2010 Cadillac Truck SRX AWD V6-2.8L Turbo 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.
