why does my GMC Sierra T1XX (2019-Present) transmission jerk when shifting

GMC Sierra T1XX (2019-Present)

Error Codes

2-4 hours

Time

medium

Difficulty

high

Severity

3 min read

516 words

⚠️ Safety Warning

This issue requires immediate attention. If you are not experienced with automotive repairs, consult a professional mechanic. Working on critical systems can be dangerous.

Problem Statement

Learn how to diagnose and fix transmission jerking issues in GMC Sierra T1XX (2019-Present). Step-by-step guide with symptoms, diagnostic steps, and repair instructions.

Affected Component

Transmission

Estimated Time

2-4 hours

⚠️ Safety Warnings

Important safety information - read before proceeding

•Disconnect the battery before working on electrical components.
•Allow the transmission to cool before draining fluid to avoid burns.

Symptoms

•Jerking or harsh shifting between gears
•Slipping of the transmission
•Delayed engagement when shifting from park to drive or reverse
•Check engine light illuminated
•Unusual noises during shifting (clunking or grinding)

Diagnostic Steps

1
Scan for error codes using an OBD-II scanner to identify any transmission-related trouble codes.
2
Check the transmission fluid level and condition; look for signs of contamination or burning.
3
Inspect the transmission mounts for wear or damage that could cause misalignment.
4
Test the transmission control module (TCM) for proper operation and connections.
5
Verify the operation of the throttle position sensor (TPS) as it affects shifting behavior.
6
Check for any software updates or recalls related to the transmission control system.

Solution

💡 Expert Tip

For complex repairs like this, consider taking photos at each step. This helps if you need to reverse a step or consult with a mechanic. Also, keep all removed parts organized - you may need to reference them during reassembly.

Verification

After completing the repair, verify that the issue has been resolved:

✓Test the affected component to ensure it functions correctly
✓Check for any error codes or warning lights
✓Monitor the vehicle for a few days to ensure the issue does not recur

Prevention Tips

To prevent this issue from occurring again:

•Follow the manufacturer's recommended maintenance schedule
•Address warning signs early before they develop into major issues
•Use quality parts and fluids recommended for your vehicle
•Keep detailed records of all repairs and maintenance

Tools & Equipment Required

•OBD-II scanner
•Socket set
•Torque wrench
•Transmission fluid pump
•Jack and jack stands

Parts Required

•Transmission fluid (specific to the vehicle)
•Transmission filter
•Gasket for transmission pan
•Transmission mounts (if needed)
•TCM (if replacement is necessary)

Related Faults

Share this solution

Comments

No comments yet

Be the first to share your thoughts

Back to Generation

Diagnostic Steps

1
Scan for error codes using an OBD-II scanner to identify any transmission-related trouble codes.
2
Check the transmission fluid level and condition; look for signs of contamination or burning.
3
Inspect the transmission mounts for wear or damage that could cause misalignment.
4
Test the transmission control module (TCM) for proper operation and connections.
5
Verify the operation of the throttle position sensor (TPS) as it affects shifting behavior.
6
Check for any software updates or recalls related to the transmission control system.

Solution

1. Preparation

Gather necessary tools and parts.
Ensure the vehicle is parked on a level surface and the engine is off.
Disconnect the battery to prevent electrical issues.

2. Check and Replace Transmission Fluid

Sub-steps:
1. Remove the transmission dipstick and wipe it clean.
2. Insert the dipstick back and remove it again to check the fluid level.
3. If low, add the recommended transmission fluid (refer to owner’s manual for specifications).
4. If fluid is dirty or burnt, drain the old fluid by removing the transmission pan.
5. Replace the filter and install the pan with a new gasket, torquing to manufacturer specifications.

3. Inspect and Replace Transmission Mounts

Sub-steps:
1. Raise the vehicle securely on jack stands.
2. Locate and inspect the transmission mounts for cracks or excessive wear.
3. If damaged, remove the old mounts and install new ones, ensuring they are torqued to the specified values.

4. Reprogram or Replace TCM

Sub-steps:
1. If the TCM is found faulty, remove the battery and disconnect the TCM connectors.
2. Replace it with a new unit or reprogram it as necessary using manufacturer-specific software.
3. Reconnect all connectors and reattach the battery.