Engine Controls - System/component Tests: Other Nissan Quest I

Actuator

Disconnect vacuum hose from actuator, located on timing belt end of upper intake plenum. Apply and release vacuum at actuator diaphragm. If rod does not move, replace actuator.

Note. On some power valve control solenoids, port "C" may be a vent that is capped with a filter. Also, if solenoid does not respond as specified, perform test again, considering port "A" as port "B" and vice versa.

Control Solenoid

Disconnect vacuum lines and electrical connector from solenoid, located on timing belt end of engine, below power valve actuator. Apply vacuum to either port. Vacuum should hold. Apply battery voltage across solenoid connector terminals. Vacuum should NOT hold. Replace solenoid if it does not operate as specified.

Surge Tank & One-Way Check Valve

Apply vacuum to surge tank, mounted on firewall. Vacuum should hold. Apply vacuum to both sides of one-way check valve. Vacuum should hold in only one direction. Ensure valve is installed with holding side away from vacuum source.

Disconnect vacuum hose from actuator, located near flywheel end of intake manifold. Apply and release vacuum at actuator diaphragm. Replace actuator if rod does not move.

Note. On some swirl control valve solenoids, port "C" may be a vent that is capped with a filter. Also, if solenoid does not respond as specified, perform test again, considering port "A" as port "B" and vice versa.

1. Disconnect vacuum lines and electrical connector from solenoid, located near flywheel end of cylinder head. Remove solenoid. Apply vacuum to port "B" of solenoid. see scheme 28 Vacuum should now be available at port "C", but not at port "A".
2. Apply battery voltage across solenoid connector terminals. Vacuum should now be available at port "A", but not at port "C". Replace solenoid if it does not operate as specified.

Scheme 102

Scheme 103

ECM POWER & GROUND CIRCUITS (ALTIMA)

1. Turn ignition on. Measure voltage between ground and ECM harness connector terminals No. 38 (Orange wire) and No. 47 (Orange wire). (Scheme 102)and (Scheme 103). ECM is located under center of instrument panel (connector is on passenger's side). Battery voltage should be present. If battery voltage is present, go to step 3). If battery voltage is not present, go to next step.
2. Turn ignition off. Disconnect ECM harness connector. Check continuity between ground and ECM harness connector terminals No. 6 (Black wire), No. 13 (Black wire), No. 107 (Black wire), No. 108 (Black wire) and No. 116 (Black wire). (Scheme 102)and (Scheme 103). Continuity should exist. If continuity does not exist, repair harness or connectors. If continuity exists, check ECM pin terminals for damage or connection of ECM harness connector.
3. Turn ignition off. Disconnect ECM harness connector. Disconnect ECM relay. ECM relay is located next to ECM. Check continuity between ECM relay harness connector Orange wire (terminal No. 3) and ECM harness connector terminals No. 38 (Orange wire) and No. 47 (Orange wire). Continuity should exist. If continuity exists, go to next step. If continuity does not exist, repair harness or connectors.
4. Measure voltage between ground and ECM relay harness connector White wire (terminals No. 1 and 5). Battery voltage should be present. If battery voltage is present, go to next step. If battery voltage is not present, check for open in harness or connectors. Check 25-amp fusible link. Check continuity between ECM relay harness connector White wire and battery.
5. Measure voltage between ground and ECM harness connector terminal No. 46 (White wire). Battery voltage should be present. If battery voltage is present, go to next step. If battery voltage is not present, check for open in harness or connectors. Check 25-amp fusible link. Check continuity between ECM relay harness connector White wire and battery.
6. Check continuity between ground and ECM harness connector terminals No. 39 (Black wire) and No. 48 (Black wire). Continuity should exist. If continuity exists, go to next step. If continuity does not exist, repair harness or connectors.
7. Check continuity between ECM harness connector terminal No. 4 (White/Green wire) and ECM relay harness connector White/Green wire (terminal No. 2). Continuity should exist. If continuity exists, go to next step. If continuity does not exist, repair harness or connectors.
8. Turn ignition on. Measure voltage between ground and ECM harness connector terminal No. 36 (Black/Red wire). Battery voltage should be present. If battery voltage is present, check ECM relay. See RELAYS under «RELAYS & SOLENOIDS»(ref-17400-S26910750242000122900000). If relay is okay, check ECM pin terminals and ECM harness connector terminals for damage or corrosion. If battery voltage is not present, check harness and connectors. Check continuity of Red/Black wire between ECM harness connector and ignition switch.

ECM POWER & GROUND CIRCUITS (MAXIMA VG30E)

1. Turn ignition on. Measure voltage between ground and ECM harness connector terminal No. 16 (Green/Orange wire). (Scheme 102)and (Scheme 103). ECM is located under center of instrument panel (connector is on driver's side). Approximately one volt should be present. Measure voltage between ground and ECM harness connector terminals No. 49 (White/Black wire) and No. 59 (White/Black wire). Battery voltage should be present. If voltages are as specified, go to step 3). If voltages are not as specified, go to next step.
2. Turn ignition off. Disconnect ECM harness connector. Connect jumper wire between ground and ECM terminal connector No. 16 (Green/Orange wire). Turn ignition on. Check continuity between battery terminal harness connector (White/Red wire at battery positive terminal) and ECM harness connector terminals No. 49 (White/Black wire) and No. 59 (White/Black wire). Continuity should exist. If continuity does not exist, check ECM relay. Relay is located in fusible link box next to battery. See «RELAYS»(ref-17400-S12256886262000122900000) under RELAYS & SOLENOIDS. If relay is okay, check ECM pin terminals and ECM harness connector terminals for damage or corrosion.
3. Turn ignition off. Disconnect ECM harness connector. Check continuity between ground and ECM harness connector terminals No. 10 (Black wire), No. 20 (Black wire), No. 50 (Black wire), No. 60 (Black wire), No. 107 (Black wire), No. 108 (Black wire) and No. 116 (Black wire). Continuity should exist. If continuity does not exist, check chassis and engine ground connections. If ground connections are okay, repair harness or connectors.

