Easy one-page printout for the garage or repair shop
This summary uses the existing diagnostic information shown in full below.
The car's computer that controls the transmission is having trouble understanding signals because there's too much interference.
The Transmission Control Module (TCM) is experiencing an error due to excessive interference, which is affecting its ability to function correctly.
The P172B code indicates that the Transmission Control Module (TCM) has detected an internal error where interference levels have exceeded the acceptable threshold for a Level 2 error. This can affect the module's ability to process and send signals effectively.
• Transmission shifting issues
• Check Engine Light illuminated
• Erratic vehicle performance
• Faulty Transmission Control Module (TCM)
• Electrical interference from other components
• Wiring issues or poor connections
Transmission Control Module (TCM): A computer that controls the transmission functions.
Interference: Unwanted signals that disrupt normal operation.
• Use an OBD-II scanner to confirm the code.
• Inspect the wiring and connections to the TCM.
• Check for any sources of electrical interference.
• Replace or reprogram the Transmission Control Module (TCM).
• Repair or replace damaged wiring or connectors.
• Eliminate sources of electrical interference.
• OBD-II Scanner
• Multimeter
• Screwdriver set
$300 - $1200
Moderate
• Volkswagen Passat
• Audi A4
• Skoda Superb
• Regular maintenance checks on the transmission system.
• Ensure all electrical connections are secure.
• Avoid modifications that can introduce electrical interference.
Transmission Control Module Issue
• Avoid driving the vehicle until the issue is diagnosed.
• Consult a professional mechanic for accurate diagnosis.
• Regularly check for updates on vehicle software.
Check with the vehicle manufacturer for warranty coverage on the Transmission Control Module.
This code is typically associated with vehicles that have complex electronic systems and have shown susceptibility to electrical interference.
High – This issue can lead to serious transmission problems if not addressed promptly.
Driving with a malfunctioning transmission control module can be dangerous and may violate vehicle safety regulations.
• Vehicle should be on a level surface.
• Ensure the engine is off and the key is removed before inspecting wiring.
The Transmission Control Module is usually located near the transmission or within the engine bay, depending on the vehicle model.
Q: Can I drive with a P172B code?
A: It's not recommended to drive with this code as it can lead to transmission issues.
Q: How serious is a P172B code?
A: It is considered serious because it affects the transmission's ability to function properly.
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