2010 Cadillac Truck SRX FWD V6-3.0L Page 215

2010 Cadillac Truck SRX FWD V6-3.0L Page 215

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

7. Test for less than 1 V between the display position signal circuit terminal 5 and ground.

瀚慽f greater than the specified range, test the position signal circuit for a short to voltage. If the circuit tests normal, replace the radio.

8. Connect a DMM between the display control circuit terminal 4 and ground. Press and release the NAV button on the Radio/HVAC Control.

Verify the voltage changes each time the display button is pressed. The value should change between less than 1 V to greater than 4 V.

瀚慖f the value is always less than 1 V, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal,

replace the radio.

瀚慖f the value is always greater than 1 V, test the control circuit for a short to voltage. If the circuit tests normal replace the radio.

9. If all circuits test normal, replace the Radio/HVAC display actuator.

Repair Instructions

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

* Radio, Video, Audio Disc Player, and Navigation Information Display Actuator Replacement (See: Accessories and Optional

Equipment/Radio, Stereo, and Compact Disc/Radio/Stereo/Service and Repair/Radio, Video, Audio Disc Player, and Navigation Information

Display Actuator Replacement)

* Control Module References (See: Testing and Inspection/Programming and Relearning)for radio replacement, setup, and programming

B138A

DTC B138A

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 B138A 03

- Control Module Voltage Reference Output Circuit Low Voltage

DTC B138A 07

- Control Module Voltage Reference Output Circuit High Voltage

Diagnostic Fault Information