What does fault code TCM-0400 mean?

Diagnostic fault code details for TCM-0400 (Volvo C30 (2007–2013), Volvo C30 (2007–2013), Volvo C30 (2007–2013)). Repair service at OBD Tuning.

VOLVO

TCM-0400 - Position sensor shift fork 1. Signal 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?

The position sensor for shift fork 1 gives too high a signal, which the control module registers as a fault. The cause may be a wire short-circuited to supply voltage, a damaged sensor or a fault in the control module. Gear changes can then become jerky or fail to occur.

Possible causes

Wire short-circuited to supply voltage
Damaged position sensor
Damaged transmission control module (TCM)

What you can do

1Clear the fault code and road test the car to see whether it returns
2Have a workshop check that the sensor wire is not short-circuited to supply voltage
3Have a workshop read the supply voltage and the sensor signals with diagnostic equipment
4If the values are close to or outside the permitted range, have a workshop decide whether the mechatronic unit needs replacing

Symptoms you may notice5

The check engine lamp lights up or behaves abnormally
Yellow warning symbol and text message in the display
Gear changes are harsh or jerky
No movement forward or in reverse when a gear is engaged
Gears change too early, too late or too often

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