497F

What the Code Means

497F points to a transmitter fault inside the FRM (Footwell Module), the module that controls cabin and body electrics. The module can't transmit CAN bus messages correctly, so the other modules stop receiving data from it.

The cause is usually an internal failure of the FRM components themselves, not the wiring or outside factors.

Symptoms

• window regulators stop working;
• hazard lights don't work;
• cabin lighting fails;
• diagnostic equipment may lose all communication with the FRM.

Diagnosis and Repair

1. Connect ISTA and confirm the communication fault with the FRM — this is the first and mandatory step to separate an internal module failure from a CAN bus problem.
2. Inspect the FRM for physical damage and corrosion.
3. Repair (rebuild) the FRM, replacing components with updated ones — the typical cause of failure is inside the module, so rebuilding with upgraded components fixes the problem more reliably than a simple reflash.
4. After the repair, check the module's bus communication and the operation of all body functions.

A common diagnostic mistake is looking for the cause in the wiring or adjacent modules without first confirming the communication fault with the FRM through ISTA.

Secondary Problems

If you ignore the FRM fault, the module can stop exchanging data entirely, which takes out all the body functions it controls: window regulators, hazard lights, cabin lighting.

A dead battery is also possible — a module in a faulty state can keep drawing current while the car sits. Don't put off the repair: the closer the FRM gets to total failure, the more of the car's functions go offline.