ECM POWER & GROUND CIRCUITS (MAXIMA VE30DE)

1. Turn ignition on. Measure voltage between ground and ECM harness connector terminals No. 49 (Red/Green wire), No. 59 (Red/Green wire) and No. 109 (Red/Green wire). (Scheme 102)and (Scheme 103). ECM is located under center of instrument panel (connector is on driver's side). Battery voltage should be present. If battery voltage is present, go to step 3). If battery voltage is not present, go to next step.
2. Turn ignition off. Disconnect ECM harness connector. Check continuity between ground and ECM harness connector terminals No. 10 (Black wire), No. 20 (Black wire), No. 107 (Black wire), No. 108 (Black wire) and No. 116 (Black wire). Continuity should exist. If continuity does not exist, repair harness or connectors. If continuity exists, check ECM pin terminals and ECM harness connector terminals for damage or corrosion.
3. Turn ignition off. Disconnect ECM harness connector. Disconnect ECM (ECCS) relay. Relay is located in fusible link box next to battery. Check continuity between ECM harness connector terminals No. 49 (Red/Green wire), No. 50 (Red/Green wire) and No. 109 (Red/Green wire) and ECM relay connector terminal No. 5 (White/Black wire). (Scheme 103) Continuity should exist. If continuity exists, go to next step. If continuity does not exist, check harness and connectors between ECM and ECM relay.
4. Measure voltage between ground and ECM relay harness connector terminals No. 2 (White/Blue wire) and No. 3 (White/Blue wire). (Scheme 103) Battery voltage should be present. If battery voltage is present, go to next step. If battery voltage is not present, check Brown fusible link. Check harness and connectors between ECM relay and battery.
5. Measure voltage between ground and ECM harness connector terminal No. 58 (White wire). Battery voltage should be present. If battery voltage is present, go to next step. If battery voltage is not present, check Brown fusible link. Check harness and connectors between ECM and battery.
6. Check continuity between ground and ECM harness connector terminals No. 50 (Black wire) and No. 60 (Black wire). Continuity should exist. If continuity exists, go to next step. If continuity does not exist, repair open in harness or connectors.
7. Check continuity between ECM harness connector terminal No. 16 (White/Black wire) and ECM relay harness connector terminal No. 1 (White/Black wire). (Scheme 103) Continuity should exist. If continuity exists, go to next step. If continuity does not exist, repair open in harness between ECM harness connector and ECM relay harness connector.
8. Turn ignition on. Measure voltage between ground and ECM harness connector terminal No. 45 (White/Green wire). Battery voltage should be present. If battery voltage is present, check ECM relay. See «RELAYS»(ref-17400-S12256886262000122900000) under RELAYS & SOLENOIDS. If relay is okay, check ECM pin terminals and ECM harness connector terminals for damage or corrosion. If battery voltage is not present, check harness and connectors. Check continuity of White/Green wire between ECM harness connector and ignition switch.

Scheme 104

ECM POWER & GROUND CIRCUITS (NX & SENTRA)

1. Start engine. If engine is running, go to next step. If engine will not start, turn ignition on. Measure voltage between ground and ECM harness connector terminal No. 36 (Black/Yellow wire).Battery voltage should be present. If battery voltage is present, go to step 7). If battery voltage is not present, repair open in Black/Yellow wire (1.6L) or Black/Red wire (2.0L) between ECM harness connector and ignition switch.
2. Turn ignition off. Measure voltage between ground and ECM harness connector terminals No. 46 (White wire) and No. 109 (Orange/Blue wire). Battery voltage should be present. If battery voltage is present, go to next step. If battery voltage is not present, check harness and connectors between ECM and battery. Check 25-amp fusible link.
3. Turn ignition on and off while measuring voltage between ground and ECM harness connector terminals No. 38 (Orange/Blue wire) and No. 47 (Orange/Blue wire). With ignition on and for a few seconds after turning ignition off, battery voltage should be present. A few seconds after turning ignition off, approximately zero volts should be present. If voltage is as specified, go to step 7). If battery voltage exists for more than a few seconds, check ECM relay. ECM relay is located next to ECM. See «RELAYS»(ref-17400-S12256886262000122900000) under RELAYS & SOLENOIDS.
4. If battery voltage does not exist for a few seconds, disconnect ECM harness connector. Disconnect ECM relay. Check continuity between ECM harness connector terminals No. 38 (Orange/Blue wire) and No. 47 (Orange/Blue wire) and ECM relay harness connector terminal No. 5 (Orange/Blue wire). (Scheme 104) Continuity should exist. If continuity exists, go to next step. If continuity does not exist, repair open in Orange/Blue wire.
5. Measure voltage between ground and ECM relay harness connector terminals No. 1 (White wire) and No. 3 (White wire). (Scheme 104) Battery voltage should exist. If battery voltage exists, go to next step. If battery voltage does not exist, check harness and connectors.
6. Check continuity between ECM harness connector terminal No. 4 (White/Green wire) and ECM relay harness connector terminal No. 2 (White/Green wire). (Scheme 104) Continuity should exist. If continuity exists. check ECM relay. See «RELAYS»(ref-17400-S12256886262000122900000) under RELAYS & SOLENOIDS. If relay is okay, go to next step. If continuity does not exist, repair harness or connectors.
7. Turn ignition off. With ECM harness connector disconnected, check continuity between ground and ECM harness connector terminals No. 6, 13, 39, 48, 107, 108 and 116 (all wires are Black). Continuity should exist. If continuity exists, check ECM pin terminals and ECM harness connector terminals for damage or corrosion. If continuity does not exist, repair harness or connectors.

