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. |
DTC Descriptor
DTC B0283: Electric Rear Defrost CircuitDiagnostic Fault Information
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
Liftgate Module B+ | 2 | 2 | -- | -- |
Rear Defog Grid Control | B0283 | B0283 | 1 | -- |
Rear Window Defogger Grid Ground | -- | 2 | 2 | -- |
1. Rear defogger always ON 2. Rear defogger Inoperative | ||||
Circuit/System Description
The liftgate module (LGM) monitors the voltage level on the supply voltage circuit of the rear window defogger. The LGM will test the supply voltage circuit of the rear window defogger every 160 milliseconds. With the rear window defogger inactive, the supply voltage circuit of the rear window defogger will have no voltage present. With the rear window defogger active, the supply voltage circuit of the rear window defogger will be near system voltage.
Conditions for Running the DTC
Battery voltage must be between 9-16 volts.
Conditions for Setting the DTC
| • | The LGM detects a short to voltage on the on the rear window defogger control circuit. |
| • | The LGM detects a short to ground on the on the rear window defogger control circuit.. |
Action Taken When the DTC Sets
The rear window defogger will malfunction
Conditions for Clearing the DTC
| • | The DTC will be current for as long as the fault is present. |
| • | When the fault is no longer present, the DTC will be a history DTC. |
| • | A history DTC will clear after 50 ignition cycles |
Reference Information
Schematic Reference
Connector End View Reference
Description and Operation
Rear Window Defogger Description and Operation
Electrical Information Reference
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
Command the Rear Defog ON and OFF with the scan tool. The rear window defogger should turn ON and OFF when changing between the commanded states.
Circuit/System Testing
- Ignition OFF, disconnect the X1 and X2 harness connectors the rear window defogger.
- Test for less than 1 ohm between the ground circuit terminal A and ground.
- Connect a test lamp between the control circuit terminal A and ground.
- Ignition ON, command the Rear Defog ON and OFF with a scan tool. The test lamp should turn ON and OFF when changing between the commanded states.
- If all circuits test normal, replace the rear window defogger grid.
| ⇒ | If greater than the specified range, test ground circuit for an open/high resistance. |
| ⇒ | If the test lamp is always OFF, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the LGM. |
| ⇒ | If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, replace the LGM. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Control Module References for LGM replacement, setup, and programming |
