Diagnostic Procedure "B"
WARNING: This page is about a different car, the 2002 Nissan Pathfinder and 2002 Infiniti QX4. However, it is still accessible from the selected car via links, so may be relevant.
- Start engine and allow to idle. Check intake air system for leaks. If no problem is found and CONSULT-II is available, go to next step. If no problem is found and CONSULT-II is not available, go to step 3 . If problem is found repair as necessary. After repair, repeat DTC CONFIRMATION TEST "B" .
- Turn ignition on. Select SWIRL CONT SOL VALVE in ACTIVE TEST mode with CONSULT-II. Touch ON and OFF on CONSULT-II screen. Listen for clicking sound from Swirl Control Valve (SCV) control solenoid valve. If valve does not click, go to next step. If valve clicks, go to step 6 .
- Turn ignition off. Disconnect SCV control solenoid valve 2-pin harness connector. See Figure . Turn ignition on. Measure voltage between ground and SCV control solenoid valve harness connector terminal No. 1 (Red/Yellow wire). If battery voltage does not exist, go to next step. If battery voltage exists, go to step 5 .
- Check following:
- Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors F23 and M32. See WIRING DIAGRAMS article.
- Check for poor, loose, corroded or damaged terminal connections in fuse block harness connector M10.
- Check fuse block fuse No. 16 (10-amp).
- Check for open or short in circuits between SCV control valve solenoid and fuse.
- Turn ignition off. Disconnect ECM 116-pin harness connector. For ECM location, see Figure . Check continuity of Green wire between SCV control solenoid valve harness connector terminal No. 2 and ECM harness connector terminal No. 29. See Figure . Continuity should exist. Also, check circuit for short to ground and short to voltage. If not problem is found, go to next step. If problem is found, repair as necessary. After repair, repeat DTC CONFIRMATION TEST "B" .
- Check vacuum hoses between intake manifold, SCV control solenoid valve and SCV actuator for leak, blockage or misrouting. See VACUUM DIAGRAMS article. If no problem is found and CONSULT-II is available, go to next step. If no problem is found and CONSULT-II is not available, go to step 8 . If problem is found, repair as necessary. After repair, repeat DTC CONFIRMATION TEST "B" .
- Connect any disconnected harness connectors. Start engine and allow to idle. Disconnect vacuum hose from SCV control solenoid valve. Select SWIRL CONT SOL VALVE in ACTIVE TEST mode with CONSULT-II. Touch ON and OFF on CONSULT-II screen. When SWIRL CONT SOL/V is ON vacuum should exist. When SWIRL CONT SOL/V is OFF vacuum should not exist. Swirl control valve on to off operation should take less than one second. If SCV valve operates as specified, go to step 9 . If SCV valve does not operate as specified, replace intake manifold collector. After repair, repeat DTC CONFIRMATION TEST "B" .
- Connect any disconnected harness connectors. Remove vacuum hose between SCV control solenoid valve and SCV control valve actuator. Start engine and let it idle. Using fused jumper wires, apply battery voltage between SCV control solenoid valve terminals. Vacuum should flow through SCV solenoid. Remove jumper wires. Vacuum should not flow. SCV control valve should switch in less than one second. If operation is as specified, go to next step. If operation is not as specified, replace intake manifold collector. After repair, repeat DTC CONFIRMATION TEST "B" .
- Reconnect vacuum hose between SCV control solenoid valve and SCV actuator. Start engine and allow to idle. Select SWIRL CONT SOL/V in ACTIVE TEST mode on CONSULT-II. Touch ON and OFF on CONSULT-II screen, while observing SCV actuator rod move as commanded. See Fig 1 . If SCV actuator rod move when commanded, go to step 11 . If SCV actuator rod does not move when commanded, replace SCV control valve and actuator. After repair, repeat DTC CONFIRMATION TEST "B" .
- Reconnect vacuum hose between SCV control solenoid valve and SCV actuator. With engine idling, reconnect jumper wires to SCV solenoid terminals. SCV actuator rod should move when SCV solenoid is energized. If operation is as specified, go to next step. If operation is not as specified, replace SCV and actuator. After repair, repeat DTC CONFIRMATION TEST "B" .