ECM POWER & GROUND CIRCUITS (PICKUP 2.4L)

1. Turn ignition on. Measure voltage between ground and ECM harness connector terminals No. 38 (Black/White wire), No. 47 (Black/White wire) and No. 109 (Black/White wire). (Scheme 102)and (Scheme 103). ECM is located under passenger's seat. Battery voltage should be present. If battery voltage is present, go to step 3). If battery voltage is not present, go to next step.
2. Turn ignition off. Disconnect ECM harness connector. Check continuity between ground and ECM harness connector terminals No. 6 (Black/Pink wire), No. 13 (Black/Pink wire), No. 107 (Black/Pink wire), No. 108 (Black/Pink wire) and No. 116 (Black/Pink wire). Continuity should exist. If continuity does not exist, repair harness or connectors. If continuity exists, check ECM pin terminals and ECM harness connector terminals for damage or corrosion.
3. Turn ignition off. Disconnect ECM harness connector. Disconnect ECM (ECCS) relay. Relay is located in relay box on right front inner fender panel. Check continuity between ECM harness connector terminals No. 38 (Black/White wire), No. 47 (Black/White wire) and No. 109 (Black/White wire) and ECM relay connector terminal No. 5 (Black/White wire). (Scheme 104) Continuity should exist. If continuity exists, go to next step. If continuity does not exist, check harness and connectors between ECM and ECM relay.
4. Measure voltage between ground and ECM relay harness connector terminals No. 1 (White wire) and No. 3 (White wire). (Scheme 104) Battery voltage should be present. If battery voltage is present, go to next step. If battery voltage is not present, check Brown fusible link. Check harness and connectors between ECM relay and battery.
5. Check continuity between ground and ECM harness connector terminals No. 39 (Black wire) and No. 48 (Black wire). Continuity should exist. If continuity exists, go to next step. If continuity does not exist, repair open in harness or connectors.
6. Check continuity between ECM harness connector terminal No. 4 (Blue/Red wire) and ECM relay harness connector terminal No. 2 (Blue/Red wire). (Scheme 104) Continuity should exist. If continuity exists, go to next step. If continuity does not exist, repair open in harness between ECM harness connector and ECM relay harness connector.
7. Turn ignition on. Measure voltage between ground and ECM harness connector terminal No. 36 (Black/White wire). Battery voltage should be present. If battery voltage is present, check ECM relay. See «RELAYS»(ref-17400-S12256886262000122900000) under RELAYS & SOLENOIDS. If relay is okay, check ECM pin terminals and ECM harness connector terminals for damage or corrosion. If battery voltage is not present, check harness and connectors. Check continuity of White/Green wire between ECM harness connector and ignition switch.

ECM POWER & GROUND CIRCUITS (PATHFINDER & PICKUP 3.0L)

1. Turn ignition on. Measure voltage between ground and ECM harness connector terminals No. 38 (Black/White wire), No. 47 (Black/White wire) and No. 109 (Black/White wire). (Scheme 102)and (Scheme 103). ECM is located under passenger's seat. Battery voltage should be present. If battery voltage is present, go to step 3). If battery voltage is not present, go to next step.
2. Turn ignition off. Disconnect ECM harness connector. Check continuity between ground and ECM harness connector terminals No. 6 (Black wire), No. 13 (Black wire), No. 107 (Black wire), No. 108 (Black wire) and No. 116 (Black wire). Continuity should exist. If continuity does not exist, repair harness or connectors. If continuity exists, check ECM pin terminals and ECM harness connector terminals for damage or corrosion.
3. Turn ignition off. Disconnect ECM harness connector. Disconnect ECM (ECCS) relay. Relay is located in relay box on right front inner fender panel. Check continuity between ECM harness connector terminals No. 38 (Black/White wire), No. 47 (Black/White wire) and No. 109 (Black/White wire) and ECM relay connector terminal No. 5 (Black/White wire). (Scheme 104) Continuity should exist. If continuity exists, go to next step. If continuity does not exist, check harness and connectors between ECM and ECM relay.
4. Measure voltage between ground and ECM relay harness connector terminals No. 2 (White wire) and No. 3 (White wire). (Scheme 104) Battery voltage should be present. If battery voltage is present, go to next step. If battery voltage is not present, check Brown fusible link. Check harness and connectors between ECM relay and battery.
5. Check continuity between ground and ECM harness connector terminals No. 39 (Black wire) and No. 48 (Black wire). Continuity should exist. If continuity exists, go to next step. If continuity does not exist, repair open in harness or connectors.
6. Check continuity between ECM harness connector terminal No. 4 (White/Red wire) and ECM relay harness connector terminal No. 1 (White/Red wire). (Scheme 104) Continuity should exist. If continuity exists, go to next step. If continuity does not exist, repair open in harness between ECM harness connector and ECM relay harness connector.
7. Turn ignition on. Measure voltage between ground and ECM harness connector terminal No. 36 (Black/White wire). Battery voltage should be present. If battery voltage is present, check ECM relay. See «RELAYS»(ref-17400-S12256886262000122900000) under RELAYS & SOLENOIDS. If relay is okay, check ECM pin terminals and ECM harness connector terminals for damage or corrosion. If battery voltage is not present, check harness and connectors.

