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

Learn how to diagnose and fix P0700 transmission issues in GMC Sierra T1XX (2019-Present). Step-by-step guide with diagnostic procedures and repair instructions.

Solution

1. Preparation

• Gather necessary tools and parts.
• Park the vehicle on a level surface and engage the parking brake.
• Disconnect the battery terminal to ensure safety while working on electrical components.

2. Check and Replace Transmission Fluid

• Tools Required: Transmission fluid pump, funnel, and fluid catch pan.
• Remove the transmission fluid dipstick or drain plug.
• Inspect the fluid; if it is contaminated or burnt, proceed to replace it.
• Replace with manufacturer-recommended transmission fluid (consult owner's manual for specifications).
• Reinsert the dipstick or plug after filling to the correct level.

3. Inspect and Repair Wiring

• Tools Required: Wire strippers, electrical tape, and a multimeter.
• Inspect the wiring harness connected to the TCM for any frays or breaks.
• Repair any damaged wiring by cutting out the faulty section and splicing in new wire.
• Ensure all connectors are secure and free of corrosion.

4. Replace Faulty Sensors

• Tools Required: Socket set and torque wrench.
• If testing reveals faulty input or output speed sensors, remove them using a socket set.
• Install new sensors, tightening them to the manufacturer's torque specifications.
• Reconnect any wiring or connectors previously disconnected.

5. Reconnect Battery and Clear Codes

• Reconnect the battery terminal.
• Use the OBD-II scanner to clear any fault codes from the system.
• Verify that the P0700 code is no longer present.