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Is there an inexpensive fix possibly to the following Reduce Power light (throttle body/sensors/wiring)?

IBleedBlues

New Member
Joined
Jul 13, 2021
Messages
3
I could really use the expertise of our members today please.

I own a.....
2003 AV---
  • 5.3L V-8 Engine
  • 1500
  • 4-spd auto,
  • 2wd, Rear-wheel Drive
My truck just recently went from, very rarely having the reduced speed indicator light come on.... too..... having the issue come up multiple times within the same trip.

What I was experiencing until now was the reduce speed light would come on whenever we, I live in the Dallas/Fort Worth area, would experience a chilly day and it doesn't happen very often. And on those limited occasions that we would have a cold day, that reduced speed funtion would always set off where I would simply pull over, turn engine off, open and close the door, and then turn the ignition back on.. which would typically reset everwything and I was off and rolling. I should also mention that everytime the sensor would go off and as a result it would immobilize me for a moment ... it seemed to always happen within the first 1/2 mile and it didn't become any kind of a concern until yesterday really. That is until yesterday where

Here's what happened....
I was working a jobsite located 65 miles away from my home and we just had a to take a snow day the day before. Unlike the other times where it would make me pull over a block or to from my home... this time it wasn't until about 30 minutes into the drive that the issue began. But this time....unlike before..... I had to pull over and go through that reset routine and although it would reset like usual... it continued to give me issues for the remainder of my trip. This happened 7 times during my drive to the jobsite.

I finally found a auto store where I picked up a can of TB Cleaner and a can of electronic/mechanical cleaner. And prior to yesterday, that would do the trick and I wouldn't experience any more issue for about 1 year. I made it to the jobsite without any issue after that and assumed all was good.

Not so much... it happened 5 more times on the way home. Now I have an issue that must be resolved. Bigger problem is that Money is extremely tight right now due to medical reasons, I will need to make a trip to Houston this week, with my wife, whom is stage 4 and that where our doctors are located..

Any thoughts... I need get some sort of troubleshooting plan that will limit upfront cost and hopefully take care of the issue.

If the cost is unavoidable, please let me know what the best plan of action might be and the parts that would be best to start with. Any help even just a quick suggestion is both welcomed and appreciated.

Oh... I did notice that my estimated fuel economy gage was all over the board, not sure how my gas mileage has been effected because I have been averaging about 13 mpg since I bought my AV about 1.5 years ago

But.... this time it was ranging anywhere to 3mpg to 90mpg and the mileage was changing very frequently. My guess to why it may have stopped shutting itself down on my way home is.... that I kept my foot on the gas rather than giving it a chance to identify a fuel injection issue caused by the constant pedal down pedal up from keeping the speed limit and it was shutting down... including when I tried using the cruise control, in hopes that it would stop. Unfortunately I do not have a code but I'm pretty sure it will come up as P2135. If I get the code confirmed today I will update the post.
. Thanks again for the help!

- B
 
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Please edit your post and hit the return button to make some paragraphs.
Currently too difficult to read for us older folks as it looks like one big sentence.
 
P2135 relates to the throttle position circuit, it would be the sensor at the pedal, throttle body, wiring or worst case the PCM..

I believe the 2003 TPS (if it's original) on the throttle body is riveted on and makes it a little harder to change and you have to replace the whole throttle body. That's the bad news, but the good news it there are OEM and aftermarket readily available on amazon, ebay and most auto parts for around $100.00.

The sensor at the pedal is not as much and easy to replace.

The problem is you don't which end to replace without diagnostic tools so I would start with cleaning everything with electronic cleaner and check the wiring and connectors for issues and see if that makes a difference. If not, I would start at the pedal since that is the code that came up..

Good luck and I know there will be prayers for your wife and family from everyone here that reads this.


 
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First thing to try, also cheapest and easiest, is to grab some MAF cleaner and Throttle body cleaner and spray both down thoroughly.
 
Prayers for your wife, you and your family.

The only time I had the reduced speed (limp mode) was when my battery was going dead and didn't have the needed minimum voltage. If would (barely) start the truck but not have enough voltage to run everything and then go into limp mode. Have you tested the battery and alt? After a new Wally World Excide battery, all good.
 
Any resolution @IBleedBlues? P2138 popped up on me today, with reduced power mode and stabilitrak disabled messages...

But 2003VAAV's note has me wondering about the battery.. Mine is less than 1.5 years old, however I've been noticing a slow crank and the variable charging alternator doesn't go below 14v like it used to after ~20 minutes of driving. I'll have the battery tested soon, but was searching the forum and found your post and was curious if you found a fix.
 
My 04 just did the same thing. I had a new pedal and throttle body replaced. My shop said they looked all over for the pedal I had. Mine has the adjustable pedal. None to be found. I am going but this issue did put my Avalanche into limp mode. It has only happened once before and the with a dying battery.


Looking to see about fixing this and having my adjustable pedals back working. One of the parts on the accelerator pedal is GM 25324762. Is there a cross for it? There is also a plug on the pedal I believe does the adjusting. I need to take it off. It has a screw drive and isn't working. There are two capped rivets I need to remove the retainers from. Will have a project to play with anyway.
 
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