• | 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 | 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 |
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.
Battery voltage must be between 9-16 volts.
• | 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.. |
The rear window defogger will malfunction
• | 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 |
Rear Window Defogger Description and Operation
Control Module References for scan tool information
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.
⇒ | 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. |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
• | Control Module References for LGM replacement, setup, and programming |