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 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 1-2:

Steps 3-4:

Steps 5-6:

Steps 7-10:

Steps 11-14: