TPS Issue

[Neuner]

Wasn't sure if this belonged here or in the Engine / Drivetrain so please move if needed. However, I would appreciate the attention as I am unable to find a resolution to this common problem.

'14 Suburban LT, 2wd.

Got the familiar p2127 error code;

• Faulty Accelerator Pedal Position Sensor
• Accelerator Pedal Position Sensor harness is open or shorted
• Accelerator Pedal Position Sensor circuit poor electrical connection
• Faulty Engine Control Module (ECM)

After the 1st occurrence, I replaced the pedal assembly with GM OEM early last year. Went awhile before acting up and thought it was a fluke. Then it would be a month or 2 before code was thrown. Now it's every day, even multiple times a day.

Nothing has been consistent to give me any hints. Issue happens while traveling fast or slow, pedal pressed or not even a foot on the pedal, smooth or bumpy road.

Been hard to review because it's been happening at the worst time and I have to clear the code to make it home.

I've inspected the wiring and connections and all looks great.

Searched heavily and found this situation quite common but haven't found a definitive resolution yet. Others have replaced almost everything except the ECM and still have the same.

Anyone know for sure the culprit?

 

[Geotrash]

Wasn't sure if this belonged here or in the Engine / Drivetrain so please move if needed. However, I would appreciate the attention as I am unable to find a resolution to this common problem.

'14 Suburban LT, 2wd.

Got the familiar p2127 error code;

• Faulty Accelerator Pedal Position Sensor
• Accelerator Pedal Position Sensor harness is open or shorted
• Accelerator Pedal Position Sensor circuit poor electrical connection
• Faulty Engine Control Module (ECM)

After the 1st occurrence, I replaced the pedal assembly with GM OEM early last year. Went awhile before acting up and thought it was a fluke. Then it would be a month or 2 before code was thrown. Now it's every day, even multiple times a day.

Nothing has been consistent to give me any hints. Issue happens while traveling fast or slow, pedal pressed or not even a foot on the pedal, smooth or bumpy road.

Been hard to review because it's been happening at the worst time and I have to clear the code to make it home.

I've inspected the wiring and connections and all looks great.

Searched heavily and found this situation quite common but haven't found a definitive resolution yet. Others have replaced almost everything except the ECM and still have the same.

Anyone know for sure the culprit?

Do you have access to a Tech2? If so, have you used it to test for proper throttle-opening and throttle-closing range? There is a readout in the tool that will tell you what the pedal is communicating to the ECU. That's the test procedure for it at least.

 

[Neuner]

Do you have access to a Tech2? If so, have you used it to test for proper throttle-opening and throttle-closing range? There is a readout in the tool that will tell you what the pedal is communicating to the ECU. That's the test procedure for it at least.

I do not. I use a simple OBDII with the Torque Pro app.

I'll need to research as I'm not familiar. Any suggestions? Thank you for the response.

 

[Geotrash]

I do not. I use a simple OBDII with the Torque Pro app.

I'll need to research as I'm not familiar. Any suggestions? Thank you for the response.

It's the dealer-level tool for doing deep systems diagnosis and resets in areas not covered by run-of-the-mill generic OBII scanners. Most of us have Chinese-made knock-offs of them from chinacardiags.com: https://www.chinacardiags.com/whole...el-suzuki-isuzu-holden-with-full-package.html

Also, there is a sticky thread containing the list of people who have them and will let you use it if you happen to live nearby.

 

[Neuner]

Thanks. It's one of those teeter-totter questions. Buy tool + find out you have to pay $1XX to replace the TPS anyways or replace the TPS, have it still act up and spend a lot more trying to resolve it in pieces because you don't have a Tech2.

Being a newb with one of those, how hard will it be for me to figure out how to read the output to diagnose? Is it a big learning curve?

 

[Geotrash]

Thanks. It's one of those teeter-totter questions. Buy tool + find out you have to pay $1XX to replace the TPS anyways or replace the TPS, have it still act up and spend a lot more trying to resolve it in pieces because you don't have a Tech2.

Being a newb with one of those, how hard will it be for me to figure out how to read the output to diagnose? Is it a big learning curve?

No, it's super easy to use. Totally menu-driven. If you're going to own one of these trucks for a few years, it'll save you money.

 

[Neuner]

Had to go out of town and got a stomach bug so haven't done anything.

The replacement pedal I got was from Mexico and so I started searching. Found reviews of others stating that their "Made in Mexico" pedal assemblies failed after only about 6 mos of use.

I'm now searching for one that is made elsewhere.

 

[NT Automotive]

Based on the thread title I for some reason thought this was a tpms thread but obviously not.

Very interested in this thread bc we sell throttle controllers (among other things) and looking to sell them to all 2007+ tahoe/yukon owners very soon...but will now require a disclaimer.

Additionally. I will ask some of the pedal assembly engineers I work with about your problem and report back if any useful feedback provided.

For now sounds like made in mehico is made to break. Is there not a USA made supplier?

 

[Neuner]

The new Pedal Assembly I picked up was the exact same. Made in Mexico but with the GM Stamp/Sticker.

Replaced it and made a small errand. Going over a speed bump it threw the code again and went into limp mode.

It can't be the pedal. I'm really thinking it's a loose connection someplace. Maybe even at the pedal connector, because I've noticed that this has primarily occurred when I've hit a bump.

1st time it happened was after I floored it getting on the highway. No bump but the pedal assembly is flimsy enough that it could have flexed and caused a bad connection at the plug?

I want to review all of the related wiring looms and connectors but I can't find a wiring schematic for the pedal. Anyone have one? I don't think the Chilton type books contain one.

 

[Fless]

Wondering if it's still the P2127 code. Can you get the current code and look at freeze frame data (when the code sets) on a scanner? That would give you some data points to compare.