2003 GMC Yukon traction control/limp mode

[rod7515]

SO heres an update on my Yukon. Im still looking for answers! lol
Im still dealing with my limp mode issue.
Heres what I have been able to do since my last post. I have cleaned the throttle body and also disabled the ABS by removing the 60 Amp fuse. I bought a better scanner and I know its not my wheel speed sensors as i dont loose a signal for speed. I have narrowed it down somewhat. WHen it happens I get a check engine light at the same time and I check the codes immediately to find code P2135 (Throttle/Peddle position Sensor/Switch A/B voltage Correlation) if i have left the engine running it is idling very rough and when i clear the check engine light with scanner it will smooth out. But the Traction light will stay on and im still in limp mode. At this point I must shut the engine off and wait a few seconds then restart. Most times it will start and all lights are off. I may go 1/2 mile or 10 miles before it will do it again. Also another thing is that if I leave the yukon runniong sometimes it will go into limp mode sitting still. Ive replaced the module on the throttle body and also the switch that is connected to the accelerator pedal. Is there any other switches tied into this? I have done the Sync procedure but it doesnt seem to work. I have also had code P1518 (PCM to TAC module Data Circiut) as well. And a few times i have had P0120 ( Generic Current Throttle/Pedal Position Sensor/Switch A Circiut). One time I had a code P1516 (COmmand vs Actual Throttle Position Perfromance (TAC Module)) come up.
Can anyone shed any light to this for me? Appreciate your help as Id like to keep this vehicle around a while. When it runs without lights it runs awesome and handles my mowers and trailer great.
Thanks Rod.

 

[Fless]

Has the TAC module and its connections been inspected?

 

[rod7515]

What is the TAC module and where is it located? I have not checked it. Each time this happens I get a code for throttle peddle pos sensor.

 

[Fless]

What is the TAC module and where is it located? I have not checked it. Each time this happens I get a code for throttle peddle pos sensor.

Hit the link below but verify your vehicle info, and navigate to the same page for yours if needed. Use the links at the top of your browser to view other items.

Electronic Throttle Actuator: Locations — 2003 GMC K 1500 Yukon 4WD V8-5.3L VIN T Service Manual | Operation CHARM

Detailed repair manual for the 2003 GMC K 1500 Yukon 4WD V8-5.3L VIN T.

charm.li

 

[LsHart]

If a correlation between throttle and throttle body, don't agree then limp mode active will come on. And or as stated before a relearn needed. Mass air flow and or air temp sensor if applicable.

 

[LsHart]

Pedal and or throttle body is ur issue. If a relearn isn't done and completed as stated on the screen of the scanner, will not go away. But I'm open to anything.

 

[rod7515]

What is the correct relearn process I should follow. I followed one when I did the new peddle switch but it never showed that it accepted. I don’t recall exactly what I did but if I remember I should have gotten some type of light verification so I never thought it completed.

 

[LsHart]

If u have a scanner or access to a good one! Read that a couple of times. A scanner can claim to do it but fail everytime. And when u go to the tool truck to say hey, what the hell! Tool truck guy goes, must need an update or I'll get back to u. Sorry eye started to twitch! That being said good quality parts and a good scanner will solve the issue. Being pigtails are good. Can't go cheap on parts like that.

Last one I did if I remember. Turn key when told to under relearn started, hold throttle and or when commanded to on screen. Then crack and I think it had to run for a period of time. And u would know cause I think it would idle down. Some or part of this might be wrong but it's close.

 

[mikez71]

Since you have a P2135 code, here is another current thread that sounds like a similar issue. (no solution yet, but he seems determined..)

Thread 'Problematic P2135 code'
https://www.tahoeyukonforum.com/threads/problematic-p2135-code.158416/

 

[Fless]

BTW, it's a PEDAL, not something you're trying to sell (e.g., peddle).

There is a TSB for the throttle body, including an updated "calibration" for the PCM. (Verify your vehicle first, though).

Fuel System - Low/Rough or Unstable Idle — 2003 GMC K 1500 Yukon 4WD V8-5.3L VIN T Service Manual | Operation CHARM

Detailed repair manual for the 2003 GMC K 1500 Yukon 4WD V8-5.3L VIN T.

charm.li

Same vehicle I selected above, here's the diagnostic path for P2135:

P2135 — 2003 GMC K 1500 Yukon 4WD V8-5.3L VIN T Service Manual | Operation CHARM

Detailed repair manual for the 2003 GMC K 1500 Yukon 4WD V8-5.3L VIN T.

charm.li

 

[rod7515]

Fless, you’ve got me on that one. Don’t tell my son I misspelled it as he’s a teacher and always on me about misspelling when I’m typing. Lol.
Mine is a 6.0 not the 5.3. That’s one of the reasons I’d like to keep this vehicle as when it’s running it’s got plenty of power and runs great.
LsHart, I bought a scanner from Mac. It’s a millennium pro 90. I’m hoping that will work for what I need to do but I have no experience so I need to learn how to use it.

