Code #23 Accelerator Pedal

[vintagehardwoods]

Does anyone know if there is a static OHM check for the accelerator pedal assembly. I have a 95 6.5TD extd. cab dual wheel C3500. I changed the pedal assembly at $340 but still get the code. I have a hysteresis issue with initial pedal movement on every new key start. After the first start the pedal responds correctly. The wire dirgram in the book I have is no help. I have changed the ECM in the past and transfered the Eprom from old to new without any problem but from all the posts I have read the Eprom could very well be the problem. After utilizing the GM dealer way too many times for code reads I am not so sure everytime it says pedal that it is correct. Down stream components are most likely the problem here. Does anyone have any tribal knowledge on where I should check. I am a structural mechanic on C-130 aircraft and I keep a ledger on weird issues and fixes so the troubleshooting path is not lost. I would appreciate it if anyone has experienced this pedal issue. Thanks for the input so far. I am on my second accelerator pedal assembly. I will do the voltage test tomorrow.

[ 02-16-2006, 08:42 PM: Message edited by: vintagehardwoods ]

[Turbo Powered]

I am not sure if this will help or not. I have found out that my accelerator pedal assembly was bad about 2 years ago. I had my truck in to my mechanic for a vaccum pump, (before I discovered this wonderful site). I told him I wanted it checked over for any other problems. He is a good friend and always lets me know what the problem is so I can fix it myself, if I can. I believe he said that he tested it with an oscillioscope. I don't know what made him suspicious of the pedal but he said it had some spikes in voltage at lower RPM's. I also am learning that this has an effect on the transmission. I usually have my foot in it so I figured it wasn't really a problem. With my newfound knowlege, I suppose I had better replace that throttle pedal.

[More Power]

Besides reading codes, a Tech II scan tool can be used to test the APP's three elements (in a range of 0-100% for each of the elements).

Otherwise: A 5-volt reference is applied to pins E, G & D on the APP module. A ground is connected to pins A, B & J of the module. The signal outputs are on pins C, F & K of the APP module, or pins C2-B2 (#1), C1-C5 (#2), and C1-D4 (#3) at the PCM.

APP #1 should vary between 0.35 volts at idle and 4.0 volts at WOT.
APP #2 should vary between 4.5 volts and 1.0 volts.
APP #3 should vary between 4.1 volts and 2.5 volts.

Jim