- Turn ignition off. Disconnect vacuum hose from swirl control vacuum check switch. See Fig 2
. Backprobing at ECM, measure voltage between ground and ECM terminal No. 55 (White/Black wire). See Figure
. Using a hand vacuum pump, apply specified amount of vacuum to swirl control vacuum check switch. See SWIRL CONTROL VACUUM CHECK SWITCH VOLTAGE
table. If voltage is as specified, go to next step. If voltage is not as specified, replace swirl control vacuum check switch. After repair, repeat DTC CONFIRMATION TEST "B"
.SWIRL CONTROL VACUUM CHECK SWITCH VOLTAGE
Vacuum - in. Hg (kPa) Volts More than 5.91 (20.0) Engine Ground 5.91-6.77 (20.0-23.0) Engine Ground Or About 4.8 Volts Less Than 6.77 (23.0) About 4.8 Volts - Reconnect all harness connectors and vacuum hoses. Start engine and warm to normal operating temperature. Backprobbing at ECM, measure voltage between ground and ECM terminal No. 61 (Orange wire) MAF sensor signal, with engine at specified speeds. See MASS AIRFLOW SENSOR VOLTAGE
table. If voltage is as specified and CONSULT-II is available, go to next step. If voltage is as specified and CONSULT-II is not available, go to step 14
. If voltage is not as specified, replace MAF sensor. After repair, repeat DTC CONFIRMATION TEST "B"
.MASS AIRFLOW SENSOR VOLTAGE
Condition Volts Key On, Engine Off About 1.0 Engine Idling 1.2-1.8 2500 RPM 1.6-2.2 Idle To 4000 RPM (1) 1.2-1.8 To About 4.0 (1) Voltage should increase in proportion to engine speed. - Start engine and warm to normal operating temperature. Turn ignition off, and then on. Select DATA MONITOR mode and observe THRTL POS SEN specified conditions. See THROTTLE POSITION SENSOR VOLTAGE (USING CONSULT-II)
table. Voltage measurement must be made with TP sensor installed. If TP sensor voltage is as specified, go to step 16
. If TP sensor voltage is not as specified, go to step 15
.THROTTLE POSITION SENSOR VOLTAGE (USING CONSULT-II)
Throttle Position THRTL POS SEN Parameter Fully Closed .15-.85 Partially Opened .15-.85 To 3.5-4.7 Fully Opened 3.5-4.7 - Start engine and warm to normal operating temperature. Turn ignition off, and then on. Backprobbing at ECM, measure voltage between ground and ECM terminal No. 91 (Red wire) TP sensor signal, with throttle valve in specified positions. See THROTTLE POSITION SENSOR VOLTAGE
table. If voltage is as specified, go to step 16
. If voltage is not as specified, go to next step.THROTTLE POSITION SENSOR VOLTAGE
Throttle Position Voltage Fully Closed .15-.85 Partially Opened .15-.85 To 3.5-4.7 Fully Opened 3.5-4.7 - Adjust closed throttle position switch. See THROTTLE POSITION SWITCH, IGNITION TIMING & IDLE SPEED in ON-VEHICLE ADJUSTMENTS article. If TP sensor can be adjusted, go to next step. If TP sensor voltage is still not as specified, replace TP sensor. After repair, repeat DTC CONFIRMATION TEST "B" .
- Remove Crankshaft Position (CKP) sensor (REF) located under crankshaft pulley. Inspect CKP sensor (REF) for chipping. If problem is found, replace as necessary. If no problem is found, measure resistance between CKP sensor (REF) terminals. If resistance is 470-570 ohms at 68°F (20°C), go to next step. If resistance is not 470-570 ohms at 68°F (20°C), replace CKP sensor (REF). After repair, repeat DTC CONFIRMATION TEST "B" .
- No problem is indicated at this time. Problem may be intermittent. See INTERMITTENTS in TROUBLE SHOOTING - NO CODES article.
CAUTION:
DO NOT use ECM ground terminals when measuring voltage.