P2138 on CHEVROLET IMPALA — Throttle/Pedal Position Sensor/Switch D/E Voltage Correlation

Q: "What does P2138 mean on a CHEVROLET IMPALA?"

"P2138 indicates: Throttle/Pedal Position Sensor/Switch D/E Voltage Correlation. This is a powertrain code. 19 CHEVROLET IMPALA owners have reported this to NHTSA."

Q: "What are the most common causes of P2138 on CHEVROLET IMPALA?"

"Based on 19 NHTSA reports, the most commonly cited components are: Engine, Vehicle Speed Control, Vehicle Speed Control,Engine. These percentages are based on the component field in owner complaints."

Q: "Is P2138 serious on my CHEVROLET IMPALA?"

"Of 19 NHTSA reports for this code on CHEVROLET IMPALA, none involved a crash or fire. However, any diagnostic code should be evaluated by a qualified mechanic."

Q: "What should I do if my CHEVROLET IMPALA 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 CHEVROLET IMPALA

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.

19 CHEVROLET IMPALA owners have reported this issue to NHTSA across model years 2006-2012. Most reports come from the 2008, 2009 model years.

Real CHEVROLET IMPALA Owner Reports

Source: NHTSA Complaints Database

"I got a P2138 code for Accelerator Pedal Sensor error. From what I have seen this is caused by the two sensors not matching. I have repaired this issue previously about 3 years ago, but it has happened again. This seems to be a common issue with GM cars of this era."

— 2006 CHEVROLET IMPALA owner · ELECTRICAL SYSTEM · Filed 12/27/2023

"Displayed on panel "reduced engine power" . on star diagnosed service code "p2138". on 05/01/2012 while driving through a large intersection my engine power was reduced to 3 or maybe 5 mph. i was trying to get through the intersection without the acceleration that was so desperately needed."

— 2006 CHEVROLET IMPALA owner · ENGINE AND ENGINE COOLING,FUEL SYSTEM, GASOLINE,ELECTRICAL SYSTEM · Filed 05/01/2012

""reduced engine power" service code p2138. on 05/01/2012 while driving through an intersection my engine power was reduced to 3, maybe 5 mph. i was trying to get through that intersection without the acceleration that was so desperately needed. this is definitely a safety issue."

— 2006 CHEVROLET IMPALA owner · ENGINE · Filed 06/01/2012

"Check engine light Code p2138 Change the throttle pedal position sensor the next day the car dropped down to 5 to 10 mph information center said engine safety been reduced to 5 to 10 mph plus my traction control light came on then information center said service traction control put my old thrott"

— 2007 CHEVROLET IMPALA owner · VEHICLE SPEED CONTROL · Filed 07/16/2022

"The gas petal sensor is reading a code P2138 (Accelerator Petal Position Sensors 1-2 not plausible). My father has changed the petal not once but twice and erased the code but it keeps coming back. Also getting a p0172 code as well."

— 2008 CHEVROLET IMPALA owner · POWER TRAIN · Filed 01/17/2023

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

📊 Complaint Trend by Model Year

3

'06

2

'07

5

'08

4

'09

1

'10

3

'11

1

'12

Common Causes on CHEVROLET IMPALA

Based on NHTSA complaint component analysis for this vehicle.

ENGINE 10.5%

VEHICLE SPEED CONTROL 10.5%

VEHICLE SPEED CONTROL,ENGINE 10.5%

ELECTRICAL SYSTEM 5.3%

ENGINE and ENGINE COOLING,FUEL SYSTEM, GASOLINE,ELECTRICAL SYSTEM 5.3%

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 CHEVROLET IMPALA? ▾

P2138 indicates: Throttle/Pedal Position Sensor/Switch D/E Voltage Correlation. This is a powertrain code. 19 CHEVROLET IMPALA owners have reported this to NHTSA.

What are the most common causes of P2138 on CHEVROLET IMPALA? ▾

Based on 19 NHTSA reports, the most commonly cited components are: Engine, Vehicle Speed Control, Vehicle Speed Control,Engine. These percentages are based on the component field in owner complaints.

Is P2138 serious on my CHEVROLET IMPALA? ▾

Of 19 NHTSA reports for this code on CHEVROLET IMPALA, none involved a crash or fire. However, any diagnostic code should be evaluated by a qualified mechanic.

What should I do if my CHEVROLET IMPALA 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.