2010 Cadillac CTS Sedan AWD V6-3.6L Page 364

2010 Cadillac CTS Sedan AWD V6-3.6L Page 364

DTC B1440 00

- Power Mode Master Input Circuits Mismatch

DTC B1441 01

- Device Ignition OFF, RUN, and CRANK Circuit Short to Battery

DTC B1441 06

- Device Ignition OFF, RUN, and CRANK Circuit Short to Ground or Open

Diagnostic Fault Information

Circuit/System Description

The vehicle power mode master (PMM) is the body control module (BCM). The ignition switch is a low current switch with multiple discrete

ignition switch signals to the PMM for determination of the power mode. The PMM receives the ignition switch signals, and additionally a

reference voltage signal from the BCM, through the ignition switch, and back to the BCM. There are redundancies within the PMM system that can

allow operation of certain subsystems when there are faults in the ignition switch circuits. Other information such as serial data input from other

modules and DTCs is also used to determine what power mode signals and information is transmitted by the PMM. The BCM logic uses all this

information to identify the operator's desired power mode and activate specific discrete signals, and serial data messages for the operation of

different subsystems as necessary. Other modules which have switched voltage inputs may operate in a default mode if the PMM serial data

message does not match what the individual module can detect from its own connections.

The PMM will activate relays and other direct outputs of the PMM as needed according to the calculated power mode. Some relays controlled by

the BCM are switched ignition voltage outputs that are pass through circuits within the BCM directly from the ignition switch. If these circuits short

to ground, the B+ circuit fuse to the ignition switch will open.

Conditions for Running the DTC

B1370 01

Ignition switch is in the OFF or ACC positions.

B1370 06, B1380 01, B1441 01, B1441 06

Ignition switch is in the START position.

B1380 06, B1440 00

Ignition switch is in the RUN position.

Conditions for Setting the DTC

B1370 01

Ignition circuit is shorted to voltage.

B1370 06

* Ignition circuit is open.

* Ignition, accessory, or off/run/crank circuit shorted to ground.

* B+ circuit of the ignition switch is open or shorted to ground.