P0D46: Battery Charger 14 Volt Output Voltage Sensor Circuit Intermittent/Erratic
What to do
The traction battery will charge normally. Watch for the 12-volt battery being weak after a long charge — that pattern, rather than going flat while parked, is what points here. A replacement 12-volt battery will not fix it.
What this code means
The circuit for the sensor measuring the charger's 14-volt output is faulty.
The on-board charger feeds the 12-volt system too, and almost nobody knows it does. It is easy to assume the charger has one job — filling the traction pack — and that the 12-volt side is the DC/DC converter's business. But a car sitting on charge for eight hours has its modules awake the whole time, and if nothing fed the 12-volt battery it would be flatter at the end of the charge than at the start.
So the charger has a 14-volt output of its own, and this sensor is what regulates it. Fourteen volts rather than twelve because that is what actually charges a lead-acid battery; twelve is roughly what a charged one sits at.
The failure is quiet and cumulative. A car that charges its traction pack perfectly and comes back to a flat 12-volt battery is describing this circuit, and it is diagnosed as a tired 12-volt battery almost every time. The discriminator is that it happens after charging rather than after standing.
The signal comes and goes. Found by moving the harness and connector with the reading live, not by a static resistance measurement — an intermittent that can be measured at rest is not intermittent any more.
Likely causes
Start here
- Faulty on-board charger · specialist
- Corroded or loose connector · specialist
Less common
- Open circuit in sensor wiring · specialist
- Damaged wiring harness · specialist
- Failed sensor reference voltage supply · specialist
Symptoms
Components involved
Information, not instruction
CarGeek is a reference, not a service manual. Its pages are written from public sources and from what other people have found, never from a manufacturer's own service information, so they can be wrong or incomplete for your particular vehicle. Some of what they describe carries real risk: high voltage, fuel under pressure, stored energy, hot and moving parts.
Have anything you intend to act on checked by a trained person against the manufacturer's own procedure for your vehicle. Nothing here replaces that procedure.
Community experience
Be the first to write this up
Nothing posted about this yet. Whatever you found is worth writing down — even a dead end saves someone the same afternoon.
What makes one worth reading:
- The car — make, model, year and engine. The same fault behaves differently on each.
- What you measured, not only what you replaced.
- What actually fixed it — or that nothing did, which is worth knowing too.
Sign in or create an account to add what you found about P0D46.