Skip the auto shop - Our mechanics make house calls

P2138 OBD-II Trouble Code: Throttle/Pedal Position Sensor/Switch D/E Voltage Correlation

Check Engine Light

P2138 Code Definition

Throttle/Pedal Position Sensor/Switch D/E Voltage Correlation

What the P2138 code means

The P2138 trouble code indicates that the Engine Control Module has detected a malfunction within the D and/or E circuits of the throttle position sensor.

What are the causes of the P2138 code?

  • A defective throttle body motor

  • A damaged connector or wiring that is associated with the throttle body motor

  • A faulty throttle position sensor

  • A damaged connector or wiring that is associated with the throttle body motor

  • A faulty Engine Control Module

What are the symptoms of the P2138 code?

  • Vehicle may stall
  • Vehicle may not start
  • Vehicle may not accelerate well
  • A Check Engine Light will be illuminated

How does a mechanic diagnose the P2138 code?

  1. A mechanic may begin diagnosing the P2138 trouble code by locating the throttle body under the hood of the vehicle.

  2. Once located, the throttle body motor and throttle position sensor will be examined for circuitry issues related to the wiring and connectors.

  3. After that the mechanic would then test the throttle body motor and the throttle position sensor for proper function using the manufacturer’s recommended procedure.

  4. Finally, the mechanic would then test the Engine Control Module for proper function.

Any parts found to be faulty during this diagnosis would be replaced at the customer’s request.

Common mistakes when diagnosing the P2138 code

An easy mistake to make when diagnosing the P2138 trouble code would be to have the throttle position sensor replaced and ‘hoping’ it fixes the problem. Although this is one of the most common causes of the P2138 trouble code, it is not always the cause. Taking this into consideration, it is always important to fully test every aspect of a circuit to diagnose an electrical problem correctly.

How serious is the P2138 code?

I would consider the P2138 trouble code to be very serious. If I am late to work due to the fact that my car is not accelerating properly or stalling on the side of the road, I am not going to be very happy. With that said, I would recommend to anyone that has a P2138 trouble code stored to have the issue handled immediately.

What repairs can fix the P2138 code?

Additional comments regarding the P2138 code?

Do not ever try to manually open the butterfly valve in an electronic throttle body with your hand or any other tool. This can severely damage the electronic throttle body motor and possibly prevent the vehicle from being operational. It is always best to use safe and cautious practices when working with electrical equipment.

Need help with a P2138 code?

YourMechanic offers certified mobile mechanics who will come to your home or office to diagnose and repair your vehicle. Get a quote and book an appointment online or speak to a service advisor at 1-800-701-6230.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
Icon-warranty_badge-02

Skip the repair shop, our top-rated mechanics come to you.

At your home or office

Choose from 600+ repair, maintenance & diagnostic services. Our top-rated mechanics bring all parts & tools to your location.

Fair & transparent pricing

See labor & parts costs upfront, so you can book with confidence.

12-month, 12,000-mile warranty

Our services are backed by a 12-month, 12,000-mile warranty for your peace of mind.

Get A Quote

Need Help With Your Car?

Our certified mobile mechanics make house calls in over 2,000 U.S. cities. Fast, free online quotes for your car repair.

GET A QUOTE

More related articles

Veteran and Military Driver Laws and Benefits in New Mexico
The state of New Mexico offers a number of benefits and perks for those Americans who have either served in an Armed Forces branch...
P2422 OBD-II Trouble Code: Evaporative Emissions Control System (EVAP) Vent Valve Stuck Closed
Diagnostic Trouble Code (DTC): P2422 P2422 code definition Evaporative Emissions Control System (EVAP) Vent Valve Stuck Closed Related Trouble Codes: P2441: EVAP Vent Valve Stuck Open EVAP trouble...
What are the Car Pool Rules in Hawaii?
Hawaii is widely regarded as a land of vacation and relaxation, and as such, its scenic roads and routes are far better known than the state’s freeways. But, as with all...


Related questions

Q: 2009 Buick Lacrosse is setting DTC codes P2125 and P2138.

Hi there. Try performing a snap throttle and see if the wave form changes on the Oscilloscope. If the waves do not change when performing a snap throttle, then the throttle position sensor on the pedal needs replaced. If the...

Q: The Check Engine Light came up with the code P2017, what do I need to replace?

If you are getting this code it is due to one of two things. The vast majority of the time it is caused by a failure in the variable charge motion actuator, which is the same part that you mentioned....

Q: Can I go to a trip through the state with the following problems with my car?

You should ask the shop that gave you the estimate since they quoted you to replace the transaxle. The transaxle problem may be something that could leave you stranded and cost thousands of dollars to replace this part. The car...