Does anyone have the wiring diagram of the 4.2L engine air flow sensor / MAF connector they could send me?
Need to know what the signals are on the five pins of the connector.
Thanks in advance.

 

You can download the wiring diagram for your car at jagrepair.com. The diagram shows 5 pins:-



How are you planning to test it?

 

Have corrected my initial post to state five pins, not four.
My thought was to back probe the connector pins with a DMM. Want to make sure the voltage levels are correct.
The aftermarket MAF I installed only lasted 2.5 weeks before it completely failed. Need to ensure the ECM is not putting an incorrect voltage to the MAF.

 

Well it looks like pin 1 should be battery voltage (12v). I don't know which one is ground, but I would guess you should get either nothing or close to nothing on the other pins (2 and 3). Maybe you can find some info on the troubleshooting guides for the MAF codes.

Most likely though is your aftermarket MAF is in fact Chinese junk and you need to buy a genuine part from a good supplier.

 

Yes, pin 1 is MAF supply voltage.
And I agree about the Chinese junk MAF I had. I was going by SNG Barratt selling it that perhaps it would be a good valid replacement....and it might be and the short in the wiring harness is what took it out.

Back to work.

 

You'd expect SNG Barratt to sell a decent aftermarket part, but I think its a false economy to do so with things like MAF and oxygen sensors - you tend to get what you pay for with parts like that. Definitely worthwhile checking the harness for any unexpected voltages or shorts though.

 

Yep, that was my thinking as well.....apparently not though. The MAF I got from SNG Barratt was a no-name one and was 3x the price of the cheap ones at RockAuto. I was going by the price at SNG Barratt as well.
Further investigation into the harness and ECM has shown there are no problems with either. The Pin Test I was using was for a 2003 and just did not match-up for my 2006. Plus there was at least one error in the wording of the test where the test parameter said to have at least 10,000 ohms when it should have been less than about 100 ohms.
Anyways, no issues with the wiring harness or ECM.
Getting a cheap MAF from RockAuto, which only needs to last a few hours as wife has traded the XK8 in for a new vehicle. After Friday will no longer be a Jaguar owner.