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. Engine running, accessories OFF, measure and record the battery voltage at the battery terminals. The voltage should be between 12.6 and
15.0 volts.
锟斤拷 If not within the specified range, refer to Charging System Test (See: Starting and Charging/Testing and Inspection/Component Tests and
General Diagnostics/Charging System Test).
2. Ignition OFF, disconnect the harness connector at the TDM. Refer to Theft Deterrent Module Replacement (See: Accessories and Optional
Equipment/Antitheft and Alarm Systems/Alarm Module/Service and Repair).
3. Ignition OFF and scan tool disconnected, open and close the drivers door, and wait 1 minute. Test for less than 5 ohms between the ground
circuit terminal 3 and ground.
锟斤拷 If greater than the specified range, test the ground circuit for an open/high resistance.
4. Verify that a test lamp illuminates between the B+ circuit terminal 1 and ground.
锟斤拷 If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance.
5. If all circuits test normal, replace the TDM.
Repair Instructions
Perform the Diagnostic Repair Verification (See: Verification Tests) after completing the diagnostic procedure.
Control Module References (See: Testing and Inspection/Programming and Relearning) for TDM replacement, set up, and programming.
B1428
DTC B1428
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 Descriptor
DTC B1428
- Ignition Switched Power Run/Crank Relay Circuit
Diagnostic Fault Information
