P1633

CIRCUIT DESCRIPTION
The powertrain control module (PCM) receives two ignition inputs from the ignition switch: IGN 0, IGN 1, and a Class II message from the power mode master (PMM) module. The PCM receives the IGN 0 input with the ignition switch in OFF and RUN. The PCM uses a PMM Class II message, and the voltage input from the ignition switch to test the IGN 0 circuit. If the PCM detects an improper IGN 0 input, DTC P1633 will set.

CONDITIONS FOR RUNNING THE DTC
No Class II serial data circuit problem.

CONDITIONS FOR SETTING THE DTC
The PCM detects an improper IGN 0 input.

ACTION TAKEN WHEN THE DTC SETS
^ The PCM will not illuminate the malfunction indicator lamp (MIL).
^ The PCM will store conditions which were present when the DTC set as Fail Records only.

CONDITIONS FOR CLEARING THE DTC
^ The history DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction.
^ The DTC can be cleared by using the scan tool Clear DTC Information function.

TEST

Steps 1-7:

Steps 8-11: