What it means
The PCM detected a range or performance problem in the throttle/pedal position sensor or switch C circuit. The code does not universally mean that three channels are compared.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
How it works
The PCM checks whether throttle or accelerator-pedal position sensor C produces a plausible signal for the pedal or throttle movement. P0226 indicates a range or performance problem in the C circuit; it does not by itself mean that the PCM compares three sensor channels.
Common causes
Most likely first.
- TPS contact aging
- Dirty or sticking throttle plate
- Sensor element aged beyond calibration window
Symptoms
- Check engine light on
- Reduced throttle response, possible limp mode
- Hesitation or surging
- Idle too high or too low
How to diagnose it
- Record freeze-frame data and check for related throttle or pedal codes to see when the C signal moved outside its expected behavior.
- Observe sensor C live data while slowly moving the pedal or throttle and look for readings that are erratic, implausible, or do not follow movement.
- Inspect the pedal or throttle for sticking or obstruction, then check the sensor C connector and harness for wear or poor contact.
- Check that the C signal changes through its travel and compare the readings with the manufacturer’s specification.
- If the mechanism and wiring pass inspection, test sensor C using the manufacturer’s diagnostic procedure.
Common fixes
- Remove an obstruction or correct sticking in the pedal or throttle mechanism.
- Repair a poor connection or damaged wiring in the C circuit.
- Replace sensor C if its output remains outside the specified range during testing.
- Perform any manufacturer-specified adjustment or relearn after repair.
Can I keep driving?
If acceleration hesitates or surges, avoid fast traffic and heavy loads until the C signal fault is diagnosed. The PCM may reduce throttle response if the reading becomes implausible.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.