What does fault code ECM-270B mean?

Diagnostic fault code details for ECM-270B (Volvo C70 (2006–2013), Volvo C70 (2006–2013), Volvo S40 (2004–2013)). Repair service at OBD Tuning.

VOLVO

ECM-270B - Engine coolant temperature (ECT) sensor. Signal missing

System

Engine Control Module (ECM)

Volvo models this fault code applies to

Applies to the following models:

3 models

C70 (2006–2013), S40 (2004–2013), V50 (2004–2013)

Show models by year and engine (7)

What does this fault code mean?

Although the fault is shown as a missing signal, the sensor reads a lower temperature than the one the engine control module (ECM) has calculated since the engine started. If the calculated temperature becomes higher than the sensor signal, the code is set.

Possible causes

The temperature sensor is damaged
The coolant thermostat is damaged

What you can do

1Disconnect the connector to the electric cooling fan before working in the engine bay, since the fan can run even when the ignition is off
2Check the connector on the temperature sensor for contact resistance and oxidation
3Check the coolant level and that the coolant has the right freeze protection, since a frozen sensor can cause this code
4With diagnostic equipment, read the engine temperature after starting and see whether it rises in step with warm-up
5Have a workshop replace the coolant thermostat or the temperature sensor if the fault remains

Symptoms you may notice2

Malfunction indicator lamp (MIL) on
The engine is hard to start

What the fault can affect3

Boost pressure is set to a basic value
The coolant temperature is calculated instead of measured, and catalytic converter heating, starting adaptation, and idle and misfire diagnostics are disabled
The electric cooling fan runs at a predefined speed

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