Thread: MAF / AFM testing

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If both show zero I would be checking the wiring at the front of the engine.
Regards Philip A

First of all check fuse F2(engine bay) if it's D2 or the fuse in C0602 if it's Defender(presumably Td5s)
Defender MAF fuse.jpg

Originally Posted by CraigE

How likely is it 2 would have failed? The second one was a very old spare.

Given the commonality of the MAF sensors failing, the fact that it's old and was likely removed due to a reason (e.g. because it had previously failed), it would be highly likely.


How's it drive with no MAF connected?

Originally Posted by twr7cx

Given the commonality of the MAF sensors failing, the fact that it's old and was likely removed due to a reason (e.g. because it had previously failed), it would be highly likely.


How's it drive with no MAF connected?

Drives ok with MAF disconnected but, fair power looss and economy dropped from around 950kms 105 litres to about 800kms, so new MAF will be ordered in the morning. Tested yesterday and getting 12v to the MAF but no voltage on the other two pins at all. It does surprise me how often these fail, have not had one fail on any other car ever, yet this will be #4 on this car and yet VDO Siemens are supposed to be the best. Might also get one from Hong Kong and trial as about 1/8th of the price.

Originally Posted by CraigE

Might also get one from Hong Kong and trial as about 1/8th of the price.

Depending on which MY D2/D2a you have, if it's automatic that can make the automatic transmission horrible. Which does indicate that they're not equal.

Originally Posted by twr7cx

Depending on which MY D2/D2a you have, if it's automatic that can make the automatic transmission horrible.

OP has Defender.

Originally Posted by CraigE

...VDO Siemens are supposed to be the best. Might also get one from Hong Kong and trial as about 1/8th of the price.

VDO/Siemens as long as it's not Genuine LR is still an aftermarket just that it's called OEM and more expensive than others... even if those from China are cheap that money is wasted, better drive with it unplugged cos one with inaccurate readings can do more harm than benefits... if you have the EGR removed on a 10P engine the MAF can't have such radical effect on consumption cos on 10Ps the fuelling is based mainly on MAP/rpm inputs while the MAF is mainly for EGR management and better on default for MAF open circuit than with one which has erratic readings... if it is 15+P engine then a genuine MAF is compulsory cos MAF/rpm inputs are mainly used for fuelling.