ECM POWER & GROUND CIRCUITS (QUEST)

1. Turn ignition on. Measure voltage between ground and ECM harness connector terminals No. 38 (Red/Black wire), No. 47 (Red/Black wire) and No. 109 (Red/Black wire). (Scheme 102)and (Scheme 103). ECM is located behind glove box. Battery voltage should be present. If battery voltage is present, go to step 3). If battery voltage is not present, go to next step.
2. Turn ignition off. Disconnect ECM harness connector. Check continuity between ground and ECM harness connector terminals No. 6 (Black wire), No. 13 (Black wire), No. 107 (Black wire), No. 108 (Black wire) and No. 116 (Black wire). Continuity should exist. If continuity does not exist, repair harness or connectors. If continuity exists, check ECM pin terminals and ECM harness connector terminals for damage or corrosion.
3. Turn ignition off. Disconnect ECM harness connector. Disconnect ECM (ECCS) relay. Relay is located in fusible link box next to battery. Check continuity between ECM harness connector terminals No. 38 (Red/Black wire), No. 47 (Red/Black wire) and No. 109 (Red/Black wire) and ECM relay connector terminal No. 5 (Red/Black wire). (Scheme 104) Continuity should exist. If continuity exists, go to next step. If continuity does not exist, check harness and connectors between ECM and ECM relay.
4. Measure voltage between ground and ECM relay harness connector terminals No. 1 (Red wire) and No. 3 (Red wire). (Scheme 104) Battery voltage should be present. If battery voltage is present, go to next step. If battery voltage is not present, check 25-amp fusible link. Check harness and connectors between ECM relay and battery.
5. Check continuity between ground and ECM harness connector terminals No. 39 (Black/Red wire) and No. 48 (Black/Red wire). Continuity should exist. If continuity exists, go to next step. If continuity does not exist, repair open in harness or connectors.
6. Check continuity between ECM harness connector terminal No. 4 (White/Green wire) and ECM relay harness connector terminal No. 2 (White/Green wire). (Scheme 104) Continuity should exist. If continuity exists, go to next step. If continuity does not exist, repair open in harness between ECM harness connector and ECM relay harness connector.
7. Turn ignition on. Measure voltage between ground and ECM harness connector terminal No. 36 (Blue/Yellow wire). Battery voltage should be present. If battery voltage is present, check ECM relay. See RELAYS under «RELAYS & SOLENOIDS»(ref-17400-S26910750242000122900000). If relay is okay, check ECM pin terminals and ECM harness connector terminals for damage or corrosion. If battery voltage is not present, check harness and connectors. Check 10-amp fuse. Check harness and connectors between ECM and ignition switch.

ECM POWER & GROUND CIRCUITS (240SX)

1. Turn ignition on. Measure voltage between ground and ECM harness connector terminals No. 38 (Black/White wire) and No. 47 (Black/White wire). (Scheme 102)and (Scheme 103). ECM is located behind right front kick panel. Battery voltage should be present. If battery voltage is present, go to step 3). If battery voltage is not present, go to next step.
2. Turn ignition off. Disconnect ECM harness connector. Check continuity between ground and ECM harness connector terminals No. 6 (Black wire), No. 13 (Black wire), No. 107 (Black wire), No. 108 (Black wire) and No. 116 (Black wire). Continuity should exist. If continuity does not exist, repair harness or connectors. If continuity exists, check ECM pin terminals and ECM harness connector terminals for damage or corrosion.
3. Turn ignition off. Disconnect ECM harness connector. Disconnect ECM (ECCS) relay. Relay is located in relay box behind battery. Check continuity between ECM harness connector terminals No. 38 (Black/White wire) and No. 47 (Black/White wire) and ECM relay connector terminal No. 3 (Black/White wire). (Scheme 104) Continuity should exist. If continuity exists, go to next step. If continuity does not exist, check harness and connectors between ECM and ECM relay.
4. Measure voltage between ground and ECM relay harness connector terminals No. 1 (Red wire) and No. 5 (Red wire). (Scheme 104) Battery voltage should be present. If battery voltage is present, go to next step. If battery voltage is not present, check Brown fusible link. Check harness and connectors between ECM relay and battery.
5. Check voltage between ground and ECM harness connector terminal No. 46 (Red wire). Battery voltage should be present. If battery voltage is present, go to next step. If battery voltage is not present, check harness and connectors. Check Brown fusible link. Check harness between ECM and battery.
6. Check continuity between ground and ECM harness connector terminals No. 39 (Black wire) and No. 48 (Black wire). Continuity should exist. If continuity exists, go to next step. If continuity does not exist, repair open in harness or connectors.
7. Check continuity between ECM harness connector terminal No. 4 (Red/Black wire) and ECM relay harness connector terminal No. 2 (Red/Black wire). (Scheme 104) Continuity should exist. If continuity exists, go to next step. If continuity does not exist, repair open in harness between ECM harness connector and ECM relay harness connector.
8. Turn ignition on. Measure voltage between ground and ECM harness connector terminal No. 36 (Black/Red wire). Battery voltage should be present. If battery voltage is present, check ECM relay. See «RELAYS»(ref-17400-S12256886262000122900000) under RELAYS & SOLENOIDS. If relay is okay, check ECM pin terminals and ECM harness connector terminals for damage or corrosion. If battery voltage is not present, check harness and connectors between ECM and ignition switch.

ECM POWER & GROUND CIRCUITS (300ZX)

1. Turn ignition on. Measure voltage between ground and ECM harness connector terminal No. 16 (Orange wire). (Scheme 102)and (Scheme 103). ECM is located behind glove box. 0.8-1.0 volt should be present. Measure voltage between ground and ECM harness connector terminals No. 49 (White wire), No. 59 (White wire) and No. 109 (White wire). Battery voltage should be present. If voltages are as specified, go to step 3). If voltages are not as specified, go to next step.
2. Check ECM (ECCS) relay. Relay is located in fuse box at left front of engine compartment. See «RELAYS»(ref-17400-S12256886262000122900000) under RELAYS & SOLENOIDS. Check Green fusible link. Fusible link is located in fusible link box next to battery. Check continuity between ECM relay and battery positive terminal. Check continuity of Orange wire between ECM harness connector terminal No. 16 and ECM relay.
3. Turn ignition off. Disconnect ECM harness connector. Check continuity between ground and ECM harness connector terminals No. 10 (Black wire), No. 20 (Black wire), No. 50 (Black wire), No. 60 (Black wire), No. 107 (Black wire), No. 108 (Black wire) and No. 116 (Black wire). Continuity should exist. If continuity does not exist, check chassis and engine ground connections. If ground connections are okay, repair harness or connectors.

