- Check Ground Circuit Turn ignition switch to OFF position. Disconnect MAF sensor harness connector and ECM harness connector. see scheme 3and (Scheme 7). Loosen and retighten engine ground screws. Using an ohmmeter, check continuity between MAF sensor harness connector terminal No. 2 and ECM terminal No. 48 (White wire). If no continuity exists, repair open in White wire. If continuity exists, go to next step.
- Check Power Supply Turn ignition switch to ON position. Using a voltmeter, measure voltage between MAF sensor harness connector terminal No. 3 (White/Red wire) and ground. If battery voltage does not exist, repair fault in White/Red wire as required. If battery voltage exists, go to next step.
- Check Input Signal Circuit Check continuity between MAF sensor harness connector terminal No. 1 and ECM harness connector terminal No. 47 (Orange wire). If no continuity exists, repair open in Orange or Green wire. If continuity exists, go to next step.
- Check Component Warm engine to operating temperature. Inspect MAF sensor for cracks or damage. If no faults are found, pull rubber protector away from mass airflow sensor connector so terminals can be backprobed. At mass airflow sensor connector, measure voltage between terminal No. 1 and ground. (Scheme 7)
- If voltage not as specified in MASS AIRFLOW SENSOR VOLTAGE TEST 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.
| Application | Volts With KOEO (2) | Volts At Idle |
|---|
| 200SX | Less Than 1.0 | 1.3-1.7 |
| (1) Engine speed between idle and 4000 RPM; 1.0-4.0 volts. (2) Key On, Engine Off. |
| (1) | Engine speed between idle and 4000 RPM; 1.0-4.0 volts. |
MASS AIRFLOW SENSOR VOLTAGE TEST (1)
Scheme 7
