What does fault code TCM-05C1 mean?

Diagnostic fault code details for TCM-05C1 (Volvo C30 (2007–2013), Volvo C30 (2007–2013), Volvo C30 (2007–2013)). Repair service at OBD Tuning.

VOLVO

TCM-05C1 - Multiplex function solenoid driver, clutch pressure/cooling odd gears. Voltage too high

System

Transmission Control Module (TCM)

Volvo models this fault code applies to

Applies to the following models:

4 models

C30 (2007–2013), C70 (2006–2013), S40 (2004–2013), V50 (2004–2013)

Show models by year and engine (10)

What does this fault code mean?

Solenoid CSMS1, which controls the cooling flow over the clutch for the odd gears and decides whether valve CSM1 routes the pressure to shifting or to the clutch, is shorted to supply voltage. The fault requires the mechatronic unit in the transmission to be replaced. The cause may also be a damaged solenoid, a damaged or dirty connector or circuit board, or a damaged transmission control module.

Possible causes

Damaged solenoid
Connector or circuit board damaged or dirty
Damaged transmission control module (TCM)

What you can do

1Read the fault codes, clear TCM-05C1 and drive the car to see whether it comes back
2Have a workshop read the fault with diagnostic equipment. The fault normally requires the mechatronic unit to be replaced
3Have a workshop replace the mechatronic unit and confirm the fault code does not return

Symptoms you may notice5

Malfunction Indicator Light (check engine) lit or behaving abnormally
Yellow warning symbol and text message in the display
No automatic gear changes
No forward or reverse movement with a gear selected
The car may feel weak or lack power when pulling away from a standstill

General guidance for car owners. Diagnosis on the car can point to a different cause.