What does it mean?
P1124 is a Powertrain (engine, transmission, fuel system) fault code. It indicates: Throttle Position Sensor A Out Of Self Test Range .
Symptoms
- Malfunction indicator lamp on and the self-test aborting before it completes
- Rough or hunting idle, sometimes with stalling when coming to a stop
- Delayed or erratic response when the pedal is first pressed
- Harsh or poorly timed automatic transmission shifts
- Higher than normal fuel consumption
Likely causes
- Carbon build-up on the throttle plate and bore holding the plate slightly off its rest position
- Throttle position sensor out of adjustment on designs where the sensor body can rotate
- Worn or scored resistive track producing a flat spot at low throttle angle
- Binding or stretched throttle cable, or a weak return spring on cable-operated bodies
- High resistance in the 5 V reference or ground circuit, shifting the whole voltage window
- Throttle body replaced without performing the required idle or throttle relearn procedure
How to fix it
- Compare the TP sensor percentage and voltage at closed throttle and at wide open with the values called for by the calibration
- Sweep the throttle slowly while watching live data; any dropout or jump points to a worn track
- Remove the intake ducting and inspect the plate and bore, then clean carbon deposits with a suitable throttle cleaner
- Verify the plate returns fully to its rest stop and that the cable and spring move freely
- Measure reference voltage and ground at the sensor connector with the key on
- On adjustable sensors, set the closed-throttle voltage to specification before condemning parts
- After cleaning or replacing the throttle body, run the relearn procedure and repeat the self-test