VOLVO
TCM-P056008 - System voltage. General fault information. Bus/message fault
System
Transmission Control Module (TCM)
Volvo models this fault code applies to
Applies to the following models:
1 modelXC90 (2003–)
Show models by year and engine (2)
What does this fault code mean?
The transmission control module compares the system voltage with the value that the central electronic control module (CEM) sends on the CAN network. The code is set when the values do not match, and this can be caused by poor contact, a battery charger with the wrong voltage, or an internal fault in the transmission control module.
Possible causes
- Poor contact or oxidation at the transmission module connector or in the gearbox
- A battery charger with the wrong voltage has been used
- Internal fault in the transmission control module
What you can do
- 1If you have diagnostic equipment, compare the voltage at the transmission control module with the CEM value in live data; they should be roughly equal
- 2Check the connector to the transmission control module for contact resistance and oxidation
- 3If a battery charger has been connected to the car, check that it has the correct voltage for the car
- 4If no fault is found in the connector, have a workshop troubleshoot the CEM
- 5Have a workshop replace the transmission control module if it has an internal fault
Symptoms you may notice1
- General warning lamp on
What the fault can affect1
- The control module switches to an emergency program
General guidance for car owners. Diagnosis on the car can point to a different cause.