VOLVO
ECM-911A - Throttle unit communication. Faulty communication
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 module (ETM) and the engine control module (ECM) communicate over the CAN network. If the throttle module registers a serious disturbance, meaning the CAN communication is blocked, the code is saved in the throttle module. If the network does not work until the next driving cycle, the information may be missing in the ECM. The code can be set together with other fault codes.
Possible causes
- Loose connections or contact resistance in the connectors to the CAN network
- Open circuit in one or both CAN signal cables
- One or both CAN signal cables are short-circuited to ground, voltage or each other
- Interference on the CAN signal cables
- A defective node in the CAN network
What you can do
- 1First remedy the CAN network fault codes in the central electronic module (CEM) and the driver information module (DIM), as this code can follow from them
- 2Check the connectors on the CAN network for loose connections and oxidation, and check the wiring for chafing and damage
- 3Use a multimeter to check that the two CAN cables are not open-circuit or short-circuited to ground or voltage
- 4Check the battery condition and charge, as low voltage can make the system relay switch on late. For longer troubleshooting, a battery charger intended for car batteries can keep the voltage stable
- 5Erase the codes, then reset: ignition off for three minutes, on and off again, then three more minutes. Add two minutes if the electric cooling fan has been running.
- 6Test drive the car. If the fault returns, ask the workshop whether upgraded software is available for the car, as it has adjustments that make it more tolerant of brief CAN interference
Symptoms you may notice5
- The accelerator pedal is ignored when the brake pedal is pressed
- The cruise control cannot be activated
- The idle is uneven and the car jerks during engine braking
- The electronic throttle system (ETS) warning lamp lights, on C70 and S/V70 -2000 only
- Throttle response is very poor and top speed is reduced, but only together with ECM-9180 or ECM-918F
What the fault can affect3
- Engine speed is regulated by fuel cut-off, with the injectors switched off one at a time, and the throttle follows the accelerator pedal position
- 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
- Together with ECM-9180 or ECM-918F, the throttle module disables throttle motor control, the throttle goes to its mechanical stop position and engine speed is limited
General guidance for car owners. Diagnosis on the car can point to a different cause.