exist, repair open in Blue wire.
4. Check for short to ground and short to power in Blue wire between AP sensor and ECM, Throttle Position (TP) sensor or Transmission Control Module (TCM). If short exists, repair Blue wire as necessary. If short does not exist, go to next step.
5. Disconnect ECM harness connector. see scheme 1 Check continuity of Pink wire between AP sensor harness connector and ECM harness connector terminal No. 45. see scheme 2 If continuity exists, go to next step. If continuity does not exist, repair open in Pink wire.
6. Check for short to ground and short to power in Pink wire between AP sensor and ECM harness connector terminal No. 45. If short exists, repair Pink wire as necessary. If short does not exist, go to next step.
7. Remove AP sensor from its bracket and disconnect vacuum hose. Reconnect all harness connectors. Turn ignition on. Measure voltage between ground and ECM harness connector terminal No. 45 by backprobing. Voltage should be 3.2-4.8 volts. Using a hand vacuum pump, apply 7.87 in. Hg of vacuum to AP sensor. Voltage should decrease to 1.0-1.4 volts less than voltage measured with no vacuum applied. (Scheme 45) If voltage is not as specified, replace AP sensor. If voltage is as specified, go to next step.
8. Disconnect 42-pin super multiple junction connector F-12 from firewall. Check continuity between ground and engine control harness connector terminal No. 8A. (Scheme 46) If continuity does not exist, repair open ground circuit. If continuity exists, no problem is indicated at this time. Problem may be intermittent. See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article.

Scheme 44

Scheme 45

Scheme 46

Test Procedure "B"

1. Warm engine to normal operating temperature. Turn ignition off. Connect a vacuum gauge, using a vacuum "T", to AP sensor hose. While monitoring vacuum gauge, start engine and let it idle. Vacuum should not exist for 5 seconds. Manifold vacuum should exist after 5 seconds. If vacuum is as specified, go to step 5. If vacuum is not as specified, go to next step.
2. Turn ignition off. Check vacuum hose to AP sensor for clogging, cracks, disconnection or improper connection. If problem exists, repair as necessary. If problem does not exist, go to next step.
3. Check vacuum port in intake manifold for clogging. If clogging exists, repair as necessary. If clogging does not exist, check MAP/BARO switch solenoid valve. See «DTC P1105: MANIFOLD ABSOLUTE PRESSURE (MAP)/BAROMETRIC PRESSURE (BARO) SWITCH SOLENOID VALVE»(ref-3202-S27968742112000041900000). If problem exists, replace MAP/BARO switch solenoid valve. If problem does not exist, go to next step.
4. Check intake system for air leaks. If air leak exists, repair as necessary. If air leak does not exist, no problem is indicated at this time. Problem may be intermittent. See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article.
5. Turn ignition off. Check AP sensor hose for clogging, cracks, disconnection or improper connection. If problem exists, repair as necessary. If problem does not exist, go to next step.
6. Disconnect AP sensor harness connector. (Scheme 44) Check AP sensor harness connector for water. If water is present, repair harness connector as necessary. If water is not present, go to next step.
7. Remove AP sensor from its bracket, and disconnect vacuum hose. Reconnect AP sensor harness connector. Turn ignition on. Measure voltage between ground and ECM harness connector terminal No. 45 by backprobing. Voltage should be 3.2-4.8 volts. Using a hand vacuum pump, apply 7.87 in. Hg of vacuum to AP sensor. Voltage should decrease to 1.0-1.4 volts less than voltage measured with no vacuum applied. (Scheme 45) If voltage is not as specified, replace AP sensor. If voltage is as specified, no problem is indicated at this time. Problem may be intermittent. See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article.

Malfunction "A" is detected when IAT sensor voltage is too high or too low.

Turn ignition on. Select DATA MONITOR mode on scan tool. Wait at least 5 seconds. If first trip DTC is detected, go to TEST PROCEDURE . If first trip DTC is not detected, go to DTC CONFIRMATION TEST "B" .

Malfunction "B" is detected when IAT voltage is incorrect compared to Engine Coolant Temperature (ECT) sensor voltage.

Turn ignition on. Select DATA MONITOR mode on scan tool. Check engine coolant temperature. If engine coolant temperature is not less than 194°F (90°C), turn ignition off and cool down engine. When engine coolant temperature is less than 194°F (90°C), turn ignition on. Select DATA MONITOR mode on scan tool. Drive vehicle at more than 43 MPH for 100 seconds. If first trip DTC is detected, go to TEST PROCEDURE . If first trip DTC is not detected, fault is intermittent. See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article.

1. Turn ignition off. Disconnect IAT sensor harness connector. (Scheme 47) Turn ignition on. Measure voltage between IAT sensor harness connector Yellow/Green wire and ground. If voltage is about 5 volts, go to next step. If voltage is not about 5 volts, repair open or short in Yellow/Green wire between ECM and IAT sensor.
2. Turn ignition off. Check continuity between IAT sensor harness connector Black/Yellow wire and ground. If continuity exists, go to next step. If continuity does not exist, repair open in Black/Yellow wire.
3. Check for short to power and short to ground in Black/Yellow wire between IAT sensor and Engine Control Module (ECM) harness connector terminal No. 43 or Transmission Control Module (TCM) harness connector terminal No. 42. If problem exists, repair Black/Yellow wire as necessary. If problem does not exist, go to next step.
4. Remove IAT sensor. Immerse sensor end in water. Measure resistance between IAT sensor terminals as water is heated. Compare to expected values. (Scheme 48) Resistance should decrease as temperature increases. If resistance is not as specified, replace IAT sensor. If resistance is as specified, no problem is indicated at this time. Problem may be intermittent. See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article.

Scheme 47

Scheme 48

DTC Confirmation Test (DTC P0115)

Malfunction is detected when ECT voltage is too high or too low. Engine Control Module (ECM) may enter fail-safe mode.

Turn ignition on. Select DATA MONITOR mode on scan tool. Wait at least 5 seconds. If first trip DTC is detected, go to TEST PROCEDURE . If first trip DTC is not detected, fault is intermittent. See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article.

DTC Confirmation Test (DTC P0125)

Malfunction is detected when ECT voltage is not within expected parameters for engine condition, or if engine coolant temperature is too low to allow closed loop fuel control.

Turn ignition on. Select DATA MONITOR mode on scan tool. Check scan tool value for coolant temperature sensor. If coolant temperature sensor value is more than 50°F (10°C), check for first trip DTC. If first trip DTC is detected, go to TEST PROCEDURE . If coolant temperature sensor value is 50°F (10°C) or less, start and run engine for up to 65 minutes at idle speed. If coolant temperature sensor value increases to more than 50°F (10°C), turn ignition off. Wait 5 seconds. Turn ignition on. Wait at least 5 seconds. If first trip DTC is detected, go to TEST PROCEDURE . If first trip DTC is not detected, fault is intermittent. See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article.

1. Turn ignition off. Disconnect ECT sensor harness connector. (Scheme 49) Turn ignition on. Measure voltage between ground and ECT sensor harness connector Light Green/Red wire. If voltage is about 5 volts, go to next step. If voltage is not about 5 volts, repair open in Light Green/red wire.
2. Turn ignition off. Check continuity between ground and ECT sensor harness connector Black/Yellow wire. If continuity exists, go to next step. If continuity does not exist, repair open in Black/Yellow wire.
3. Check for short to power and short to ground in Black/Yellow wire between ECT sensor and ECM harness connector terminal No. 43 or Transmission Control Module (TCM) harness connector terminal No. 42. If problem exists, repair Black/Yellow wire as necessary. If problem does not exist, go to next step.
4. Remove ECT sensor. Immerse sensor end in water. Measure resistance between ECT sensor terminals as water is heated. Compare resistance with expected value. (Scheme 48) Resistance should decrease as temperature increases. If resistance is not as specified, replace ECT sensor. If resistance is as specified, install ECT sensor, then go to next step.
5. If DTC P0115 is present, go to next step. If DTC P0125 is present, allow engine to cool until coolant temperature is less than 158°F (70°C). Start engine. Grasp lower radiator hose. If coolant is flowing through lower radiator hose, check for stuck open thermostat. If coolant is not flowing through lower radiator hose, go to next step.
6. No problem is indicated at this time. Problem may be intermittent. See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article.

Scheme 49

Malfunction "A" is detected when TP sensor voltage is too high or too low. Engine Control Module (ECM) will enter fail-safe mode.

Turn ignition on. Select DATA MONITOR mode on scan tool. Drive vehicle 2 MPH or more for at least 5 seconds. If first trip DTC is detected, go to TEST PROCEDURE . If first trip DTC is not detected, go to DTC CONFIRMATION TEST "B" .

Malfunction "B" is detected when TP sensor voltage is high under light-load driving conditions.

Turn ignition on. Select DATA MONITOR mode on scan tool. Start engine and let idle for at least 10 seconds. Ensure idle speed is less than 1000 RPM. If first trip DTC is detected, go to TEST PROCEDURE . If first trip DTC is not detected, go to DTC CONFIRMATION TEST "C" .

Malfunction "C" is detected when TP sensor voltage is low under heavy-load driving conditions.

Start engine and warm to normal operating temperature. Turn ignition off and wait at least 5 seconds. Start and drive vehicle uphill for at least 10 consecutive seconds. Using scan tool, ensure following conditions are met during drive

1. Engine speed is more than 2000 RPM.
2. Mass Airflow (MAF) sensor output is more than 3 volts.
3. Coolant temperature sensor output is more than 158°F (70°C).
4. Idle Air Control Valve-Auxilliary Air Control (IACV-AAC) valve is less than 80 percent.

If first trip DTC is detected, go to

TEST PROCEDURE

. If first trip DTC is not detected, fault is intermittent. See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article.

1. If malfunction "A" or "B" was duplicated, go to next step. If malfunction "C" was duplicated, adjust TP sensor. See ON-VEHICLE ADJUSTMENTS article. Check air intake duct and vacuum hoses for leaks or improper connection. If problem exists, repair as necessary. If problem does not exist, go to next step.
2. Turn ignition off. Loosen and retighten 2 engine ground bolts. (Scheme 43) Disconnect TP sensor harness connector. (Scheme 50) Turn ignition on. Measure voltage between ground and TP sensor harness connector Brown wire. If voltage is about 5 volts, go to next step. If voltage is not about 5 volts, repair open or short between TP sensor and ECM or Absolute Pressure (AP) sensor.
3. Turn ignition off. Check continuity of Black/Yellow wire between ground and TP sensor harness connector. If continuity exists, go to next step. If continuity does not exist, repair open in Black/Yellow wire.
4. Check for short to power and short to ground in Black/Yellow wire between TP sensor and ECM harness connector terminal No. 43 or Transmission Control Module (TCM) harness connector terminal No. 42. If problem exists, repair Black/Yellow wire as necessary. If problem does not exist, go to next step.
5. Disconnect ECM harness connector. see scheme 1 Check continuity of Red wire between TP sensor harness connector and ECM harness connector terminal No. 23. see scheme 2 If continuity exists, go to next step. If continuity does not exist, repair open in Red wire.
6. Check for short to power and short to ground in Red wire between TP sensor and ECM harness connector terminal No. 23. If problem exists, repair Red wire as necessary. If problem does not exist, go to next step.
7. Reconnect all harness connectors. Start engine and warm to normal operating temperature. Stop engine and turn ignition on. With throttle in specified position, measure voltage between ground and ECM harness connector terminal No. 23. See «THROTTLE POSITION SENSOR VOLTAGE»(ref-3202-S40851491772000041900000) table. (Scheme 50) If voltage is as specified, go to next step. If voltage is not as specified, replace TP sensor.
8. Check MAF sensor. See «DTC P0100: MASS AIRFLOW (MAF) SENSOR»(ref-3202-S10437396702000041900000). If problem exists, replace MAF sensor. If problem does not exist, check CMP sensor. See «DTC P0340: CAMSHAFT POSITION (CMP) SENSOR»(ref-3202-S18561369382000041900000). If problem exists, replace CMP sensor. If problem does not exist, go to next step.
9. Check fuel injectors. See FUEL CONTROL under FUEL SYSTEM in SYSTEM & COMPONENT TESTING article. If problem exists, repair or replace fuel injector(s) as necessary. If problem does not exist, go to next step.
10. Disconnect 42-pin engine control harness connector F-12 from firewall. Check continuity between ground and engine control harness connector F-12 terminal No. 8A. (Scheme 46) If continuity does not exist, repair open ground circuit. If continuity exists, no problem is indicated at this time. Problem may be intermittent. See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article.

THROTTLE POSITION SENSOR VOLTAGE

Scheme 50

DTC Confirmation Test (Overall Function Check)

Malfunction is detected when HO2S voltage is constantly .2-.4 volt.

Start engine and warm to normal operating temperature. Ensure battery voltage is more than 11 volts at idle. Measure voltage between ground and Engine Control Module (ECM) harness connector terminal No. 50 by backprobing. see scheme 2 Increase engine speed to 2000 RPM under no load conditions. If at constant 2000 RPM, voltage stays in.2-.4 volt range, go to TEST PROCEDURE. If at constant 2000 RPM voltage does not stay in.2-.4 volt range, problem may be intermittent. See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article.

1. Turn ignition off. Loosen and retighten engine ground bolts. (Scheme 43) Disconnect front HO2S harness connector and ECM harness connector. see scheme 1 Check continuity of Light Green wire between front HO2S harness connector and ECM harness connector terminal No. 50. see scheme 2 If continuity exists, go to next step. If continuity does not exist, repair open in Light Green wire.
2. Check for short to ground and short to power in Light Green wire between front HO2S and ECM harness connector terminal No. 50. If problem exists, repair Light Green wire as necessary. If problem does not exist, reconnect all harness connectors and go to next step.
3. Start engine and warm to normal operating temperature. Measure voltage between ground and ECM harness connector terminal No. 50 by backprobing. Increase engine speed and hold at 2000 RPM. HO2S should switch rich-lean-rich 5 or more times in 10 seconds, and the following conditions should exist: Maximum voltage is more than.6 volt at least one time. Minimum voltage is less than.3 volt at least one time. Voltage never is more than 1.0 volt. If HO2S voltage is as specified, go to next step. If HO2S voltage is not as specified, replace front HO2S.
4. On vehicles equipped with California emissions, go to step 6. On vehicles not equipped with California emissions, disconnect Gray, 12-pin connector F-3 located on right side of engine compartment. Check continuity between ground and connector F-3 terminal No. 5. (Scheme 51) If continuity exists, go to next step. If continuity does not exist, repair open ground circuit.
5. Check for voltage between ground and connector F-3 terminal No. 5. If voltage exists, repair short to power on shield circuit. If voltage does not exist, go to step 8.
6. On vehicles equipped with California emissions, disconnect 42-pin multiple junction connector F-12 located on right side of engine compartment. Check continuity between ground and connector F-12 terminal No. 5A. (Scheme 46) If continuity exists, go to next step. If continuity does not exist, repair open ground circuit.
7. Check for voltage between ground and connector F-12 terminal No. 5A. If voltage exists, repair short to power on shield circuit. If voltage does not exist, go to next step.
8. No problem is indicated at this time. Problem may be intermittent. See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article.

Scheme 51

DTC P0131 indicates front HO2S output has shifted lean. DTC P0132 indicates front HO2S output has shifted rich.

