VOLVO
TCM-P171986 - Engine Torque Signal. Bus Signal / Message Failures. Signal invalid
System
Transmission Control Module (TCM)
Volvo models this fault code applies to
Applies to the following models:
9 modelsS60 (2011–), S80 (2007–), V40 (2013–), V40 Cross Country (2013–), V60 (2011–), V60 Cross Country (2015–), V70 (2008–), XC60 (2009–), XC70 (2008–)
Show models by year and engine (9)
- Volvo S60 (2011–)2014–2015Transmission TG-81SC only
- Volvo S80 (2007–)2014–2015Transmission TG-81SC only
- Volvo V40 (2013–)2015Transmission TG-81SC only
- Volvo V40 Cross Country (2013–)2015Transmission TG-81SC, TG-81SC AWD only
- Volvo V60 (2011–)2014–2015Transmission TG-81SC only
- Volvo V60 Cross Country (2015–)2015Transmission TG-81SC only
- Volvo V70 (2008–)2014–2015Transmission TG-81SC only
- Volvo XC60 (2009–)2014–2015Transmission TG-81SC only
- Volvo XC70 (2008–)2014–2015Transmission TG-81SC only
What does this fault code mean?
The fault code concerns the engine torque signal on HS-CAN 1, which the transmission control module uses for shift points and system pressure. The signal is missing or indicated as faulty. The fault is general and does not say more precisely what type of fault it is. The cause may lie in the engine control module or in the CEM.
Possible causes
- Sporadic open or shorted CAN wire between the engine control module and the transmission control module
- Fault in the engine control module (ECM)
- Fault in the central electronic module (CEM)
What you can do
- 1Read the fault codes in the engine control module and the CEM, and fix those first
- 2This code can be cleared only after the root fault has been fixed and its fault code cleared
- 3Have a workshop check the CAN network between the engine control module and the transmission control module for open circuits and short-circuits
Symptoms you may notice5
- Warning symbol and text message in the display, and the check engine light lit or behaving abnormally
- Engine stalls when a gear is engaged
- Engine stalls when slowing down
- Lockup does not work
- Gear changes harsh or jerky on both upshifts and downshifts
What the fault can affect3
- If the torque signal on HS-CAN 2 is also faulty, the control module uses a basic value for the signal
- Adaptation is blocked
- Slip lock-up and automatic engine start/stop are switched off
General guidance for car owners. Diagnosis on the car can point to a different cause.