Trans Cooler Valve Replacement (Code P2753)

Credit: AudiC7Owners
Edits By: C7Wiki

Signs of Failure:

• You get code P2753.
• You smell a faint coolant odor near the driver's side door, but don't see any leaks anywhere.
• You see small puddles of coolant under the car on the driver's side, right under your downpipes (like silver dollar-sized puddles, not much, and it doesn't happen all the time).

Replacing this valve when it goes bad is crucial because, if neglected, it can result in catastrophic damage to your TCU. Instead of spending $150 on parts and an hour of your time, you could end up spending thousands of dollars replacing your TCU or transmission. This happens because when the valve fails, coolant migrates out of it via the electrical connector plugged into it. It then travels up the wires of the wiring harness. If it reaches the TCU, you're in serious trouble.

Tools List:

• Work light
• Jack stands & jack
• T30 Torx bit (it might be smaller)
• Locking hose clamps (like these: I got 2 for $11 each at Harbor Freight https://amzn.to/3ueG0wN)
• Wire cutter/stripper
• Heat-shrinked crimp connectors
• Pliers
• Something to catch dripping coolant
• Eye protection

Parts Needed:

• Valve: 4H0121671D
• Connector Housing: 8K0973702
• Repair Wire: 000979025EA
• Wire Weather Seal: 4B0972740

Noteworthy Information:

• In the video, there are many parts removed that you probably don't have to remove. This is because we were working on multiple things at once on the car. You need to remove the belly pan to access the valve. You might not have to remove the cross brace like we did, but it may give you more room to access the valve. Be careful of the wiring harnesses attached to it if you do remove it.
• Watch the entire video with the volume on so you can listen to what my friend is explaining. He details how to determine how much of your wiring harness you need to replace.
• Make sure you check which side each wire plugs into the OEM connector before you cut it. There is a green wire and a purple (or black) wire. The connector is labeled "1" and "2". Make note of which color goes to which number because your repair wire is yellow. If you plug them into the wrong sides, you will get a fault code.