No Response From PCM
POSSIBLE CAUSES
- Fused B+ circuit open
- Fused engine control relay output circuit open
- PCM ground circuits
- SCI receive circuit open
- SCI receive circuit shorted to ground
- SCI receive circuit shorted to voltage
- SCI transmit circuit open
- SCI transmit circuit shorted to ground
- SCI transmit circuit shorted to voltage
- Sensor ground circuit open
- Sensor ground circuit shorted to voltage
- Powertrain control module
Diagnostic Test
1. FUSED B(+) CIRCUIT OPEN
Turn the ignition off.
Disconnect the PCM C5 harness connector.
NOTE: Check connector Clean/repair as necessary.
Turn the ignition on.
Measure the voltage of the Fused Ignition Switch Output circuit at the PCM C5 harness connector.
Q: Is the voltage above 10 volts?
YES: Go to 2
NO: Repair the Fused Ignition Switch Output circuit for an open.Perform POWERTRAIN VERIFICATION TEST - VER 2.
2. FUSED ENGINE CONTROL RELAY OUTPUT CIRCUIT OPEN
Turn the ignition on.
Measure the voltage of the Fused Engine Control Relay Output circuit at the PCM C5 harness connector.
Q: Is the voltage above 10 volts?
YES: Go to 3
NO: Repair the Fused Engine Control Relay Output circuit for an open. Perform POWERTRAIN VERIFICATION TEST - VER 2.
3. PCM GROUND CIRCUITS OPEN
Turn the ignition off.
Measure the resistance of the Ground circuits from the PCM C5 harness connector.
Q: Is the resistance below 5.0 ohms on each ground circuit?
YES: Go to 4
NO: Repair the Ground circuit(s) for an open.Perform POWERTRAIN VERIFICATION TEST - VER 2.
4. SCI RECEIVE CIRCUIT OPEN
With the ignition off.
Disconnect the PCM C4 harness connector.
NOTE: Check connector Clean/repair as necessary.
Measure the resistance of the PCM SCI Receive circuit from the PCM C4 harness connector to the DLC.
Q: Is the resistance below 5.0 ohms?
YES: Go to 5
NO: Repair the PCM SCI Receive circuit for an open.Perform POWERTRAIN VERIFICATION TEST - VER 2
5. SCI RECEIVE CIRCUIT SHORTED TO GROUND
With the ignition off.
Measure the resistance between ground and the PCM SCI Receive circuit.
Q: Is the resistance below 100 kiloohms?
YES: Repair the PCM SCI Receive circuit for a short to ground.Perform POWERTRAIN VERIFICATION TEST - VER 2.
NO: Go to 6
6. SCI RECEIVE CIRCUIT SHORTED TO VOLTAGE
Turn the ignition on.
Measure the voltage of the PCM SCI Receive circuit at the DLC.
Q: Is the voltage above 0.5 volt?
YES: Repair the PCM SCI Receive circuit for a short to voltage.Perform POWERTRAIN VERIFICATION TEST - VER 2.
NO: Go to 7
7. SCI TRANSMIT CIRCUIT OPEN
Turn the ignition off.
Measure the resistance of the PCM SCI Transmit circuit from the PCM harness connector to the DLC.
Q: Is the resistance below 5.0 ohms?
YES: Go to 8
NO: Repair the PCM SCI Transmit circuit for an open.Perform POWERTRAIN VERIFICATION TEST - VER 2.
8. SCI TRANSMIT CIRCUIT SHORTED TO GROUND
With the ignition off.
Measure the resistance between ground and the PCM SCI Transmit circuit.
Q: Is the resistance below 100 kohms?
YES: Repair the PCM SCI Transmit circuit for a short to ground.Perform POWERTRAIN VERIFICATION TEST - VER 2.
NO: Go to 9
9. SCI TRANSMIT CIRCUIT SHORTED TO VOLTAGE
Turn the ignition on.
Measure the voltage of the PCM SCI Transmit circuit at the DLC.
Q: Is the voltage above 0.5 volt?
YES: Repair the PCM SCI Transmit circuit for a short to voltage. Perform POWERTRAIN VERIFICATION TEST - VER 2.
NO: Go to 10
10. SENSOR GROUND CIRCUIT OPEN
Turn the ignition off.
Measure the resistance of the Sensor Ground circuit from the PCM C5 harness connector, cavity 10, to the DLC.
Q: Is the resistance below 5.0 ohms?
YES: Go to 11
NO: Repair the Sensor Ground circuit for an open.Perform POWERTRAIN VERIFICATION TEST - VER 2.
11. SENSOR GROUND CIRCUIT SHORTED TO VOLTAGE
Turn the ignition on.
Measure the voltage of the Sensor Ground circuit at the DLC.
Q: Is the voltage above 0.5 volt?
YES: Repair the Sensor Ground circuit for a short to voltage. Perform POWERTRAIN VERIFICATION TEST - VER 2.
NO: Replace the Powertrain Control Module.Perform POWERTRAIN VERIFICATION TEST -VER 2.