2010 Cadillac CTS Sedan AWD V6-3.6L Page 488
Circuit/System Description
The OnStar(R) button assembly consists of 3 buttons, Call/Answer, OnStar(R) Call Center, and OnStar(R) Emergency. The communication
interface module (CIM) supplies the OnStar(R) button assembly with 10 V via the keypad supply voltage circuit. Each of the buttons, when
pressed, completes the circuit across a resistor allowing a specific voltage to be returned to the CIM over the keypad signal circuit. Depending upon
the voltage range returned, the CIM is able to identify which button has been activated.
Conditions for Running the DTC
* Ignition ON.
* Battery voltage must be between 9-16 V.
Conditions for Setting the DTC
B2476 04
The CIM detects an open/high resistance on the keypad supply voltage circuit.
B2482 and B2476 59
The CIM detects a valid signal on the keypad signal circuit for longer than 15 seconds. If one of the OnStar(R) buttons is held or stuck for 15
seconds or greater, the CIM will set this DTC.
Action Taken When the DTC Sets
* The OnStar(R) status LED turns red.
* No calls can be placed.
* The CIM will ignore all inputs from the OnStar(R) button assembly.
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)
Description and Operation
OnStar Description and Operation (See: Accessories and Optional Equipment/Description and Operation/OnStar 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 harness connector at the A10 inside rearview mirror.
2. Test for less than 10 Ohms between the mirror ground circuit terminal 8 and ground.
瀚慖f greater than the specified range, test the ground circuit for an open/high resistance.
3. Ignition ON, test for less than 1 V between the keypad signal circuit terminal 11 and ground.
瀚慖f greater than the specified range, test the keypad signal circuit for a short to voltage. If the circuit tests normal, replace the CIM.
4. Ignition OFF, test for 600k-800k Ohms between the keypad signal circuit terminal 11 and ground.
