VOLVO
ECM-940A - Brake pedal position sensor. Signal outside its permitted range
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:
5 modelsS60 (2001–2009), S80 (1999–2006), V70 (2000–2008), V70 XC / XC70 (2001–2007), XC90 (2003–)
Show models by year and engine (7)
- Volvo S60 (2001–2009)2002–2003, 2006Engine D5244T, D5244T2 only
- Volvo S60 (2001–2009)2004–2005Engine D5244T, D5244T2, D5244T3 only
- Volvo S80 (1999–2006)2002–2006Engine D5244T, D5244T2 only
- Volvo V70 (2000–2008)2002–2003, 2006Engine D5244T, D5244T2 only
- Volvo V70 (2000–2008)2004–2005Engine D5244T, D5244T2, D5244T3 only
- Volvo V70 XC / XC70 (2001–2007)2003–2006Engine D5244T only
- Volvo XC90 (2003–)2003–2006Engine D5244T only
What does this fault code mean?
The ECM checks the brake pedal position sensor signal, which reaches it over CAN from the brake control module (BCM), against the brake light switch position. The code is set if the signal is missing or unreasonable compared with the switch. The fault may lie in the BCM, the brake light switch or how it is adjusted.
Possible causes
- Fault in the brake control module (BCM)
- Brake light switch incorrectly adjusted
- Brake light switch has come loose from its pedal mounting
- Play, contact resistance or oxidation in the brake light switch connector
- Break in the power supply reaching the brake light switch
- Damaged brake light switch
What you can do
- 1Read the fault codes in the brake control module (BCM) and the central electronic module (CEM) first, and deal with them
- 2If the BCM shows no fault code, make sure the brake light switch is properly adjusted and fixed to the pedal mount
- 3Check the brake light switch connector for play and oxidation, and use a multimeter to check that the supply and signal wire have no open circuit or short
- 4If you have a diagnostic tool: read the brake light switch status in live data while the brake is pressed and released. The switch should close when the pedal is pressed
- 5The brake system is safety-critical. If the fault remains or the brake light stays on, have a workshop check it, and do not drive with a safety fault in the brakes
Symptoms you may notice2
- Cruise control does not work
- Brake light constantly on
What the fault can affect1
- Cruise control is switched off while the fault is active
General guidance for car owners. Diagnosis on the car can point to a different cause.