2010 Cadillac Truck SRX FWD V6-3.0L Page 725

2010 Cadillac Truck SRX FWD V6-3.0L Page 725

Ignition ON, observe the function of the left trailer turn signal lamp and the right trailer turn signal lamp while commanding the Left Trailer Turn

Signal Lamp and the Right Trailer Turn Signal Lamp ON and OFF with a scan tool. The left trailer turn signal lamp and the right trailer turn signal

lamp should turn ON and OFF while changing between the commanded states.

Circuit/System Testing

1. Ignition OFF, disconnect the X1 harness connector at the K68 trailer lighting control module.

2. Test for infinite resistance between the control circuit terminal listed below and ground:

* Right trailer turn signal lamp control terminal 2

* Left trailer turn signal lamp control terminal 17

瀚慖f less than the specified value, test the control circuit for a short to ground. If the circuit tests normal, replace the X88 trailer connector.

3. Test for less than 1 ohm between the control circuit terminals listed below:

* Control terminal 2 at the K68 trailer lighting control module and control terminal 4 at the X88 trailer connector.

* Control terminal 17 at the K68 trailer lighting control module and control terminal 1 at the X88 trailer connector.

瀚慖f greater than the specified range, test the control circuit for a short to voltage or an open/high resistance.

4. If all the circuits test normal, replace the K68 trailer lighting control module.

Repair Instructions

Perform the Diagnostic Repair Verification (See: Verification Tests) after completing the diagnostic procedure.

Control Module References (See: Testing and Inspection/Programming and Relearning) for trailer brake control module replacement,

programming and setup

Without U4G

DTC B3887 or B3888 (Without U4G)

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic System

Check - Vehicle) prior to using this diagnostic procedure.

* Review Strategy Based Diagnosis (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Strategy Based Diagnosis) for an

overview of the diagnostic approach.

* Diagnostic Procedure Instructions (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic Procedure

Instructions)provides an overview of each diagnostic category.

DTC Descriptors

DTC B3887 02

- Trailer Left Turn Signal Circuit Short to Ground

DTC B3887 04

- Trailer Left Turn Signal Circuit Open

DTC B3888 02

- Trailer Right Turn Signal Circuit Short to Ground

DTC B3888 04

- Trailer Right Turn Signal Circuit Open

Diagnostic Fault Information

Circuit/System Description