What does fault code ECM-P08B100 mean?

Diagnostic fault code details for ECM-P08B100 (Volvo S60 (2011–), Volvo S80 (2007–), Volvo V40 (2013–)). Repair service at OBD Tuning.

VOLVO

ECM-P08B100 - Neutral Position Sensor "B" Circuit Intermittent/Erratic. General Failure Information. No sub type information

System

Engine Control Module (ECM)

Volvo models this fault code applies to

Applies to the following models:

8 models

S60 (2011–), S80 (2007–), V40 (2013–), V40 Cross Country (2013–), V60 (2011–), V70 (2008–), XC60 (2009–), XC70 (2008–)

Show models by year and engine (8)

What does this fault code mean?

The fault concerns the neutral position sensor circuit, marked A/B, and indicates that the signal from the sensor is uneven or erratic. The engine control module monitors the gear lever position while automatic stop-start is active, and the fault is checked with the engine running.

Possible causes

Loose contact or oxidation in the connector
Short to voltage on the signal wire
Damaged neutral position sensor

What you can do

1Check that the fuses are intact. The locations are shown in the instruction manual or on the fuse list
2Check that the connector at the neutral position sensor is firmly seated and free from oxidation and looseness
3Use a multimeter to check that the signal wire has no contact with the battery positive
4Check that the sensor is firmly fixed to the gearbox and is not damaged
5If you have a diagnostic tool, check in live data that the sensor value changes smoothly as the gear lever is moved, without jumps
6If the fault remains after these checks, have a workshop investigate the neutral position sensor

Symptoms you may notice3

Automatic engine stop-start does not work while driving
Automatic engine stop-start does not work at idle
Starting and auto-start do not work

What the fault can affect1

The automatic engine stop-start function is switched off

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