2010 Cadillac Truck SRX AWD V6-3.0L Page 547
Circuit/System Description
The telematics communication interface control module provides the cellular phone microphone with a supplied voltage on the cellular phone
microphone signal circuit. When the microphone is in use, voice data from the user is sent back to the telematics communication interface control
module on the signal circuit. The telematics communication interface control module provides a ground for the cellular phone microphone via the
low reference wire.
Conditions for Running the DTC
* The ignition must be in the RUN or ACC position.
* The system voltage is at least 9.5 V and no more than 15.5 V.
* All the above conditions are present for greater than 10 seconds.
Conditions for Setting the DTC
* The telematics communication interface control module detects an open, short to ground or short to voltage in the cellular phone microphone
signal circuit for 10 seconds or greater.
* The telematics communication interface control module detects an open/high resistance in the low reference circuit for 10 seconds or greater.
Action Taken When the DTC Sets
* The OnStar(R) status LED turns red.
* The telematics communication interface control module will not receive a signal from the cellular phone microphone.
* Calls can be placed but the caller cannot be heard.
Conditions for Clearing the DTC
* The condition responsible for setting the DTC no longer exists.
* A history DTC will clear once 50 consecutive malfunction-free ignition cycles have occurred.
Reference Information
Schematic Reference
OnStar Schematics (See: Accessories and Optional Equipment/Diagrams/Electrical Diagrams/OnStar Schematics)
Connector End View Reference
Component Connector End Views (See: Diagrams/Connector Views/Connector End Views By Name)
Description and Operation
OnStar Description and Operation (See: Accessories and Optional Equipment/Description and Operation/OnStar)
Electrical Information Reference
* Circuit Testing (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic Procedures/Circuit
Testing/Circuit Testing)
* Connector Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic
Procedures/Connector Repairs/Connector Repairs)
* Testing for Intermittent Conditions and Poor Connections (See: Testing and Inspection/Component Tests and General Diagnostics/General
Electrical Diagnostic Procedures/Circuit Testing/Testing for Intermittent Conditions and Poor Connections)
* Wiring Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic Procedures/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 harness connector at the B24 cellular phone microphone.
2. Ignition OFF and scan tool disconnected, wait until all retained accessory power is OFF, test for less than 10 ohm between the low reference
circuit terminal 1 or A (depending on vehicle) and ground, allowing up to 5 minutes for the circuit resistance to drop to its lowest reading.
瀚慖f greater than the specified range, test the circuit for an open/high resistance.
3. Ignition ON, test for 9.5-10.5 V between the signal circuit terminal 2 or B (depending on vehicle) and ground.
