For 1990-2009 cars only
Exhaust Brake Indicator Lamp Inoperative with RPO LLY
Diagnostic Instructions
| • | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. |
| • | Review Strategy Based Diagnosis for an overview of the diagnostic approach. |
| • | Diagnostic Procedure Instructions provides an overview of each diagnostic category. |
Circuit/System Description
Ground is supplied to the exhaust brake indicator lamp. The engine control module (ECM) turns the lamp ON by supplying power to the lamp supply circuit.
Reference Information
Schematic Reference
Connector End View Reference
Engine Control Module Connector End Views
Electrical Information Reference
Scan Tool Reference
Circuit/System Verification
The exhaust brake lamp should turn ON when the exhaust brake is active, and turn OFF when the exhaust brake is not active.
Circuit/System Testing
Disconnect the ECM and jumper the exhaust brake lamp voltage circuit to voltage through a fused jumper.
| ⇒ | If the jumper fuse opens, repair the short to ground in the voltage supply circuit. |
| ⇒ | If the lamp illuminates, replace the ECM. |
| ⇒ | If the lamp does not illuminate, test the voltage and ground circuits of the exhaust brake indicator lamp for an open, or a faulty indicator bulb. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
Control Module References for ECM and instrument panel cluster (IPC) replacement, setup, and programming
