2010 Cadillac Truck SRX AWD V6-2.8L Turbo Page 355
DTC B388A 02
- Trailer Park Lamps Circuit Short to Ground
DTC B388A 04
- Trailer Park Lamps Circuit Open
Diagnostic Fault Information
Circuit/System Description
The trailer park lamp relay is supplied with battery voltage at all times. The trailer park lamp signal circuit is grounded by turning the headlamp
switch. The body control module (BCM) energizes the trailer park lamp relay by applying ground to the trailer park lamp relay control circuit.
When the trailer park lamp relay is energized, the relay switch contacts close and battery voltage is applied through the trailer park lamp relay fuse
to the trailer park lamp supply voltage circuit which illuminates the trailer park lamps if a trailer is connected.
Conditions for Running the DTC
When the trailer park lamp relay is actively being requested by the BCM.
Conditions for Setting the DTC
B388A 01
The BCM detects a short to voltage on the park lamp supply voltage/marker lamp supply voltage circuit.
B388A 02
The BCM detects a short to ground on the park lamp supply voltage/marker lamp supply voltage circuit
B388A 04
The BCM detects an open/high resistance on the park lamp supply voltage/marker lamp supply voltage circuit
Action Taken When the DTC Sets
B388A 01 or B388A 04
The trailer park lamps are inoperative
B388A 02
The trailer park lamps are always ON
Conditions for Clearing the DTC
* The DTC will be current for as long as the fault is present.
* When the fault is no longer present, the DTC will be a history DTC.
* A history DTC will clear after 40 ignition cycles.
Reference Information
Schematic Reference
Trailer Connector/Provision Schematics (See: Diagrams/Electrical Diagrams/Starting and Charging/Power and Ground Distribution/System
Diagram/Trailer Connector/Provision Schematics)
Connector End View Reference
Component Connector End Views (See: Diagrams/Connector Views/Connector End Views By Name)
Description and Operation
Exterior Lighting Systems Description and Operation (See: Lighting and Horns/Description and Operation/Exterior Lighting Systems)
Electrical Information Reference
