P1634

DTC P1634

DTC 1634:

DTC 1634 (cont'd) Step 8 - 19:

DTC 1634, STEP 20 - 22:

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 1 signal with the ignition switch in the ON and START positions. The PCM uses a Class II ignition mode message and voltage input from the ignition switch to test the ignition 1 voltage circuit. If the PCM detects an improper ignition 1 signal, DTC P1634 will set.

Conditions for Running the DTC

No Class II serial data circuit problem.

Conditions for Setting the DTC

The PCM detects an improper ignition 1 voltage signal.



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 information 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.