What does fault code ECM-0642 mean?

Diagnostic fault code details for ECM-0642 (Volvo C30 (2007–2013), Volvo C30 (2007–2013), Volvo C70 (2006–2013)). Repair service at OBD Tuning.

VOLVO

ECM-0642 - Power supply 1. Signal too low

System

Engine Control Module (ECM)

Volvo models this fault code applies to

This fault code has different meanings depending on model, model year or engine. Select the meaning that applies to your car.

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 supply voltage to all emission-related sensors is too low, and the engine control module sets the code. The cause may be poor connections, or a supply wire shorted to earth. The sensors may then give incorrect signals, which can show up as starting problems or poor driving.

Possible causes

Contact resistance or oxidation in the connections
Supply wire short-circuited to earth

What you can do

1Check the connectors to the engine control module for contact resistance and oxidation
2Inspect the wiring from the engine control module to the sensors for chafing, since a chafed wire can short to earth
3With the ignition off, use a multimeter to check that the supply wire has no contact with earth (the body)
4If the fault remains after these checks, have a workshop read the sensors and control module with diagnostic equipment and remedy what is found

Symptoms you may notice3

The engine starts unreliably or not at all
The car runs poorly and lacks power
Yellow warning symbol with text message in the display

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

VOLVO

ECM-0642 - Power supply 1. Signal too low

System

Engine Control Module (ECM)

Volvo models this fault code applies to

This fault code has different meanings depending on model, model year or engine. Select the meaning that applies to your car.

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?

Possible causes

Contact resistance or oxidation in the connections
Supply wire short-circuited to earth

What you can do

1Check the connectors to the engine control module for contact resistance and oxidation
2Inspect the wiring from the engine control module to the sensors for chafing, since a chafed wire can short to earth
3With the ignition off, use a multimeter to check that the supply wire has no contact with earth (the body)
4If the fault remains after these checks, have a workshop read the sensors and control module with diagnostic equipment and remedy what is found

Symptoms you may notice3

The engine starts unreliably or not at all
The car runs poorly and lacks power
Yellow warning symbol with text message in the display

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

ECM-0642 - Power supply 1. Signal too low

Volvo models this fault code applies to

Power supply 1. Signal too low

Reference voltage A. Signal too low

Applies to the following models:

What does this fault code mean?

Possible causes

What you can do

Symptoms you may notice3

ECM-0642 - Power supply 1. Signal too low

Volvo models this fault code applies to

Power supply 1. Signal too low

Reference voltage A. Signal too low

Applies to the following models:

What does this fault code mean?

Possible causes

What you can do

Symptoms you may notice3