Discovery II
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
