Diagnostic Procedure (2.4L)
WARNING: This page is about a different car, the 2002 Nissan Xterra and 2002 Nissan Frontier. However, it is still accessible from the selected car via links, so may be relevant.
- Turn ignition off. Loosen and retighten engine ground bolts. See Figure . Start engine and warm to normal operating temperature. If using CONSULT-II, go to next step. If not using CONSULT-II, go to step 3 .
- Select SELF-LEARNING CONT in WORK SUPPORT mode with CONSULT-II. Clear self-learning control coefficient by pressing CLEAR. Let engine idle for at least 10 minutes. If 1st trip DTC P0171 or P0172 is detected and engine is difficult to start, perform diagnosis for DTC P0171 or P0172. See DTC P0171, DTC P0172, DTC P0174 OR DTC P0175: FUEL INJECTION SYSTEM FUNCTION . If 1st trip DTC P0171 or P0172 is not detected and engine is not difficult to start, go to step 4 .
- Turn ignition off. Disconnect MAF sensor harness connector. See Figure . Start engine and let it idle for at least 5 seconds. Turn ignition off. Reconnect MAF sensor. Ensure DTC P0102 is set. Clear DTCs. Start engine and let it idle for at least 10 minutes. If 1st trip DTC P0171 or DTC P0172 is detected and engine is difficult to start, perform diagnosis for DTC P0171 or P0172. See DTC P0171, DTC P0172, DTC P0174 OR DTC P0175: FUEL INJECTION SYSTEM FUNCTION . If 1st trip DTC P0171 or P0172 is not detected and engine is not difficult to start, go to next step.
- Disconnect HO2S2 harness connector. See Figure . Disconnect ECM harness connector. See Figure or Figure . Check continuity of Orange wire between HO2S2 harness connector terminal No. 1 and ECM harness connector terminal No. 56. See Figure . Also, check circuit for short to ground and short to voltage. If problem is found, repair as necessary. If problem is not found, go to next step.
- Check continuity between engine ground and HO2S2 harness connector terminal No. 4 (Yellow wire). Continuity should exist. Also, check circuit for short to voltage. If problem is found, repair as necessary. If problem is not found, go to next step.
- Reconnect all harness connectors. Start engine. Drive vehicle at a speed of more than 43 MPH for 2 consecutive minutes. Stop vehicle with engine running. If using CONSULT-II, go to next step. If not using CONSULT-II, go to step 8 .
- Using CONSULT-II, select FUEL INJECTION in ACTIVE TEST mode. Select HO2S2 (B1) as the monitor item. Adjust FUEL INJECTION to +25%. HO2S2 (B1) voltage should be more than .56 volt at least once. Adjust FUEL INJECTION to -25%. HO2S2 (B1) voltage should be less than .54 volt at least once. If operation is as specified, go to step 10 . If operation is not as specified, replace HO2S2.
- Measure voltage between ground and ECM terminal No. 56 by backprobing. While observing voltmeter, snap throttle to 4000 RPM at least 10 times. Voltage should be more than .56 volt at least once. If voltage is as specified, go to step 10 . If voltage is not as specified, go to next step.
- Let engine idle for 10 minutes, then measure voltage again. Or, measure voltage while coasting from 50 MPH in 3rd gear. Voltage should be less than .54 volt at least once. If voltage is as specified, go to next step. If voltage is not as specified, replace HO2S2.
- Turn ignition off. Remove Gray, 6-pin joint connector No. 1 (connector F31) located near ECM. See Figure
. Check the following:
- Check continuity between ground and connector F31 terminal No. 1 (Black/Yellow wire).
- Check continuity between each joint connector terminal.
Continuity should exist. Also, check circuit for short to voltage. If problem is found, repair as necessary. If problem is not found, go to next step.
- No problem is indicated at this time. Problem may be intermittent. See INTERMITTENTS in TROUBLE SHOOTING - NO CODES article.