B1440

DTC B1440

CIRCUIT DESCRIPTION




The body control module (BCM) is the power mode master (PMM) responsible for sending ignition switch position information on the class 2 serial data link. The BCM monitors 3 discrete inputs from the ignition switch and the engine run flag (ERF) in order to determine the power mode. The BCM communicates this power mode information to all class 2 modules on the class 2 serial data link. The table represents correct BCM power mode data.

DTC DESCRIPTOR
This diagnostic procedure supports the following DTC:
DTC B1440 Power Mode Master Input Circuits Mismatch

CONDITIONS FOR RUNNING THE DTC
Battery positive voltage is 9-16 volts.

CONDITIONS FOR SETTING THE DTC




One of the 3 monitored ignition switch circuits has malfunctioned. The DTC will set if one of the situations shown is present.

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

CONDITIONS FOR CLEARING THE DTC
- A current DTC clears when the malfunction is no longer present for 1 second.
- A history DTC clears when the ignition cycle counter reaches the reset threshold, without a repeat of the malfunction.

TEST

Steps 1-7:

Steps 8-14: