VOLVO
ECM-91C7 - Throttle unit. Faulty signal
System
Engine Control Module (ECM)
Volvo models this fault code applies to
Applies to the following models:
8 modelsC70 Cabriolet (1998–2005), S40 (2004–2013), S60 (2001–2009), S80 (1999–2006), V50 (2004–2013), V70 (2000–2008), V70 XC / XC70 (2001–2007), XC90 (2003–)
Show models by year and engine (15)
- Volvo C70 Cabriolet (1998–2005)2003–2005
- Volvo S40 (2004–2013)2004Engine B5254T3 only
- Volvo S60 (2001–2009)2002Engine B5204T5, B5234T3, B5234T7, B5244T3 only
- Volvo S60 (2001–2009)2003Engine B5204T5, B5234T3, B5234T7, B5244T3, B5254T2 only
- Volvo S60 (2001–2009)2004Engine B5204T5, B5234T3, B5234T7, B5254T2, B5254T4 only
- Volvo S80 (1999–2006)2002Engine B5204T5, B5234T7, B5244T3, B6294S2, B6294T only
- Volvo S80 (1999–2006)2003Engine B5204T5, B5234T7, B5244T3, B5254T2, B6294S2, B6294T only
- Volvo S80 (1999–2006)2004Engine B5204T5, B5234T7, B5254T2, B6294S2, B6294T only
- Volvo V50 (2004–2013)2004Engine B5254T3 only
- Volvo V70 (2000–2008)2002Engine B5204T5, B5234T3, B5234T7, B5244T3 only
- Volvo V70 (2000–2008)2003Engine B5204T5, B5234T3, B5234T7, B5244T3, B5254T2 only
- Volvo V70 (2000–2008)2004Engine B5204T5, B5234T3, B5234T7, B5254T2, B5254T4 only
- Volvo V70 XC / XC70 (2001–2007)2002
- Volvo V70 XC / XC70 (2001–2007)2003–2004All engines except: D5244T
- Volvo XC90 (2003–)2003–2004All engines except: D5244T
What does this fault code mean?
The engine control module (ECM) tries to adapt the throttle unit. If it finds that the throttle's movement is blocked, or if its opening spring is not working properly, the code is set. The fault can come from a sticking throttle, poor contacts, damaged wiring or a damaged throttle unit.
Possible causes
- The throttle sticks or is blocked by oil film or dust
- Contact resistance or oxidation in the connectors between the throttle unit and the ECM
- Open circuit or short-circuit to ground or voltage in the wiring to the damper motor
- The wiring to the damper motor is short-circuited to itself
- Defective or damaged throttle unit
What you can do
- 1Read off the fault codes and first troubleshoot ECM-9150 and/or ECM-9160 if they are stored
- 2Check the connectors at the throttle unit and the engine control module for contact resistance and oxidation
- 3Check that the throttle is not blocked by any object or sticking, and clean it if necessary
- 4Use a multimeter to check that the damper motor wires have no open circuit and are not short-circuited to ground, voltage or each other
- 5If the fault code returns, the throttle unit is damaged, and a workshop should replace it and carry out the adaptation
Symptoms you may notice2
- The Check engine lamp lights
- Performance is reduced
What the fault can affect1
- Depending on the fault, the ECM can disconnect the damper motor, and the throttle then tries to go back to rest
General guidance for car owners. Diagnosis on the car can point to a different cause.