Easy one-page printout for the garage or repair shop
This summary uses the existing diagnostic information shown in full below.
This code means the car's computer that controls the transmission is having trouble because something is interfering with its signals.
The Transmission Control Module (TCM) is detecting interference or errors in its communication, which are above the acceptable limit.
The P172A code indicates that the Transmission Control Module (TCM) has detected an internal error due to interference or noise in the communication lines that exceed the threshold level. This could affect the TCM's ability to properly control the transmission's functions.
• Transmission not shifting properly
• Check Engine Light illuminated
• Erratic or harsh shifting
• Faulty Transmission Control Module
• Electrical interference in the TCM wiring
• Poor connections or damaged wiring harness
Transmission Control Module (TCM): A computer that controls the transmission functions in a vehicle.
Interference: Unwanted signals that disrupt normal communication or operation.
• Scan the vehicle for codes and note any other related codes.
• Inspect the TCM and its wiring for any signs of damage or corrosion.
• Check for proper grounding and connections to the TCM.
• Repair or replace damaged wiring or connectors.
• Replace the Transmission Control Module if faulty.
• Ensure all electrical connections are clean and secure.
• OBD-II scanner
• Multimeter
• Basic hand tools
$300 - $1200
Moderate
• Ford Focus
• Chevrolet Malibu
• Honda Accord
• Regular maintenance of the transmission system
• Ensure all electrical connections are secure
• Avoid exposure to excessive moisture or corrosion
Transmission Control Issue
• Do not ignore the Check Engine Light.
• Have the transmission system inspected by a professional.
• Avoid driving the vehicle if transmission issues worsen.
Check with the vehicle manufacturer for warranty coverage on the transmission system.
This code is relatively uncommon and typically associated with specific models known for TCM issues.
High – Transmission issues can lead to unsafe driving conditions if not addressed promptly.
Driving with a malfunctioning transmission can be dangerous. Address this issue as soon as possible to ensure vehicle safety.
• Vehicle at operating temperature
• Transmission engaged in drive mode
The Transmission Control Module is typically located near the transmission or under the hood, depending on the vehicle model.
Q: Can I drive with a P172A code?
A: It's not recommended to drive with this code as it can lead to transmission failure.
Q: Will resetting the code fix the problem?
A: Resetting the code may temporarily clear the warning, but the underlying issue needs to be addressed.
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