P0D45
Battery Charger 14 Volt Output Voltage Sensor Circuit High.
- Generic
- Powertrain
- Generic code
- Medium severity
How this code is built
- P
- SystemPowertrain
- 0
- Defined bySAE, the same on every car
- D
- AreaReserved
- 45
- FaultThe specific fault in that area
What it means
P0D45 means the control unit monitoring the battery charger (the converter that supplies the 14 volt system on a hybrid or electric vehicle) saw a signal from its 14 volt output voltage sensor circuit that was higher than the expected range. This points to a fault in the sensor circuit or its reading, and it may not be a true overvoltage. Which module owns the code, and how the charger is arranged, depends on the model.
Symptoms
- Warning lamp on, possibly a hybrid or EV system or charging system message
- Low 12/14 volt battery voltage or a flat auxiliary battery
- Reduced power or the vehicle going into a limited operating mode
- Vehicle slow to start, or not ready to drive
- Flickering lights or unstable voltage on the 14 volt system
- Charging of the high voltage battery restricted or not starting
Possible causes
- Wiring or connector fault in the 14 volt output voltage sensor circuit, such as a short to voltage, corrosion or a damaged pinlikely
- Faulty output voltage sensor or sensing circuit inside the charger/converter unitlikely
- Poor earth or voltage reference problem causing a false high readingpossible
- Genuine overvoltage on the 14 volt system caused by a regulation fault in the charger/converterpossible
- Faulty auxiliary battery or poor battery terminal connection affecting the voltage seenpossible
- Faulty control module or outdated software or calibration, where the manufacturer has identified thisrare
How to diagnose
- Read all stored and pending codes and the freeze frame data, noting any other charging, battery or high voltage system codes.
- Check the auxiliary battery condition, terminal tightness and resting voltage with a multimeter.
- Inspect the wiring, connectors and earths for the charger/converter and its voltage sensor for damage, water ingress, corrosion or chafing.
- Compare live data for the 14 volt output voltage with a measured voltage at the battery while the system is running.
- Check the sensor circuit for a short to voltage, open circuit or high resistance, using the wiring diagram for the specific model.
- Check the supply, reference and earth voltages at the sensor or charger connector.
- Check for manufacturer bulletins or available software updates that apply to this vehicle and code.
- Follow the manufacturer's procedure to test the charger/converter unit, using high voltage safety precautions where required.
How to fix
- Repair or replace damaged wiring, terminals or connectors in the sensor circuit.
- Clean and tighten the earths and battery terminals.
- Replace the auxiliary battery if it is found to be faulty.
- Replace the charger/converter or its sensor if testing proves it faulty, following the manufacturer's procedure.
- Update or reprogram the control module software only if an outdated or faulty calibration is a known cause for this vehicle.
- Clear the code after repair and road test to confirm it does not return.
Can I keep driving?
The car may be drivable for a short time, but the 14 volt supply could fail and leave you stranded or in a limited power mode, so get it checked soon. Stop driving if warning lamps show a charging failure or if the car loses power. Only trained technicians should work on high voltage components.
Guide written by AI from the code's definition. Confirm with a diagnosis before replacing parts.