ENGINE SENSORS & SWITCHES

Note. For ECM connector terminal identification, see PIN VOLTAGE CHART S or WIRING DIAGRAMS articles.

MASS AIRFLOW SENSOR

Faults in mass airflow sensor circuit may set Code 12. To test system, see CODE 12 diagnostic procedures in TESTS W/CODES article.

1. To test airflow sensor, warm engine to operating temperature. Pull rubber protector away from mass airflow sensor connector so terminals can be backprobed. At mass airflow sensor connector, measure voltage at Orange wire (Altima, NX and Sentra), or White/Blue (Quest), or White wire (all others).
2. If voltage is not as specified in «MASS AIRFLOW SENSOR VOLTAGE TEST»(ref-17400-S32854732892000122900000) table, check for dust or foreign material in hot wire air passage of mass airflow sensor. If air passage is okay, replace mass airflow sensor.

Note. On 300ZX, measure voltage at White wire terminal closest to Orange wire terminal; other White wire is for power supply.

MASS AIRFLOW SENSOR VOLTAGE TEST (1)

A/C SWITCH

See PIN VOLTAGE CHARTS article.

AIR TEMPERATURE SENSOR (PICKUP 2.4L)

Faults in air temperature sensor circuit may set Code 41. To test system, see CODE 41 diagnostic procedures in TESTS W/CODES - 2.4L article.

To test sensor, disconnect sensor connector. Sensor is on air cleaner assembly. Measure resistance across sensor connector terminals. At 68°F (20°C), resistance should be about 2100-2900 ohms. At 176°F (80°C), resistance should be about 270-380 ohms. If resistance is not as specified, replace sensor.

CRANKSHAFT POSITION SENSOR

Faults in crankshaft position sensor circuit may set Code 11. To test system, see CODE 11 diagnostic procedures in TESTS W/CODES - 2.4L article.

Crankshaft position sensor is mounted on flywheel end of left cylinder head (Maxima VE30DE engine), or on front end of left cylinder head (300ZX). On all other vehicles, crankshaft position sensor is part of distributor.

1. To test crankshaft position sensor, remove crankshaft position sensor (or distributor). Leave wiring harness connected. On vehicles with distributor, disconnect secondary coil wire from distributor cap, and then connect wire to ground. On all vehicles, turn ignition on.
2. Connect logic probe or DVOM with an analog bar graph function to ground. While slowly rotating sensor shaft by hand, backprobe specified wire terminals of sensor connector. See «CRANKSHAFT POSITION SENSOR VOLTAGE TEST»(ref-17400-S32003367652000122900000) table.
3. If voltage does not fluctuate between 0 and 5 volts, check for damaged or dirty signal plate in crankshaft position sensor, and for shorted or open harness. If harness and signal plate are okay, replace crankshaft position sensor.

Note. It is possible to measure crankshaft position sensor voltage with a conventional DVOM without bar graph function; however, it may be difficult to determine peak voltage signal due to averaging of signal.

CRANKSHAFT POSITION SENSOR VOLTAGE TEST (1)

KNOCK (DETONATION) SENSOR

Faults in detonation sensor circuit may set Code 34. To test system, see CODE 34 diagnostic procedures in TESTS W/CODES - 2.4L article.

To test sensor, disconnect sensor connector. See DETONATION SENSOR LOCATION table. Check continuity between ground and sensor connector terminal. If there is no continuity, replace sensor. Check detonation sensor shield ground wire for continuity to ground. Ensure detonation sensor wire is not routed near spark plug wires or high-output electrical accessories. Discard any knock sensor which has been dropped or undergone shocks.

DETONATION SENSOR LOCATION

ENGINE (COOLANT) TEMPERATURE SENSOR

Faults in engine (coolant) temperature sensor circuit may set Code 13. To test system, see CODE 13 diagnostic procedures in appropriate TESTS W/CODES article.

To test sensor, disconnect sensor connector. See ENGINE (COOLANT) TEMPERATURE SENSOR LOCATION table. Measure resistance across sensor connector terminals. If resistance is not as specified in ENGINE (COOLANT) TEMPERATURE SENSOR RESISTANCE table, replace sensor.

ENGINE (COOLANT) TEMPERATURE SENSOR LOCATION

ENGINE (COOLANT) TEMPERATURE SENSOR RESISTANCE

Note. Oxygen sensor with a heater element is identified by 3-wire connector.

OXYGEN SENSOR (O2)

Faults in oxygen sensor circuit may set Code 33 (and/or Code 53 on 300ZX). To test system, see CODE 33 (and/or CODE 53) diagnostic procedures in TESTS W/CODES article.

To test HEATER element of Heated Oxygen Sensor (HO2S), check resistance between outer 2 terminals of 3-wire connector. If resistance is not 3-1000 ohms, replace sensor.

EXHAUST GAS TEMPERATURE SENSOR (CALIFORNIA)

Faults in exhaust gas temperature sensor circuit may set Code 35. To test system, refer to CODE 35 diagnostic procedures in appropriate TESTS W/CODES article.

To test sensor, place sensor in boiling water at 212°F (100°C). Resistance at 212°F (100°C) should be 76,770-93,830 ohms. As temperature increases, sensor resistance should decrease. If resistance is not as specified, replace sensor.

FUEL TEMPERATURE SENSOR (300ZX)

Faults in fuel temperature sensor circuit may set Code 42. To test system, see CODE 42 diagnostic procedures in TESTS W/CODES article.

To test sensor, disconnect sensor connector. Sensor is on top center of engine, left of centerline. Measure resistance between sensor connector terminal and ground. See FUEL TEMPERATURE SENSOR RESISTANCE table. If resistance is not as specified, replace sensor.

