P1633

DTC P1633

Circuit Description

The powertrain control module (PCM) receives the following ignition inputs from the ignition switch:

- The ignition 0 signal.
- The ignition 1 signal.
- The crank signal.

The PCM uses a class 2 Ignition mode message and the voltage input from 2 separate systems to test the ignition 0 circuit. If the PCM detects an improper ignition 0 signal, DTC P1633 will set.

DTC Descriptor

This diagnostic procedure supports the following DTC:

- DTC P1633 Ignition 0 Switch Circuit.

Conditions for Running the DTC

There is no class 2 serial data circuit condition.

Conditions for Setting the DTC

The ignition 1 signal is present, but the ignition 0 signal is not.

Action Taken When the DTC Sets

- The control module stores the DTC information into memory when the diagnostic runs and fails.
- The malfunction indicator lamp (MIL) will not illuminate.
- The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Failure Records.
- The driver information center, if equipped, may display a message.

Conditions for Clearing the DTC

- A current DTC Last Test Failed clears when the diagnostic runs and passes.
- A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other non-emission related diagnostic.
- Clear the DTC with a scan tool.