Start engine and warm to normal operating temperature. Measure voltage between ground and Engine Control Module (ECM) harness connector terminal No. 50 by backprobing. see scheme 2 Increase engine speed and hold at 2000 RPM. Monitor HO2S voltage output. For DTC P0131, maximum voltage should be more than.6 volt at least one time and minimum voltage should be more than.1 volt at least one time. For DTC P0132, maximum voltage should be less than.8 volt at least one time and minimum voltage should be less than.35 volt at least one time. If voltages are not as specified, go to TEST PROCEDURE. If voltages are as specified, problem may be intermittent. See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article.

1. Turn ignition off. Loosen and retighten engine ground bolts. (Scheme 43) Loosen front HO2S and retighten to 30-37 ft. lbs. (40-50 N.m). Start engine and warm to normal operating temperature. Turn ignition off. Disconnect Mass Airflow (MAF) sensor harness connector located near air cleaner housing. Start engine and let idle for at least 5 seconds. Turn ignition off and reconnect MAF sensor harness connector. Go to next step.
2. Ensure first trip DTC P0100 is displayed. Clear DTCs. Ensure DTC P0100 is displayed. Start engine and let idle for at least 10 minutes. Recheck for DTCs. If first trip DTC P0171 or P0172 is present and engine is hard to start, perform diagnosis for DTC P0171 or P0172. See «DTC P0171 OR P0172: FUEL INJECTION SYSTEM FUNCTION»(ref-3202-S09678426772000041900000). If DTC P0171 or P0172 is not present and engine is not hard to start, go to next step.
3. Turn ignition off. Disconnect front HO2S harness connector. Measure resistance between front HO2S outer terminals. Resistance should be 2.3-4.3 ohms at 77°F (25°C). Check continuity between both outer front HO2S terminals and center terminal. Continuity should not exist. If resistance and continuity are as specified, go to next step. If resistance or continuity is not as specified, replace front HO2S.
4. Reconnect all harness connectors. Start engine and warm to normal operating temperature. Measure voltage between ground and ECM harness connector terminal No. 50 by backprobing. Increase engine speed and hold at 2000 RPM. Front HO2S should switch rich-lean-rich 5 or more times in 10 seconds, and the following conditions should exist: Maximum voltage is more than.6 volt at least one time. Minimum voltage is less than.3 volt at least one time. Voltage never is more than 1.0 volt. If HO2S voltage is as specified, go to next step. If HO2S voltage is not as specified, replace front HO2S.
5. On vehicles equipped with California emissions, go to next step. On vehicles not equipped with California emissions, disconnect Gray, 12-pin connector F-3 located on right side of engine compartment. Check continuity between ground and connector F-3 terminal No. 5. (Scheme 51) If continuity exists, next step. If continuity does not exist, repair open ground circuit.
6. Check for voltage between ground and connector F-3 terminal No. 5. If voltage exists, repair short to power on shield circuit. If voltage does not exist, go to step 8.
7. On vehicles equipped with California emissions, disconnect 42-pin multiple junction connector F-12 located on right side of engine compartment. Check continuity between ground and connector F-12 terminal No. 5A. (Scheme 46) If continuity exists, go to next step. If continuity does not exist, repair open ground circuit.
8. Check for voltage between ground and connector F-12 terminal No. 5A. If voltage exists, repair short to power on shield circuit. If voltage does not exist, go to next step.
9. No problem is indicated at this time. Problem may be intermittent. See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article.

Malfunction is detected when HO2S response time is too long.

Start engine and warm to normal operating temperature. Measure voltage between ground and Engine Control Module (ECM) harness connector terminal No. 50 by backprobing. see scheme 2 Increase engine speed and hold at 2000 RPM under no load. Front HO2S output voltage should switch from more than.55 volt to less than.35 volt to more than.55 volt (rich-lean-rich) more than 5 times in 10 seconds. If voltage does not switch as specified, go to TEST PROCEDURE. If voltage switches as specified, problem may be intermittent. See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article.

1. Turn ignition off. Loosen and retighten engine ground bolts. (Scheme 43) Loosen front HO2S and retighten to 30-37 ft. lbs. (40-50 N.m). Start engine and let idle. Check for exhaust leak in front of 3-way catalytic converter. Also, check for air intake leak downstream of Mass Airflow (MAF) sensor. If problem exists, repair as necessary. If problem does not exist, go to next step.
2. Start engine and warm to normal operating temperature. Turn ignition off. Disconnect MAF sensor harness connector located near air cleaner housing. Start engine and let idle for at least 5 seconds. Turn ignition off and reconnect MAF sensor harness connector. Go to next step.
3. Ensure DTC P0100 is displayed. Clear DTCs. Ensure DTC P0100 is displayed. Start engine and let idle for at least 10 minutes. If first trip DTC P0171 or P0172 is present and engine is hard to start, perform diagnosis for DTC P0171 or P0172. See «DTC P0171 OR P0172: FUEL INJECTION SYSTEM FUNCTION»(ref-3202-S09678426772000041900000). If first trip DTC P0171 or P0172 is not present and engine is not hard to start, go to next step.
4. Turn ignition off. Disconnect front HO2S and ECM harness connectors. see scheme 1 Check continuity of Light Green wire between front HO2S harness connector and ECM harness connector terminal No. 50. see scheme 2 If continuity exists, go to next step. If continuity does not exist, repair open in Light Green wire.
5. Check for short to ground and short to power in Light Green wire between ground and front HO2S harness connector. If problem exists, repair Light Green wire as necessary. If problem does not exist, go to next step.
6. Measure resistance between front HO2S outer terminals. Resistance should be 2.3-4.3 ohms at 77°F (25°C). Check continuity between both outer HO2S terminals and center terminal. Continuity should not exist. If resistance and continuity are as specified, go to next step. If resistance or continuity is not as specified, replace HO2S.
7. Check MAF sensor. See «DTC P0100: MASS AIRFLOW (MAF) SENSOR»(ref-3202-S10437396702000041900000). If problem exists, replace MAF sensor. If problem does not exist, check PCV valve. See POSITIVE CRANKCASE VENTILATION (PCV) under EMISSION SYSTEMS & SUB-SYSTEMS in SYSTEM & COMPONENT TESTING article. If problem exists, replace PCV valve. If problem does not exist, go to next step.
8. Reconnect all harness connectors. Start engine and warm to normal operating temperature. Measure voltage between ground and ECM harness connector terminal No. 50 by backprobing. Increase engine speed and hold at 2000 RPM. HO2S should switch rich-lean-rich 5 or more times in 10 seconds, and the following conditions should exist: Maximum voltage is more than.6 volt at least one time. Minimum voltage is less than.3 volt at least one time. Voltage never is more than 1.0 volt. If HO2S voltage is as specified, go to next step. If HO2S voltage is not as specified, replace front HO2S.
9. On vehicles equipped with California emissions, go to next step. On vehicles not equipped with California emissions, disconnect Gray, 12-pin connector F-3 located on right side of engine compartment. Check continuity between ground and connector F-3 terminal No. 5. (Scheme 51) If continuity exists, next step. If continuity does not exist, repair open ground circuit.
10. Check for voltage between ground and connector F-3 terminal No. 5. If voltage exists, repair short to power on shield circuit. If voltage does not exist, go to step 8.
11. On vehicles equipped with California emissions, disconnect 42-pin multiple junction connector F-12 located on right side of engine compartment. Check continuity between ground and connector F-12 terminal No. 5A. (Scheme 46) If continuity exists, go to next step. If continuity does not exist, repair open ground circuit.
12. Check for voltage between ground and connector F-12 terminal No. 5A. If voltage exists, repair short to power on shield circuit. If voltage does not exist, go to next step.
13. No problem is indicated at this time. Problem may be intermittent. See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article.

DTC Confirmation Test

Malfunction is detected when HO2S voltage is too high.

Start engine and warm to normal operating temperature. Turn ignition off and wait at least 5 seconds. Restart engine and let idle for 20 seconds. Turn ignition off and wait at least 5 seconds. Restart engine and let idle for 20 seconds. Select DTC mode on scan tool. If DTC is detected, go to TEST PROCEDURE . If DTC is not present, problem may be intermittent. See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article.

1. Disconnect front HO2S and Engine Control Module (ECM) harness connectors. see scheme 1 Loosen front HO2S and retighten to 30-37 ft. lbs. (40-50 N.m). Check continuity of Light Green wire between front HO2S harness connector and ECM harness connector terminal No. 50. see scheme 2 If continuity exists, go to next step. If continuity does not exist, repair open in Light Green wire.
2. Check for short to ground and short to power in Light Green wire between ground and front HO2S harness connector. If problem exists, repair Light Green wire as necessary. If problem does not exist, go to next step.
3. Inspect front HO2S harness connector for water. If water is present, repair or replace connector. If water is not present, reconnect front HO2S harness connector. Start engine and warm to normal operating temperature. Measure voltage between ground and ECM harness connector terminal No. 50 by backprobing. see scheme 2 Increase engine speed and hold at 2000 RPM. Front HO2S should switch rich-lean-rich 5 or more times in 10 seconds, and the following conditions should exist: Maximum voltage is more than.6 volt at least one time. Minimum voltage is less than.3 volt at least one time. Voltage never is more than 1.0 volt. If front HO2S voltage is as specified, go to next step. If front HO2S voltage is not as specified, replace front HO2S.
4. No problem is indicated at this time. Problem may be intermittent. See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article.

Malfunction is detected when front HO2S heater circuit current is out of normal range.

Turn ignition on. Select DATA MONITOR mode on scan tool. Start engine and let idle at least 6 seconds. If first trip DTC is detected, go to TEST PROCEDURE . If first trip DTC is not detected, problem may be intermittent. See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article.

1. Turn ignition off. Disconnect front HO2S harness connector. Turn ignition on. Measure voltage between ground and front HO2S harness connector Blue/Yellow wire. If battery voltage exists, go to next step. If battery voltage does not exist, repair open or short circuit in Blue/Yellow wire. See appropriate wiring diagram in WIRING DIAGRAMS article.
2. Turn ignition off. Disconnect Engine Control Module (ECM) harness connector. see scheme 1 Check continuity of Black wire between front HO2S harness connector and ECM harness connector terminal No. 119. see scheme 2 If continuity exists, go to next step. If continuity does not exist, repair open in Black wire.
3. Check for short to ground and short to power in Black wire between front HO2S harness connector and ECM harness connector terminal No. 119. If problem exists, repair Black wire as necessary. If problem does not exist, go to next step.
4. Turn ignition off. Measure resistance between front HO2S outer terminals. Resistance should be 2.3-4.3 ohms at 77°F (25°C). Check continuity between both outer HO2S terminals and center terminal. Continuity should not exist. If front HO2S does not test as specified, replace front HO2S. If front HO2S tests as specified, no problem is indicated at this time. Problem may be intermittent. See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article.

DTC P0137 will set if rear HO2S minimum voltage is too high. DTC P0138 will set if rear HO2S maximum voltage is too low. DTC P0139 will set if rear HO2S response time is too long. DTC P0140 will set if rear HO2S voltage is too high.

Drive vehicle at a speed of more than 43 MPH for 2 consecutive minutes. Stop vehicle and leave engine running. Measure voltage between ground and ECM harness connector terminal No. 56 by backprobing. see scheme 2 While monitoring voltmeter, quickly increase engine speed to 4000 RPM under no load conditions and release accelerator pedal. Repeat 10 times.

1. Voltage should be less than .47 volt (vehicles with California emissions) or .48 volt (vehicles without California emissions) at least once.
2. Voltage should be more than .52 volt (vehicles with California emissions) or .67 volt (vehicles without California emissions) at least once.
3. Voltage should change at least .06 volt in one second.
4. Voltage should be less than 2 volts during test.

If voltages are not as specified, allow engine to idle for 10 minutes and recheck voltage or allow vehicle to coast at 50 MPH with overdrive off and recheck voltage. If voltages still are not as specified, go to

TEST PROCEDURE

. If voltages are as specified, problem may be intermittent. See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article.

1. Turn ignition off. Loosen and retighten 2 engine ground bolts. (Scheme 43) If diagnosing for DTC P0140, go to step 3. If diagnosing for DTC P0137, P0138 or P0139, start engine and warm to normal operating temperature. Turn ignition off. Disconnect Mass Airflow (MAF) sensor harness connector located near air cleaner housing. Start engine and let idle for at least 5 seconds. Turn ignition off and reconnect MAF sensor harness connector. Go to next step.
2. Ensure first trip DTC P0100 is displayed. Clear DTCs. Ensure DTC P0100 is displayed. Start engine and let idle for at least 10 minutes. Recheck for DTCs. If DTC P0171 or P0172 is present and engine is hard to start, perform diagnosis for those DTCs first. See «DTC P0171 OR P0172: FUEL INJECTION SYSTEM FUNCTION»(ref-3202-S09678426772000041900000). If DTC P0171 or P0172 is not present and engine is not hard to start, go to next step.
3. Turn ignition off. Disconnect rear HO2S connector. Inspect rear HO2S connector for water. If problem exists, repair or replace connector. If problem does not exist, go to next step.
4. Disconnect Engine Control Module (ECM) harness connector. see scheme 1 Check continuity of White wire between rear HO2S harness connector and ECM harness connector terminal No. 56. see scheme 2 If continuity exists, go to next step. If continuity does not exist, repair open in White wire.
5. Check continuity between ground and rear HO2S harness connector White wire. If continuity exists, repair short to ground. If continuity does not exist, check for short to ground or short to power in White wire between rear HO2S and ECM harness connector terminal No. 56. If problem exists, repair short as necessary. If problem does not exist, go to next step.
6. Check continuity between ground and rear HO2S harness connector Black wire. If continuity does not exist, repair open ground circuit. If continuity exists, check for short to power in Black wire between rear HO2S and ground. If problem exists, repair short as necessary. If problem does not exist, go to next step.
7. Reconnect all harness connectors. Drive vehicle at a speed of more than 43 MPH for 2 consecutive minutes. Stop vehicle and leave engine running. Measure voltage between ground and ECM harness connector terminal No. 56 by backprobing. While observing voltage, quickly increase engine speed to 4000 RPM and quickly decelerate at least 10 times. If voltage increases to more than.56 volt at least one time, go to step 9. If voltage does not increase to more than.56 volt, go to next step.
8. Idle engine for 10 minutes and recheck voltage or coast from 50 MPH with overdrive turned off and recheck voltage. If voltage still does not decrease to less than.54 volt at least one time, replace rear HO2S and retest system. If voltage drops less than.54 volt at least once, go to next step.
9. On vehicles equipped with California emissions, go to next step. On vehicles not equipped with California emissions, disconnect connector M-62 (White, 16-pin connector, located behind right kick panel). Check continuity between ground and connector M-62 terminal No. 14. (Scheme 52) If continuity exists, go to step 13. If continuity does not exist, repair open ground circuit.
10. Check for voltage between ground and connector M-62 terminal No. 14. If voltage exists, repair short to power in ground circuit. If voltage does note exist, go to step 13.
11. On vehicles not equipped with California emissions, disconnect Gray, 12-pin connector F-3 located on right side of engine compartment. Check continuity between ground and connector F-3 terminal No. 5. (Scheme 51) If continuity exists, go to next step. If continuity does not exist, repair open ground circuit.
12. Check for voltage between ground and connector F-3 terminal No. 5. If voltage exists, repair short to power in ground circuit. If voltage does not exist, go to next step.
13. No problem is indicated at this time. Problem may be intermittent. See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article.

Scheme 52

Malfunction is detected when rear HO2S heater circuit current is out of normal range.

