Easy one-page printout for the garage or repair shop
This summary uses the existing diagnostic information shown in full below.
This code means that the computer inside the car that helps control the transmission has a memory error. It's like when your game console can't read a saved game correctly.
The Transmission Control Module (TCM) uses EEPROM to store data. If there's a checksum error, it means the data might be corrupted or unreadable.
The P1791 code indicates a problem with the EEPROM (Electrically Erasable Programmable Read-Only Memory) inside the Transmission Control Module. This memory is used to store important data for transmission operation. A checksum error suggests that the data integrity is compromised, possibly due to corruption or hardware failure.
• Check Engine Light is on
• Transmission may not shift correctly
• Vehicle may go into limp mode
• Faulty Transmission Control Module (TCM)
• Corrupted EEPROM data
• Electrical issues such as poor connections or damaged wiring
EEPROM: Electrically Erasable Programmable Read-Only Memory, a type of non-volatile memory used in computers and other devices.
TCM: Transmission Control Module, the computer responsible for controlling the transmission.
• Use an OBD-II scanner to confirm the code.
• Inspect the TCM and its connections for damage or corrosion.
• Check for any updates or reprogramming options for the TCM.
• Repair or replace any damaged wiring or connectors.
• Reprogram or update the TCM software if available.
• Replace the TCM if it is confirmed to be faulty.
• OBD-II scanner
• Multimeter
• Screwdrivers and basic hand tools
$300 - $1200
Moderate
• Chrysler 300
• Dodge Ram
• Jeep Grand Cherokee
• Regularly check and maintain electrical connections.
• Avoid exposure to extreme temperatures that may affect electronic components.
• Keep the vehicle's software updated.
Transmission Control Module Issue
• Do not ignore the Check Engine Light.
• Have the vehicle inspected by a professional if you notice transmission issues.
Check if the vehicle's powertrain warranty covers TCM repairs.
This code has been associated with vehicles using electronic transmission control systems since the late 1990s.
High – Transmission issues can lead to further vehicle damage or unsafe driving conditions.
Driving with a malfunctioning transmission can be dangerous. Have the issue inspected and repaired promptly.
• Vehicle at operating temperature
• Perform diagnostic tests in a safe environment
The Transmission Control Module is usually located in the engine bay or under the dashboard, depending on the vehicle model.
Q: Can I drive with a P1791 code?
A: It's not recommended to drive with this code as it can lead to transmission damage or unsafe driving conditions.
Q: Will resetting the code fix the problem?
A: Resetting the code may temporarily clear the Check Engine Light, but it won't fix the underlying issue.
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