Hello all. Does the P0100 indicate that I have a faulty MAF sensor ? Just cleaned it due to the codes. Have gotten these codes in conjunction with an occasional "Performance" warning. Gas mileage has dropped from around 25 and change to low 23. New plugs and air filter. No other alarms.

 

Just checking but do you mean P0100 or P1000?

 

P0100

 

OK. It could be a circuit fault rather than the MAF itself.

It's odd for 2 codes to appear at once and often means one caused the other or there's a common issue.

You can check whether the P0171 is meaningful by looking at the LTFTs. (Also, whether you nearly have P0174 as well.)

 

Hi JaguarXJ8L2005,

You can download a couple of relevant Jaguar Diagnostic Trouble Code Summaries here:

Jaguar X350 DTC Summaries P, B, C, U

Jaguar X350 Powertrain DTC Summaries

Plenty of possible causes for P0171 are listed, but as you will notice, P0100 is not listed in either of these manuals.

In the Powertrain section of the Workshop Manual, P0100 expands to the proprietary Jaguar code P010000, which generic scanners truncate to P0100. Here's what the Workshop Manual says:




It is unlikely, but possible, that your MAFS or ECM is failing, but more likely there's a problem with the MAFS or ECM electrical connector or the wiring between the two.

Another possibility is corrosion on the ground point referenced by the ECM, which is just rearward of the right front suspension tower, concealed by the front edge of the cabin air microfilter housing. The ground stud, nut and wire eyelet terminals are all aluminum and a thin whitish layer of electrically non-conductive aluminum oxide forms on the parts, interfering with sensitive sensor readings. Remove the nut and wire terminals, clean all the parts with a small brass brush and zero-residue contact cleaner, allow to dry and reassemble, noting that the torque for the nut is a very low 6.5 ft. lbs., or just a little more than hand tight - don't overtighten or you'll snap the stud off the body.

Below are links for all six sections of the Workshop Manual. In the Powertrain section, the Pinpoint Test listed above will help diagnose the issue.

Table Of Contents

General Information

Chassis

Powertrain

Electrical

Body

Cheers,

Don