P0E8B: Battery Charger B Input Voltage Sensor Circuit
What to do
Charging will be slow, or may trip the charge point. Nothing here prevents driving. If a breaker keeps tripping, stop using that supply and have the car checked rather than fitting a larger breaker.
What this code means
The circuit for the second charger's input voltage sensor is faulty.
A second on-board charger is not a spare — it is capacity, and knowing that changes what a fault means.
Alternating-current charging is limited by the charger, not by the battery. A pack that can accept a hundred kilowatts from a rapid charger will still take all night on a domestic socket, because the on-board charger converting the mains is the bottleneck. So a manufacturer wanting faster AC charging fits a bigger charger — or two.
Which means losing charger B is a halving rather than a failure. The car still charges, at roughly half the rate it used to, with no warning light the driver would notice and nothing wrong with the charge point. The complaint that arrives is "it has got slower", months after the fault, and it is exactly the complaint that gets attributed to the battery ageing or to the charge point being tired.
The discriminator is that the rate will have halved rather than drifted. Battery ageing is gradual and proportional; losing a charger is a step change to a specific number. Ask what the car used to draw and what it draws now, because a clean halving is close to diagnostic on its own.
The sensor's job is described at P0D3D, where the first charger's equivalent is written, and nothing about it changes here.
Note that the standard gives charger B only these two sensor codes, where charger A has a full five-variant family for each. So there is no Low, High or Intermittent to distinguish between — one code covers every way this circuit can fail, and the detail has to come from live data rather than from the code number.
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
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