VOLVO
ECM-0123 - Accelerator pedal (AP) position sensor. Signal too high
System
Engine Control Module (ECM)
Volvo models this fault code applies to
This fault code has different meanings depending on model, model year or engine. Select the meaning that applies to your car.
Applies to the following models:
4 modelsC30 (2007–2013), C70 (2006–2013), S40 (2004–2013), V50 (2004–2013)
Show models by year and engine (10)
- Volvo C30 (2007–2013)2007Engine D4204T only
- Volvo C30 (2007–2013)2008–2010Engine D4204T only · Transmission MMT6, MPS6 only
- Volvo C70 (2006–2013)2008Engine D4204T only
- Volvo C70 (2006–2013)2009–2010Engine D4204T only · Transmission MMT6, MPS6 only
- Volvo S40 (2004–2013)2004–2006Engine D4204T, D4204T2 only
- Volvo S40 (2004–2013)2007Engine D4204T only
- Volvo S40 (2004–2013)2008–2010Engine D4204T only · Transmission MMT6, MPS6 only
- Volvo V50 (2004–2013)2004–2006Engine D4204T, D4204T2 only
- Volvo V50 (2004–2013)2007Engine D4204T only
- Volvo V50 (2004–2013)2008–2010Engine D4204T only · Transmission MMT6, MPS6 only
What does this fault code mean?
The code is titled signal too high, but it concerns the pulse width modulated (PWM) signal from the accelerator pedal sensor to the engine control module. The code is stored when that signal is faulty, most often because the signal wire touches supply voltage. The throttle response can then feel weak.
Possible causes
- Signal wire shorted to supply voltage
- Damaged accelerator pedal position sensor
What you can do
- 1With the ignition off, check the pedal sensor connector for contact resistance and oxidation
- 2With the ignition on and the connector unplugged, use a multimeter on the signal wire; voltage there indicates a short to supply voltage
- 3If you have a diagnostic tool, read the pedal position in live data with the pedal released and pressed, and check that the value changes smoothly
- 4If the wiring is sound and the fault remains, have a workshop replace the accelerator pedal sensor
Symptoms you may notice2
- Car feels weak or performs poorly
- Warning symbol and text message in the display
What the fault can affect1
- The analog accelerator pedal signal is used instead, if it is working correctly
General guidance for car owners. Diagnosis on the car can point to a different cause.