Turn ignition on. Select DATA MONITOR mode on scan tool. Drive vehicle at a speed of more than 43 MPH for 2 consecutive minutes. Stop vehicle and let engine idle for at least 6 seconds. If first trip DTC is displayed, go to TEST PROCEDURE . If first trip DTC is not detected, problem may be intermittent. See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article.

1. Turn ignition off. Disconnect rear HO2S harness connector. Turn ignition on. Measure voltage between ground and rear HO2S harness connector Blue/Yellow wire. If battery voltage exists, go to next step. If battery voltage does not exist, repair open or short circuit. See appropriate wiring diagram in WIRING DIAGRAMS article.
2. Turn ignition off. Disconnect Engine Control Module (ECM) harness connector. see scheme 1 Check continuity of Yellow wire between rear HO2S harness connector and ECM harness connector terminal No. 122. see scheme 2 If continuity exists, go to next step. If continuity does not exist, repair open in Yellow wire.
3. Check for short to ground and short to power in Yellow wire between front HO2S harness connector and ECM harness connector terminal No. 122. If problem exists, repair Yellow wire as necessary. If problem does not exist, go to next step.
4. Leave rear HO2S wiring harness disconnected. Measure resistance between rear HO2S connector Blue/Yellow wire and Yellow wire (component side). Resistance should be 2.3-4.3 ohms at 77°F (25°C). Continuity should not exist between any other rear HO2S terminals. If resistance and continuity are as specified, go to next step. If resistance and continuity are not as specified, replace rear HO2S.
5. No problem is indicated at this time. Problem may be intermittent. See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article.

Malfunction is detected when air/fuel ratio compensation amount is too large. DTC P0171 will set when mixture is too lean. DTC P0172 will set when mixture is too rich.

1. Start engine and warm to normal operating temperature. Turn ignition off and wait at least 5 seconds. Disconnect Mass Airflow (MAF) sensor harness connector located near air cleaner housing. Start engine and let idle for at least 5 seconds. Go to next step.
2. Turn ignition off and reconnect MAF sensor harness connector. Turn ignition on. Select DATA MONITOR on scan tool. Ensure first trip DTC P0100 is displayed. Clear DTCs. Ensure DTC P0100 is displayed. Go to next step.
3. Start engine and let idle for at least 10 minutes. If first trip DTC P0171 or P0172 is detected, go to «TEST PROCEDURE»(ref-3202-S19938415292000041900000) . If engine was difficult to start, go to next step. If first trip DTC P0171 or P0172 is not detected and engine starts okay, problem may be intermittent. See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article.
4. Attempt to start engine while depressing accelerator pedal. If engine starts, go to «TEST PROCEDURE»(ref-3202-S19938415292000041900000) . If engine does not start, check for intake or exhaust leaks or spark plug fouling.

1. Start engine and let idle. Check for leaks in exhaust system before 3-way catalytic converter. Check for leaks in intake system after MAF sensor. If problem exists, repair or replace faulty components as necessary. If problem does not exist, go to next step.
2. Turn ignition off. Disconnect front HO2S harness connector and Engine Control Module (ECM) harness connector. see scheme 1 Check continuity of Light Green wire between front HO2S harness connector and ECM harness connector terminal No. 50. see scheme 2 If continuity does not exist, repair open in Light Green wire. If continuity exists, go to next step.
3. Check for short to ground and short to power in Light Green wire between front HO2S harness connector and ECM harness connector terminal No. 50. If problem exists, repair short as necessary. If problem does not exist, go to next step.
4. Check fuel pressure. See CHECKING FUEL PRESSURE under FUEL SYSTEM in BASIC DIAGNOSTIC PROCEDURES article. At idle, fuel pressure should be 34 psi (2.4 kg/cm 2 ) with regulator vacuum hose connected and 43 psi (3.0 kg/cm 2 ) with regulator vacuum hose disconnected. If fuel pressure is not as specified, check fuel pump, fuel pressure regulator and fuel lines. Repair fuel system as necessary. If fuel pressure is as specified, check MAF sensor. See «DTC P0100: MASS AIRFLOW (MAF) SENSOR»(ref-3202-S10437396702000041900000). If problem exists, replace MAF sensor. If problem does not exist, go to next step.
5. With engine idling, listen to each fuel injector for clicking noise. If any fuel injector does not click, repair circuit or replace fuel injector. If all fuel injectors click, turn ignition off and allow engine to cool. Ensure no fire hazards exist and remove fuel injector assembly with fuel lines and harness connectors connected. Place a suitable cup under each fuel injector to collect fuel. Disconnect ignition coil harness connector. Turn ignition on. Verify fuel is not dripping from fuel injectors. Crank engine for 3 seconds and ensure each fuel injector sprays fuel. If problem exists, clean or replace appropriate fuel injector(s). If problem does not exist, reinstall fuel injectors with NEW "O" rings and go to next step.
6. No problem is indicated at this time. Problem may be intermittent. See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article.

Malfunction is detected when FTT sensor voltage is too high or low, or when FTT voltage is rationally incorrect compared to ECT sensor and IAT sensor.

1. Turn ignition on. Select DATA MONITOR mode on scan tool. Wait at least 10 seconds. If first trip DTC is displayed, go to «TEST PROCEDURE»(ref-3202-S22784058012000041900000) . If first trip DTC is not displayed, go to next step.
2. Check coolant temperature sensor value. If coolant temperature sensor value is less than 140°F (60°C), problem may be intermittent. See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article. If coolant temperature sensor value is 140°F (60°C) or more, turn ignition off and allow engine to cool down until coolant temperature sensor value is less than 140°F (60°C). Go to next step.
3. Turn ignition on. Wait at least 10 seconds. If first trip DTC is displayed, go to «TEST PROCEDURE»(ref-3202-S22784058012000041900000) . If first trip DTC is not displayed, problem may be intermittent. See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article.

1. Turn ignition off. Disconnect FTT sensor harness connector, located behind fuel tank. Turn ignition on. Measure voltage between ground and FTT sensor harness connector Red/Yellow wire. If voltage is about 5 volts, go to next step. If voltage is not about 5 volts, repair open or short in Red/Yellow wire.
2. Turn ignition off. Check continuity between ground and FTT harness connector terminal Black/Yellow wire. If continuity exists, go to next step. If continuity does not exist, repair open in Black/Yellow wire.
3. Check for short to ground and short to power in Black/Yellow wire between FTT harness connector and ECM harness connector terminal No. 60. If problem exists, repair Black/Yellow wire as necessary. If problem does not exist, go to next step.
4. Remove FTT sensor. Measure resistance between FTT sensor terminals while heating FTT sensor end in hot water or with heat gun. Resistance should be 2300-2700 ohms at 68°F (20°C), and 790-900 ohms at 122°F (50°C). Resistance should decrease as temperature increases. (Scheme 48) If resistance is not as specified, replace FTT sensor. If resistance is as specified, go to next step.
5. No problem is indicated at this time. Problem may be intermittent. See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article.

Misfire is detected when Crankshaft Position (CKP) sensor detects a fluctuation in engine speed. DTC P0300 indicates multiple cylinder misfire. The last digit of DTCs P0301-P0306 indicate at which cylinder misfire occurred.

Start engine and warm to normal operating temperature. Turn ignition off and wait at least 5 seconds. Start engine. Select DATA MONITOR mode on scan tool. Drive vehicle at 1500-3000 RPM for at least 3 minutes. Refer to freeze frame data for driving conditions in which DTC was set. Hold accelerator pedal as steady as possible. If first trip DTC is displayed, go to TEST PROCEDURE . If first trip DTC is not detected, problem may be intermittent. See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article.

1. Start engine and let idle. Check for intake system leaks. Stop engine and visually inspect exhaust system, 3-way catalytic converter and muffler for damage. If problem exists, repair as necessary. If problem does not exist, check EGR operation. See DTC CONFIRMATION TEST under «DTC P1402: EGR FUNCTION»(ref-3202-S11406782502000041900000). If problem exists, repair as necessary. If problem does not exist, go to next step.
2. Start engine and allow to idle. Individually, disconnect and reconnect fuel injector harness connectors. If engine speed momentarily drops after each fuel injector is disconnected, go to step 4. If engine speed drops as each fuel injector is disconnected, go to next step. If engine speed does not drop for any fuel injector, reconnect connector and listen to fuel injector while engine is running. Fuel injector should be rapidly clicking at engine idle speed. If no sound is detected, check fuel injector for proper operation and check fuel injector harness for open or short. See FUEL CONTROL under FUEL SYSTEM in SYSTEM & COMPONENT TESTING article. Repair as necessary.
3. Disconnect ignition wire from spark plug. Connect a known-good spark plug. Place end of spark plug against a suitable ground and crank engine. If spark is detected, go to next step. If no spark is detected, check ignition wires for defects. Check ignition coil, power transistor and related circuits. See «DTC P1320: IGNITION SIGNAL»(ref-3202-S27381140612000041900000). Repair as necessary.
4. Remove spark plugs. Inspect spark plugs for proper gap, fouling or damage. Replace spark plugs as necessary. Check cylinder compression. See MECHANICAL INSPECTION in BASIC DIAGNOSTIC PROCEDURES article. If compression is not within specification, check pistons, rings, valves and head gasket. If compression is within specification, go to next step.
5. Install all parts that were removed. Check fuel pressure. See CHECKING FUEL PRESSURE under FUEL SYSTEM in BASIC DIAGNOSTIC PROCEDURES article. At idle, fuel pressure should be 34 psi (24 kg/cm 2 ) with regulator vacuum hose connected and 43 psi (3.0 kg/cm 2 ) with regulator vacuum hose disconnected. If fuel pressure is as specified, go to next step. If fuel pressure is not as specified, check fuel pump circuit, fuel pressure regulator, fuel lines and fuel filter. Repair as necessary.
6. Check ignition timing. See IGNITION TIMING in ON-VEHICLE ADJUSTMENTS article. If timing is not as specified, adjust ignition timing. If timing is as specified, go to next step.
7. Adjust closed throttle position switch. See THROTTLE POSITION (TP) SENSOR in ON-VEHICLE ADJUSTMENTS article. If closed throttle position switch is adjustable, adjust closed throttle position switch and go to next step. If closed throttle position switch can not be properly adjusted, replace TP sensor.
8. Disconnect front HO2S harness connector. Inspect front HO2S harness connector for water. If water is present, repair or replace connector as necessary. If water is not present, reconnect front HO2S harness connector and go to next step.
9. Start engine and warm to normal operating temperature. Measure voltage between ground and ECM harness connector terminal No. 50 by backprobing. see scheme 2 Increase engine speed and hold at 2000 RPM. Front HO2S should switch rich-lean-rich 5 or more times in 10 seconds, and the following conditions should exist: Maximum voltage is more than.6 volt at least one time. Minimum voltage is less than.3 volt at least one time. Voltage never is more than 1.0 volt. If front HO2S voltage is as specified, go to next step. If front HO2S voltage is not as specified, replace front HO2S.
10. Check MAF sensor. See «DTC P0100: MASS AIRFLOW (MAF) SENSOR»(ref-3202-S10437396702000041900000). If problem exists, repair as necessary. If problem does not exist, go to next step.
11. Diagnose by symptom. See TROUBLE SHOOTING - NO CODES article. Repair as necessary. Some tests may cause a DTC to set. Clear DTCs. Problem may be intermittent. See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article.

Malfunction is detected when knock sensor voltage is too high or too low.

Turn ignition on. Select DATA MONITOR mode on scan tool. Start engine and let idle. Wait at least 5 seconds. If first trip DTC is detected, go to TEST PROCEDURE . If first trip DTC is not detected, problem may be intermittent. See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article.

1. Turn ignition off. Disconnect Engine Control Module (ECM) harness connector. see scheme 1 Measure resistance between ground and ECM harness connector terminal No. 64. see scheme 2 Resistance should be about 500-620 k/ohms at 77°F (25°C). If resistance is as specified, go to step 4. If resistance is not as specified, go to next step.
2. Disconnect knock sensor harness connector, located near fuel injector No. 5 harness connector. Check for open or short in White wire between knock sensor harness connector and ECM harness connector terminal No. 64. If problem exists, repair White wire. If problem does not exist, go to next step.
3. Measure resistance between ground and knock sensor connector White wire (component side). Resistance should be about 500-620 k/ohms at 77°F (25°C). If resistance is not as specified, replace knock sensor. If resistance is as specified, go to next step.
4. Loosen and retighten engine ground bolts. (Scheme 43) Disconnect knock sensor harness connector, located near fuel injector No. 5 harness connector. Check continuity between ground and knock sensor sub-harness connector terminal No. 2 (shield circuit). If continuity exists, go to next step. If continuity does not exist, repair open ground circuit. See appropriate wiring diagram in WIRING DIAGRAMS article.
5. No problem is indicated at this time. Problem may be intermittent. See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article.

DTC P0335 will set if Engine Control Module (ECM) does not receive proper pulse signal from CKP sensor while engine is running at a certain speed. DTC P1336 will set if chipping of flywheel teeth is detected by ECM.

Turn ignition on. Select DATA MONITOR mode on scan tool. Start engine and let idle. Wait at least 15 seconds. If first trip DTC is detected, go to TEST PROCEDURE . If first trip DTC is not detected, problem may be intermittent. See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article.

1. Turn ignition off. Loosen and retighten engine ground bolts. (Scheme 43) Disconnect CKP sensor harness connector. (Scheme 53) Disconnect ECM harness connector. see scheme 1 Check continuity of Light Green wire between CKP sensor harness connector and ECM harness connector terminal No. 47. see scheme 2 If continuity exists, go to next step. If continuity does not exist, repair open in Light Green wire.
2. Check for short to power and short to ground in Light Green wire between CKP sensor harness connector and ECM harness connector terminal No. 47. If problem exists, repair Light Green wire as necessary. If problem does not exist, go to next step.
3. Reconnect ECM harness connector. Check continuity between ground and CKP sensor harness connector Black/Yellow wire. If continuity does not exist, repair open in Black/Yellow wire. If continuity exists, go to next step.
4. Check for short to power and short to ground in Black/Yellow wire between CKP sensor harness connector and ECM harness connector terminal No. 43. If problem exists, repair Black/Yellow wire as necessary. If problem does not exist, go to next step.
5. Remove CKP sensor. Inspect CKP sensor for physical damage. Measure resistance between CKP sensor terminals. Resistance should be 512-632 ohms at 68°F (20°C). If CKP sensor is damaged or if CKP sensor resistance is not as specified, replace CKP sensor. If CKP sensor is okay, go to next step.
6. Disconnect Gray, 3-pin connector F-307 located on left side of engine compartment. Check continuity between ground and connector F-307 terminal No. 1 (shield circuit). If continuity exists, go to next step. If continuity does not exist, repair open shield circuit.
7. Inspect flywheel or drive plate teeth for damage. Replace flywheel or drive plate, if necessary. If flywheel or drive plate is okay, no problem is indicated at this time. Problem may be intermittent. See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article.

Scheme 53

Malfunction is detected when either one-degree signal or 120-degree signal is not sent to Engine Control Module (ECM) during engine cranking.

Turn ignition on. Select DATA MONITOR mode on scan tool. Crank engine at least 2 seconds. If first trip DTC is detected, go to TEST PROCEDURE . If first trip DTC is not detected, go to DTC CONFIRMATION TESTS "B" & "C" .

