Hi jayartibee,

The two diagnostic codes you posted don't necessarily indicate a problem with the MAFS or IATS, but with the electrical circuit for those sensors. It would be worth double-checking the electrical connectors at the MAFS/IATS and at the ECM, since corrosion on those connectors is a known issue.

At the links below you can download the DTC Summaries guide closest to your model year so you can look up the specific Jaguar definitions and possible causes of DTCs:

Jaguar DTC Summaries Guide AJ26 1997
Jaguar DTC Summaries Guide AJ26 1998
Jaguar DTC Summaries Guide AJ27 2000
Jaguar DTC Summaries Guide AJ27 2001 On

If you'll tell us the model year and region of your car (U.K., USA/Canada, France, Germany, etc.), it will help us give you more specific information.

Cheers,

Don

 

Thanks Don

Now the ECU is in the box below the tools is that right? Mine appears to be closed with clutch-head screws and one is very tight. What is one supposed to do with those??

MY is 2000 - UK - not sure if AJ26 or 27 see earlier - nicasil I think but no problems on that front - rebuilt 18 months ago with latest steel-backed tensioners & uprated oil pump

 

A dis-functioning MAF sensor does not give a code, unless disconnected, you will only get a sense if you get other, out of wack data.
Jaguar provided OBD2 data for a well functioning MAF sensor, to be measured in PARK and DRIVE, at idle and higher RPM's.

Looks an AJ26 to me, in that case you will also have a black vacuum reservoir next to the Throttle Body sticking up.

 

On Right Hand Drive cars the ECU is on the left side of the engine compartment inside the Engine Control Module Housing. Here's a snip from the diagram in the Electrical Guide:




Here's the parts diagram from jaguarclassicparts.com; the ECM is part 1:



Here's a photo grabbed from eBay:



Cheers,

Don

 

Thanks. Can't imagine why the clutch-head (one way) bolts on the ECM box

 

Helps prevent theft.

Also, there was an expectation that the module would not need to be removed.