What does fault code ECM-0104 mean?

Diagnostic fault code details for ECM-0104 (Volvo C30 (2007–2013), Volvo C30 (2007–2013), Volvo C70 (2006–2013)). Repair service at OBD Tuning.

VOLVO

ECM-0104 - Mass air flow (MAF) sensor. Signal missing

System

Engine Control Module (ECM)

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?

Although the code is named signal missing, the MAF sensor's reading is erratic or unreasonable. The engine control module (ECM) keeps watch on the signal and stores the code when it does not add up. The cause can be an air leak in the intake, poor contact or a damaged MAF sensor.

Possible causes

Air leakage in the intake system
Looseness, contact resistance or oxidation in the connections
Damaged mass air flow sensor

What you can do

1With the ignition off, check the intake for air leaks, for example at hoses and connections
2Check the connector to the mass air flow sensor for looseness, contact resistance and oxidation
3Check that the fuse for the mass air flow sensor circuit is intact
4Use a multimeter to check that the signal wire does not break intermittently when you move the harness, and has no short to ground or supply voltage
5If the fault returns after erasing codes and a test drive although the leaks and connectors are sound, have a workshop replace the mass air flow sensor

Symptoms you may notice1

Check engine lamp lights up or behaves abnormally

What the fault can affect1

A calculated air mass is used instead of the measured value

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