2010 Cadillac Truck Escalade RWD V8-6.0L Hybrid Page 242

2010 Cadillac Truck Escalade RWD V8-6.0L Hybrid Page 242

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

Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the appropriate microphone.

2. Ignition ON Radio ON, test for 0.47-2.75 V between the microphone (-) signal circuit terminal A and ground.

瀚慖f greater than the specified range, test the circuit for a short to voltage. If the circuit tests normal, replace the amplifier.

瀚慖f less than the specified range, test the circuit for an open/high resistance or a short to ground. If the circuit tests normal, replace the

amplifier.

3. Test for 5.75-8.03 V between the microphone (+) signal circuit terminal B and ground.

瀚慖f greater than the specified range, test the circuit for a short to voltage. If the circuit tests normal, replace the amplifier.

瀚慖f less than the specified range, test the circuit for an open/high resistance or a short to ground. If the circuit tests normal, replace the

amplifier.

4. If all circuits test normal, replace the appropriate microphone.

Repair Instructions

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

* Radio Volume Compensator Interior Noise Microphone Replacement (Floor Console) (See: Accessories and Optional Equipment/Radio,

Stereo, and Compact Disc/Automatic Volume Control/Service and Repair/Radio Volume Compensator Interior Noise Microphone

Replacement (Floor Console))Radio Volume Compensator Interior Noise Microphone Replacement (Headliner) (See: Accessories and

Optional Equipment/Radio, Stereo, and Compact Disc/Automatic Volume Control/Service and Repair/Radio Volume Compensator Interior

Noise Microphone Replacement (Headliner))

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

B127D

DTC B1277, B127C, or B127D

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) provide an overview of each diagnostic category.

DTC Descriptors

DTC B1277 01

- Microphone 1 (LF) Input Signal Circuit Short to Battery

DTC B1277 02

- Microphone 1 (LF) Input Signal Circuit Short to Ground

DTC B1277 04

- Microphone 1 (LF) Input Signal Circuit Open

DTC B1277 1A

- Microphone 1 (LF) Input Signal Circuit Bias Level Out of Range

DTC B127C 01

- Microphone 2 (RF) Input Signal Circuit Short to Battery

DTC B127C 02

- Microphone 2 (RF) Input Signal Circuit Short to Ground

DTC B127C 04

- Microphone 2 (RF) Input Signal Circuit Open

DTC B127C 1A

- Microphone 2 (RF) Input Signal Circuit Bias Level Out of Range