Code 70, A/C Compressor Relay Driver: Notes

Relay is supplied voltage when ignition is on. PCM controls solenoid valve by providing a ground through one of its Quad-Driver Modules (QDM). When relay is actuated, terminal is grounded and its monitored voltage will be low. When an output is off, its terminal voltage will be high. Each QDM has a separate fault line to indicate presence of a current fault to control module central processor.

1. Tech 1 will enable circuit for 5 seconds.
2. This check can detect a partially shorted coil which would cause excessive current flow. Excessive current flow to a QDM will be detected as a fault and set a code.
3. The remaining checks will identify a circuit problem that has caused an excessive current flow or inoperative relay.