FAULTBASE
Error CodesASKCars
© 2025 FAULTBASE
All rights reserved.
v2.0.0 • Production
ContactPrivacyImpressum
Home/Cars/GMC/Sierra/T1XX (2019-Present)/how to fix P0700 transmission code in GMC Sierra T1XX (2019-Present)?

how to fix P0700 transmission code in GMC Sierra T1XX (2019-Present)?

GMC Sierra T1XX (2019-Present)

Error Codes
Severity: highDifficulty: mediumError Code: P07002-4 hours
3 min read
519 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 P0700 transmission code in GMC Sierra T1XX. Step-by-step guide with diagnostic procedures and repair instructions.

Error Code
P0700
Affected Component
Transmission
Estimated Time
2-4 hours

Safety Warnings

  • ⚠Disconnect battery before working on electrical systems.
  • ⚠Allow the engine to cool before opening the transmission system.

Symptoms

  • •Check engine light illuminated
  • •Erratic shifting or harsh transmission behavior
  • •Engine stalling during shifting
  • •Transmission slipping or failing to engage
  • •Poor fuel economy
  • •Delayed or no response when shifting gears

Diagnostic Steps

  1. 1Scan the vehicle’s computer using an OBD-II scanner to confirm the P0700 code and check for any additional codes.
  2. 2Inspect the transmission fluid level and condition; look for signs of contamination or burning.
  3. 3Examine the wiring harness and connectors related to the transmission for damage or corrosion.
  4. 4Test the Transmission Control Module (TCM) for proper voltage and ground signals.
  5. 5Check for any issues with the vehicle's battery and charging system, which can affect transmission performance.
  6. 6Inspect the transmission solenoids for proper operation using a multimeter.

Solution

Solution

1. Preparation

  • Gather all necessary tools and parts.
  • Disconnect the battery to ensure safety while working on electrical systems.

2. Replace Transmission Fluid and Filter

  • Sub-steps:
    1. Raise the vehicle securely using jack stands.
    2. Place a drain pan under the transmission pan.
    3. Remove the transmission pan bolts using a socket set and carefully lower the pan.
    4. Remove and replace the transmission filter.
    5. Clean the transmission pan and magnet, then reinstall it with a new gasket.
    6. Refill the transmission with the recommended fluid type.

3. Repair or Replace Faulty Components

  • Sub-steps:
    1. If wiring or connectors are damaged, replace them with OEM parts.
    2. If the TCM is faulty, remove it and install a new TCM, following the manufacturer-specific procedures.
    3. If solenoids are not functioning, replace them according to the service manual.

4. Reconnect Battery and Clear Codes

  • Sub-steps:
    1. Reconnect the battery terminals.
    2. Use the OBD-II scanner to clear all diagnostic trouble codes.
    3. Start the vehicle and allow it to idle.

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
  • •Multimeter
  • •Drain pan
  • •Screwdrivers
  • •Jack and jack stands

Parts Required

  • •Transmission filter
  • •Transmission fluid (specific to GMC Sierra)
  • •Transmission pan gasket
  • •Transmission solenoids (if needed)
  • •Transmission Control Module (if needed)

Additional Information

Error Code
P0700
Affected Component
Transmission
Estimated Time
2-4 hours
Difficulty
medium
Severity
high
Tools Required
7 items
Parts Required
5 items

Related Faults

  1. why does my GMC Sierra T1XX (2019-Present) have a rattling noise under the hood?

    Learn how to diagnose and fix a rattling noise under the hood of your GMC Sierra T1XX (2019-Present). Step-by-step guide with diagnostic procedures and repair instructions.

    Engine5 symptoms

  2. why is my GMC Sierra using so much oil

    Learn how to diagnose and fix excessive oil consumption in GMC Sierra. Step-by-step guide with diagnostic procedures and repair instructions.

    Engine6 symptoms

  3. what causes my GMC Sierra to have low oil pressure warnings

    Learn how to diagnose and fix low oil pressure warnings in GMC Sierra. Step-by-step guide with diagnostic procedures and repair instructions.

    Engine6 symptoms

  4. GMC Sierra T1XX (2019-Present) AC not blowing cold air

    Learn how to diagnose and fix AC not blowing cold air in GMC Sierra T1XX. Step-by-step guide with diagnostic procedures and repair instructions.

    HVAC6 symptoms

  5. my GMC Sierra pulls to the right when driving what could be wrong

    Learn how to diagnose and fix the right pull issue in GMC Sierra. Step-by-step guide with diagnostic procedures and repair instructions.

    Suspension6 symptoms

  6. my GMC Sierra defroster is not working what could be the cause

    Learn how to diagnose and fix the defroster issue in GMC Sierra. Step-by-step guide with symptoms, diagnostic steps, and repair instructions.

    HVAC5 symptoms

Share this solution

Comments

Sign in to share your thoughts

Sign In

No comments yet

Be the first to share your thoughts

Back to Generation