Normal Operation
WARNING: This page is about a different car, the 2009 Ford Mustang. However, it is still accessible from the selected car via links, so may be relevant.
When the rear defrost switch on the HVAC module is pressed, a ground signal is sent to the smart junction box (SJB) on circuit 1426 (PK). The SJB then grounds circuit 1389 (WH) which energizes the heated rear window relay. When the relay is active, voltage is supplied to the heated rear window grid through circuit 186 (BN/LB). The heated rear window grid is grounded by circuit 1205 (BK). The SJB provides heated backlight status to the HVAC module through circuit 1427 (TN/LB).
| DTC Description | Fault Trigger Conditions |
|---|---|
| B1345 - Heated Backlight Input Circuit Short to Ground | Defrost switch or input circuit short to ground. |
| B1348 - Heated Backlight Relay Circuit Open | Open or short to ground in relay control circuit. |
| B1349 - Heated Backlight Relay Short to Battery | Short to battery in relay control circuit. |
| B2060 - Heated Backlight Indicator Circuit Failure | Short to battery in heated backlight status circuit. |
| B2061 - Heated Backlight Indicator Circuit Shorted to Ground | Short to ground in heated backlight status circuit. |
This pinpoint test is intended to diagnose the following:
- Fuse(s)
- Wiring, terminals or connectors
- Heated rear window relay
- HVAC module
- Heated rear window grid
- SJB