P0729 2018 GMC Sierra Code - Transmission 6th Gear Ratio Incorrect
Quick Answer
The P0729 diagnostic trouble code (DTC) for the 2018 GMC Sierra indicates that the transmission 6th gear ratio is incorrect. Common causes include Faulty transmission solenoid, Malfunctioning transmission sensor, Low transmission fluid levels. 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
- P0729 2018 GMC Sierra indicates Transmission 6th Gear Ratio Incorrect.
- Common causes
- Common causes include Faulty transmission solenoid, Malfunctioning transmission sensor, Low transmission fluid levels.
- 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.
Fix Your Car Smarter
Try the New AutoCodes App!
Get complete OBDII diagnostics, repair solutions, and cost estimates, plus AI chat support on demand.
Code P0729 2018 GMC Sierra Description
The P0729 diagnostic trouble code (DTC) for the 2018 GMC Sierra indicates that the transmission 6th gear ratio is incorrect. This means that the Engine Control Module (ECM) has detected a discrepancy between the actual gear ratio in the transmission's 6th gear and the expected ratio. This issue can lead to poor vehicle performance, decreased fuel efficiency, and potential damage to the transmission if not addressed promptly.
Common Causes of P0729 2018 GMC Sierra
- Faulty transmission solenoid
- Malfunctioning transmission sensor
- Low transmission fluid levels
- Transmission fluid contamination
- Wiring or connection issues in the transmission system
Symptoms of P0729 2018 GMC Sierra
- Harsh shifting between gears
- Slipping gears, especially in 6th gear
- Delayed engagement when shifting into 6th gear
- Decreased fuel efficiency
- Illumination of the Check Engine Light
How to Fix P0729 2018 GMC Sierra
- Begin by conducting a thorough diagnostic scan to confirm the P0729 code and identify any other related issues.
- Inspect the transmission solenoid and sensor for any signs of damage or malfunction. Replace any faulty components.
- Check the transmission fluid level and condition. Top up or replace the fluid if necessary.
- Inspect the wiring and connections in the transmission system for any loose or damaged components. Repair or replace as needed.
- Clear the DTC and test drive the vehicle to ensure that the issue has been resolved and that the transmission is operating correctly.
Cost to Fix P0729 2018 GMC Sierra
The typical repair costs for addressing the transmission 6th gear ratio incorrect issue can range from $200 to $800, depending on the extent of the repairs needed and the cost of parts. This estimate includes the cost of diagnostic scans, replacement components, transmission fluid, and labor. It's important to note that specific diagnosis time and labor rates at auto repair shops can vary, so it's advisable to check with local shops for a more accurate estimate based on your location and vehicle specifics.
Tech Notes for P0729 2018 GMC Sierra
Need more information about the P0729 2018 GMC Sierra code?
Need more information on how to fix the P0729 2018 GMC Sierra code? Get Access to Factory Service Manuals
Need Help with the Code?
Get the P0729 2018 GMC Sierra code diagnosed by a professional: Find a repair shop in your area
Frequently Asked Questions about P0729 2018 GMC Sierra Code
No Frequently Asked Questions about P0729 2018 GMC Sierra Code found.
Discuss the causes and fixes for P0729 2018 GMC Sierra OBDII Code
Code P0729 2018 GMC Sierra comments
No comments found for this page.
Fix Your Car Smarter
Try the New AutoCodes App!
Get complete OBDII diagnostics, repair solutions, and cost estimates, plus AI chat support on demand.