DTC Confirmation Tests "B" & "C"

Malfunction "B" is detected when either one-degree signal or 120-degree signal is not sent to ECM often enough when engine speed is higher than specified engine speed. Malfunction "C" is detected when the relationship between one-degree signal and 180-degree signal is out of normal range.

Turn ignition on. Select DATA MONITOR mode on scan tool. Start engine and let idle at least 2 seconds. If first trip DTC is detected, go to TEST PROCEDURE . If first trip DTC is not detected, problem may be intermittent. See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article.

1. Turn ignition off. Loosen and retighten engine ground bolts. (Scheme 43) Disconnect distributor assembly 6-pin harness connector (to CMP sensor in distributor). Turn ignition on. Measure voltage between ground and distributor assembly 6-pin harness connector terminal No. 5 (Black/White wire). (Scheme 54) If battery voltage exists, go to next step. If battery voltage does not exist, repair open or short circuit. See appropriate diagram in WIRING DIAGRAMS article.
2. Turn ignition off. Disconnect ECM harness connector. see scheme 1 Check continuity of White wire between distributor assembly 6-pin harness connector terminal No. 3 and ECM harness connector terminals No. 44 and 48. see scheme 2and (Scheme 54). Also check continuity of Orange wire between distributor assembly 6-pin harness connector terminal No. 4 and ECM harness connector terminal No. 49. If continuity exists, go to next step. If continuity does not exist, repair open circuit(s).
3. Check for short to power and short to ground in White wire between distributor assembly 6-pin harness connector terminal No. 3 and ECM harness connector terminals No. 44 and 48. Also, check for short to power and short to ground in Orange wire between distributor assembly 6-pin harness connector terminal No. 4 and ECM harness connector terminal No. 49. If problem exists, repair White wire or Orange wire as necessary. If problem does not exist, go to next step.
4. Check continuity between ground and distributor assembly 6-pin harness connector terminal No. 6 (Black/Red wire). If continuity exists, go to next step. If continuity does not exist, repair open ground circuit.
5. Check for short to power in Black/Red wire between ground and distributor assembly 6-pin harness connector. If problem exists, repair short in Black/Red wire. If problem does not exist, go to next step.
6. Reconnect all harness connectors. Start engine and warm to normal operating temperature. Measure voltage between ground and ECM harness connector terminals No. 44, 48 and 49 with engine at idle and at 2000 RPM. Voltage at ECM harness connector terminals No. 44 and 48 should be.3-.5 volt at idle and 2000 RPM. Voltage at ECM harness connector terminal No. 49 should be about 2.5 volts at idle and 2000 RPM. If voltages are as specified, go to next step. If voltages are not as specified, replace distributor assembly.
7. No problem is indicated at this time. Problem may be intermittent. See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article.

Scheme 54

Malfunction is detected when EGR flow is not detected by EGR temperature sensor when EGR Control (EGRC) solenoid is energized by ECM.

Start engine and warm to normal operating temperature. Check for EGR valve opening while quickly increasing engine speed to 3000 RPM. EGR valve should open and close without sticking. If operation is not as specified, go to TEST PROCEDURE . If operation is as specified, diagnose EGR temperature sensor or circuit failure. See DTC P1401: EGR TEMPERATURE SENSOR .

1. Start engine and warm to normal operating temperature. Check exhaust system for leaks. If exhaust leak is found, repair as necessary. If exhaust leak is not found, disconnect vacuum hose from EGR valve. With engine idling, check for vacuum at EGR valve hose. Vacuum should not exist at idle. Check for vacuum while quickly increasing engine speed to 3000 RPM. Vacuum should exist while increasing engine speed. If vacuum is as specified, go to next step. If vacuum is not as specified, go to step 3.
2. Turn ignition off. Using a hand vacuum pump, apply vacuum to EGR valve. EGR valve should open. If EGR valve opens, go to step 7. If EGR valve does not open, remove EGR valve and check for sticking and clean or replace as necessary.
3. Turn ignition off. Inspect vacuum hose for blockage, leak or improper connection. Repair as necessary. If vacuum hose is okay, disconnect ECM harness connector. see scheme 1 Turn ignition on. Connect a jumper wire between ground and ECM harness connector terminal No. 103. see scheme 2 Listen for EGR Control (EGRC) solenoid valve operating sound while connecting and disconnecting jumper wire. If operating sound is heard, go to next step. If operating sound is not heard, repair EGRC solenoid valve or circuit. See «DTC P1400: EGR CONTROL (EGRC) SOLENOID VALVE»(ref-3202-S02191987712000041900000).
4. Check EGRC solenoid. See «DTC P1400: EGR CONTROL (EGRC) SOLENOID VALVE»(ref-3202-S02191987712000041900000). If problem exists, replace EGRC solenoid valve. If problem does not exist, go to next step.
5. Check EGR Control-Back Pressure Transducer (EGRC-BPT) valve. See «DTC P0402: EGR CONTROL BACKPRESSURE TRANSDUCER (EGRC-BPT) VALVE»(ref-3202-S20408370582000041900000). If problem exists, replace EGRC-BPT valve. If problem does not exist, go to next step.
6. Check EGR temperature sensor. See «DTC P1401: EGR TEMPERATURE SENSOR»(ref-3202-S08657450332000041900000). If problem exists, replace EGR temperature sensor. If problem does not exist, go to next step.
7. No problem is indicated at this time. Problem may be intermittent. See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article.

Malfunction is detected when EGR Control-Back Pressure Transducer (EGRC-BPT) valve does not operate properly.

Install vacuum gauge using a "T" fitting in hose between EGRC-BPT valve and EGR valve. Raise drive wheels and support vehicle. Start engine and shift transmission into 1st gear. Observe vacuum gauge while keeping engine speed at 2000-2800 RPM. Vacuum should be 0-5.91 in. Hg. If vacuum is not as specified, go to TEST PROCEDURE . If vacuum is as specified, check EGR system vacuum hoses for blockage, leaks or improper connection.

1. Turn ignition off. Check EGR system vacuum hoses for blockage, leaks or improper connection. If problem exists, repair hose(s) as necessary. If problem does not exist, check for restricted exhaust. If exhaust is restricted, repair as necessary. If exhaust system is not restricted, go to next step.
2. Check if orifice is installed in vacuum hose between EGRC-BPT valve and EGRC solenoid valve. If orifice is not present, replace vacuum hose. If orifice is present, go to next step.
3. Remove EGR Control-Back Pressure Transducer (EGRC-BPT) valve. Plug one vacuum port and apply vacuum to other vacuum port. Vacuum should not hold. Apply pressure to backpressure port. Applied vacuum should now hold. If EGRC-BPT valve does not operate as specified, replace EGRC-BPT valve. If EGRC-BPT valve operates as specified, go to next step.
4. Check CMP sensor. See «DTC P0340: CAMSHAFT POSITION (CMP) SENSOR»(ref-3202-S18561369382000041900000) . If problem exists, replace CMP sensor. If problem does not exist, check MAF sensor. See «DTC P0100: MASS AIRFLOW (MAF) SENSOR»(ref-3202-S10437396702000041900000) . If problem exists, replace MAF sensor. If problem does not exist, check EGRC solenoid valve. See «DTC P1400: EGR CONTROL (EGRC) SOLENOID VALVE»(ref-3202-S02191987712000041900000) . If problem exists, replace EGRC solenoid valve. If problem does not exist, go to next step.
5. Remove EGR valve. Using a hand vacuum pump, apply vacuum to EGR valve. EGR valve should open. If EGR valve does not open, check for sticking, and clean or replace as necessary. If EGR valve opens, no problem is indicated at this time. Problem may be intermittent. See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article.

Malfunction is detected when 3-way catalytic converter does not operate properly.

Start engine and drive vehicle at 43 MPH or more for 2 consecutive minutes. Stop vehicle and leave engine running. Measure voltage between ground and Engine Control Module (ECM) harness connector terminals No. 50 (front HO2S) and No. 56 (rear HO2S). Increase engine speed and hold at 2000 RPM. Front HO2S should switch rich-lean-rich more than 5 times each 10 seconds. If front HO2S does not switch more than 5 times within 10 seconds, diagnose front HO2S first. See DTC P0133: FRONT HEATED OXYGEN SENSOR (HO2S) SLOW RESPONSE . The amplitude of rear HO2S voltage signal (difference between high and low voltages) should be less than 75 percent of front HO2S voltage signal amplitude. If the amplitude is more than 75 percent, the warm-up 3-way catalytic converter is not operating properly. See TEST PROCEDURE .

1. Inspect exhaust system for damage and repair as necessary. Start engine and let idle. Check for exhaust leak before 3-way catalytic converter. Check for intake air leak after Mass Airflow (MAF) sensor. If problem exists, repair as necessary. If problem does not exist, go to next step.
2. Check ignition timing. See IGNITION TIMING in ON-VEHICLE ADJUSTMENTS article. Adjust ignition timing as necessary. If ignition timing is okay, stop engine and turn ignition on. Measure voltage between ground and ECM harness connector terminals No. 102, 104, 106, 109, 111 and 113 by backprobing. see scheme 2 If battery voltage exists, go to next step. If battery voltage does not exist, repair appropriate fuel injector or circuit. See FUEL CONTROL under FUEL SYSTEM in SYSTEM & COMPONENT TESTING article.
3. Turn ignition off. Disconnect ignition wires from each spark plug and connect a known-good spark plug to plug wire. Place spark plug on good ground. Crank engine and check for spark. If spark exists at each plug wire, go to next step. If spark does not exist each plug wire, check and repair spark plug wires, ignition coil and power transistor as necessary. See «DTC P1320: IGNITION SIGNAL»(ref-3202-S27381140612000041900000).
4. Turn ignition off. Remove fuel injector assembly. Keep all associated fuel lines connected. Disconnect distributor assembly 6-pin harness connector. Turn ignition on. Verify fuel is not dripping from fuel injectors. Replace fuel injectors which are leaking. If no fuel injectors are leaking, go to next step.
5. No problem is indicated at this time. Problem may be intermittent. See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article. If DTC still exists, replace warm-up 3-way catalytic converter.

Note. An improperly tightened fuel cap may set this code. Ensure fuel cap is properly seated and tightened. Always perform test at ambient temperature of 32-86°F (0-30°C). Fuel level should be 1/4 to 3/4 full during this test. It is preferable to have it on the low side.

Note. When DTCs are cleared, all system readiness tests will go to incomplete. The first time a monitor is run, if no faults are found, system readiness test status will go to complete. If a fault is found first time a monitor is run, system readiness test status will remain incomplete. If the drive cycle did not meet all requirements for monitor to run, system readiness test status will remain incomplete. The second time a monitor is run, system readiness test status will go to complete whether or not a fault is present.

Malfunction is detected when Evaporative Emissions (EVAP) system has a leak or does not operate properly.

1. Drive vehicle according to specified driving pattern required to run EVAP system monitor. See SYSTEM READINESS TEST (SRT) CODES under ADDITIONAL SYSTEM FEATURES in SELF-DIAGNOSTICS - INTRODUCTION article. Stop vehicle and go to next step.
2. Select SYSTEM READINESS TEST mode on scan tool and check system readiness test status of EVAP system. If EVAP system readiness test is incomplete, go to next step. If EVAP system readiness test is complete, check for first trip DTC. If first trip DTC is detected, go to «TEST PROCEDURE»(ref-3202-S06558729842000041900000) . If first trip DTC is not detected, system is okay at this time. Problem may be intermittent. See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article. NOTE: It is not necessary to allow engine to cool before driving vehicle.
3. Turn ignition off and wait at least 5 seconds. Perform driving pattern again. Stop vehicle and select DTCS on scan tool. If DTC P0440, P1440 or P1447 is set, perform appropriate diagnostic procedure. If DTC P0440, P1440 or P1447 is not set, go to next step.
4. Select SYSTEM READINESS TEST mode on scan tool and check EVAP system readiness test status. If EVAP system readiness test is incomplete, EVAP monitor did not run. Repeat step 3) . If EVAP system readiness test is complete, fault is intermittent. See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article.

1. Ensure fuel cap is genuine Nissan part. Check fuel cap is properly tightened by rotating clockwise. Remove fuel cap. If air releasing sound was heard while removing fuel cap, go to next step. If air releasing sound was not heard while removing fuel cap or fuel cap was not tightened properly, clean fuel cap and filler neck with compressed air and reinstall cap. If fuel cap was installed properly, check fuel cap vacuum release valve opening pressure and vacuum. Valve should open when pressure reaches 2.22-2.90 psi (.15-.20 kg/cm 2 ) and when vacuum reaches 0.98-1.77 in. Hg. If problem exists, replace fuel cap. If problem does not exist, go to next step.
2. Check EVAP system for leaks. See FUEL EVAPORATION (EVAP) CONTROL SYSTEMS under EMISSION SYSTEMS & SUB-SYSTEMS in SYSTEM & COMPONENT TESTING article. If leak exists, repair as necessary. If leak does not exist, check for blockage in water separator. If problem exists, clean or replace water separator as necessary. If problem does not exist, go to next step.
3. Remove EVAP canister with EVAP Canister Vent Control Valve (EVAP-CVCV) attached. Attempt to drain water from EVAP canister. If water does not drain from EVAP canister, go to next step. If water drains from EVAP canister, weigh EVAP canister with EVAP-CVCV attached. If weight is less than 4.0 lbs. (1.8 kg), go to next step. If weight is more than 4.0 lbs. (1.8 kg), inspect EVAP canister for damage and check hose between water separator and EVAP canister for blockage or leak. If problem exists, repair hose or replace EVAP canister as necessary. If problem does not exist, go to next step.
4. Start engine and warm to normal operating temperature. Turn ignition off. Disconnect purge hose to EVAP Canister Purge Volume Control Solenoid Valve (EVAP-CPVCV) at EVAP service port. Start engine and let idle for at least 80 seconds. Check vacuum hose for vacuum when revving engine up to 2000 RPM. Vacuum should exist. If vacuum is as specified, go to step 6 . If vacuum is not as specified, go to next step.
5. Check vacuum hoses to EVAP-CPVCV for blockage or leak. Repair as necessary and retest system. If vacuum hoses are okay, check EVAP-CPVCV. See «DTC P0443: EVAP CANISTER PURGE VOLUME CONTROL VALVE (EVAP-CPVCV)»(ref-3202-S35912412242000041900000) . If problem exists, replace EVAP-CPVCV. If problem does not exist, go to next step.
6. Check AP sensor. See «DTC P0105: ABSOLUTE PRESSURE (AP) SENSOR»(ref-3202-S33965217602000041900000) . If problem exists, replace AP sensor. If problem does not exist, check MAP/BARO switch solenoid valve. See «DTC P1105: MANIFOLD ABSOLUTE PRESSURE (MAP)/BAROMETRIC PRESSURE (BARO) SWITCH SOLENOID VALVE»(ref-3202-S27968742112000041900000) . If problem exists, replace MAP/BARO switch solenoid valve. If problem does not exist, go to next step.
7. Check Fuel Tank temperature (FTT) sensor. See «DTC P0180: TANK FUEL TEMPERATURE (FTT) SENSOR»(ref-3202-S40848384882000041900000) . If problem exists, replace FTT sensor. If problem does not exist, check EVAP-CSPS. See «DTC P0450: EVAP CONTROL SYSTEM PRESSURE SENSOR (EVAP-CSPS)»(ref-3202-S11146958382000041900000) . If problem exists, replace EVAP-CSPS. If problem does not exist, go to next step.
8. Check for leaks in EVAP purge line. If problem exists, replace appropriate hose(s). If problem does not exist, clean purge line with compressed air. Remove fuel level sensor assembly. Check resistance between fuel level sensor connector Black wire and Blue/Red wire. See «FUEL LEVEL SENSOR RESISTANCE»(ref-3202-S01882190682000061700000) table. If resistances are not as specified, replace fuel level sensor assembly. If resistances are as specified, problem may be intermittent. See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article.

