VOLVO
ECM-9540 - Accelerator pedal (AP) sensor power supply. Signal too low
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:
8 modelsC70 Cabriolet (1998–2005), C70 Coupé (1998–2002), S60 (2001–2009), S70 (1997–2000), S80 (1999–2006), V70 (1997–2000), V70 (2000–2008), V70 XC (1998–2000)
Show models by year and engine (20)
- Volvo C70 Cabriolet (1998–2005)1999–2002
- Volvo C70 Coupé (1998–2002)1999–2002
- Volvo S60 (2001–2009)2001Engine B5244S, B5244S2 only
- Volvo S60 (2001–2009)2002Engine B5244S, B5244S2, B5244SG, B5244SG2 only
- Volvo S60 (2001–2009)2003–2005Engine B5244SG, B5244SG2 only
- Volvo S60 (2001–2009)2006–2008Engine B5244SG only
- Volvo S70 (1997–2000)1999Engine B5204T3, B5204T4, B5234T3, B5234T7, B5254S DENSO, B5254T only
- Volvo S70 (1997–2000)2000All engines except: D5252T MSA 15.8
- Volvo S80 (1999–2006)1999–2000Engine B5244S, B5244S2 only
- Volvo S80 (1999–2006)2001Engine B5244S, B5244S2, B5244SG only
- Volvo S80 (1999–2006)2002Engine B5244S, B5244S2, B5244SG, B5244SG2 only
- Volvo S80 (1999–2006)2003–2005Engine B5244SG, B5244SG2 only
- Volvo S80 (1999–2006)2006Engine B5244SG only
- Volvo V70 (1997–2000)1999Engine B5204T3, B5204T4, B5234T3, B5234T7, B5234T8, B5254S DENSO, B5254T only
- Volvo V70 (1997–2000)2000All engines except: D5252T MSA 15.8
- Volvo V70 (2000–2008)2001Engine B5244S, B5244S2, B5244SG only
- Volvo V70 (2000–2008)2002Engine B5244S, B5244S2, B5244SG, B5244SG2 only
- Volvo V70 (2000–2008)2003–2005Engine B5244SG, B5244SG2 only
- Volvo V70 (2000–2008)2006–2008Engine B5244SG only
- Volvo V70 XC (1998–2000)1999–2000
What does this fault code mean?
The code concerns the voltage supply to the accelerator pedal position sensor, and the signal from that supply is too low. The engine control module (ECM) monitors the supply and stores the code when it deviates. The cause can be a short to ground or an open circuit in the supply wire.
Possible causes
- Supply wire shorted to ground
- Open circuit in the supply wire
What you can do
- 1Read out the fault code status, which shows whether the fault is intermittent or permanent
- 2Check the battery condition, since it is part of the troubleshooting
- 3With a multimeter, check that the supply wire to the pedal sensor has voltage with the ignition on and is not touching ground
- 4Inspect the wiring of the supply wire for chafing and breaks, especially at the connectors
- 5After repair: clear the code and reset the throttle module by switching the ignition off for a while, then on and off, and waiting a bit more before test driving
- 6Upgraded software for the car (released 2006 or later) is more tolerant of brief disturbances, and a workshop can load it
Symptoms you may notice2
- ETS warning lamp comes on
- Poor accelerator pedal response
What the fault can affect2
- Throttle opening becomes sluggish, since it is controlled by a single signal
- The throttle closes under braking, and pedal input is ignored while the brake is pressed
General guidance for car owners. Diagnosis on the car can point to a different cause.