P1633

CIRCUIT DESCRIPTION
The powertrain control module (PCM) receives three ignition inputs from the ignition switch: ignition 0 signal, ignition 1 signal, and crank signal. The PCM receives the ignition 0 signal with the ignition switch in the CRANK position. The ignition switch sends this signal through the Off/Run/Crank voltage circuit. The PCM uses a Class II ignition mode message and voltage input from separate systems to test the Off/Run/Crank voltage circuit. If the PCM detects an improper ignition 0 signal, 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 1-5:

Steps 6-10: