BMW DTC P171D – Internal Transmission Control Module Watchdog Electrical Error
DTC P171D meaning on BMW
The DTC P171D on a BMW indicates an Internal Transmission Control Module Watchdog Electrical Error. This fault code is specific to the transmission control module and signifies a potential issue with the electrical circuitry or communication within the module.
BMW DTC P171D symptoms
Symptoms associated with the BMW DTC P171D may include erratic shifting behavior, transmission slipping, harsh shifting, or the transmission going into limp mode. Additionally, the vehicle may display a warning light on the dashboard indicating a transmission fault.
BMW DTC P171D causes
The causes of the DTC P171D on a BMW can vary but commonly include wiring harness issues, faulty transmission control module, poor electrical connections, or internal module failures. Water ingress or corrosion in the module can also lead to this error code.
BMW DTC P171D seriousness
The DTC P171D is a serious fault code as it directly relates to the transmission control module, which is crucial for the proper operation of the transmission system. Ignoring or neglecting this fault can lead to further transmission damage and potential safety hazards.
How to diagnose DTC P171D on BMW
To diagnose the DTC P171D on a BMW, a comprehensive scan tool capable of reading transmission fault codes is required. The technician will need to inspect the wiring harness for any visible damage, check the electrical connections to the transmission control module, and perform a thorough diagnostic scan to pinpoint the exact cause of the error.
How to fix DTC P171D on BMW
Fixing the DTC P171D on a BMW typically involves repairing or replacing the faulty wiring harness, addressing any poor electrical connections, or replacing the transmission control module if necessary. It is crucial to follow the manufacturer’s diagnostic procedures and use genuine parts to ensure a proper repair.
How to erase DTC P171D on BMW
Once the underlying issue causing the DTC P171D on a BMW has been resolved, the fault code can be erased using a diagnostic scan tool. The technician can clear the code from the transmission control module’s memory, and after driving the vehicle to ensure the fault does not reoccur, the code should be successfully erased.
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
Some of the links on this page may be affiliate links, which means we may earn a small commission if you make a purchase. This helps us keep our DTC database up to date and provide valuable content for free. We only recommend products that we have tested and believe to be the best in their class.