• If you currently own, previously owned or want to own an Avalanche, we welcome you to become a member today. Membership is FREE, register now!

03 Alanche problems with TPS and Accelerator pedal sensor

03 Avalanche III

Full Member
Joined
Jan 5, 2012
Messages
9
:help:  I have an 03 Z71 277,000 miles. best truck ever. Now I have an issue..... I have a reduced engine power message. Codes say its the TPS and APP sensor. I have replaced the Throttle body with the TPS sensor. The Accelerator sensor on the pedal. The wire harness from the pedal to the Control unit on the firewall, and the Unit on the firewall.

I have checked the wires near the TPS and they look, and feel OK. But I still have the problem. If I clear the codes I can start and drive between 2 and 10 mile before the issue appears again. (Truck has no codes if I clear them and then only Idle) :help: :help: :help:
 
:welcome: to the club what numbers were the codes.
 
I cleared the codes today, and drove ten miles to town, reduce engine power came back, so i stoped at Autozone and had the codes read again.

There were three    P1875  P1516  P1125

The guy at Autozone stated that this could be a speed sensor? In the transfer case or Transmision. Any thoughts?
I havent had a lot of luck with what these guys think the problem is so far.

I then made a couple of stops, the engine codes cleared on their own, and I drove home without any issues...This is driving me crazy. :help:
 
DTC P1125 Accelerator Pedal Position (APP) System

DTC P1516 Throttle Actuator Control (TAC) Module Throttle Actuator Position Performance

DTC P1875 4WD Low Switch Circuit Electrical

Kind of all over the place.

How is the battery is it fully charged.


 
Any other strange problem like guages going crazy, interior lights staying on.
 
No other issues. And I checked the grounds at the engine and firewall to the negative on the battery and all have continuity.

 
From what I looked up it's seems like a low voltage issue, if you search the site with those codes you will see what I mean. There are some older post about it, when doing the search type in 1 code at a time.

As far as the TB code try taking off the electrical plug and put so dielectric grease in it and see it that helps.
 
I went through the same intermittent problems for too long. Reduced engine speed due to communication errors. The TB and pedal sensors did not offer equal values. Default is reduced engine speed for safety.

Check the yellow wire again. You will have to unwrap about eight inches of the loom to expose the wires. Inspect each wire individually. Pull on it and you will see the separation. Feel for a dimple in the insulation. Look hard. It will be hard to find.
Look for a bent or missing pin in one of the connectors. I have seen that in one case.

I went through multiple TB, pedal assemblies and lots of frustration. Once warranty was up, I finally fixed the problem when I found an article about the brittle wire used in these models. Fewer strands and not as flexible as it needs to be. Once I soldered that bad section  back together, the problem was fixed.
 
I tried the dielectric grease, and checked the wire again. No luck :E:. I have scheduled the truck to see the overpriced dealership at 8:00 AM on Saturday. I will keep everyone posted as to the root cause and cost when I get it back.

Thanks for all the helpfull posts.
 
I had those codes on my 2002. It ended up being the TAC the member who fixed it said that he heard a "clicking" like a short in the box when the key was turned on and was 90% sure that was my problem. I bought the new control box and he was correct.
 
Took  truck in today and the dealer called an hour later stating they hope I did not need the truck back too soon. They said that they didn't know what was wrong yet but they.think its a wiring problem. I understand why they agent working for.NASA.

I told them that when I dropped it off. Sounds like they will be trouble shooting for a while. $$$$$$
 
Those electrical gremlins are a pain to track down  hopefully they will put it on the monitor and find it quick.
 
OK the dealer called earlier and stated that the issue is actually the GAS PEDAL. $325.00 to fix the issue.

I have already replaced the accelerator pedal position sensor, and they are aware of that, but I guess we will see when I pick it up on Friday Morning.
 
Keep your receipts and get your parts back too. They replaced the throttle body twice and the pedal once on one of ours. Still didn't fix the communication problem that was causing the default to "safe mode".
Once I found the bad spot in the yellow wire about 6" from the throttle body and fixed that break, no more problems.

They might have fixed it for you, but be ready to fight if it is not.
 
Any update as to what the problem was 03 avalanche.....having similar issues with my 03 avalanche.  Thanks. 
 
It was the Gas pedal...I had the dealer replace it and now its running great.
I don't know why the pedal would make a difference. I replaced the pedal position sensor two weeks earlier, but all is good now
 
Cross your fingers. Dealer replaced the pedal and throttle body twice before I fixed the yellow wire and solved the problem for good.
 
I went through the same intermittent problems for too long. Reduced engine speed due to communication errors. The TB and pedal sensors did not offer equal values. Default is reduced engine speed for safety.

Check the yellow wire again. You will have to unwrap about eight inches of the loom to expose the wires. Inspect each wire individually. Pull on it and you will see the separation. Feel for a dimple in the insulation. Look hard. It will be hard to find.
Look for a bent or missing pin in one of the connectors. I have seen that in one case.

I went through multiple TB, pedal assemblies and lots of frustration. Once warranty was up, I finally fixed the problem when I found an article about the brittle wire used in these models. Fewer strands and not as flexible as it needs to be. Once I soldered that bad section back together, the problem was fixed.
Thank you I will try this on my 2004
 
Back
Top