VOLVO
TCM-P086083 - Gear Shift Control Module "A" Communication Circuit. Bus Signal / Message Failures. Value of signal protection calculation incorrect
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 signal from the gear selector control module (GSM) is faulty, and the code indicates that the checksum protecting the signal does not match. The fault may come from interference on the LIN wire between the GSM and the transmission control module (TCM), or from an internal fault in the GSM. The gear display and manual shifting can then be affected.
Possible causes
- Interference on the LIN wire linking the selector module (GSM) and the TCM
- Internal fault in the gear selector control module (GSM)
What you can do
- 1If there are other fault codes from the same module that end in 86 or 88, fix them first, as they point to a fault on the LIN bus.
- 2Use a multimeter to check that the supply and ground wires to the selector are intact.
- 3Have a workshop check the LIN bus, as the fault can lie in any of the connected units.
- 4If a control module is replaced, have a workshop download the new software.
- 5If no fault is found on the bus, have a workshop replace the gear selector control module (GSM).
Symptoms you may notice4
- Warning with a message and yellow warning symbol
- The gear indicator in the gauges does not work
- Manual gear changes are not possible
- Low battery voltage is shown
What the fault can affect1
- The transmission control module (TCM) uses a default value for the signal
General guidance for car owners. Diagnosis on the car can point to a different cause.