What does it mean?
P1297 is a Powertrain (engine, transmission, fuel system) fault code. It indicates: Electrical Load Detector (ELD) Circuit Low Voltage .
Symptoms
- MIL (check engine lamp) on
- Charging voltage stuck low or unusually high, with dim or overly bright lights
- Battery repeatedly going flat, or overcharging with a hot battery and an acid smell
- Idle speed does not rise when heavy loads such as headlamps, blower or heated glass are switched on
- Battery warning lamp on some vehicles
Likely causes
- ELD signal wire shorted to ground or open between the detector and the module
- Failed ELD unit, usually built into the under-hood fuse and relay box
- Water or corrosion inside the fuse box affecting the ELD connector
- Loss of the reference voltage or ground supplied to the ELD
- Damaged wiring between the fuse box and the engine control module
- Internal fault in the under-hood fuse box assembly
How to fix it
- Read the ELD live value with all consumers off, then switch on headlamps and blower; the value should change clearly
- Inspect the ELD connector inside the under-hood fuse box for water, corrosion and green terminals
- Measure the reference voltage and the ground at the ELD connector with the key on, engine off
- Check continuity of the signal wire between the ELD and the engine control module
- Measure actual charging voltage at the battery with and without load using a meter
- Replace the ELD, or the fuse box assembly where the detector is integral, once the wiring is proven
- Clear the code and confirm charging voltage responds normally to changing electrical load