Code Definition

B1347 — Heated Backlite Relay Circuit Failure

System: Body  |  Type: Manufacturer-Specific  |  Make: Ford

About B1347

B1347 is a manufacturer-specific body diagnostic trouble code recorded for Ford vehicles. It belongs to the B-prefix family of codes, which covers body, interior, airbag, or comfort-electronics faults.

When B1347 is stored, the module has detected an electrical-circuit fault in the wiring, connector, or driver associated with the named component.

Scanning & clearing: Body (B) codes are often stored in the body control module, airbag module, or climate module. A basic OBD-II tool usually will not read body codes — an enhanced or OEM-level scan tool is typically required.

B1347 is a manufacturer-specific code. The same code string on a different make may have a different meaning. Always confirm the code's definition against the vehicle's service information for the specific make and model under test.

Code Information

The Body Control Module (BCM) commands the heated backlite (rear defroster) relay through a low side or high side driver, energising the relay coil to close its contacts and apply battery voltage to the rear glass conductive grid. DTC B1347 is set when the BCM detects an electrical fault on the relay control circuit, which may be an open, a short to ground, a short to battery, or an out of range current draw on the driver output. The relay sits between the high current grid supply and the low current command from the BCM, and the BCM monitors the driver feedback to confirm the coil is energisi...

Join TaT to view the complete code information and diagnostic details.

Quick Facts