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/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 A10 inside rearview mirror.
2. Test for less than 10 Ohms between the mirror ground circuit terminal 8 and ground.
锟斤拷 If 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.
锟斤拷 If 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.
锟斤拷 If less than the specified range, test the keypad signal circuit for a short to ground. If the circuit tests normal, replace the CIM.
锟斤拷 If greater than the specified range, test the keypad signal circuit for an open/high resistance. If the circuit tests normal, replace the CIM.
5. Ignition ON, test for 9.5-10.5 V between the keypad supply voltage circuit terminal 12 and ground.
锟斤拷 If less than the specified range, test the supply voltage circuit for a short to ground or open/high resistance. If the circuit tests normal,
replace the CIM.
锟斤拷 If greater than the specified range, test the supply voltage circuit for a short to voltage. If the circuit tests normal, replace the CIM.
6. If all circuits test normal, test or replace the button assembly.
Repair Instructions
Perform the Diagnostic Repair Verification (See: Verification Tests) after completing the diagnostic procedure.
* Inside Rearview Mirror Replacement (See: Body and Frame/Mirrors/Service and Repair/Inside Rearview Mirror Replacement)
* Control Module References (See: Testing and Inspection/Programming and Relearning) for CIM replacement, setup, and programming
B2482
DTC B2476 or B2482
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 B2476 04
- Cellular Phone Select Service Switch Open Circuit
