Throttle Actuator Control Help

[03YukonNH]

So the other day I got an engine light and a "Reduced engine power" message driving on the highway. The code that came up was P1125. I've read up on this code alot and apparently it comes when both of the sensors inside the accelerator pedal position (APP) module do not agree witih each other. So I started doing some diagnostic work using the wiring diagrams from the Chilton manual.

The APP sensor is connected directly to the throttle body actuator control module under the hood. There are nine wires at the APP sensor(which is next to the gas pedal) but only eight come into the TAC under the hood. I noticed that the missing wire is the dark blue wire which is a signal wire. According to the chilton manual, this wire is used for sensor 1 and the dark green wire is not used. However, I have a dark green at the TAC.

So I am a bit confused and wondering if anyone with a 2003 Yukon can check at the throttle body and tell me the number of wires that are there and whether or not there is a dark blue wire there. Thanks.

 

[slocaddy]

on my 03 caddy : 8 wires no dark blue. ive also had the same problem and found shutting the truck off and wiggleing the plug at the app sensor has worked for me. i dont perfer to buy a new $300 part as the dealer is my only option.(adjustable pedals)

 

[03YukonNH]

Slocaddy, I have the adjustable pedals as well. You are right, the dealer will only sell me the app sensor with the whole pedal, not the sensor by itself. Although I did the same as you (wiggled the connectors) I did buy an aftermarket Dorman sensor from RockAuto.com. It was only $40 and it doesn't come with the whole pedal. To remove the sensor from the pedal, you need a Torx security bit (not sure of the size).

The sensor came but I haven't replaced it yet because I haven't had any problems for over 300 miles.

 

[slocaddy]

so doese it look like you can interchanger sensors? or maybe swap internals? that was going to be my plan but its been fine for about 4k mi

 

[03YukonNH]

Yes, the APP sensor is held onto the side of the pedal by those 2 security torx bits. It can easily be swapped out once those are removed. I've now done about 500 miles and still no more issues. Truck runs like it was brand new.

 

[MLRomento]

Hey man, just wanted to know if you have solve that problem with that code p1125. My name is Marshall and I live in Honolulu, Hawaii. I going nuts and crazy tring to fix this problem. I replace the harness that connectʻs from the pedal to the engine compartment, also the Accelarator pedal position sensor, and still have that code reading p1125. Can you let me know if fixed your tahoe of know anyone who has solved this problem.

 

[Patrick P]

wiring short

I am currently dealing with the same problem... lose of power while driving. It's been isolatated to the wiring harness connector to the throttle actuator control module under the hood against the firewall near the drivers side fender brace. Can you believe it, $1,000.00 later at Martin Chevrolet, they taped it up with electrical tape, that didn't actually resolve the problem.
It looks like it will need a new plug spliced in or a new harness. I have searched online for just the harness for the TAC module., but can't find one. I am trying to avoid another $1,000 bill, when I get a call back from the shop.
Any ideas where I can find a harness other than a junk yard or just the end plug to splice it in?
PatrickP

 

[03YukonNH]

I think I finally solved the problem. I had the truck go into reduced engine power mode again and found that the connector at the Throttle body actuator had wiggled loose. The tabs that hold the connector on were brittle and had broken. Amazon actually sells the connector (AC Delco PT2628 - http://www.amazon.com/ACDelco-PT2628-Harness-Connector-Assembly/dp/B0055AMANA/ref=sr_1_1?s=automotive&ie=UTF8&qid=1384172967&sr=1-1&keywords=pt2628) with pig tails for crimping into the existing wiring harness. I used solder for a more durable connection. Here are the pictures of my install.

 

[Yukon Lover]

Thats awesome man. Glad someone finally found a solution to their problems, as long as thats the real culprit. Anymore issues with the truck? Mine is just getting worse and worse. Now it acts like its going into redused engine power mode but if i keep pumping or let off the gas and get back on it it comes out of it and then takes off like im in it half to three quarters throttle. Also it is kicking in the auto 4 wheel drive. But it only does this from a complete stop if i am rolling through a yield or a corner or something at 5 or 10 mile an hour it doesnt do this. Any ideas? Is the 4x4 actuator causing all of it or can the pedal sensor be the cause? Thanks.

---------- Post added at 07:35 PM ---------- Previous post was at 07:27 PM ----------

Patrick, what year, make, model, engine is your truck?

 

[Yukon Lover]

Sorry Patrick didnt notice you replied to the msg or get notified that you did. Truck is 03 yukon with the 5.3, The auto 4x4 thing has stopped now is thumping like a bearing so im thinking hub or diff, but still have reduced engine power if i cruise with light throttle so i avoid it by going in and out of the throttle every so often but is annoying and would like to figure it out. Code is for the tac but from what ive read it doesnt necessarily mean its that plus i tried a used one with no change. Jenna from blackbear said maybe bad throttle body and i also just read that it could be that on a trouble code sight.