P2138 on GMC ACADIA — Throttle/Pedal Position Sensor/Switch D/E Voltage Correlation

Q: "What does P2138 mean on a GMC ACADIA?"

"P2138 indicates: Throttle/Pedal Position Sensor/Switch D/E Voltage Correlation. This is a powertrain code. 4 GMC ACADIA owners have reported this to NHTSA."

Q: "What are the most common causes of P2138 on GMC ACADIA?"

"Based on 4 NHTSA reports, the most commonly cited components are: Electrical System,Unknown Or Other, Electrical System,Vehicle Speed Control,Fuel/Propulsion System, Air Bags,Structure,Vehicle Speed Control. These percentages are based on the component field in owner complaints."

Q: "Is P2138 a safety concern on GMC ACADIA?"

"Of 4 NHTSA reports for P2138 on GMC ACADIA, 1 involved a crash. Always consult a qualified mechanic for any diagnostic trouble code."

Q: "What should I do if my GMC ACADIA shows P2138?"

"1) Check for recalls on your VIN at nhtsa.gov/recalls. 2) Get a professional diagnosis — a code alone doesn't identify the exact failed part. 3) Get 2-3 repair estimates to compare."

What P2138 Means on Your GMC ACADIA

P2138 is a diagnostic trouble code indicating: Throttle/Pedal Position Sensor/Switch D/E Voltage Correlation. This code relates to the powertrain system. The vehicle's computer detected a condition outside normal operating parameters and stored this code.

4 GMC ACADIA owners have reported this issue to NHTSA across model years 2012-2021. Most reports come from the 2012, 2017 model years.

Real GMC ACADIA Owner Reports

Source: NHTSA Complaints Database

"Vehicle producing code P2138 then goes into limp mode stating to service stability, traction control off and engine reduced power. Replaced Throttle Body and Acceleration Pedal Position Sensor and error was still present."

— 2012 GMC ACADIA owner · ELECTRICAL SYSTEM,UNKNOWN OR OTHER · Filed 05/09/2025

"I’m just reporting several known issues. First, with code P2138, which I got today at Oreilly after my car started throwing warnings."

— 2017 GMC ACADIA owner · ELECTRICAL SYSTEM,VEHICLE SPEED CONTROL,FUEL/PROPULSION SYSTEM · Filed 05/03/2025

"The ACADIA 2020 while in slow motion approaching my private condominium parking spot, accelerated autonomously and then slammed into the cement wall. Airbags deployed, no warning of collision, seriously damaged both car and cement wall. No bodily injuries."

— 2020 GMC ACADIA owner · AIR BAGS,STRUCTURE,VEHICLE SPEED CONTROL · Filed 06/01/2021 ⚠️ Crash reported

"The contact owns a 2021 GMC Acadia. The contact stated while driving 50 MPH, the vehicle suddenly decelerated to 35 MPH. The vehicle stalled, and the "Steering Assistance Reduced" message was displayed. The vehicle was restarted."

— 2021 GMC ACADIA owner · STEERING,VEHICLE SPEED CONTROL · Filed 07/28/2024

All reports filed by vehicle owners directly with the U.S. Department of Transportation.

📊 Complaint Trend by Model Year

1

'12

1

'17

1

'20

1

'21

Common Causes on GMC ACADIA

Based on NHTSA complaint component analysis for this vehicle.

ELECTRICAL SYSTEM,UNKNOWN or OTHER 25%

ELECTRICAL SYSTEM,VEHICLE SPEED CONTROL,FUEL/PROPULSION SYSTEM 25%

AIR BAGS,STRUCTURE,VEHICLE SPEED CONTROL 25%

STEERING,VEHICLE SPEED CONTROL 25%

What To Do Next

1
Check for recalls on YOUR VIN
Go to nhtsa.gov/recalls and enter your VIN. If your vehicle is covered, repairs are free.
2
Get a proper diagnosis
A code alone doesn't tell you the exact failed part. A diagnostic at a shop ($50–$150) pinpoints the root cause before you spend money on parts.
3
Compare repair quotes
Get 2–3 quotes. Dealer vs. independent shop prices often differ 30–50% for the same repair.

Frequently Asked Questions

What does P2138 mean on a GMC ACADIA? ▾

P2138 indicates: Throttle/Pedal Position Sensor/Switch D/E Voltage Correlation. This is a powertrain code. 4 GMC ACADIA owners have reported this to NHTSA.

What are the most common causes of P2138 on GMC ACADIA? ▾

Based on 4 NHTSA reports, the most commonly cited components are: Electrical System,Unknown Or Other, Electrical System,Vehicle Speed Control,Fuel/Propulsion System, Air Bags,Structure,Vehicle Speed Control. These percentages are based on the component field in owner complaints.

Is P2138 a safety concern on GMC ACADIA? ▾

Of 4 NHTSA reports for P2138 on GMC ACADIA, 1 involved a crash. Always consult a qualified mechanic for any diagnostic trouble code.

What should I do if my GMC ACADIA shows P2138? ▾

1) Check for recalls on your VIN at nhtsa.gov/recalls. 2) Get a professional diagnosis — a code alone doesn't identify the exact failed part. 3) Get 2-3 repair estimates to compare.