VOLVO
ECM-9400 - Brake pedal sensor. 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:
7 modelsC70 Cabriolet (1998–2005), C70 Coupé (1998–2002), S60 (2001–2009), S70 (1997–2000), S80 (1999–2006), V70 (1997–2000), V70 (2000–2008)
Show models by year and engine (11)
- Volvo C70 Cabriolet (1998–2005)2000Engine B5244S only
- Volvo C70 Coupé (1998–2002)1999Engine B5254S DENSO only
- Volvo C70 Coupé (1998–2002)2000Engine B5244S only
- Volvo S60 (2001–2009)2001Engine B5244S, B5244S2 only
- Volvo S70 (1997–2000)1999Engine B5254S DENSO only
- Volvo S70 (1997–2000)2000Engine B5244S, B5244S2, B5244SG, B5244SG2 only
- Volvo S80 (1999–2006)1999–2000Engine B5244S, B5244S2 only
- Volvo S80 (1999–2006)2001Engine B5244S, B5244S2, B5244SG only
- Volvo V70 (1997–2000)1999Engine B5254S DENSO only
- Volvo V70 (1997–2000)2000Engine B5244S, B5244S2, B5244SG, B5244SG2 only
- Volvo V70 (2000–2008)2001Engine B5244S, B5244S2, B5244SG only
What does this fault code mean?
The code means the brake pedal position sensor signal is too low. On cars of model year 1999 to 2001 the signal is measured directly at the sensor. On model year 2002 the ECM instead takes the brake pedal position from the brake control module (BCM) over the CAN network. The brake pedal sensor belongs to the brake system, so the fault should be dealt with.
Possible causes
- Signal cable short-circuited to ground
- On model year 2002: a fault in the CAN communication between the BCM and the ECM
What you can do
- 1Read the fault codes in the brake control module (BCM) and in the ECM. If the BCM has codes that point to the brake pedal sensor, deal with those first
- 2If you have a diagnostic tool: read the fault status. It shows whether the fault is permanent or intermittent, and whether other codes are stored
- 3Use a multimeter to check that the signal cable from the sensor is not shorted to ground (body). Check the wiring and connectors: are they secure, and is there oxidation
- 4The brake system is safety-critical. If the fault remains, have a workshop check it, and do not drive with a safety fault in the brakes
Symptoms you may notice2
- Electronic throttle system (ETS) warning lamp lights
- Cruise control does not function at all
What the fault can affect2
- Cruise control is off for the driving cycle in which the fault was detected
- At the next start the function is available, if the fault is no longer present
General guidance for car owners. Diagnosis on the car can point to a different cause.