P0D9B: Battery Charger Coupler Temperature Sensor A Circuit Low
What to do
The car may refuse to charge, or may charge only at reduced current. That is the right behaviour — without this sensor the car cannot tell whether the connector is overheating. Look at the inlet pins for discolouration or melted plastic and mention anything you find; if the connector has ever felt hot to the touch, say so.
What this code means
The circuit for the temperature sensor in the charging coupler is faulty.
This sensor is the single most important safety device in the charging system, and it is in the connector rather than in the car.
Charging fires start at the plug. Not in the battery, not in the charger — at the connection, because that is the one high-current joint in the whole path that is made and broken by hand, thousands of times, outdoors. A pin that has corroded, spread, or lost its spring tension makes contact over a smaller area than it should, and a smaller contact area at the same current means more resistance, which means heat, which oxidises the surface further and raises the resistance again. It is a runaway, and it can reach the melting point of the plastic housing.
So a thermistor sits in the coupler watching for it, and when the connector gets hot the car reduces the current or stops the session — which is the only thing standing between a degraded pin and a fire. That is why this code should not be cleared and ignored, and why an owner who has noticed a charge connector feeling hot has noticed something real.
Note it protects the vehicle inlet specifically. The other end of the cable and the charge point have their own sensors, which is why a cable that gets hot at the wall end is the charge point's problem and not this one.
At or below the lower limit, usually a short to earth.
Likely causes
Start here
- Damaged charging inlet or pins · moderate
- Corroded or loose connector · specialist
- Open circuit in sensor wiring · specialist
Less common
- Water ingress into connector · specialist
- Damaged wiring harness · 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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