Hey there everybody… new to this forum and in search for some help… I have a 2001 c3500hd that I’ve been having some issues with.. and could surely use some help/guidance…
Been struggling with a reduced power issue…but in the process, noticed that when I had the accelerator pedal pressed and pushed the brake pedal, the gas pedal was not working….

any one know if this is normal or maybe I have a fault?

any help would be appreciated..🙏🏽

 

does it have drive by wire throttle or a cable operated throttle? post the engine size.
reduced power messages will set codes. post the codes here when you get them read with a scan tool and i can help with diagnosis.

 

It’s a c3500hd with the 8.1L
Drive by wire…

I’ll get the codes shortly


thanks for taking the time to help 🙏🏽

 

So at the moment, we have

p1220

p1221

 

check for broken wires inside the insulation 1 to 4 inches away from the TAC.
if the wires are good could be a bad tps or APP

 

The throttle body actuator has a yellow and brown wire… good connection👍
the throttle position sensor and accelerator position sensor was changed as well…

 

that leaves only the module and throttle body as faulty.
did you check the 5 volt ref voltages for tps 1 and tps 2?
what voltages r u getting for tps 1 & 2 at closed throttle and wot?

 

Truck still has these codes but now revs a little over 2k …..
but one thing I find interesting is that while I was pressing the gas pedal I pressed on the brake pedal and it disabled the accelerator pedal..
Having said that, I was curious and disconnected the brake relay… and that disabled the gas pedal!

is this normal?

 

Let me get those readings for you…

and again, thank you for your time! 🙏🏽

 

Thank you for your help and patience…
Got really busy with the kiddos. Anyhow… so I just checked voltage..

so for tps 1 : Tps 2 : wouldn’t move
passed 4.85v.
WOT = .35v. This reading was at
Idle, closed and wot!
IDLE = 4.01- 4.02

CLOSED = 4.55