Description - engine management (ENGINE MANAGEMENT SYSTEM - V8) (page 20 of 43)

ENGINE MANAGEMENT SYSTEM - V8

DESCRIPTION AND OPERATION 18-2-25

In the event of a MAF sensor signal failure any of the following symptoms may be observed:

l

During driving engine rev/min may dip, before recovering.

l

Difficult starting.

l

Engine stalls after starting.

l

Delayed throttle response.

l

Emissions control inoperative.

l

Idle speed control inoperative.

l

Reduced engine performance.

l

MAF sensor signal offset.

There are two types of MAF sensor diagnostic check:

l

The MAF sensor signal is less than the minimum threshold for specific speed range – the engine must have 
exceeded 200 rev/min for longer than 300 ms and remain above 400 rev/min. The signal must be less than the 
threshold mapped against engine speed for longer than 500 ms.

l

The MAF sensor signal is greater than the maximum threshold for specific speed range – the engine must have 
exceeded 200 rev/min for longer than 10 ms. The signal must be greater than the threshold mapped against 
engine speed for longer than 300 ms.

If the MAF sensor fails the following fault codes will be produced and can be retrieved by TestBook:

P code

J2012 description

Land Rover description

P0102

Mass or volume air flow low input

MAF signal < minimum threshold, which is speed 
dependent

P0103

Mass or volume air flow circuit high input

MAF signal > maximum threshold, which is speed 
dependent