PGM-FI System

MIL Circuit Troubleshooting (cont'd)

11-548  

  1. Check for continuity between ECM/PCM connector terminal A21 and body ground.

ECM/PCM CONNECTOR A (31P)

Wire side of female terminals

Is there continuity?

YES

- Repair short in the wire between the ECM/PCM (A21) and the MAP sensor.

NO

- Substitute a known-good ECM/PCM and recheck. If the symptom/indication goes away, replace the original ECM/PCM.


  1. Measure voltage between body ground and ECM/PCM connector terminal A20.

ECM/PCM CONNECTOR A (31P)

Wire side of female terminals

Is there about 5 V?

YES

- Go to step 62

NO

- Go to step 56.


  1. Turn the ignition switch OFF.
  1. Disconnect the 3P connector from each of these sensors, one at a time, and measure voltage between body ground and ECM/PCM connector terminal A20 with the ignition switch ON (II).
  • Exhaust gas recirculation (EGR) valve position sensor
  • Knock sensor
  • Throttle position (TP) sensor

ECM/PCM CONNECTOR A (31P)

Wire side of female terminals

Is there about 5 V?

YES

- Replace the sensor that restored about 5 V when disconnected.

NO

- Go to step 58.


  1. Turn the ignition switch OFF.
  2. Disconnect the 3P connector from the following sensors.
  • Exhaust gas recirculation (EGR) valve position sensor
  • Knock sensor
  • Throttle position (TP) sensor
  1. Disconnect ECM/PCM connector A (31P).