Pinpoint Test MAF - Mass Airflow Meter
| Circuit | PCM Pin | BOB Pin | Wire Color |
|---|---|---|---|
| MAF | 2Q | 27 | GRN/BLK |
| SIGRTN | 2C | 16 | BLK/LT GRN |
| VPWR | 1B | 37, 57 | YEL/WHT |
1) Turn ignition off. Connect BOB. Reconnect PCM. Turn ignition on. Measure voltage between BOB test pins MAF and SIGRTN, first with engine off, then with engine running. If voltage is not 1.0-1.5 volts with off, and 1.5-5.0 volts with engine running, go to next step. If voltage is as specified, MAF circuit is okay. Return to QUICK TESTS if sent here from there; otherwise temporarily substitute known good PCM and retest.
2) Turn ignition off. Unplug PCM connectors. Unplug MAF sensor connector, located between air cleaner and throttle body. Measure resistance between BOB test pin MAF and MAF terminal (Green/Black wire) on harness connector. If resistance is less than 5 ohms, go to next step. If resistance is not as specified, repair open Green/Black wire.
3) Measure resistance between BOB test pin MAF and ground. Measure resistance between BOB test pin MAF and BOB test pin VPWR. If both measurements are greater than 10,000 ohms, go to next step. If either measurement is not as specified, repair shorted MAF (Green/Black) wire.
4) Turn ignition on. Check for battery voltage at VPWR terminal (Yellow/White wire) at MAF harness connector. If battery voltage exists, go to next step. If battery voltage does not exist, go to PINPOINT TEST VPWR. If VPWR is okay, repair shorted Yellow/White wire.
5) Turn ignition off. Measure resistance between MAF harness connector SIGRTN terminal (Black/Light Green wire) and ground. If resistance is less than 5 ohms, replace MAF sensor. If resistance is not less than 5 ohms, repair Black/Light Green wire.