FUEL TEMPERATURE SENSOR RESISTANCE (1)

THROTTLE POSITION SENSOR (TPS)

Faults in TPS circuit may set Code 43. To test system, see CODE 43 diagnostic procedures in TESTS W/CODES article.

1. To test TPS, disconnect TPS connector. TPS is mounted on side of throttle body. While opening and closing throttle, check resistance across specified wire terminals of TPS connector. See THROTTLE POSITION SENSOR RESISTANCE TEST table. If resistance value does not change smoothly, replace TPS.
2. If resistance is not as specified, check harness. If harness is okay, adjust TPS. See «ADJUSTMENTS»(ref-17387) article. If resistance is still not as specified after adjustment, replace TPS.

THROTTLE POSITION SENSOR RESISTANCE TEST

VEHICLE SPEED SENSOR (ALTIMA, MAXIMA, NX, SENTRA, QUEST, 240SX & 300ZX)

Faults in vehicle speed sensor circuit may set Code 14. To test system, see CODE 14 diagnostic procedures in TESTS W/CODES article.

To test sensor, remove vehicle speed sensor from transmission. While rotating sensor shaft by hand, check AC voltage across sensor connector terminals. If about .5 volt AC is not present, replace sensor.

VEHICLE SPEED SENSOR (PATHFINDER & PICKUP)

Faults in vehicle speed sensor circuit may set Code 14. To test system, see CODE 14 diagnostic procedures in TESTS W/CODES article.

To test sensor, remove instrument cluster (sensor is a reed switch inside cluster). While slowly rotating speedometer drive receptacle, check continuity between terminals of instrument cluster connector. (Scheme 105) If continuity does not exist twice for each revolution, replace speedometer assembly.

Scheme 105

RELAYS

A variety of relays are used and can be tested 2 different ways. The following relays can be tested using an ohmmeter and remotely supplied power and ground circuits

1. Electronic Control Module (ECM or ECCS) relay.
2. Fuel pump relay.
3. Main relay.
4. Radiator/condenser (cooling) fan relay.
5. Mixture heater relay.
6. Neutral/inhibitor relay.

Safety relays can be tested using an ohmmeter, voltmeter and remote-ly supplied power and ground circuits. All testing procedures require proper identification of relay internals. See WIRING DIAGRAMS article.

Except Safety Relay

Turn ignition on. Ensure power to relay exists. Turn ignition off. Disconnect connector from relay being tested. Using ohmmeter, check for relay winding continuity across appropriate relay terminals. See WIRING DIAGRAMS article to identify proper relay terminals (wire colors) for testing. Energize relay and check continuity of relay output circuit.

EXAMPLE: Maxima Fuel Pump Relay

1. Turn ignition on. Ensure battery voltage exists at Blue wire of fuel pump relay. (Scheme 106) If battery voltage is not present at Blue wire, check for a blown 10-amp power fuse or an open circuit between fuse and relay.
2. Turn ignition off. Unplug fuel pump relay. Check for continuity across Blue wire and Blue/White wire terminals. If continuity does not exist, relay is defective. If continuity exists, connect ohmmeter leads across Orange wire and Black wire terminals. Energize relay by applying battery voltage to Blue wire terminal and ground to Blue/White wire terminal. Ensure continuity exists while relay is energized.

Scheme 106

Safety Relay

Turn ignition on and ensure power to relay exists. Turn ignition off. Disconnect safety relay connector. Using an ohmmeter, check one-way internal diode in safety relay by checking for continuity in both directions. Energize relay and check for voltage signal on relay output circuit.

EXAMPLE: Maxima Safety Relay

1. Turn ignition on. Using a voltmeter, check for battery voltage at Blue wire of safety relay. (Scheme 106) If voltage is not present, check for blown 10-amp fuse or open circuit between fuse and relay.
2. Turn ignition off. Disconnect safety relay connector. Using ohmmeter, check for continuity across relay's Black wire and Blue wire terminals. Reverse ohmmeter leads. Continuity should only exist in one direction. Connect voltmeter positive lead to Red/Blue wire terminal. Connect negative voltmeter lead to Black wire terminal. Apply battery voltage to Blue wire terminal and ground to Black wire terminal. Voltmeter should show battery voltage while relay is energized.

Air Injection Valve Control Solenoid

See AIR INJECTION under EMISSION SYSTEMS & SUB-SYSTEMS .

EGR Control Solenoid

See EXHAUST GAS RECIRCULATION (EGR) under EMISSION SYSTEMS & SUB-SYSTEMS .

Fast Idle Control Device (FICD) Solenoid

See FAST IDLE CONTROL DEVICE (FICD) under IDLE CONTROL SYSTEM .

Power Valve Control Solenoid

See POWER VALVE under AIR INDUCTION SYSTEMS .

Pressure Regulator Vacuum Relief (PRVR) Control Solenoid

See FUEL DELIVERY under FUEL SYSTEM .

Swirl Control Valve Control Solenoid

See SWIRL CONTROL VALVE under AIR INDUCTION SYSTEMS .

FUEL DELIVERY

Note. For fuel system pressure testing, see FUEL PRESSURE under FUEL SYSTEM in BASIC TESTING article.

Start Signal

If ECM receives incorrect start (cranking) signal, fuel delivery system may not operate properly. See START SIGNAL under IGNITION SYSTEMS.

Fuel Pressure Regulator

Connect fuel pressure gauge. Disconnect vacuum hose from fuel pressure regulator. Plug hose end. Connect hand-held vacuum pump to fuel pressure regulator. Start engine. Gradually apply vacuum to fuel pressure regulator. Compare fuel pressure to regulated pressure in FUEL PRESSURE table in BASIC TESTING article. If pressure is not as specified, replace fuel pressure regulator.

Fuel Pump Relay

See RELAYS under RELAYS & SOLENOIDS.

