BMW DTC P1791 – Internal Transmission Control Module Memory Check Sum/EEPROM Error
DTC P1791 meaning on BMW
DTC P1791 on a BMW indicates an Internal Transmission Control Module Memory Check Sum/EEPROM Error. This error code is related to a fault in the transmission control module’s memory or EEPROM, which stores critical data for the transmission system.
BMW DTC P1791 symptoms
Symptoms of DTC P1791 on a BMW may include erratic shifting behavior, transmission slipping, harsh shifting, or the transmission going into limp mode. The vehicle may also display a warning light on the dashboard indicating a transmission fault.
BMW DTC P1791 causes
The causes of DTC P1791 on a BMW can vary, but common reasons include a faulty transmission control module, corrupted memory or EEPROM data, wiring issues, or a software glitch in the transmission control module.
BMW DTC P1791 seriousness
DTC P1791 is a serious fault code as it directly affects the transmission control module’s ability to operate correctly. Ignoring this error code can lead to further transmission issues and potential drivability problems.
How to diagnose DTC P1791 on BMW
To diagnose DTC P1791 on a BMW, a professional diagnostic scan tool capable of reading transmission fault codes is required. The technician will perform a scan to retrieve the specific error code and then proceed with further testing to pinpoint the exact cause of the issue.
How to fix DTC P1791 on BMW
Fixing DTC P1791 on a BMW typically involves addressing the root cause of the issue. This may include repairing or replacing the transmission control module, reprogramming the module, checking and repairing any wiring faults, or resetting the transmission control module.
How to erase DTC P1791 on BMW
To erase DTC P1791 on a BMW, the fault code must be cleared using a diagnostic scan tool. Once the underlying issue has been resolved, the technician can clear the code, and if the problem has been successfully fixed, the error code should not reappear.
Recommended tools & DTC Scanners for BMW
Best Diagnostic App for modern BMWs: BimmerLink
Recommended Bluetooth adapter for Bimmerlink: OBDLink CX
Cable adapter for Bimmerlink: Enet Cable USB Type C
For older BMWs we recommend: Autel AutoLink AL319 (2024 version)
Easy-to-use Multimeter for reliable diagnostics: AstroAI Auto-ranging Multimeter
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