What does fault code TCM-0072 mean?

Diagnostic fault code details for TCM-0072 (Volvo C30 (2007–2013), Volvo C30 (2007–2013), Volvo C30 (2007–2013)). Repair service at OBD Tuning.

VOLVO

TCM-0072 - Start lock function. Signal too low

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 start inhibitor makes sure the engine cannot be started with a gear engaged, because the car could then move off when it starts. The signal from the gear selector assembly tells the engine control module whether starting is allowed, and starting is allowed when the signal is low. The fault means the signal is too low even though the gear selector is in a position where starting should not be allowed.

Possible causes

The signal cable is short-circuited to ground
Open circuit in the signal cable
Damaged connector or damaged cable

What you can do

1Read off the fault code, clear it and check whether it comes back
2Have a diagnostic tool? With the brake pressed, move the selector through P, R, N and D; start should show permitted only in P and N
3Check the connector and wire to the start inhibitor for loose contacts, oxidation and chafing; a multimeter can check for an open circuit or a short to ground
4If the fault remains, checking the transmission control module and the mechatronic unit is a workshop task, since the control module handles the start inhibitor signal

Symptoms you may notice2

The engine starts with the gear selector in position R or D
The engine does not start, sometimes or always

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