BMW DTC P1901 – Pressure Control Solenoid ‘B’ Shift Progress Too Low
DTC P1901 meaning on BMW
The Diagnostic Trouble Code (DTC) P1901 for BMW indicates an issue with the Pressure Control Solenoid ‘B’ Shift Progress being too low. This means that the transmission control module has detected that the pressure control solenoid responsible for regulating hydraulic pressure during gear shifts is not functioning within the expected parameters.
BMW DTC P1901 symptoms
Symptoms of DTC P1901 on a BMW may include harsh or delayed shifting, erratic shifting behavior, transmission slipping, and in some cases, the transmission may go into a limp mode where it operates in a limited capacity to prevent further damage.
BMW DTC P1901 causes
The common causes of DTC P1901 on a BMW include a faulty pressure control solenoid ‘B’, low transmission fluid level or poor quality fluid, wiring issues, or a malfunctioning transmission control module.
BMW DTC P1901 seriousness
Ignoring DTC P1901 on a BMW can lead to further damage to the transmission system, potentially resulting in costly repairs. It is important to address this issue promptly to prevent any long-term damage to the vehicle.
How to diagnose DTC P1901 on BMW
To diagnose DTC P1901 on a BMW, a mechanic would typically use a diagnostic scanner to retrieve the fault codes from the transmission control module. They would then perform a visual inspection of the transmission components, check the transmission fluid level and condition, and conduct tests on the pressure control solenoid ‘B’ to determine if it is functioning correctly.
How to fix DTC P1901 on BMW
Fixing DTC P1901 on a BMW may involve replacing the pressure control solenoid ‘B’ if it is found to be faulty. Additionally, ensuring the transmission fluid is at the correct level and in good condition, checking and repairing any damaged wiring, and resetting the transmission control module may be necessary to resolve the issue.
How to erase DTC P1901 on BMW
Once the underlying issue causing DTC P1901 on a BMW has been fixed, the fault codes can be cleared using a diagnostic scanner. This will reset the transmission control module and erase the DTC P1901 code from the system. It is important to verify that the issue has been resolved before clearing the fault codes.
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.