Diagnostic Modes

When the diagnostic terminal is grounded with ignition On and the engine Off, the system will enter what is called the Diagnostic Mode. In this mode the PCM will:

^ Display a DTC 12 by flashing the malfunction indicator lamp (MIL) (indicating the system is operating correctly).
^ Display any stored diagnostic trouble codes by flashing the malfunction indicator lamp (MIL). Each diagnostic trouble code will be flashed three times, then DTC 12 will be flashed again, if no transaxle diagnostic trouble codes are present.
^ Energize all PCM controlled relays and solenoids except fuel pump relay. This allows checking circuits which may be difficult to energize without driving the vehicle and being under particular operating conditions.
^ The IAC valve will pulse in and out with a pause before moving each direction.