Hi all,
I'm about at the end of options on trying to solve my pedal sensor problem with my '64 LS2 restomod project. I've got access to all data, I've scanned with a basic scanner program I have on my iphone, I've diagnosed as far as I can with a multi-meter..

If someone that has an OBDII scan tool that can see ALL parameters, sensor data, etc like a Tech 2, please contact me soonest. My car isn't driveable because it goes into a limp mode due to code P2138 being set easily (pedal position sensor correlation error). I don't think I'm going to be able to further diagnose this without seeing what the computer is seeing.

Not sure if HP tuners can see this level of detail, but someone chime in if something like that would work also..

I'm on the north side of Tampa Bay area and need the help scanning at my house since I can't get the car very far down the road

Can anybody help?

-mikey

 

I assume you are using a wire harness from an LS2 car - one that has the OBD port to plug a scan tool into.

You can get a CAN capable scan tool at Walmart or most any parts store, but it won't show all the data a Tech 2 will.

You're right - you might need a Tech 2 for more detailed info.

I have a Traqmate data-logger for data acquisition during track sessions. When splicing into the dark blue wire at the connector on top of the accelerator to log throttle position (I was actually tapping into the Accel Pedal Position, but with throttle by wire it's essentially the same as tapping into the TPS in the engine bay), I got a CEL and the limp mode. This was on an LS7 engined Z06, but it's the same throttle by wire as the LS2/3/9.

I hooked up my scan tool and got that same code you got. I cleared it with my scan tool, unhooked the battery for about 2 minutes, hooked the battery back up, and everything worked fine.

Unhooking the battery for a few minutes has a funny way of clearing computer problems on the C6 - and probably your LS2 engined/computerized car as well.

The other thing that I have read about C6 guys having problems with - and I think it gives the same code you're getting - is when they mod the TB by porting. There have been quite a few reports of guys having a sticky throttle blade after work has done on the TB, and that causes a difference in voltages between the APP and the TPS, which I think is exactly what throws that code.

So......maybe checking the throttle for smooth action with no binding of the blade in the body, and maybe unhooking the battery for a couple of minutes might magically cure the problem.

At least we can hope that it's something real simple like that!!!

Good luck!

Bob

 

yes, i do have an LS2 harness w/ALDL connector.

I can clear the code as you suggested below, by disconnecting the battery, however it always comes back.. all data discusses the troubleshooting and corrective actions and never mentions the TB or TPS. the code is set when the two pedal position sensors provide different data than expected by the computer. what is unclear to me is how the computer predicts the expected value. one would assume that if the TPS was in play during this, then checking the TPS would be part of the diagnostics for the P2138 code, but it isn't..

So I'm back to where I started, need to be able to see what the computer sees via tech 2, hp tuners or efi live..

thanks for the input, hope somebody nearby has a scanner!
mike