What does fault code TCM-0408 mean?

Diagnostic fault code details for TCM-0408 (Volvo C30 (2007–2013), Volvo C30 (2007–2013), Volvo C30 (2007–2013)). Repair service at OBD Tuning.

VOLVO

TCM-0408 - Position sensor shift fork 2. Signal to 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?

The transmission control module (TCM) engages the gears using shift forks, and each fork has a position sensor. The sensor for shift fork 2 is giving too high a signal, so the module cannot be sure where the fork is and switches to a protective mode.

Possible causes

Sensor wire shorted to supply voltage
Damaged position sensor
Fault in the transmission control module

What you can do

1Check the transmission module connectors for oil ingress, poor contact and corrosion
2Check that the battery is charged, as low voltage can cause false transmission faults
3Have a workshop check the sensor supply with diagnostic equipment – if the fault is in the module, it must be replaced and programmed
4Avoid driving far with the fault, especially if the car loses drive or shifts harshly

Symptoms you may notice4

Engine (Check Engine) warning lamp on and warning message shown
Gear changes are harsh, jerky or happen at the wrong time
Gear changes take a long time
In the worst case the car may not drive forwards or backwards

What the fault can affect1

The transmission enters a protective mode with limited function

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