FUEL LEVEL SENSOR RESISTANCE

Malfunction is detected when improper voltage is sent to Engine Control Module (ECM) through EVAP-CPVCV.

Turn ignition on. Select DATA MONITOR mode. Start engine and let idle. Wait at least 13 seconds. If first trip DTC is detected, go to TEST PROCEDURE . If first trip DTC is not detected, fault is intermittent. See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article.

1. Turn ignition off. Disconnect EVAP-CPVCV harness connector. (Scheme 55) Turn ignition on. Measure voltage between ground and EVAP-CPVCV harness connector Black/White wire. If battery voltage exists, go to next step. If battery voltage does not exist, repair open or short circuit. See appropriate diagram in WIRING DIAGRAMS article.
2. Turn ignition off. Disconnect ECM harness connector. see scheme 1 Check continuity of Green/Black wire between EVAP-CPVCV harness connector and ECM harness connector terminal No. 5. see scheme 2 If continuity exists, go to next step. If continuity does not exist, repair open in Green/Black wire.
3. Check for short to power and short to ground in Green/Black wire between EVAP-CPVCV harness connector and ECM harness connector terminal No. 5. If problem exists, repair short in Green/Black wire. If problem does not exist, go to next step.
4. Remove EVAP-CPVCV. Using jumper wires, apply battery voltage and ground to EVAP-CPVCV terminals. (Scheme 56) Check for airflow between ports "A" and "B". Air should flow. Remove jumper wires. Air should not flow. EVAP-CPVCV should switch in one second or less. If EVAP-CPVCV does not operate as specified, replace EVAP-CPVCV. If EVAP-CPVCV operates as specified, go to next step.
5. No problem is indicated at this time. Problem may be intermittent. See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article.

Scheme 55

Scheme 56

Malfunction is detected when improper voltage is sent to Engine Control Module (ECM) through EVAP-CVCV.

Turn ignition on. Select DATA MONITOR mode on scan tool. Start engine. Wait at least 8 seconds. If first trip DTC is detected, go to TEST PROCEDURE . If first trip DTC is not detected, fault is intermittent. See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article.

1. Turn ignition off. Disconnect EVAP-CVCV harness connector. (Scheme 57) Turn ignition on. Measure voltage between ground and EVAP-CVCV harness connector Blue/Yellow wire. If battery voltage exists, go to next step. If battery voltage does not exist, repair open or short circuit. See appropriate diagram in WIRING DIAGRAMS article.
2. Turn ignition off. Disconnect ECM harness connector. see scheme 1 Check continuity of Light Green/Black wire between EVAP-CVCV harness connector and ECM harness connector terminal No. 108. see scheme 2 If continuity exists, go to next step. If continuity does not exist, repair open in Light Green/Black wire.
3. Check for short to power or short to ground in Light Green/Black wire between EVAP-CVCV harness connector and ECM harness connector terminal No. 108. If problem exists, repair Light Green/Black wire. If problem does not exist, go to next step.
4. Remove EVAP-CVCV. Using jumper wires, apply battery voltage and ground to EVAP-CVCV terminals. (Scheme 58) Check for airflow between ports "A" and "B". Air should not flow. Remove jumper wires. Air should flow between ports "A" and "B". EVAP-CVCV should switch in one second or less. If EVAP-CVCV does not operate as specified, replace EVAP-CVCV. If EVAP-CVCV operates as specified, go to next step.
5. No problem is indicated at this time. Problem may be intermittent. See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article.

Scheme 57

Scheme 58

Malfunction is detected when improper voltage is sent to Engine Control Module (ECM) from EVAP-CSPS.

Start engine and warm to normal operating temperature. Turn ignition off and wait at least 5 seconds. Turn ignition on. Select DATA MONITOR mode on scan tool. Ensure fuel temperature displayed on scan tool is more than 32°F (0°C). Start engine and wait at least 20 seconds. If first trip DTC is detected, go to TEST PROCEDURE . If first trip DTC is not detected, fault is intermittent. See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article.

1. Check EVAP-CSPS hose for blockage or leak. (Scheme 59) If problem exists, repair hose as necessary and retest system. If problem does not exist, loosen and retighten engine ground bolts. (Scheme 43) Disconnect EVAP-CSPS harness connector. Check for water in connector. If water is present, repair or replace connector and retest system. If water is not present, go to next step.
2. Turn ignition on. Measure voltage between ground and EVAP-CSPS harness connector Brown wire. If voltage is not about 5 volts, repair open or short in Brown wire. If voltage is about 5 volts, turn ignition off. Check continuity between ground and EVAP-CSPS harness connector Green wire. If continuity exists, go to next step. If continuity does not exist, repair open in Green wire.
3. Check for short to power and short to ground in Green wire between ground and EVAP-CSPS harness connector. If problem exists, repair Green wire as necessary. If problem does not exist, go to next step.
4. Disconnect ECM harness connector. see scheme 1 Check continuity of Red wire between EVAP control system pressure sensor harness connector and ECM harness connector terminal No. 62. see scheme 2 If continuity exists, go to next step. If continuity does not exist, repair open in Red wire.
5. Check for short to power and short to ground in Red wire between EVAP control system pressure sensor harness connector and ECM harness connector terminal No. 62. If problem exists, repair Red wire as necessary. If problem does not exist, go to next step.
6. Check EVAP-CPVCV. See «DTC P0443: EVAP CANISTER PURGE VOLUME CONTROL VALVE (EVAP-CPVCV)»(ref-3202-S35912412242000041900000). If problem exists, replace EVAP-CPVCV. If problem does not exist, check EVAP-CVCV. See «DTC P0446: EVAP CANISTER VENT CONTROL VALVE (EVAP-CVCV)»(ref-3202-S39011910902000041900000). If problem exists, replace EVAP-CVCV and retest system. If problem does not exist, go to next step. CAUTION: DO NOT apply more than 5.91 in. Hg of vacuum to EVAP-CSPS. DO NOT reuse EVAP-CSPS that has been dropped from a height of 20" (.5 m) or more onto a hard surface such as concrete.
7. Remove EVAP-CSPS with harness connector connected. Disconnect hose from EVAP-CSPS. Turn ignition on. Using a hand vacuum pump, apply vacuum to EVAP-CSPS. With vacuum as specified, measure voltage between ground and ECM harness connector terminal No. 62 by backprobing. see scheme 2 See «EVAP CONTROL SYSTEM PRESSURE SENSOR VOLTAGE»(ref-3202-S07064023542000041900000) table. If voltage is not as specified, replace EVAP-CSPS. If voltage is as specified, go to next step.
8. Check for blockage in water separator and EVAP-CVCV hose. If problem exists, clean or repair as necessary and retest system. If problem does not exist, check EVAP canister for water. See «P0440 OR P1440: EVAP CONTROL SYSTEM SMALL LEAK»(ref-3202-S23802861962000041900000). If problem exists, replace canister. If problem does not exist, go to next step.
9. Reconnect all connectors. Disconnect Gray 8-pin connector M-119 located near EVAP canister. Check continuity between ground and connector M-119 terminal No. 5. (Scheme 60) If continuity exists, go to next step. If continuity does not exist, repair open ground circuit.
10. No problem is indicated at this time. Problem may be intermittent. See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article.

EVAP CONTROL SYSTEM PRESSURE SENSOR VOLTAGE

Scheme 59

Scheme 60

Note. An improperly tightened fuel cap may set this code. Ensure fuel cap is properly seated and tightened. Always perform test at ambient temperature of 32-86°F (0-30°C). Fuel level should be 1/4 to 3/4 full during this test. It is preferable to have it on the low side.

Note. When DTCs are cleared, all system readiness tests will go to incomplete. The first time a monitor is run, if no faults are found, system readiness test status will go to complete for that monitor. If a fault is found first time a monitor is run, system readiness test status will remain incomplete. If the drive cycle did not meet all requirements to get the monitor to run, system readiness test status will remain incomplete for that monitor. The second time a monitor is run, system readiness test status will go to complete whether or not a fault is present.

Malfunction is detected when EVAP system has a large leak or does not operate properly.

1. Drive vehicle according to specified driving pattern required to run EVAP system monitor. See SYSTEM READINESS TEST (SRT) CODES under ADDITIONAL SYSTEM FEATURES in SELF-DIAGNOSTICS - INTRODUCTION article. Stop vehicle and go to next step.
2. Select SYSTEM READINESS TEST mode on scan tool and check system readiness test status of EVAP system. If EVAP system readiness test is incomplete, go to next step. If EVAP system readiness test is complete, check for first trip DTC. If first trip DTC is detected, go to «TEST PROCEDURE»(ref-3202-S30522535482000061900000) . If first trip DTC is not detected, system is okay at this time. Problem may be intermittent. See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article. NOTE: It is not necessary to allow engine to cool before driving vehicle.
3. Turn ignition off and wait at least 5 seconds. Perform driving pattern again. Stop vehicle and select DTCS on scan tool. If DTC P0455 is set, go to «TEST PROCEDURE»(ref-3202-S30522535482000061900000) . If DTC P0440, P1440 or P1447 is set, perform appropriate diagnostic procedure. See «P0440 OR P1440: EVAP CONTROL SYSTEM SMALL LEAK»(ref-3202-S23802861962000041900000) or «DTC P1447: EVAP CONTROL SYSTEM PURGE FLOW MONITORING»(ref-3202-S25937785932000041900000) . If DTC P0455, P0440, P1440 or P1447 is not set, go to next step.
4. Select SYSTEM READINESS TEST mode on scan tool and check EVAP system readiness test status. If EVAP system readiness test is incomplete, EVAP monitor did not run. Repeat step 3) . If EVAP system readiness test is complete, fault is intermittent. See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article.

1. Ensure fuel cap is genuine Nissan part. Check cap is properly tightened by rotating clockwise. Remove fuel cap. If air releasing sound was heard while removing fuel cap, go to next step. If air releasing sound was not heard while removing fuel cap or fuel cap was not tightened properly, clean fuel cap and filler neck with compressed air and reinstall cap. If fuel cap was installed properly, check fuel cap vacuum release valve opening pressure and vacuum. Valve should open when pressure reaches 2.22-2.90 psi (.15-.20 kg/cm 2 ) and when vacuum reaches 0.98-1.77 in. Hg. If problem exists, replace fuel cap. If problem does not exist, go to next step.
2. Check EVAP system for leaks. See FUEL EVAPORATION (EVAP) CONTROL SYSTEMS under EMISSION SYSTEMS & SUB-SYSTEMS in SYSTEM & COMPONENT TESTING article. If leak exists, repair as necessary. If leak does not exist, blow out purge line with compressed air and go to next step.
3. Turn ignition on. Select DATA MONITOR mode on scan tool. Start engine. Wait at least 8 seconds. If first trip DTC is detected, repair or replace EVAP Canister Vent Control Valve (EVAP-CVCV) and "O" ring and/or harness/connector. If first trip DTC is not detected, go to next step.
4. Turn ignition off. Install EVAP service port adapter on EVAP service port, located near brake fluid reservoir. Connect hand pressure pump to EVAP service port adapter. Disconnect EVAP-CVCV connector and vacuum cut valve by-pass valve connector. Using jumper wires, apply battery voltage and ground to EVAP-CVCV terminals (valve will close). (Scheme 58) Using jumper wires, apply battery voltage and ground to vacuum cut valve by-pass valve terminals (valve will open). (Scheme 61) Go to next step. CAUTION: DO NOT exceed.6 psi (.042 kg/cm 2 ) pressure in EVAP system.
5. Using hand pressure pump, apply.19-.40 psi (.01-.03 kg/cm 2 ) pressure to EVAP line. Using EVAP system leak detector, locate EVAP system leak. If problem exists, repair as necessary. If problem does not exist, go to next step.
6. Start engine and warm to normal operating temperature. Turn ignition off. Disconnect vacuum hose to EVAP Canister Purge Volume Control Solenoid Valve (EVAP-CPVCV) at EVAP service port. Start engine and let idle for at least 80 seconds. Check vacuum hose for vacuum when revving engine up to 2000 RPM. Vacuum should exist. If vacuum is as specified, go to step 8. If vacuum is not as specified, go to next step.
7. Check vacuum hoses to EVAP-CPVCV for blockage or leak. If problem exists, repair hose(s) as necessary and retest system. If problem does not exist, go to next step.
8. Check EVAP-CPVCV. See «DTC P0443: EVAP CANISTER PURGE VOLUME CONTROL VALVE (EVAP-CPVCV)»(ref-3202-S35912412242000041900000). If problem exists, replace EVAP-CPVCV. If problem does not exist, go to next step.
9. Check AP sensor. See «DTC P0105: ABSOLUTE PRESSURE (AP) SENSOR»(ref-3202-S33965217602000041900000). If problem exists, replace AP sensor. If problem does not exist, go to next step.
10. Check Fuel Tank temperature (FTT) sensor. See «DTC P0180: TANK FUEL TEMPERATURE (FTT) SENSOR»(ref-3202-S40848384882000041900000). If problem exists, replace FTT sensor. If problem does not exist, check EVAP-CSPS. See «DTC P0450: EVAP CONTROL SYSTEM PRESSURE SENSOR (EVAP-CSPS)»(ref-3202-S11146958382000041900000). If problem exists, replace EVAP-CSPS. If problem does not exist, go to next step.
11. No problem is indicated at this time. Problem may be intermittent. See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article.

Scheme 61

Malfunction is detected when zero MPH signal is sent to Engine Control Module (ECM) while vehicle is moving.

Raise drive wheels and support vehicle. Connect an oscilloscope between ground and ECM harness connector terminal No. 29 by backprobing. see scheme 2 Start engine. Shift transmission into a forward gear. Increase engine RPM until drive wheels are rotating at 25 MPH. VSS signal should be as shown in illustration. (Scheme 62)

Scheme 62

1. Turn ignition off. Disconnect ECM harness connector. see scheme 1 Remove instrument cluster and disconnect instrument cluster harness connectors. Check continuity of Green/Yellow wire between ECM harness connector terminal No. 29 and instrument cluster Black 12-pin harness connector terminal No. 31. see scheme 2and (Scheme 63). If continuity exists, go to next step. If continuity does not exist, repair open in Green/Yellow wire.
2. Check for short to power and short to ground in Green/Yellow wire between instrument cluster and ECM or Transmission Control Module (TCM). If problem exists, repair Green/Yellow wire as necessary. If problem does not exist, go to next step.
3. Reconnect all harness connectors. Check speedometer operation. If speedometer operates, go to next step. If speedometer does not operate, repair speedometer or circuit. See appropriate INSTRUMENT PANELS article in ACCESSORIES & EQUIPMENT.
4. No problem is indicated at this time. Problem may be intermittent. See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article.

Scheme 63

Malfunction is detected when IACV-AAC valve circuit is open.

Turn ignition on. Select DATA MONITOR mode on scan tool. Wait at least 2 seconds. If first trip DTC is detected, go to TEST PROCEDURE . If first trip DTC is not detected, go to DTC CONFIRMATION TEST "B" .

