BMW DTC P1666 – EWS (Electronic Immobilizer) Tampering via KWP2000UE / Start Value not Accepted
DTC P1666 meaning on BMW
DTC P1666 on a BMW refers to an issue with the Electronic Immobilizer system, specifically related to tampering via KWP2000UE or the Start Value not being accepted. The Electronic Immobilizer is a security feature that prevents the vehicle from being started without the correct key or authorization code.
BMW DTC P1666 symptoms
Symptoms of DTC P1666 on a BMW may include the engine not starting, the immobilizer warning light illuminating on the dashboard, or the vehicle going into a security lockout mode. In some cases, the vehicle may start but then immediately shut off.
BMW DTC P1666 causes
The main causes of DTC P1666 on a BMW are related to tampering with the Electronic Immobilizer system using KWP2000UE or the Start Value not being accepted. This could be due to a fault in the immobilizer system itself, a problem with the key or key fob, or issues with the communication between the key and the immobilizer module.
BMW DTC P1666 seriousness
DTC P1666 on a BMW is a serious issue as it can prevent the vehicle from starting or lead to security concerns if the immobilizer system is compromised. It is important to address this issue promptly to ensure the security and functionality of the vehicle.
How to diagnose DTC P1666 on BMW
To diagnose DTC P1666 on a BMW, a diagnostic scan tool capable of reading BMW specific fault codes is required. The technician will need to retrieve the fault code and then perform further testing to determine the exact cause of the issue. This may involve checking the key fob, the immobilizer module, and the communication between the two components.
How to fix DTC P1666 on BMW
Fixing DTC P1666 on a BMW may involve reprogramming the key fob, replacing the key or immobilizer module if faulty, or addressing any issues with the communication between the key and the immobilizer system. It is recommended to consult with a qualified automotive technician or BMW specialist to properly diagnose and repair the issue.
How to erase DTC P1666 on BMW
To erase DTC P1666 on a BMW, a diagnostic scan tool capable of clearing fault codes is needed. The technician can use the scan tool to erase the fault code associated with DTC P1666 from the vehicle’s ECU. Once the fault code is cleared, the technician can then verify that the issue has been resolved by checking for any reoccurring fault codes or symptoms.
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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