Technical Accelerator Pedal Potentiometer

[Greggers]

When my Abarth was hooked up to Examiner recently, it reported the following error, " No Accelerator Pedal Information, No Transmission, Intermittent".

Has anyone had this error before? I'm assuming that it's an intermittent error with the Accelerator Pedal Potentiometer... I'd not really noticed an issue with the accelerator until it was mentioned to me but now I noticed that the initial pickup when you depress the throttle a little bit is a bit inconsistent.

How easy is this to get replaced? I think it's part of the pedal itself and you just replace the pedal as a whole unit, is that right?

I'd be interested to hear if others have had any experience with this. Camalot Knights, didn't you have a similar error?

Greggers

 

[Camelot Knights]

ok.ive the examiner printout in front of me....ERRORS DETECTED BY THE CONTROL UNIT......Brake switch>intermittent.................... no accelerator pedal information>intermittent............................ so fiat cleared the errors about two wks ago,but my auto gear box fault came on again two days ago again...fiat told me its a brake switch that i need about £8.00 £48.00 supply and fit...as far as i remember the said its when i break to slow down the switch is sending the wrong info to the gearbox,so the gearbox dose not kno if i have my foot on the break or not, causing me to have the auto gearbox fault.the 3 times i have had this fault is when i have been slowing down with my foot on the brake.the gears will change down but not up.only if i put it into manual i can change up or down,or if i stop turn the engine on and of then all is well,so i guess i have to book it in to get done,hope this helps....

 

[Deckchair5]

First of all make sure your brake switch is adjusted correctly as otherwise it will flash your brake lights intermitently and cause the same fault (See Stilo guides). It's really easy to knock it out of adjustment, all you need to do is jam your foot under the brake pedal so the pedal comes up too far and hey ho your switch now operates incorrectly

Brake switch operation is a real weak spot on Stilos. If the brakes lights are always on or intermittent then the car thinks you're braking and accelerating at the same time and modern cars dont like that (Goodbye heeling and toeing then)

Switch is about £10 and isnt too difficult to replace. 10mins once you've done it a few times. I put a "How to" guide in the Stilo Guides up above. Be aware that you may need to modify the new switch by filing the securing lugs on the switch a little as the casing manufacture is a bit sloppy and it will never go in if the locating lugs are too big

 

[Greggers]

What about intermittent accelerator pedal information though? Surely that's not caused by the brake pedal switch... is it?

 

[Camelot Knights]

fiat said its all linked,if the switch is faulty then braking and accelerating is bypassing the switch,so if switch is faulty the gearbox will show a fault.ie when you are accelerating their could be a split second where the gearbox thinks you still have your foot on the brake and visa versa,so there for new switch and all should be well....

 

[Greggers]

I've checked my brake switch and all seems to be working as expected... also, Examiner didn't throw up any warnings about it, so I'm reasonably happy that my brake switch is okay.

My concern has been with the accelerator pedal... you'd expect that as you press the accelerator pedal in a linear manner eg. slow and constant pressure, the revs should increase in a linear manner. I don't seem to have this My revs seem to increase inconsistently for the first 1,000 revs (over idle) and then settles into the linear increase. BTW, this is when the car is in neutral and brake pedal not depressed.

To me, this sounds like the accelerator pedal potentiometer is a bit dodgy... not a terminal issue mind, but something that needs sorting at some point.

So... has anyone had any experience with issues with the accelerator pedal potentiometer or how easy it is to change?

Cheers!

 

[Deckchair5]

The gas pedal comms go through the D4 connector. Ding dong!

Think i'd look there for problems and you can do resistance checks there too and check for drop outs as someone moves the gas pedal - to save time - but that's not the easiest thing in the world. Easier if you have it out and on a bench

K55 shown here


Here's the D4 connector and pins from the gas pedal K055



If you have to get at the gas pedal then it's a bit of a pig to get at but it's held in with 4 screws. Connector is at the highest point so it's difficult to get at that without removing the whole pedal. The gas pedal has two linear potentiometers that change resistance at different rates so that the ecu gets a very accurate picture of where the gas pedal is. More people have trouble with it if they are getting in with wet boots etc as it all gets a bit damp and steamy down there