Technical MAF sensor / Engine fault

[Macwalsh]

Hi Guys, I was looking at some of the "loss in MPG" threads for the JTD engine and something that cropped up several times was to disconnet the MAF sensor and then run the car to see if there was any improvement. My 54 plate JTD Multiwagon is hitting about 41 mpg at the moment which is down on previous months so I thought I'd give it a try. Ran the car for about 2-3 mles with no real difference and so reconnected the MAF sensor. I realise that 2-3 miles is not really long enough but didn't want to cause any damage to said sensors. Now I get the engine fault warning whenever I start the car - is there any "reset" functions I can perform or unplugging the ecu etc or is it a case of getting the fault codes read at huuuuuge expense at the local dealer?

Thanks guys.

Andy

 

[Sparky1483]

it should go out by itself after about 5 clean starts, or fiats reset, up to the limiter 3 times, idle-limiter-idle x3

 

[Argonought]

I'm not even sure it should generate an engine fault - normally just stores the code and keeps quiet about it.

Are you sure you've got a clean connection ?

 

[Sparky1483]

mine wouldnt all the time, but every now and then after i disconneted mine, it would flash up, depending on how long it was off for, and wouldnt go out for days when i drove with it off:bang:

 

[Macwalsh]

I'm not even sure it should generate an engine fault - normally just stores the code and keeps quiet about it.

Are you sure you've got a clean connection ?

Just keeps quiet about it? Are you telling me that my car keeps secrets from me? How am i supposed to look after it if it wont tell me whats wrong with it?
My god - its just like having 2 wives.........

 

[Sparky1483]

Just keeps quiet about it? Are you telling me that my car keeps secrets from me? How am i supposed to look after it if it wont tell me whats wrong with it?
My god - its just like having 2 wives.........

thats the stilo all over, even better when it tries to play games, giving warnings to things that dont exist

mine tried to tell me i had parking sensor failure, even though i didnt have them:bang:

 

[Macwalsh]

Hi Guys,

Well, tried the 5 restarts (actually tried about a dozen on the way into work this morning) and also tried hitting the 4500 rpm red line a few times as well (a liitle bit over 4500 actually) and still the damn engine fault error comes up. This is the first time that I have disconnected the MAF sensor and all the contacts look clean and shiny - I even covered up both sides of the plug when disconnected to ensure no contamination whilst driving. As a final resort, can I buy a code reader that will reset the code and shut the car up? Like I said earlier - its like having 2 wives at the moment!!!

If so - any suggestions as to a reasonable one to get and where I can get it from - there are a few on E-bay but dont want to buy the wrong type and possibly cause more problems.

Cheers again guys

Andy

 

[Argonought]

The fact it doesn't reset indicates the fault is still present

Are you certain you haven't dislodged something else in the process?

I'd recommend you get code reader with a 7 days return option as they're not guaranteed to be compatible with early JTDs (even an 04)

A battery reset (remove power for 30 minutes) might just be worth trying - and will also reset the ECU learning cycle - good for improving mpg.

 

[Sparky1483]

err, can i just say, may be a bit silly, but probable, you sure you put it back in the right way up?

 

[Macwalsh]

err, can i just say, may be a bit silly, but probable, you sure you put it back in the right way up?

how dare you sir!!! I'm not THAT daft (hang on just check) - nope its definately back on the same way as it came off (little yellow locking clip towards front of the car). Argonaught :worship: - I understand what you mean IE there must be a fault somewhere for it not to "reset" but I cant figure out what. There was nothing wrong beforehand - all I did was carefully remove the MAF plug, cover both male and female bits, drive for a few miles and then replace it. The only thing I can think of it that I have maybe disturbed a bad connection somewhere else in that part of the loom when unplugging it? I'll try the battery disconnect tomorrow (whilst changing another knackered rear caliper) and if that doesn't work then its getting torched.

Thanks for your time and patience guys

 

[Argonought]

The only thing I can think of it that I have maybe disturbed a bad connection somewhere else in that part of the loom when unplugging it?

That's all I can think of

Unplugging it really is very routine. I did it on a return run from Paris for a 50 mile mpg test run - only takes seconds to plug/unplug and I've NEVER seen it generate a warning light (although as I've said before a fault code is always stored).

Like you I also protected both ends with a plastic bag.