2010 Cadillac Truck SRX FWD V6-3.0L Page 220

2010 Cadillac Truck SRX FWD V6-3.0L Page 220

DTC B144B 02

- Run/Start Power Relay Circuit Short to Ground

DTC B144B 04

- Run/Start Power Relay Circuit Open

Diagnostic Fault Information

Circuit/System Description

The body control module (BCM) controls the RUN/CRNK relay through the control circuit by applying voltage to the run/crank relay coil control

circuit. The ignition RUN/CRNK is energized when the ignition mode is ON or START, or when a remote start is requested. This is part of the

BCM's primary function in controlling the vehicle power mode.

The keyless entry control module controls the backup power for the RUN/CRNK relay through the control circuit by applying voltage to the

run/crank ignition 1 voltage circuit. This circuit is a pass-thru in the BCM and will energize the RUN/CRNK when the ignition mode is ON or

START, or when a remote start is requested.

Conditions for Running the DTC

System voltage is greater than 9 V

Conditions for Setting the DTC

B144B 01

The run/crank output is not active and a short to battery is detected 3 consecutive times on the run/crank ignition 1 voltage circuit

B144B 02 - BCM

A short to ground is detected on the run/crank relay coil control circuit

B144B 02 - Keyless Entry Control Module

The run/crank output is active and a short to ground is detected 3 consecutive times on the run/crank ignition 1 voltage circuit

B144B 04

The run/crank output is not active and an open is detected 20 consecutive times on the run/crank ignition 1 voltage circuit

Action Taken When the DTC Sets

B144B 01, B144B 04

No action is taken

B144B 02

The RUN/CRANK relay is deactivated when the fault is set. After 100ms, the RUN/CRANK relay will be activated. If the fault is still set, the relay

will be deactivated. The RUN/CRANK relay will again be activated after 100ms. If this also results in a fault, the relay will be deactivated until a

new run/crank request is received.

Conditions for Clearing the DTC

* The current DTC will clear when the malfunction is no longer present and a run/crank request is received.

* A history DTC will clear after 40 malfunction-free ignition cycles.