VOLVO
ECM-91DF - Brake pedal position. Faulty position
System
Engine Control Module (ECM)
Volvo models this fault code applies to
Applies to the following models:
9 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), V70 XC / XC70 (2001–2007)
Show models by year and engine (22)
- Volvo C70 Cabriolet (1998–2005)1999–2002
- Volvo C70 Coupé (1998–2002)1999–2002
- Volvo S60 (2001–2009)2001All engines except: D5244T
- 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)1999–2000All engines except: D5252T MSA 15.8
- Volvo S80 (1999–2006)2001All engines except: D5244T, D5252T MSA 15.8
- 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)2000All engines except: D5252T MSA 15.8
- Volvo V70 (2000–2008)2001All engines except: D5244T, D5252T MSA 15.8
- 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
- Volvo V70 XC / XC70 (2001–2007)2001
What does this fault code mean?
The throttle unit (ETM) compares the brake pedal position from the brake light switch signal with the position the engine control module (ECM) sends on the CAN network. If they differ for too long, the code is set. It can also be stored when CAN communication with the ECM fails.
Possible causes
- Power supply to the engine control module
- Open circuit, short-circuit to voltage or short-circuit to ground in the brake light switch signal cable between the ECM and the throttle unit
What you can do
- 1Use the frozen values and counters of the fault code. If the fault has occurred often recently, it is easier to recreate it during troubleshooting
- 2Check that the engine control module receives power, and that its fuses and earth points are in order
- 3Check the connectors in the brake light switch signal cable for loose connections and oxidation
- 4Use a multimeter to check that the brake light switch signal cable has no open circuit and is not short-circuited to voltage or ground
- 5If the fault remains after a test drive, have a workshop check the CAN communication and whether upgraded software is available for the car
Symptoms you may notice3
- The accelerator pedal is ignored when the brake pedal is pressed
- The cruise control cannot be activated
- The ETS warning lamp lights, on C70 and S/V70 -2000 only
What the fault can affect3
- The throttle closes when braking, and pedal input is ignored while the brake is pressed
- The cruise control is switched off during the driving cycle when the fault was detected, and it works again the next time the car starts if the fault is gone
- During the driving cycle when the fault is active, no substitute values are generated
General guidance for car owners. Diagnosis on the car can point to a different cause.