BMW DTC U1891 – Electric/Auxiliary Transmission Fluid Pump Control Module Lost Communication With Hybrid/EV Powertrain Control Module
DTC U1891 meaning on BMW
DTC U1891 on a BMW indicates that there is a communication error between the Electric/Auxiliary Transmission Fluid Pump Control Module and the Hybrid/EV Powertrain Control Module. This error code signifies that the modules are not able to exchange information properly, which can lead to issues in the transmission system of the vehicle.
BMW DTC U1891 symptoms
Symptoms of DTC U1891 on a BMW may include:
- Transmission shifting problems
- Reduced fuel efficiency
- Check Engine Light illuminated
- Vehicle going into limp mode
BMW DTC U1891 causes
The possible causes of DTC U1891 on a BMW include:
- Faulty Electric/Auxiliary Transmission Fluid Pump Control Module
- Issues with the Hybrid/EV Powertrain Control Module
- Wiring or connection problems between the modules
BMW DTC U1891 seriousness
DTC U1891 should be addressed promptly as it can lead to transmission malfunctions and affect the overall performance of the vehicle. Ignoring this error code may result in further damage to the transmission system and potentially other components of the vehicle.
How to diagnose DTC U1891 on BMW
To diagnose DTC U1891 on a BMW, a mechanic would typically:
- Use a diagnostic scanner to retrieve the fault codes
- Inspect the wiring and connections between the Electric/Auxiliary Transmission Fluid Pump Control Module and the Hybrid/EV Powertrain Control Module
- Perform a communication test between the modules to identify any issues
How to fix DTC U1891 on BMW
To fix DTC U1891 on a BMW, the following steps may be taken:
- Repair or replace any damaged wiring or connectors
- Address any faults in the Electric/Auxiliary Transmission Fluid Pump Control Module or the Hybrid/EV Powertrain Control Module
- Clear the fault codes and perform a test drive to ensure the issue has been resolved
How to erase DTC U1891 on BMW
To erase DTC U1891 on a BMW, a mechanic can use a diagnostic scanner to clear the fault codes stored in the vehicle’s system. Once the codes have been cleared, the mechanic should perform a final check to ensure that the error code does 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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