Engine-Codes.com
Engine-Codes – GMC – P0843 2017 GMC Sierra

P0843 2017 GMC Sierra Code - Transmission Fluid Pressure Switch 1 Circuit High Voltage

Quick Answer

The P0843 diagnostic trouble code (DTC) for a 2017 GMC Sierra indicates a problem with the Transmission Fluid Pressure Switch 1 Circuit High Voltage. Common causes include Faulty transmission fluid pressure switch, Wiring issues or shorts in the circuit, Malfunctioning transmission control module (TCM). Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

What it means
P0843 2017 GMC Sierra indicates Transmission Fluid Pressure Switch 1 Circuit High Voltage.
Common causes
Common causes include Faulty transmission fluid pressure switch, Wiring issues or shorts in the circuit, Malfunctioning transmission control module (TCM).
Severity
High - diagnose this code as soon as possible.
Can I drive?
Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
What is this?
Table of contents Created and updated by William Orellana on Sep 13, 2024
💬 Need more help? Ask Auto Expert for instant answers — it's free!
AutoCodes App

Fix Your Car Smarter

Try the New AutoCodes App!

Get complete OBDII diagnostics, repair solutions, and cost estimates, plus AI chat support on demand.

AutoCodes App on Google Play

Code P0843 2017 GMC Sierra Description

The P0843 diagnostic trouble code (DTC) for a 2017 GMC Sierra indicates a problem with the Transmission Fluid Pressure Switch 1 Circuit High Voltage. This code is specifically related to the transmission system of the vehicle. The transmission fluid pressure switch is responsible for monitoring the hydraulic pressure within the transmission. When the switch detects a high voltage signal, it triggers the P0843 code, indicating an issue with the transmission fluid pressure.

OBDII Code P0843 2017 GMC Sierra - Transmission Fluid Pressure Switch 1 Circuit High Voltage
P0843 2017 GMC Sierra Code - Transmission Fluid Pressure Switch 1 Circuit High Voltage

Common Causes of P0843 2017 GMC Sierra

  1. Faulty transmission fluid pressure switch
  2. Wiring issues or shorts in the circuit
  3. Malfunctioning transmission control module (TCM)
  4. Low or contaminated transmission fluid
  5. Internal transmission problems

Symptoms of P0843 2017 GMC Sierra

  1. Harsh or erratic shifting
  2. Slipping gears
  3. Delayed engagement when shifting
  4. Transmission overheating
  5. Illumination of the Check Engine Light

How to Fix P0843 2017 GMC Sierra

  1. Begin by diagnosing the specific cause of the high voltage signal, using a scan tool to retrieve the DTC and perform further testing as needed.
  2. Inspect the transmission fluid pressure switch and its wiring for any signs of damage or corrosion. Replace the switch if necessary.
  3. Check the transmission control module (TCM) for proper operation and potential faults. Repair or replace as needed.
  4. Perform a transmission fluid flush and refill with the manufacturer-recommended fluid if the existing fluid is low or contaminated.
  5. Clear the DTC from the vehicle's memory using the scan tool and test drive the vehicle to ensure the issue has been resolved.

Cost to Fix P0843 2017 GMC Sierra

The typical repair costs for addressing a P0843 code on a 2017 GMC Sierra can vary depending on the specific cause of the issue. In general, the cost of replacing a transmission fluid pressure switch can range from $100 to $300, including parts and labor. However, if additional repairs or component replacements are needed, the total cost could increase. It's recommended to consult with a qualified mechanic or auto repair shop for a more accurate estimate based on the specific diagnosis and repair requirements. Keep in mind that labor rates at auto repair shops can vary, with hourly rates typically ranging between $80 and $150. Additional costs may apply for diagnostic time, parts, and any necessary fluid changes.

Need more information about the P0843 2017 GMC Sierra code?

Need more information on how to fix the P0843 2017 GMC Sierra code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P0843 2017 GMC Sierra code diagnosed by a professional: Find a repair shop in your area

About the author: William Orellana is a Master Mechanic and Mechanical Engineer with over 30 years of experience diagnosing and repairing vehicles. Learn more about his background.

Frequently Asked Questions about P0843 2017 GMC Sierra Code

1. What does the OBDII code P0843 mean on a 2017 GMC Sierra?

P0843 indicates a "Transmission Fluid Pressure Switch 1 Circuit High Voltage," meaning the transmission control module (TCM) has detected an unusually high voltage signal from the pressure switch circuit.

2. What are common symptoms of code P0843 in a 2017 GMC Sierra?

Symptoms may include harsh or delayed shifting, transmission slipping, the vehicle entering limp mode, and the check engine light being illuminated.

3. What causes the P0843 code on a GMC Sierra?

Common causes include a faulty transmission fluid pressure sensor, damaged or corroded wiring, a short circuit, a poor electrical connection, or low transmission fluid levels.

4. Can I drive my 2017 GMC Sierra with a P0843 code?

Driving with this code is not recommended as it could cause further damage to the transmission or affect the vehicle's performance due to improper shifting.

5. How do I fix the P0843 code on my GMC Sierra?

Repairs may involve inspecting and repairing wiring or connectors, replacing the transmission fluid pressure sensor, or addressing transmission fluid issues like low levels or contamination.

6. How do I diagnose a P0843 code in a 2017 GMC Sierra?

Diagnosis typically involves using an OBDII scanner to confirm the code, visually inspecting the wiring and connectors, testing the sensor's voltage with a multimeter, and checking transmission fluid levels.

7. Can low transmission fluid cause a P0843 code?

Yes, low or contaminated transmission fluid can cause incorrect pressure readings, which may trigger the P0843 code.

8. How much does it cost to repair a P0843 code on a GMC Sierra?

The cost can vary, but replacing a transmission fluid pressure sensor typically ranges from $150 to $400, including parts and labor. Wiring repairs may cost less depending on the issue.

9. Does a faulty transmission fluid pressure sensor always cause a P0843 code?

Not always. While the sensor is a common culprit, other factors like wiring issues, connector damage, or transmission fluid problems can also cause the code.

10. Will clearing the P0843 code fix the problem on my GMC Sierra?

Clearing the code may temporarily remove the check engine light, but it won’t resolve the underlying issue. Proper diagnosis and repair are necessary to prevent the code from returning.

Discuss the causes and fixes for P0843 2017 GMC Sierra OBDII Code

Submit a New Comment

Code P0843 2017 GMC Sierra comments

No comments found for this page.