If ECM receives incorrect start (cranking) signal, fuel control system may not operate properly. See START SIGNAL under IGNITION SYSTEM.

Feedback System (Maxima VG30E, Pathfinder & Pickup)

1. Ensure ignition timing and idle speed are adjusted. Refer to «ADJUSTMENTS»(ref-17387) article. Warm engine to operating temperature. Run engine unloaded at 2000 RPM for 2 minutes. Green LED on ECM should flash at least 5 times during a 10-second period. If LED flashes less than 5 times, replace exhaust gas (oxygen) sensor. If LED does not flash, check exhaust gas (oxygen) sensor circuit.
2. Race engine 2-3 times, and allow it to idle. Enter self-diagnostic Mode II. See TESTS W/CODES article. With engine running unloaded at 2000 RPM, Green and Red LEDs on ECM should flash simultaneously more than 5 times during 10-second period. If LED does not respond as described, perform IDLE MIXTURE adjustment procedure in «ADJUSTMENTS»(ref-17387) article.

Feedback System (Altima, Maxima VE30DE, NX, Sentra, Quest, 240SX & 300ZX)

Ensure ignition timing and idle speed are adjusted. Refer to ADJUSTMENTS article. Warm engine to operating temperature. Run engine unloaded at 2000 RPM for 2 minutes. Enter self-diagnostic Mode II. See TESTS W/CODES article. If Red LED on ECM (or CHECK ENGINE light) does not flash at least 5 times in a 10-second period, perform IDLE MIXTURE adjustment procedure in ADJUSTMENTS article.

If ECM receives incorrect start (cranking) signal, idle control system may not operate properly. See START SIGNAL under IGNITION SYSTEM.

Note. Altima and Maxima use a thermal-mechanical device. See AIR REGULATOR TEST (ALTIMA & MAXIMA).

IGNITION SYSTEMS

Note. For basic ignition checks, see BASIC TESTING article.

Maxima (VE30DE Engine)

1. Disconnect power transistor connector. Check continuity between terminal "d" and terminals "a", "b", "c", "e", "f" and "g" of power transistor connector (check with polarity in one direction, and then with polarity in opposite direction). (Scheme 107)- (Scheme 109). If there is no continuity regardless of ohmmeter test lead polarity, replace power transistor.
2. If there is continuity, connect ohmmeter positive lead to terminal "d" and negative lead to terminals No. 1, 2, 3, 4, 5 and 6. If there is no continuity, replace power transistor. If there is continuity, reverse ohmmeter test lead polarity, checking continuity between the same terminals.
3. If there is continuity, replace power transistor. If there is no continuity, check continuity between the following terminals, noting ohmmeter test lead polarity: "a" (+) and No. 1 (-). "b" (+) and No. 2 (-). "c" (+) and No. 3 (-). "e" (+) and No. 4 (-). "f" (+) and No. 5 (-). "g" (+) and No. 6 (-).
4. If there is no continuity, replace power transistor. If there is continuity, reverse ohmmeter test lead polarity and check continuity between terminals listed in previous step. If there is continuity, replace power transistor. If there is no continuity, power transistor is okay.

Maxima (VG30E Engine)

1. Disconnect power transistor connector. (Scheme 107)- (Scheme 109). At power transistor connector, check continuity between the following terminals, noting ohmmeter test lead polarity: "a" (+) and "b" (-). "a" (+) and "c" (-).
2. If there is no continuity, replace power transistor. If there is continuity, reverse ohmmeter test lead polarity and check continuity between terminals listed in previous step. If there is continuity, replace power transistor. If there is no continuity, power transistor is okay.

Altima, NX, Sentra, Pathfinder, Pickup, Quest & 240SX

1. Disconnect power transistor connector. (Scheme 107)- (Scheme 109). At power transistor connector, check continuity between the following terminals, noting ohmmeter test lead polarity: "a" (+) and "b" (-). "a" (+) and "c" (-).
2. If there is continuity, replace power transistor. If there is no continuity, reverse ohmmeter test lead polarity and check continuity across terminals listed in previous step. If there is no continuity, replace power transistor. If there is continuity, power transistor is okay.

300ZX

1. Disconnect power transistor connector. Connect ohmmeter positive lead to terminal "g" and negative lead to terminals "a", "b", "c", "d", "e" and "f" of power transistor connector. (Scheme 107)- (Scheme 109). If there is continuity, replace power transistor.
2. If there is no continuity, reverse ohmmeter test lead polarity and check continuity between terminals listed in previous step. If there is no continuity, replace power transistor. If there is continuity, check continuity between terminal "g" and terminals No. 1, 2, 3, 4, 5 and 6 (check with polarity in one direction, and then with polarity in opposite direction).
3. There should be continuity regardless of ohmmeter test lead polarity. If there is no continuity, replace power transistor. If there is continuity, check continuity between the following terminals, noting ohmmeter test lead polarity: "a" (+) and No. 1 (-). "b" (+) and No. 2 (-). "c" (+) and No. 3 (-). "d" (+) and No. 4 (-). "e" (+) and No. 5 (-). "f" (+) and No. 6 (-).
4. If there is no continuity, replace power transistor. If there is continuity, reverse ohmmeter test lead polarity and check continuity between terminals listed in previous step. If there is continuity, replace power transistor. If there is no continuity, power transistor is okay.

Scheme 107

Scheme 108

Scheme 109

Timing Advance

Ignition timing advance is controlled by the ECM based upon sensor input signals. If timing problems are experienced, inspect input signals for proper operation. See PIN VOLTAGE CHARTS article. Inputs that affect timing include the following

1. Crank angle sensor.
2. Airflow meter.
3. Engine (coolant) temperature sensor.
4. Idle switch.
5. Start (cranking) signal.
6. Battery voltage.

