B1440

DTC B1440

CIRCUIT DESCRIPTION
Class 2 communications will not start until the vehicle systems "on" power mode has been identified. Three discrete wires from the ignition switch contacts are monitored by the instrument cluster (IPC) in order to determine the present power mode (ignition switch position). The IPC communicates the system power mode to all class 2 modules on the class 2 serial data line.

CONDITIONS FOR RUNNING THE DTC
The IPC must be powered.

CONDITIONS FOR SETTING THE DTC
One of the three monitored ignition switch circuits has malfunctioned.

ACTION TAKEN WHEN THE DTC SETS
The IPC implements default actions for each ignition switch position when faults are detected.

CONDITIONS FOR CLEARING THE DTC
The power moding malfunction must be corrected and then the code can be cleared by using the scan tool. The code also clears after 100 ignition cycles.

Normal Device Power Moding:

NORMAL DEVICE POWER MODING

Code Setting Criteria (Fault) For Device Power Moding:

CODE SETTING CRITERIA (FAULT) FOR DEVICE POWER MODING

TEST

Steps 1 - 7: