P2163: Throttle/Pedal Position Sensor A/B Maximum Stop Performance
What to do
The car will usually drive with reduced power rather than stop. If this appeared after throttle body cleaning, an air intake repair or a relearn procedure, say so — a stop learned incorrectly during that work is a repeat of the procedure, not a new throttle body. Cleaning is much less likely to be the answer here than for the closed-throttle codes, because the plate does not collect carbon at the open end.
What this code means
The position reading at the fully open end of travel is not where the module expects it to be. This is the counterpart to the minimum stop codes at P2109 and P2113, and the two ends fail for different reasons — which is what makes knowing the end useful.
A throttle has two mechanical stops, and the module treats them as calibration references. They are physical: screws or moulded limits that the plate rests against, and their positions are learned and stored so the module knows what its sensor voltages mean in degrees. Everything the throttle does afterwards is measured against them.
The minimum stop drifts because of carbon. Deposits build up around the plate at the closed end, where the plate spends most of its life and where crankcase and recirculated gases condense. That is the common one, and it is why the corpus keeps returning to throttle cleaning.
The maximum stop does not accumulate carbon — the plate is nowhere near it in normal driving, and airflow at full open keeps it clean. So a maximum stop that has moved is usually saying something has changed mechanically or electrically, not that the throttle is dirty: a bent or damaged plate, a stop adjusted by hand at some point in the vehicle's history, a sensor track worn at the end it is least often driven to, or a relearn performed while something was obstructing full travel.
That last one deserves attention, because it is self-inflicted and common: a relearn carried out with the air intake ducting disconnected, or with a hand resting on the linkage, stores a maximum stop that the throttle can never reach again.
Likely causes
Start here
Less common
- Damaged or bent throttle plate · moderate
- Faulty throttle body · moderate
- Foreign object in the throttle body · easy
Rare
- Failed sensor reference voltage supply · moderate
Symptoms
Components involved
Information, not instruction
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Community experience
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