• | 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 |
---|---|---|---|---|
K2 Relay B+ | 2 | 2 | -- | -- |
Rear Defrost Switch Signal | B3743 5A | 2 | 2 | -- |
Rear Defog Relay Control | B0283 00 | B0283 00 | B0283 00 | -- |
Rear Defog Indicator Control | B0969 02 | 3 | B0969 01 | -- |
Rear Window Defogger Grid Control | 2 | 2 | 1 | -- |
Rear Window Defogger Grid Ground | -- | 2 | 2 | -- |
1. Rear Defogger Always On 2. Rear Defogger Inoperative 3. Rear Defogger Indicator Inoperative |
The rear fuse block monitors the voltage level on the supply voltage circuit of the K2 relay. The voltage level should be low while the K2 relay is de-energized. The voltage will be near system voltage when the rear fuse block energizes the K2 relay.
Battery voltage must be between 9-16 volts.
When the rear fuse block detects a fault in the relay control circuit for 1 second or greater.
The rear window defogger will not operate.
• | 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
Ignition ON, command the REC Heated Rear Window Test ON and OFF with a scan tool. The rear window defogger should turn ON and OFF when changing between the commanded states.
⇒ | If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, replace the rear fuse block. |
⇒ | 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 rear fuse block. |
⇒ | If not within the specified range, replace the relay. |
• | 30 and 86 |
• | 30 and 87 |
• | 30 and 85 |
• | 85 and 87 |
⇒ | If greater than the specified range, replace the relay. |
⇒ | If greater than the specified range, replace the relay |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
• | Control Module References for rear fuse block replacement, setup, and programming |