What does fault code TCM-0073 mean?

Diagnostic fault code details for TCM-0073 (Volvo C30 (2007–2013), Volvo C30 (2007–2013), Volvo C30 (2007–2013)). Repair service at OBD Tuning.

VOLVO

TCM-0073 - Start lock function. 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 start inhibitor makes sure the engine can only be started in position P or N, where starting is allowed. The signal to the engine control module is grounded when starting is allowed. The fault means the signal is too high even though the gear selector is in a position where starting should be allowed, so the engine does not start.

Possible causes

The signal cable is short-circuited to voltage

What you can do

1Read off the fault code, clear it and check whether it comes back
2Have a diagnostic tool? Read the start inhibitor status with the brake pedal pressed in positions P and N; it should show start permitted there
3Use a multimeter to check that the wire from the start inhibitor is not live, and check that the connections are free from oxidation and firmly seated
4If the fault remains, checking the transmission control module and the mechatronic unit is a workshop task

Symptoms you may notice1

The engine does not start, sometimes or always

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