Diagnostic Procedure
WARNING: This page is about a different car, the 2002 Nissan Sentra. However, it is still accessible from the selected car via links, so may be relevant.
NOTE:
For circuit wiring diagram, see Fig 1
. For connector identification and locations, see CONNECTOR IDENTIFICATION
.
- If malfunction "A", "C" or "E" is present, go to next step. If malfunction "B" or "D" is present, go to step 3 .
- Check Intake System
Check the following connections:- Air duct.
- Vacuum hoses.
- Intake air passage between air duct and intake manifold collector.
If problem is found, repair as necessary. Perform appropriate DTC CONFIRMATION TEST to verify repair. If problem is not found, go to next step.
- Retighten Ground Screws
Turn ignition off. Loosen and retighten engine ground screws. See Figure . Go to next step. - Check Power Supply
Disconnect MAF sensor harness connector. See Fig 2 . Turn ignition on. Measure voltage between ground and MAF sensor harness connector terminals No. 2 and 4. See Fig 1 . About 5 volts should exist at terminal No. 2, and battery voltage should exist at terminal No. 4. If voltage is as specified, go to step 6 . If voltage is not as specified, go to next step. - Detect Malfunctioning Part
Check the following:- Joint connector No. 2.
- Harness for open or short between ECM relay and MAF sensor.
- Harness for open or short between ECM and MAF sensor.
Repair as necessary. Perform appropriate DTC CONFIRMATION TEST to verify repair.
- Check Ground Circuit
Turn ignition off. Disconnect ECM harness connector. Check continuity between MAF sensor harness connector terminal No. 3 and ECM harness connector terminal No. 73. See Fig 1 . Continuity should exist. Also, check harness for short to power. If problem is found, repair as necessary. Perform appropriate DTC CONFIRMATION TEST to verify repair. If problem is not found, go to next step. - Check Input Signal Circuit
Check continuity between MAF sensor harness connector terminal No. 1 and ECM harness connector terminal No. 61. See Fig 1 . Continuity should exist. Also, check harness for short to ground and short to power. If problem is found, repair as necessary. Perform appropriate DTC CONFIRMATION TEST to verify repair. If problem is not found, go to next step. - Check MAF Sensor
Reconnect all harness connectors. Start engine and warm to normal operating temperature. Check MAF sensor as shown in illustration. See Fig 3 . If MAF sensor is okay, go to next step. If MAF sensor is not okay, replace MAF sensor. Perform appropriate DTC CONFIRMATION TEST to verify repair. - Check For Intermittent
Check for intermittent condition. See INTERMITTENTS in TROUBLE SHOOTING - NO CODES article. Perform appropriate DTC CONFIRMATION TEST to verify repair.