Help! Accelerator Pedal Position Sensor (P2138)
 

Hopefully someone here has some suggestions. I've searched the forums and everywhere else online but i can't seem to find someone who has had the same problem.

I was on my way to get an oil change, waiting at a light when all of a sudden the gas pedal did nothing. My CEL came on and so did the traction control light. the engine held at 2500 rpm so i was able to limp back home. I called the service department at my Mazda dealer and he had no clue. When i got back home I used my Scan Tool and got a P2138 Accelerator Pedal Position Sensor.....

Has anyone had this problem or does anyone have any idea how much this would cost to repair? I've done pretty much everything myself on my 8 but I'm reluctant to touch this drive by wire system......

I have an 04 GT...

Thanks guys

I've never heard of this before... I reviewed the Renesis training module and shop manual and got his:
Attached is the shop manual break-down for the accelerator pedal.
Maybe a loose connection to the pedal? Try checking the harness.
Maybe someone who has messed with this pedal can chime in and help more.

Thanks for your help I'll check out the connector and report back, hope its something simple to fix...

Despite the cold and snow here, I went outside and removed the pedal. I used a meter and it seems as though there is a connection in the pedal but when you depress the pedal there is no change with any combination of connections..

The code was P2138

Looking online I Found:

APP sensor No.1/No.2 voltage correlation problem ON 1 CCM ´
(See DTC P2138 )


Do you guys think I should just replace the pedal assembly based on the what I've found out so far? My only other guess is that there is something wrong with the PCM but I think it would have thrown a different code it was..

Any suggestions ?

well i think its unlikely to be mechanical and not be obvious. the fly by wire is a redundant system, but its entirely possible that both sensors are bad, although less likely that they both went out at the same time(ie not having a CEL for ione of them already)

I too think it could be a bad sensor, probably just one.
Unfortunately, the parts catalog doesn't show and pedal assembly broken down anymore than the assembly itself, so it might be difficult to find the correct sensor.
Might want to hit up junk yards and try to find a pedal.

i pm'd him, i have a pedal assymbly for cheap. If you are getting no different readings when depressed its obviously bad..

I took the pedal assembly apart and everything looks fine although the actual wiring the goes to the connector is molded into one of the side housing pieces.

The pedal works with magnets to provide different voltage readings as far as I can tell. There isn't any metal to metal contact inside at all, in fact the whole thing is made of plastic except for the spring inside and the plate on the foot pedal itself

I really have to keep this in mind with that girls car I'm helping debug!!!!!

tell ya what.. ill send you this pedal, you put it on and see if it works, if it does you can pay me, if not send it back. ?

I might take you up on that, I'm gonna call Mazda tomorrow again and see what the tech has to say before i do anything else

thats a great guy right there!

keep us posted on what happens and what you find. i was thinking more about what i said about the odds of both sensors dying at once... i havent taken the time to look it up, but i think it may actually be likely that if one of the sensors goes bad that the car goes into a limp mode as a safety feature. that way your not out on the freeway having ignored a CEL for months as many do, and have the 2nd sensor fail while at speed.

Hey guys, so I put the pedal back together after checking it out. I needed to move my car on the driveway and was forced to start it without the pedal in it. I moved it again using the engine rpm's and going easy on the clutch.

I decided to try and plus the pedal back in while the car was running.... Still nothing... there was no response from the pedal and the CEL and Traction Control lights were still on.

Then I turned the car off and tried starting it again. It started up but this time the Traction Control Light was off and to my amazement the gas pedal worked perfectly fine!!!.

I cleared the code, started it up again, and went for a drive. It works exactly the same as it did before this all happened and the CEL hasn't come back on yet.

My guess is that because the Traction and stability control system moderate the throttle it was messing with the inputs from the pedal somehow and the car went into some kind of fail safe mode and made the pedal inactive....... I guess.....

My mother got the same problem like you do. She often check her oil & one time the pedal just ran out on her again.

I'm having the same problem. Did you ever get it cleared up and if so how?

Did you read post #13?