Here’s the relearn I found on the web last time but I didn’t seem to do anything different.
Throttle Body (TPS) Relearn Procedure
If you have replaced the throttle body, cleaned it, or disconnected the battery, follow these steps:

1. Clear Codes: Clear any existing check engine lights or trouble codes using a scanner.
2. Idle Procedure: Start the engine and let it idle in park for 3 minutes.
3. Key Off: Turn the ignition off for 60 seconds.
4. Second Idle: Start the engine again and let it idle in park for another 3 minutes.
5. Drive Cycle: The engine should now be idling normally. If not, drive the vehicle at speeds above 44 MPH to complete the learning process.
   
   
   YouTube·CARDONE Industries +1

Note: Ensure the accelerator pedal moves freely and does not stick.

Is there another way?
Thanks Rod

 

[Fless]

Fless, you’ve got me on that one. Don’t tell my son I misspelled it as he’s a teacher and always on me about misspelling when I’m typing. Lol.
Mine is a 6.0 not the 5.3. That’s one of the reasons I’d like to keep this vehicle as when it’s running it’s got plenty of power and runs great.
LsHart, I bought a scanner from Mac. It’s a millennium pro 90. I’m hoping that will work for what I need to do but I have no experience so I need to learn how to use it.

Here’s the relearn I found on the web last time but I didn’t seem to do anything different.
Throttle Body (TPS) Relearn Procedure
If you have replaced the throttle body, cleaned it, or disconnected the battery, follow these steps:

1. Clear Codes: Clear any existing check engine lights or trouble codes using a scanner.
2. Idle Procedure: Start the engine and let it idle in park for 3 minutes.
3. Key Off: Turn the ignition off for 60 seconds.
4. Second Idle: Start the engine again and let it idle in park for another 3 minutes.
5. Drive Cycle: The engine should now be idling normally. If not, drive the vehicle at speeds above 44 MPH to complete the learning process.
   View attachment 485037YouTube·CARDONE Industries +1

Note: Ensure the accelerator pedal moves freely and does not stick.

Is there another way?
Thanks Rod

Don't take me too seriously -- I'm somewhat of a spelling nerd. My whole business career was in telecom regulatory compliance (FCC, FAA, other gov't. entities) which required good spelling skills. Correct spelling helps others that may search for issues and solutions.

I'm not sure about other ways to do the relearn. But when tagging another member, be sure to start that member's name with the "@" sign and start typing the name. Pick it from the list that's shown (you may need to type a few more characters to get the name to show up on the picklist). I'll tag @LsHart like this, and he'll be notified.

You should get a notification that I quoted/mentioned you since 1) I used the "reply button to quote you and 2) you're the one who started the thread. Presuming, of course, that you're getting notifications when your thread is updated by another poster.

 

[rod7515]

Thought I would update where I’m at with the Yukon. I decided to head to local you pull salvage and see if I could find a throttle body to switch out. No luck as all the Yukons there (6 of them) they all were 5.3L. I pulled my connector on my throttle body before I left to make sure the old connector that I had swapped out about a year ago was the correct one and then I could take the old one with me to the salvage and make sure if I found something it would work but as I said no luck. Now the day went there my Yukon went into limp mode 7 times in about 22 miles.
Well the next day after I unplugged and plugged that connector the Yukon didn’t go into limp mode at all. About 30 miles. So I decided to go get some electric diogreese and I loaded t up and plugged it back together. It’s been about 150 miles and I have no check engine light and it hasn’t acted up since. I know it’s not a cure but it’s very puzzling!

 

[LsHart]

Nice! As stated before the pigtail is a replacement part. It's always good to get a headache gone!

 

[rod7515]

Quick update, been almost 3 full weeks and it hasn’t gone into limp mode one time. Hell I don’t even have a check engine light on in all that time. Now the plugging and unplugging of the TPS makes no sense because at least a year ago I replaced the pigtail with a new connector and last year I replaced the actual TPS switch on the throttle body. So it’s been plugged and unplugged before many many times! lol, but the bottom line is that the truck is running great at this time so I’m gonna roll the dice and keep this unit. It drives so damn good when it’s not throwing a fit. I’m done mowing now so I will put about 10 miles a week on it going forward.
Thanks. I’ll keep you updated should it decide to start limp mowing again.
Rod