Operation CHARM: Car repair manuals for everyone.

No ASD Relay Output Voltage At PCM

WHEN MONITORED
With the ignition key ON and battery voltage greater than 10 volts.

SET CONDITION
No voltage sensed at the Powertrain Control Module (PCM) when the Auto Shutdown (ASD) Relay is energized.

THEORY OF OPERATION
Whenever the PCM energizes the ASD relay, it checks the feedback circuit to ensure voltage is present at the ASD relay output.

- When the ASD relay is energized, the relay's contacts connect the fused B(+) circuit to the relay output circuit.

- The PCM is connected in parallel with the ASD relay output circuit, providing the PCM with a circuit to monitor the ASD relay output state.

If voltage is not present, a trouble code is set.

PROBABLE CAUSES
- ASD relay output circuit open
- Fused B(+) circuit open
- ASD relay
- Circuit in PCM