P1633
DTC P1633
Circuit Description
The engine control module (ECM) / powertrain control module (PCM) receives 2 ignition inputs from the ignition switch, ignition 1 signal, and ignition accessory signal. The ECM/PCM receives the crank input from a serial data message from the body control module (BCM). The ECM/PCM determines the state of the ignition switch based on these 3 inputs. If the ECM/PCM detects an improper ignition accessory 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
No class 2 serial data circuit problem.
Conditions for Setting the DTC
The ECM/PCM detects an improper ignition accessory input voltage.
Action Taken When the DTC Sets
* The ECM/PCM will not illuminate the malfunction indicator lamp (MIL).
* The ECM/PCM will store conditions which were present when the DTC set as Failure 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