Malfunction is detected when IACV-AAC valve circuit is shorted.

Start and warm engine to normal operating temperature. Turn ignition off. Wait at least 5 seconds, then turn ignition on. Select DATA MONITOR mode on scan tool. Start engine and let idle at least one minute. If first trip DTC is detected, go to TEST PROCEDURE . If first trip DTC is not detected, system is okay at this time. Problem may be intermittent. See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article.

1. Turn ignition off. Disconnect IACV-AAC valve harness connector. (Scheme 64) Turn ignition on. Measure voltage between ground and IACV-AAC valve harness connector Blue/Yellow wire. If battery voltage exists, go to next step. If battery voltage does not exists, repair open or short circuit. See appropriate diagram in WIRING DIAGRAMS article.
2. Turn ignition off. Disconnect Engine Control Module (ECM) harness connector. see scheme 1 Check continuity of Light Blue wire between IACV-AAC valve harness connector and ECM harness connector terminal No. 101. see scheme 2 If continuity exists, go to next step. If continuity does not exist, repair open in Light Blue wire.
3. Check for short to power and short to ground in Light Blue wire between IACV-AAC valve harness connector and ECM harness connector terminal No. 101. If problem exists, repair Light Blue wire as necessary. If problem does not exist, go to next step.
4. Measure resistance between IACV-AAC valve terminals. Resistance should be about 10 ohms at 68°F (20°C). Check IACV-AAC valve plunger for sticking. Also, check for broken IACV-AAC valve spring. Using jumper wires, apply battery voltage and ground to IACV-AAC valve terminals. IACV-AAC valve plunger should move when voltage is applied. If problem exists, replace IACV-AAC valve. If problem does not exist, go to next step.
5. No problem is indicated at this time. Problem may be intermittent. See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article.

Scheme 64

Malfunction is detected when voltage is sent to Engine Control Module (ECM) from closed throttle position switch when throttle valve is open.

Start engine and warm to normal operating temperature. Measure voltage between ground and ECM harness connector terminal No. 28 by backprobing. see scheme 2 At idle, battery voltage should exist. At 2000 RPM, about zero volts should exist.

1. Turn ignition off. Disconnect closed throttle position switch harness connector. (Scheme 65) Turn ignition on. Measure voltage between ground and closed throttle position switch harness connector terminal No. 5 (Blue/Yellow wire). If battery voltage exists, go to next step. If battery voltage does not exist, repair open or short circuit. See appropriate wiring diagram in WIRING DIAGRAMS article.
2. Turn ignition off. Disconnect ECM harness connector. see scheme 1 Check continuity of Brown/Yellow wire between ECM harness connector terminal No. 28 and closed throttle position switch harness connector terminal No. 6. see scheme 2 If continuity exists, go to next step. If continuity does not exist, repair open in Brown/Yellow wire.
3. Check for short to power and short to ground in Brown/Yellow wire between ECM harness connector terminal No. 28 and closed throttle position switch harness connector terminal No. 6. If problem exists, repair Brown/Yellow wire as necessary. If problem does not exist, go to next step.
4. Reconnect all harness connectors. Adjust closed throttle position switch. See THROTTLE POSITION (TP) SENSOR in ON-VEHICLE ADJUSTMENTS article. Start engine and warm to normal operating temperature. Turn ignition off. Disconnect closed throttle position switch harness connector. Check continuity between closed throttle position switch terminals No. 5 and 6. (Scheme 65) Continuity should exist when accelerator pedal is released. Continuity should not exist when accelerator pedal is depressed. If continuity is not as specified, replace closed throttle position switch. If continuity is as specified, go to next step.
5. Check Throttle Position (TP) sensor. See «DTC P0120: THROTTLE POSITION (TP) SENSOR»(ref-3202-S08944230622000041900000). If problem exists, replace TP sensor. If problem does not exist, no fault is indicated at this time. Problem may be intermittent. See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article.

Scheme 65

Malfunction is detected when Engine Control Module (ECM) receives incorrect voltage from Transmission Control Module (TCM) continuously.

Start engine. Measure voltage between ground and ECM harness connector terminals No. 26 and 27 by backprobing. see scheme 2 Each voltage should be 6-8 volts.

1. Turn ignition off. Disconnect ECM and TCM) harness connectors. see scheme 1 TCM is located behind left side of instrument panel, to right of steering column. Check continuity of the following: Green/White wire between TCM harness connector terminal No. 5 and ECM harness connector terminal No. 26. White wire between TCM harness connector terminal No. 6 and ECM harness connector terminal No. 27. Pink/Black wire between TCM harness connector terminal No. 7 and ECM harness connector terminal No. 35. see scheme 2and (Scheme 66). If continuity does not exist, repair open in appropriate wire. If continuity exists, go to next step.
2. Check continuity between ground and ECM harness connector terminals No. 26, 27 and 35. If continuity exists, repair short to ground in appropriate wire. If continuity does not exist, check for short to power in each wire. If short to power exists, repair appropriate wire. If short to power does not exist, go to next step.
3. No problem is indicated at this time. Problem may be intermittent. See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article.

Scheme 66

Malfunction is detected when Engine Control Module (ECM) calculation function is malfunctioning.

Turn ignition on. Select DATA MONITOR mode on scan tool. Start engine and let idle at least 2 seconds. If first trip DTC is detected, go to TEST PROCEDURE . If first trip DTC is not detected, system is okay at this time. Problem may be intermittent. See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article.

Turn ignition on. Clear ECM memory. Perform DTC CONFIRMATION TEST . If first trip DTC P0605 is detected again, replace ECM. If first trip DTC P0605 is not detected, fault is intermittent and cannot be isolated at this time.

Malfunction is detected when open or short is detected in MAP/BARO switch solenoid valve circuit.

Turn ignition on. Select DATA MONITOR mode on scan tool. Wait at least 10 seconds. If first trip DTC is detected, go to TEST PROCEDURE "A" . If first trip DTC is not detected, go to DTC CONFIRMATION TEST "B" .

Malfunction is detected when there is little difference between MAP/BARO switch solenoid valve input voltage between ambient barometric pressure and intake manifold pressure.

Start engine and warm to normal operating temperature. Turn ignition off and wait at least 5 seconds. Turn ignition on. Select DATA MONITOR mode on scan tool. Ensure Fuel Tank Temperature (FTT) sensor reading is more than 32°F (0°C). Start engine and let idle for at least 10 seconds. If first trip DTC is detected, go to TEST PROCEDURE "B" . If first trip DTC is not detected, system is okay at this time. Problem may be intermittent. See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article.

1. Turn ignition off. Disconnect MAP/BARO switch solenoid valve harness connector. (Scheme 67) Turn ignition on. Measure voltage between ground and MAP/BARO switch solenoid valve harness connector Blue/Yellow wire. If battery voltage exists, go to next step. If battery voltage does not exist, repair open or short circuit. See appropriate diagram in WIRING DIAGRAMS article.
2. Turn ignition off. Disconnect Engine Control Module (ECM) harness connector. see scheme 1 Check continuity of Purple wire between MAP/BARO switch solenoid valve harness connector and ECM harness connector terminal No. 118. see scheme 2 If continuity exists, go to next step. If continuity does not exist, repair open in Purple wire.
3. Check for short to power and short to ground in Purple wire between MAP/BARO switch solenoid valve harness connector and ECM harness connector terminal No. 118. If problem exists, repair Purple wire as necessary. If problem does not exist, go to next step.
4. Remove MAP/BARO switch solenoid valve. Using jumper wires, apply battery voltage and ground to MAP/BARO switch solenoid valve terminals. (Scheme 68) Air should flow between ports "A" and "B". Air should not flow between ports "A" and "C". Remove jumper wires. Air should flow between ports "A" and "C". Air should not flow between ports "A" and "B". MAP/BARO switch solenoid valve should switch in less than one second. If MAP/BARO switch solenoid valve does not operate as specified, replace MAP/BARO switch solenoid valve. If MAP/BARO switch solenoid valve operates as specified, go to next step.
5. No problem is indicated at this time. Problem may be intermittent. See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article.

Scheme 67

Scheme 68

1. Start engine and warm to normal operating temperature. Turn ignition off. Connect a vacuum gauge using "T" fitting to hose between MAP/BARO switch solenoid valve and Absolute Pressure (AP) sensor. (Scheme 67) Start engine and let it idle. Observe vacuum gauge. Vacuum should not exist for 5 seconds after starting engine. Vacuum should exist after engine has run for 5 seconds. If vacuum is as specified, go to step 8. If vacuum is not as specified, go to next step.
2. Turn ignition off. Check vacuum hose for leaks, blockage or improper connection. Also, check intake manifold vacuum port for blockage. If problem exists, repair as necessary. If problem does not exist, go to next step.
3. Disconnect MAP/BARO switch solenoid valve harness connector. Turn ignition on. Measure voltage between ground and MAP/BARO switch solenoid valve harness connector Blue/Yellow wire. If battery voltage exists, go to next step. If battery voltage does not exist, repair open or short circuit. See appropriate diagram in WIRING DIAGRAMS article.
4. Turn ignition off. Disconnect ECM harness connector. see scheme 1 Check continuity of Purple wire between MAP/BARO switch solenoid valve and ECM harness connector terminal No. 118. see scheme 2 If continuity exists, go to next step. If continuity does not exist, repair open in Purple wire between MAP/BARO switch solenoid valve and ECM harness connector terminal No. 118.
5. Check for short to power and short to ground in Purple wire between MAP/BARO switch solenoid valve and ECM harness connector terminal No. 118. If problem exists, repair Purple wire as necessary. If problem does not exist, go to next step.
6. Remove MAP/BARO switch solenoid valve. Using jumper wires, apply battery voltage and ground to MAP/BARO switch solenoid valve terminals. (Scheme 68) Air should flow between ports "A" and "B". Air should not flow between ports "A" and "C". Remove jumper wires. Air should flow between ports "A" and "C". Air should not flow between ports "A" and "B". MAP/BARO switch solenoid valve should switch in less than one second. If MAP/BARO switch solenoid valve does not operate as specified, replace MAP/BARO switch solenoid valve. If MAP/BARO switch solenoid valve operates as specified, go to next step.
7. Check intake system for leaks. If problem exists, repair as necessary. If problem does not exist, go to step 10.
8. Check hose between AP sensor and MAP/BARO switch solenoid valve for blockage, leaks or improper connection. If problem exists, repair hose as necessary. If problem does not exist, go to next step.
9. Disconnect AP sensor harness connector. Inspect harness connector for water. If water is present, repair or replace connector. If water is not present, check AP sensor. See «DTC P0105: ABSOLUTE PRESSURE (AP) SENSOR»(ref-3202-S33965217602000041900000). If problem exists, replace AP sensor. If problem does not exist, go to next step.
10. No problem is indicated at this time. Problem may be intermittent. See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article.

Malfunction is detected when Engine Control Module (ECM) does not operate in closed loop.

Start engine and warm to normal operating temperature. Measure voltage between ground and ECM harness connector terminal No. 50 by backprobing. see scheme 2 Monitor voltmeter with engine at 2000 RPM. Voltage should be less than.21 volt at least once and more than.70 volt at least once. If voltage is not as specified, go to TEST PROCEDURE. If voltage is as specified, problem may be intermittent. See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article.

See DTC P0133: FRONT HEATED OXYGEN SENSOR (HO2S) SLOW RESPONSE .

Malfunction is detected when Engine Control Module (ECM) does not receive signal from ignition primary circuit during cranking or engine running.

Turn ignition off. Select DATA MONITOR mode on scan tool. Start engine. If engine will not start, turn ignition on for at least 5 seconds. If first trip DTC is detected, go to TEST PROCEDURE . If first trip DTC is not detected, system is okay at this time. Problem may be intermittent. See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article.

1. Turn ignition off and restart engine. If engine starts, go to step 8. If engine does not start, turn ignition off. Disconnect distributor assembly 2-pin harness connector (for ignition coil). Turn ignition on. Measure voltage between ground and distributor assembly 2-pin harness connector Brown wire. If battery voltage exists, go to next step. If battery voltage does not exist, repair open or short circuit. See appropriate wiring diagram in WIRING DIAGRAMS article.
2. Turn ignition off. Disconnect distributor assembly 6-pin harness connector (to power transistor and camshaft position sensor). Check continuity between ground and distributor assembly 6-pin harness connector terminal No. 2 (Black wire). (Scheme 54) If continuity exists, go to next step. If continuity does not exist, repair open in Black wire.
3. Check for short to power in Black wire between ground and distributor assembly 6-pin harness connector terminal No. 2. If problem exists, repair Black wire. If problem does not exist, go to next step.
4. Disconnect ECM harness connector. see scheme 1 Check continuity of Blue wire between distributor assembly 6-pin harness connector terminal No. 1 and ECM harness connector terminal No. 1. see scheme 2 If continuity exists, go to next step. If continuity does not exist, repair open in Blue wire.
5. Check for short to power and short to ground in Blue wire between distributor assembly 6-pin harness connector terminal No. 1 and ECM harness connector terminal No. 1. If problem exists, repair Blue wire. If problem does not exist, go to next step.
6. Turn ignition off. Measure resistance between distributor assembly 2-pin connector terminals. Resistance should be 0.5-1.0 ohm at 77°F (25°C). Also measure resistance between distributor assembly 2-pin connector terminal No. 7 (Brown wire) and coil tower. (Scheme 69) Resistance should be about 12,000 ohms at 77°F (25°C). If resistances are as specified, go to next step. If resistances are not as specified, replace distributor assembly.
7. Measure resistance between distributor assembly 6-pin connector terminal No. 2 (Black wire) and distributor assembly 2-pin connector terminal No. 8 (Green wire - power transistor). (Scheme 54)and (Scheme 69). If resistance is zero ohms, replace distributor assembly. If resistance is not zero ohms, go to step 11.
8. Turn ignition off. Disconnect distributor assembly 2-pin harness connector. Remove tape from resistor and disconnect resistor harness connector. (Scheme 70) Disconnect ECM harness connector. see scheme 1 Check continuity of Green wire between resistor harness connector and distributor assembly 2-pin harness connector terminal No. 8. Also, check continuity of White wire between resistor harness connector and ECM harness connector terminal No. 2. If continuity exists, go to next step. If continuity does not exist, repair open circuit.
9. Check for short to power and short to ground in Green wire between resistor harness connector and distributor assembly 2-pin harness connector terminal No. 8. Also, check for short to power and short to ground in White wire between resistor harness connector and ECM harness connector terminal No. 2. If problem exists, repair appropriate wire. If problem does not exist, go to next step.
10. Measure resistance of resistor. Resistance should be about 2200 ohms at 77°F (25°C). If resistance is not as specified, replace resistor. If resistance is as specified, no problem is indicated at this time. Problem may be intermittent. See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article.
11. Disconnect 42-pin super multiple junction connector F-12 from firewall. Check continuity between ground and engine control harness connector terminal No. 8A. (Scheme 46) If continuity does not exist, repair open ground circuit. If continuity exists, no problem is indicated at this time. Problem may be intermittent. See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article.

Scheme 69

Scheme 70

Malfunction is detected when Engine Control Module (ECM) receives improper voltage signal through EGRC solenoid valve.

Turn ignition on. Select DATA MONITOR mode on scan tool. Wait at least 5 seconds. If first trip DTC is detected, go to TEST PROCEDURE . If first trip DTC is not detected, system is okay at this time. Problem may be intermittent. See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article.