Detonation (Knock) Retard

Faults in detonation retard circuit may set Code 34. To test system, see CODE 34 diagnostic procedures in TESTS W/CODES article. To test knock (detonation) sensor, see ENGINE SENSORS & SWITCHES.

Carbon Canister

Remove hoses from carbon canister. Blow air into canister ports as shown. (Scheme 110) Air should pass through vent and purge lines, but should not pass through vacuum lines.

Fuel Tank Vacuum Relief Valve

Valve is located in fuel tank filler cap. Wipe cap clean to prevent inhaling fuel vapors. Find a way to safely apply light vacuum to cap on side of cap that faces fuel tank. A slight resistance accompanied by clicks indicates the valve is okay. By applying more vacuum, resistance should no longer be felt and clicks should no longer be heard. If valve does not operate as specified, replace fuel tank filler cap.

Fuel Vapor Check Valve

Disconnect hoses from fuel vapor check valve. Apply light air pressure to fitting on side of valve that leads to fuel tank. Resistance should be felt, but some air should flow out of fitting that leads to carbon canister. Apply light air pressure to fitting that leads to carbon canister. Air should flow freely through valve. If valve does not operate as described, replace valve.

Scheme 110

If ECM receives an incorrect start (cranking) signal, EGR control solenoid may not operate properly. See START SIGNAL under IGNITION SYSTEMS .

EGR Function (Altima & 240SX - California)

Faults in EGR function circuit may set Code 32. To test function, see CODE 32 diagnostic procedures in G - TESTS CODES article.

EGR Function (Maxima - California)

Faults in EGR function circuit may set Code 32. To test function, see CODE 32 diagnostic procedures in TESTS W/CODES article.

EGR Function (NX & Sentra - California)

Faults in EGR function circuit may set Code 32. To test function, see CODE 32 diagnostic procedures in TESTS W/CODES article.

EGR Function (Pathfinder & Pickup - California)

Faults in EGR function circuit may set Code 32. To test function, see CODE 32 diagnostic procedures in TESTS W/CODES article.

EGR Function (Quest - California)

Faults in EGR function circuit may set Code 32. To test function, see CODE 32 diagnostic procedures in TESTS W/CODES article.

EGR Function (300ZX - California)

Faults in EGR function circuit may set Code 32. To test function, see CODE 32 diagnostic procedures in TESTS W/CODES article.

EGR Backpressure Transducer (EGR-BPT)

Plug one port of EGR backpressure transducer (EGR-BPT) and apply vacuum to other port. (Scheme 111)and (Scheme 112). Vacuum should NOT hold. Apply light pressure to bottom port (DO NOT apply more pressure than is necessary to cause vacuum to hold). If vacuum does not hold with pressure applied, replace EGR-BPT valve.

Scheme 111

Scheme 112

EGR Valve

Using a hand-held vacuum pump, apply vacuum to EGR valve diaphragm. (Scheme 113) Replace EGR valve if pintle does not open.

Scheme 113

Note. On some EGR control solenoids, port "C" may be a vent that is capped with a filter. Also, if solenoid does not respond as specified, perform test again, considering port "A" as port "B" and vice versa.

1. Disconnect vacuum lines and electrical connector from solenoid. Remove solenoid. Using hand-held vacuum pump, apply vacuum to port "B" of solenoid. see scheme 28 Vacuum should now be available at port "C", but not at port "A".
2. Apply battery voltage across solenoid connector terminals, ensuring polarity is correct to prevent solenoid damage. Vacuum should now be available at port "A", but not at port "C". Replace solenoid if it does not operate as specified.

POSITIVE CRANKCASE VENTILATION (PCV)

With engine idling, disconnect ventilation hose from PCV valve. If a hissing noise and strong vacuum are not present at hose end, check hose and hose connections for leaks or obstructions. Repair or replace as necessary.

MISCELLANEOUS CONTROLS

Note. Although some of the controlled devices listed here are not technically engine performance components, they can affect driveability if they malfunction.

CONDENSER COOLING FAN (240SX)

The ECM controls condenser cooling fan based on vehicle speed, engine coolant temperature and A/C switch position. Compare cooling fan operation with operation specified in A/C SWITCH ON OR OFF (240SX) table. If cooling fan does not operate as specified, see CONDENSER (COOLING) FAN CONTROL TEST.

A/C SWITCH ON OR OFF (240SX)

RADIATOR COOLING FANS (EXCEPT 240SX)

The ECM controls radiator cooling fan(s) based on vehicle speed, engine coolant temperature and A/C switch position. The following tables list correct cooling fan operation based on certain conditions. See appropriate A/C SWITCH ON or A/C SWITCH OFF table. If cooling fan does not operate as specified, see appropriate RADIATOR (COOLING) FAN CONTROL TEST. Tests are not available for Pathfinder and Pickup.

A/C SWITCH ON (ALTIMA)

A/C SWITCH OFF (ALTIMA)

A/C SWITCH ON (MAXIMA VE30DE ENGINE)

A/C SWITCH OFF (MAXIMA VE30DE ENGINE)

A/C SWITCH ON (MAXIMA VG30E ENGINE)

A/C SWITCH OFF (MAXIMA VG30E ENGINE)

A/C SWITCH ON (NX & SENTRA - 1.6L)

A/C SWITCH OFF (NX & SENTRA - 1.6L)

A/C SWITCH ON (NX & SENTRA - 2.0L A/T)

A/C SWITCH OFF (NX & SENTRA - 2.0L A/T)

A/C SWITCH ON (NX & SENTRA - 2.0L M/T)

A/C SWITCH OFF (NX & SENTRA - 2.0L M/T)

A/C SWITCH ON (QUEST)

A/C SWITCH OFF (QUEST)

A/C SWITCH ON (300ZX TURBO)

A/C SWITCH ON (300ZX NON-TURBO)

A/C SWITCH OFF (300ZX TURBO & NON-TURBO)