2010 Cadillac CTS Sedan AWD V6-3.6L Page 509

2010 Cadillac CTS Sedan AWD V6-3.6L Page 509

circuit. This energizes the park lamp relay coil causing the relay switch contacts to close allowing battery voltage to flow through the LT/POS/LP

and RT/POS/LP fuses to all of the park, tail, license, and marker lamps.

Conditions for Running the DTC

* Battery voltage must be between 9-16 V.

* Park lamps ON.

Conditions for Setting the DTC

The BCM detects a short to voltage in the park lamp relay control circuit.

Actions Taken When the DTC Sets

The park lamps will not operate.

Conditions for Clearing the DTC

* The condition responsible for setting the DTC no longer exists.

* A history DTC will clear once 100 consecutive malfunction-free ignition cycles have occurred.

Reference Information

Schematic Reference

Exterior Lights Schematics (See: Diagrams/Electrical Diagrams/Lighting and Horns/System Diagram/Exterior Lights Schematics)

Connector End View Reference

Component Connector End Views (See: Diagrams/Connector Views)

Description and Operation

Exterior Lighting Systems Description and Operation (See: Lighting and Horns/Description and Operation/Exterior Lighting Systems Description

and Operation)

Electrical Information Reference

* Circuit Testing (See: Testing and Inspection/Component Tests and General Diagnostics/Circuit Testing/Circuit Testing)

* Connector Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/Connector Repairs/Connector Repairs)

* Testing for Intermittent Conditions and Poor Connections (See: Testing and Inspection/Component Tests and General Diagnostics/Circuit

Testing/Testing for Intermittent Conditions and Poor Connections)

* Wiring Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/Wiring Repairs/Wiring Repairs)

Scan Tool Reference

Control Module References (See: Testing and Inspection/Programming and Relearning) for scan tool information

Circuit/System Testing

1. Ignition OFF, disconnect the LT/POS/LP relay.

2. Ignition ON, verify a test lamp does not illuminate between the control circuit terminal 87 and ground.

瀚慖f the test lamp illuminates, test the control circuit for a short to voltage.

3. Verify a test lamp illuminates between the B+ circuit terminal 30 and ground.

瀚慖f the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance. If the circuit tests normal and the

B+ circuit fuse is open, test the control circuit terminal 87 for a short to ground. If the circuit tests normal, test or replace the LT/POS/LP

relay.

4. Verify a test lamp illuminates between the B+ circuit terminal 85 and ground.

瀚慖f the test lamp does not illuminate, test the B+ circuit for an open/high resistance.

5. Connect a test lamp between the B+ circuit terminal 85 and the control circuit terminal 86.

6. Command the Parking Lamps ON and OFF with a scan tool. The test lamp should turn ON and OFF when changing between the commanded

states.

瀚慖f the test lamp is always ON, test the control circuit for a short to ground. If the circuit tests normal, replace the BCM.

瀚慖f the test lamp is always OFF, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace

the BCM.

7. If all circuits test normal, replace the LT/POS/LP relay.