1. Turn ignition off. Disconnect EGRC solenoid valve harness connector. (Scheme 71) Turn ignition on. Measure voltage between ground and EGRC solenoid valve harness connector Blue/Yellow wire. If battery voltage exists, go to next step. If battery voltage does not exist, repair open or short circuit. See appropriate wiring diagram in WIRING DIAGRAMS article.
2. Turn ignition off. Disconnect ECM harness connector. see scheme 1 Check continuity of Gray wire between EGRC solenoid valve harness connector and ECM harness connector terminal No. 103. see scheme 2 If continuity exists, go to next step. If continuity does not exist, repair open in Gray wire.
3. Check for short to power and short to ground in Gray wire between EGRC solenoid valve harness connector and ECM harness connector terminal No. 103. If problem exists, repair Gray wire as necessary. If problem does not exist, go to next step.
4. Remove EGRC solenoid valve. Using jumper wires, apply battery voltage and ground to EGRC solenoid valve terminals. see scheme 32 Air should flow between ports "A" and "B". Air should not flow between ports "A" and "C". Remove jumper wires. Air should not flow between ports "A" and "B". Air should flow between ports "A" and "C". EGRC solenoid valve should switch in one second or less. If EGRC solenoid valve does not operate as specified, replace EGRC solenoid valve. If EGRC solenoid valve operates as specified, go to next step.
5. No problem is indicated at this time. Problem may be intermittent. See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article.

Scheme 71

Malfunction is detected when EGR temperature sensor voltage is excessively low when engine coolant temperature is low.

Turn ignition on. Select DATA MONITOR mode on scan tool. Ensure engine coolant temperature is less than 104°F (40°C). If engine temperature is more than specified, allow engine to cool. Start engine and let idle for at least 8 seconds. If first trip DTC is detected, go to TEST PROCEDURE . If first trip DTC is not detected, go to DTC CONFIRMATION TEST "B" (OVERALL FUNCTION CHECK) .

DTC Confirmation Test "B" (Overall Function Check)

Malfunction is detected when EGR temperature sensor voltage is excessively high when engine coolant temperature is high.

Start engine and warm to normal operating temperature. Ensure EGR valve is not opening at idle. If EGR valve is opening at idle, go to DTC P1402: EGR FUNCTION. If EGR valve is not opening at idle, measure voltage between ground and ECM harness connector terminal No. 63 by backprobing. see scheme 2 With engine speed increased to 1500 RPM, fully open EGR valve by hand. Voltage should decrease to less than 1.5 volts. If voltage is as specified, perform diagnosis for DTC P0400 and P1400. See DTC P0400: EGR FUNCTION and DTC P1400: EGR CONTROL (EGRC) SOLENOID VALVE. If voltage is not as specified, go to TEST PROCEDURE.

1. Turn ignition off. Disconnect EGR temperature sensor harness connector located near EGR Control-Back Pressure Transducer (EGRC-BPT) valve. Turn ignition on. Measure voltage between ground and EGR temperature sensor harness connector White/Purple wire. If voltage is about 5 volts, go to next step. If voltage is not about 5 volts, repair open or short in White/Purple wire between EGR temperature sensor and ECM harness connector terminal No. 63.
2. Turn ignition off. Check continuity between ground and EGR temperature sensor harness connector Black/Yellow wire. If continuity exists, go to next step. If continuity does not exist, repair open in Black/Yellow wire.
3. Check for short to power and short to ground in Black/Yellow wire between EGR temperature sensor and ECM harness connector terminal No. 43 or Transmission Control Module (TCM) harness connector terminal No. 42. If problem exists, repair Black/Yellow wire as necessary. If problem does not exist, go to next step.
4. Remove EGR temperature sensor. Measure resistance between EGR temperature sensor terminals with EGR temperature sensor at specified temperatures. See «EGR TEMPERATURE SENSOR RESISTANCE»(ref-3202-S14601499912000041900000) table. If resistance is not as specified, replace EGR temperature sensor. If resistance is as specified, go to next step.
5. No problem is indicated at this time. Problem may be intermittent. See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article.

EGR TEMPERATURE SENSOR RESISTANCE

Malfunction is detected when EGR flow is detected under conditions that do not call for EGR.

Turn ignition on. Select DATA MONITOR mode on scan tool. Ensure engine coolant temperature is 14-86°F (-10-30°C) and EGR temperature sensor voltage is less than 4.8 volts. Start engine and let idle for at least 60 seconds. Turn ignition off. Wait at least 5 seconds. Repeat previous steps. Turn ignition on. Check for DTC P1402 on scan tool. If DTC P1402 is present, go to TEST PROCEDURE . If DTC P1402 is not present, problem may be intermittent. See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article.

1. Turn ignition off. Inspect vacuum hoses for leaks, blockage or improper connection. See VACUUM DIAGRAMS article. If problem exists, repair hose(s) as necessary. If problem does not exist, turn ignition off. Disconnect ECM harness connector. see scheme 1 Turn ignition on. Connect a jumper wire between ground and Engine Control Module (ECM) harness connector terminal No. 103. see scheme 2 Listen for EGR Control (EGRC) solenoid valve operating sound while connecting and disconnecting jumper wire. If operating sound is heard, go to next step. If operating sound is not heard, repair circuit or replace EGRC solenoid valve.
2. Remove EGRC solenoid valve. Using jumper wires, apply battery voltage and ground to EGRC solenoid valve terminals. see scheme 32 Air should flow between ports "A" and "B". Air should not flow between ports "A" and "C". Remove jumper wires. Air should not flow between ports "A" and "B". Air should flow between ports "A" and "C". EGRC solenoid valve should switch in one second or less. If EGRC solenoid valve does not operate as specified, replace EGRC solenoid valve. If EGRC solenoid valve operates as specified, go to next step.
3. Disconnect hose from EGR valve and connect hand vacuum pump to EGR port. Using hand vacuum pump, apply vacuum to EGR valve and observe valve movement. If EGR valve moves when vacuum is applied, go to next step. If EGR valve does not move when vacuum is applied, replace EGR valve.
4. Remove EGR Control-Back Pressure Transducer (EGRC-BPT) valve. Plug one vacuum port and apply vacuum to other vacuum port. Vacuum should not hold. Apply pressure to backpressure port. Applied vacuum should now hold. If EGRC-BPT valve does not operate as specified, replace EGRC-BPT valve. If EGRC-BPT valve operates as specified, go to next step.
5. Remove EGR temperature sensor. With EGR temperature sensor at specified temperatures, measure resistance between EGR temperature sensor terminals. See «EGR TEMPERATURE SENSOR RESISTANCE»(ref-3202-S14601499912000041900000) table. If resistance is not as specified, replace EGR temperature sensor. If resistance is as specified, no problem is indicated at this time. Problem may be intermittent. See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article.

Malfunction is detected when canister purge flow is detected when EVAP-CPVCV is closed.

Start engine and warm to normal operating temperature. Turn ignition off. Wait at least 5 seconds. Start engine and let idle for at least 20 seconds. Select DATA MONITOR mode on scan tool. If first trip DTC is detected, go to TEST PROCEDURE . If first trip DTC is not detected, system is okay at this time. Problem may be intermittent. See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article.

1. Turn ignition off. Disconnect EVAP-CPVCV harness connector. (Scheme 55) Measure voltage between ground and EVAP-CPVCV harness connector Black/White wire. If battery voltage exists, go to next step. If battery voltage does not exist, repair open or short circuit. See appropriate wiring diagram in WIRING DIAGRAMS article.
2. Turn ignition off. Disconnect Engine Control Module (ECM) harness connector. Check continuity of Green/Black wire between EVAP-CPVCV harness connector and ECM harness connector terminal No. 5. If continuity exists, go to next step. If continuity does not exist, repair open in Green/Black wire.
3. Check for short to power and short to ground in Green/Black wire between EVAP-CPVCV harness connector and ECM harness connector terminal No. 5. If problem exists, repair Green/Black wire as necessary. If problem does not exist, go to next step.
4. Check connections and routing of hose connected to EVAP Control System Pressure Sensor (EVAP-CSPS). If problem exists, repair as necessary. If problem does not exist, go to next step.
5. Disconnect EVAP-CSPS harness connector. (Scheme 59) Check connector for water. If water is present, replace EVAP-CSPS. If water is not present, go to next step. CAUTION: DO NOT apply more than 5.91 in. Hg of vacuum or 2.9 psi (.20 kg/cm 2 ) to EVAP-CSPS. DO NOT reuse EVAP-CSPS that has been dropped from a height of 20" (.5 m) or more onto a hard surface such as concrete.
6. Remove EVAP-CSPS with harness connector connected. Disconnect hose from EVAP-CSPS. Turn ignition on. Using a hand vacuum pump, apply vacuum to EVAP-CSPS. With vacuum as specified, measure voltage between ground and ECM harness connector terminal No. 62 by backprobing. see scheme 2 See «EVAP CONTROL SYSTEM PRESSURE SENSOR VOLTAGE»(ref-3202-S07064023542000041900000) table under DTC P0450: EVAP CONTROL SYSTEM PRESSURE SENSOR (EVAP-CSPS). If voltage is not as specified, replace EVAP-CSPS. If voltage is as specified, go to next step.
7. Remove EVAP-CPVCV. Using jumper wires, apply battery voltage and ground to EVAP-CPVCV terminals. (Scheme 56) Check for airflow between ports "A" and "B". Air should flow. Remove jumper wires. Air should not flow. EVAP-CPVCV should switch in one second or less. If EVAP-CPVCV does not operate as specified, replace EVAP-CPVCV. If EVAP-CPVCV operates as specified, go to next step.
8. Remove EVAP Canister Vent Control Valve (EVAP-CVCV). Using jumper wires, apply battery voltage and ground to EVAP-CVCV terminals. (Scheme 58) Check for airflow between ports "A" and "B". Air should not flow. Remove jumper wires. Air should flow between ports "A" and "B". EVAP-CVCV should switch in one second or less. If EVAP-CVCV does not operate as specified, replace EVAP-CVCV and "O" ring. If EVAP-CVCV operates as specified, go to next step.
9. Check for blockage in water separator or hose to EVAP-CVCV. If problem exists, repair as necessary. If problem does not exist, remove EVAP canister with EVAP-CVCV attached. Attempt to drain water from EVAP canister. If water drains from EVAP canister, go to next step. If water does not drain from EVAP canister, go to step 11.
10. Weigh EVAP canister with EVAP-CVCV attached. If EVAP canister weighs less than 4.0 lbs. (1.8 kg), go to next step. If EVAP canister weighs more than 4.0 lbs. (1.8 kg), inspect EVAP canister for damage and check hose between water separator and EVAP canister for blockage or leak. If problem exists, repair hose or replace EVAP canister as necessary. If problem does not exist, check water separator for blockage or damage. Replace as necessary and retest system.
11. No problem is indicated at this time. Problem may be intermittent. See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article.

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

Turn ignition on. Select DATA MONITOR mode on scan tool. Start engine and drive vehicle at a speed of about 50 MPH for 15 minutes. If first trip DTC is detected, go to TEST PROCEDURE . If first trip DTC is not detected, problem may be intermittent. See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article.

1. Turn ignition off. Check for blockage in water separator or hose to EVAP Canister Vent Control Valve (EVAP-CVCV). See VACUUM DIAGRAMS article. If problem exists, repair as necessary. If problem does not exist, go to next step.
2. Remove EVAP-CVCV. Using jumper wires, apply battery voltage and ground to EVAP-CVCV terminals. (Scheme 58) Check for airflow between ports "A" and "B". Air should not flow. Remove jumper wires. Air should flow between ports "A" and "B". EVAP-CVCV should switch in one second or less. If EVAP-CVCV does not operate as specified, replace EVAP-CVCV and "O" ring. If EVAP-CVCV operates as specified, go to next step.
3. Remove EVAP canister with EVAP-CVCV attached. Attempt to drain water from EVAP canister. If water does not drain from EVAP canister, go to step 5. If water drains from EVAP canister, weigh EVAP canister with EVAP-CVCV attached. If EVAP canister weighs less than 4.0 lbs. (1.8 kg), go to step 5. If EVAP canister weighs more than 4.0 lbs. (1.8 kg), go to next step.
4. Inspect EVAP canister for damage and check hose between water separator and EVAP canister for blockage or leak. If problem exists, repair hose or replace EVAP canister as necessary. If problem does not exist, check water separator for blockage or damage. Replace as necessary and retest system.
5. Check for proper connection and routing of hose connected to EVAP Control System Pressure Sensor (EVAP-CSPS). If problem exists, repair as necessary. If problem does not exist, check EVAP-CSPS harness connectors for water. If water is present, replace EVAP-CSPS. If water is not present, go to next step.
6. Check EVAP Control System Pressure Sensor (EVAP-CSPS) function. See DTC CONFIRMATION TEST under «DTC P0450: EVAP CONTROL SYSTEM PRESSURE SENSOR (EVAP-CSPS)»(ref-3202-S11146958382000041900000). If EVAP-CSPS fault is detected, proceed with TEST PROCEDURE under «DTC P0450: EVAP CONTROL SYSTEM PRESSURE SENSOR (EVAP-CSPS)»(ref-3202-S11146958382000041900000). If EVAP-CSPS is okay, no problem is indicated at this time. Problem may be intermittent. See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article.

Malfunction is detected when EVAP system is not functioning properly or there is a leak in hose between EVAP Control System Pressure Sensor (EVAP-CSPS) and intake manifold.

Raise drive wheels and support vehicle. Start engine and warm to normal operating temperature. Turn ignition off. Wait at least 5 seconds. Start engine and wait at least 70 seconds. With engine idling, measure and record voltage between ground and ECM harness connector terminal No. 62 by backprobing. see scheme 2 While monitoring voltage, maintain the following conditions for at least one minute

1. A/C on.
2. Steering wheel turned fully.
3. Headlights on.
4. Rear window defogger on.
5. Engine speed at 3000 RPM.
6. Transmission in any forward gear.

EVAP-CSPS voltage should remain .1 volt less than voltage measured at idle for at least one second. If voltage is not as specified, go to

TEST PROCEDURE

. If voltage is as specified, problem may be intermittent. See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article.

1. Check EVAP canister for cracks and replace as necessary. Start engine and warm to normal operating temperature. Turn ignition off. Disconnect vacuum hose (on EVAP service port side) from EVAP Canister Purge Volume Control Valve (EVAP-CPVCV). Install vacuum gauge to port on EVAP-CPVCV. Go to next step.
2. Start engine and let idle for at least 80 seconds. Increase engine speed to 2000 RPM and observe vacuum gauge. Vacuum should exist. Release throttle and let engine idle. Vacuum should not exist. If vacuum is as specified, go to step 5. If vacuum is not as specified, go to next step.
3. Turn ignition off. Ensure purge hoses are properly routed and connected. Disconnect purge hoses from EVAP-CPVCV. Ensure air flows freely through hoses and intake manifold purge port. If problem exists, repair as necessary. If problem does not exist, go to next step.
4. Remove EVAP Canister Purge Volume Control Valve (EVAP-CPVCV). Using jumper wires, apply battery voltage and ground to EVAP-CPVCV terminals. (Scheme 56) Check for airflow between ports "A" and "B". Air should flow. Remove jumper wires. Air should not flow. EVAP-CPVCV should switch in one second or less. If EVAP-CPVCV does not operate as specified, replace EVAP-CPVCV. If EVAP-CPVCV operates as specified, go to next step.
5. Turn ignition off. Check for proper connection and routing of hose connected to EVAP Control System Pressure Sensor (EVAP-CSPS). If problem exists, repair as necessary. If problem does not exist, disconnect EVAP-CSPS harness connector and check for water in connector. If water is present, replace EVAP-CSPS. If water is not present, go to next step.
6. Check EVAP Control System Pressure Sensor (EVAP-CSPS) function. See DTC CONFIRMATION TEST under «DTC P0450: EVAP CONTROL SYSTEM PRESSURE SENSOR (EVAP-CSPS)»(ref-3202-S11146958382000041900000). If EVAP-CSPS fault is detected, proceed with TEST PROCEDURE under «DTC P0450: EVAP CONTROL SYSTEM PRESSURE SENSOR (EVAP-CSPS)»(ref-3202-S11146958382000041900000). If EVAP-CSPS is okay, go to next step.
7. Remove EVAP Canister Vent Control Valve (EVAP-CVCV). Using jumper wires, apply battery voltage and ground to EVAP-CVCV terminals. (Scheme 58) Check for airflow between ports "A" and "B". Air should not flow. Remove jumper wires. Air should flow between ports "A" and "B". EVAP-CVCV should switch in one second or less. If EVAP-CVCV does not operate as specified, replace EVAP-CVCV and "O" ring. If EVAP-CVCV operates as specified, go to next step.
8. Start engine and warm to normal operating temperature. Turn ignition off. Disconnect closed throttle position switch harness connector. Check continuity between closed throttle position switch terminals No. 5 and 6. (Scheme 65) Continuity should exist when accelerator pedal is released. Continuity should not exist when accelerator pedal is depressed. If continuity is not as specified, replace closed throttle position switch. If continuity is as specified, go to next step.
9. Check EVAP purge line for leaks. If problem exists, clean or replace as necessary. If EVAP purge line is okay, clean purge line with compressed air. Test is complete. Problem may be intermittent. See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article.

Malfunction is detected when EVAP Canister Vent Control Valve (EVAP-CVCV) remains open under certain driving conditions.

Remove EVAP-CVCV. Using jumper wires, apply battery voltage and ground to EVAP-CVCV terminals. (Scheme 58) Check for airflow between ports "A" and "B". Air should not flow. Remove jumper wires. Air should flow between ports "A" and "B". EVAP-CVCV should switch in one second or less. If EVAP-CVCV does not operate as specified, go to TEST PROCEDURE. If EVAP-CVCV operates as specified, go to DIAGNOSTIC PROCEDURE under P0440 OR P1440: EVAP CONTROL SYSTEM SMALL LEAK.

1. Check for blockage in water separator and hose connected to EVAP-CVCV. If problem exists, repair as necessary. If problem does not exist, check EVAP-CVCV. See «DTC P0446: EVAP CANISTER VENT CONTROL VALVE (EVAP-CVCV)»(ref-3202-S39011910902000041900000). Replace EVAP-CVCV as necessary. If EVAP-CVCV is okay, check vacuum cut valve. See «DTC P1491: EVAP VACUUM CUT VALVE BY-PASS VALVE»(ref-3202-S28340831922000041900000). Replace vacuum cut valve as necessary. If vacuum cut valve is okay, go to next step.
2. Remove EVAP-CVCV. Using jumper wires, apply battery voltage and ground to EVAP-CVCV terminals. (Scheme 58) Check for airflow between ports "A" and "B". Air should not flow. Remove jumper wires. Air should flow between ports "A" and "B". EVAP-CVCV should switch in one second or less. If EVAP-CVCV does not operate as specified, replace EVAP-CVCV and "O" ring. If EVAP-CVCV operates as specified, go to next step.
3. Remove vacuum cut valve. Plug ports "C" and "D" with fingers. (Scheme 72) Apply vacuum to port "A" and check for vacuum at port "B". Vacuum should not exist at port "B". Apply vacuum to port "B" and check for vacuum at port "A". Vacuum should not exist at port "A". Blow air in port "B" and check for resistance to air flow out of port "A". Resistance to air flow should exist. Open ports "C" and "D". Blow air in port "A" and check for air flow out of port "C". Air should flow freely. Blow in port "B" and check for air flow out of port "D". Air should flow freely. If vacuum cut valve performs as specified, go to next step. If vacuum cut valve does not perform as specified, replace vacuum cut valve.
4. Remove EVAP canister with EVAP-CVCV attached. Attempt to drain water from EVAP canister. If water does not drain form EVAP canister, go to step 6. If water drains from EVAP canister, weigh EVAP canister with EVAP-CVCV attached. If EVAP canister weighs less than 4.0 lbs. (1.8 kg), go to step 6. If EVAP canister weighs more than 4.0 lbs. (1.8 kg), go to next step.
5. Inspect EVAP canister for damage and check hose between water separator and EVAP canister for blockage or leak. If problem exists, repair hose or replace EVAP canister as necessary. If problem does not exist, check water separator for blockage or damage. Replace as necessary and retest system.
6. Check for proper connection and routing of hose connected to EVAP Control System Pressure Sensor (EVAP-CSPS). If problem exists, repair as necessary. If problem does not exist, disconnect EVAP-CSPS harness connector and check for water in connector. If water is present, replace EVAP-CSPS. If water is not present, go to next step.
7. Check EVAP-CSPS function. See DTC CONFIRMATION TEST under «DTC P0450: EVAP CONTROL SYSTEM PRESSURE SENSOR (EVAP-CSPS)»(ref-3202-S11146958382000041900000). If EVAP-CSPS fault is detected, proceed with TEST PROCEDURE under «DTC P0450: EVAP CONTROL SYSTEM PRESSURE SENSOR (EVAP-CSPS)»(ref-3202-S11146958382000041900000). If EVAP-CSPS is okay, no problem is indicated at this time. Problem may be intermittent. See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article.

Scheme 72

Malfunction is detected when an improper voltage signal is sent to Engine Control Module (ECM) through vacuum cut valve by-pass valve.

Turn ignition on. Select DATA MONITOR mode on scan tool. Start engine. Wait at least 5 seconds. If first trip DTC is detected, go to TEST PROCEDURE . If first trip DTC is not detected, problem may be intermittent. See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article.

1. Turn ignition off. Disconnect vacuum cut valve by-pass valve harness connector. (Scheme 73) Turn ignition on. Measure voltage between ground and vacuum cut valve by-pass valve harness connector Blue/Yellow wire. If battery voltage exists, go to next step. If battery voltage does not exist, repair open or short circuit. See appropriate wiring diagram in WIRING DIAGRAMS article.
2. Turn ignition off. Disconnect ECM harness connector. see scheme 1 Check continuity of Blue/Green wire between EVAP vacuum cut valve by-pass valve harness connector and ECM harness connector terminal No. 120. see scheme 2 If continuity exists, go to next step. If continuity does not exist, repair open in Blue/Green wire.
3. Check for short to power and short to ground in Blue/Green wire between EVAP vacuum cut valve by-pass valve harness connector and ECM harness connector terminal No. 120. If problem exists, repair Blue/Green wire. If problem does not exist, go to next step.
4. Remove vacuum cut valve by-pass valve. Using jumper wires, apply battery voltage and ground to vacuum cut valve by-pass valve terminals. (Scheme 61) Air should flow between ports "A" and "B". Remove jumper wires. Air should not flow between ports "A" and "B". Vacuum cut valve by-pass valve should switch in one second or less. If vacuum cut valve by-pass valve does not operate as specified, replace vacuum cut valve by-pass valve. If vacuum cut valve by-pass valve operates as specified, go to next step.
5. No problem is indicated at this time. Problem may be intermittent. See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article.

Scheme 73

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

Go to TEST PROCEDURE .

1. Remove vacuum cut valve and vacuum cut valve by-pass valve as an assembly. Apply vacuum to vacuum cut valve port "A" and check for vacuum at port "B". (Scheme 72) Vacuum should not exist at port "B". Apply vacuum to port "B" and check for vacuum at port "A". Vacuum should not exist at port "A". Blow air in port "B" and check for resistance to air flow out of port "A". Resistance to air flow should exist. Go to next step.
2. apply battery voltage and ground to vacuum cut valve by-pass valve terminals. Blow air in vacuum cut valve port "A" and check for air flow out of port "B". Air should flow freely. Blow in port "B" and check for air flow out of port "A". Air should flow freely. If vacuum cut valve by-pass valve and vacuum cut valve perform as specified, go to next step. If vacuum cut valve by-pass valve or vacuum cut valve does not perform as specified, go to step 4.
3. Check EVAP purge line between EVAP canister and fuel tank for blockage or leak. Check EVAP purge port of fuel tank for blockage. Check EVAP canister for blockage. See EMISSION SYSTEMS & SUB-SYSTEMS in SYSTEM & COMPONENT TESTING article. If problem exists, repair as necessary. If problem does not exist, go to next step.
4. Check by-pass hoses for blockage. If problem exists, repair as necessary. If problem does not exist, go to next step.
5. Remove vacuum cut valve by-pass valve. Using jumper wires, apply battery voltage and ground to vacuum cut valve by-pass valve terminals. (Scheme 61) Air should flow between ports "A" and "B". Remove jumper wires. Air should not flow between ports "A" and "B". Vacuum cut valve by-pass valve should switch in one second or less. If vacuum cut valve by-pass valve does not operate as specified, replace vacuum cut valve by-pass valve. If vacuum cut valve by-pass valve operates as specified, go to next step.
6. Remove vacuum cut valve. Plug ports "C" and "D" with fingers. (Scheme 72) Apply vacuum to port "A" and check for vacuum at port "B". Vacuum should not exist at port "B". Apply vacuum to port "B" and check for vacuum at port "A". Vacuum should not exist at port "A". Blow air in port "B" and check for resistance to air flow out of port "A". Resistance to air flow should exist. Open ports "C" and "D". Blow air in port "A" and check for air flow out of port "C". Air should flow freely. Blow in port "B" and check for air flow out of port "D". Air should flow freely. If vacuum cut valve performs as specified, go to next step. If vacuum cut valve does not perform as specified, replace vacuum cut valve.
7. Check for proper connection and routing of hose connected to EVAP Control System Pressure Sensor (EVAP-CSPS). If problem exists, repair as necessary. If problem does not exist, disconnect EVAP-CSPS harness connector and check for water in connector. If water is present, replace EVAP-CSPS. If water is not present, go to next step.
8. Check EVAP Control System Pressure Sensor (EVAP-CSPS) function. See DTC CONFIRMATION TEST under «DTC P0450: EVAP CONTROL SYSTEM PRESSURE SENSOR (EVAP-CSPS)»(ref-3202-S11146958382000041900000). If EVAP-CSPS fault is detected, proceed with TEST PROCEDURE under «DTC P0450: EVAP CONTROL SYSTEM PRESSURE SENSOR (EVAP-CSPS)»(ref-3202-S11146958382000041900000). If EVAP-CSPS is okay, go to next step.
9. Remove EVAP Canister Vent Control Valve (EVAP-CVCV). Using jumper wires, apply battery voltage and ground to EVAP-CVCV terminals. (Scheme 58) Check for airflow between ports "A" and "B". Air should not flow. Remove jumper wires. Air should flow between ports "A" and "B". EVAP-CVCV should switch in one second or less. If EVAP-CVCV does not operate as specified, replace EVAP-CVCV and "O" ring. If EVAP-CVCV operates as specified, go to next step.
10. No problem is indicated at this time. Problem may be intermittent. See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article.

Malfunction is detected when ECM receives incorrect signal from Transmission Control Module (TCM).

Turn ignition on. Select DATA MONITOR mode on scan tool. Start engine. Wait at least 40 seconds. If first trip DTC is detected, go to TEST PROCEDURE . If first trip DTC is not detected, problem may be intermittent. See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article.

1. Turn ignition off. Disconnect ECM and Transmission Control Module (TCM) harness connectors. see scheme 1 TCM is located behind instrument panel, right side of steering column. Check continuity of Green/Black wire between TCM harness connector terminal No. 15 and ECM harness connector terminal No. 7. see scheme 2and (Scheme 66). If continuity exists, go to next step. If continuity does not exist, repair open in Green/Black wire.
2. Check for short to power and short to ground in Green/Black wire between TCM harness connector terminal No. 15 and ECM harness connector terminal No. 7. If problem exists, repair Green/Black wire. If problem does not exist, go to next step.
3. No problem is indicated at this time. Problem may be intermittent. See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article.

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

Turn ignition on. Measure voltage between ground and Engine Control Module (ECM) harness connector terminal No. 22 by backprobing. see scheme 2 With transmission in Park or Neutral, voltage should be about zero volts. With transmission in any other gear, voltage should be about 5 volts. If voltage is not as specified, go to TEST PROCEDURE. If voltage is as specified, problem may be intermittent. See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article.

1. Turn ignition off. Disconnect Transmission Control Module (TCM) harness connector, located behind instrument panel, to right of steering column. Turn ignition on. Measure voltage between ground and TCM harness connector terminal No. 36. (Scheme 66) With transmission in Park or Neutral, about zero volts should exist. With transmission in any other gear, about 5 volts should exist. If voltage is as specified, go to step 3. If voltage is not as specified, go to next step.
2. Turn ignition off. Disconnect PNP switch harness connector. (Scheme 74) Turn ignition on. Measure voltage between ground and PNP switch harness connector terminal No. 3 (Light Green wire). (Scheme 75) If battery voltage exists, go to next step. If battery voltage does not exist, repair open or short circuit. See appropriate wiring diagram in WIRING DIAGRAMS article.
3. Turn ignition off. Check continuity of Blue wires between TCM harness connector terminal No. 36 and PNP switch harness connector terminals No. 7 and 9. (Scheme 66)and (Scheme 75). If continuity exists, go to next step. If continuity does not exist, repair open in Blue wire(s).
4. Check for short to power and short to ground in Blue wires between TCM harness connector terminal No. 36 and PNP switch harness connector terminals No. 7 and 9. If problem exists, repair Blue wire(s). If problem does not exist, go to next step.
5. Check continuity of specified PNP switch terminals with gearshift in appropriate position. See «PNP SWITCH CONTINUITY»(ref-3202-S28898625062000041900000) table. If continuity is as specified, go to step 7. If continuity is not as specified, go to next step.
6. Disconnect gearshift cable and recheck continuity. If continuity is as specified, adjust gearshift cable. See appropriate appropriate AUTOMATIC TRANSMISSION article in TRANSMISSION SERVICING. If continuity is not as specified, remove PNP switch and recheck continuity. If continuity is as specified, adjust PNP switch. See appropriate AUTOMATIC TRANSMISSION article in TRANSMISSION SERVICING. If continuity is not as specified, replace PNP switch.
7. Turn ignition off. Disconnect ECM and TCM harness connectors. see scheme 1 TCM is located behind instrument panel, to right of steering column. Check continuity of Gray/Red wire between ECM harness connector terminal No. 22 and TCM harness connector terminal No. 14. see scheme 2and (Scheme 66). If continuity exists, go to next step. If continuity does not exist, repair open in Gray/Red wire.
8. Check for short to power and short to ground in Gray/Red wire between ECM harness connector terminal No. 22 and TCM harness connector terminal No. 14. If problem exists, repair Gray/Red wire. If problem does not exist, go to next step.
9. No problem is indicated at this time. Problem may be intermittent. See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article.

PNP SWITCH CONTINUITY

Scheme 74

Scheme 75