BMW DTC P1940 – Hydraulic Pressure Unit Pressure Too High
DTC P1940 meaning on BMW
DTC P1940 on a BMW indicates that the hydraulic pressure unit pressure is too high. This fault code is typically triggered when the pressure in the hydraulic unit exceeds the specified threshold.
BMW DTC P1940 symptoms
Symptoms of BMW DTC P1940 may include harsh shifting, transmission slipping, difficulty engaging gears, illuminated warning lights on the dashboard related to the transmission system, and in severe cases, the transmission may go into limp mode.
BMW DTC P1940 causes
The high hydraulic pressure in the unit that triggers DTC P1940 on a BMW can be caused by issues such as a faulty pressure control solenoid, a clogged hydraulic passage, a malfunctioning pressure sensor, or a problem with the transmission pump.
BMW DTC P1940 seriousness
Ignoring DTC P1940 on a BMW can lead to further damage to the transmission system and potentially result in costly repairs. It is important to address this issue promptly to prevent any long-term damage to the vehicle.
How to diagnose DTC P1940 on BMW
To diagnose DTC P1940 on a BMW, a mechanic would typically start by using a diagnostic scanner to retrieve the fault codes stored in the vehicle’s computer. They would then perform a visual inspection of the transmission system, check the hydraulic pressure levels, test the pressure control solenoid, inspect the pressure sensor, and conduct a thorough examination of the transmission pump.
How to fix DTC P1940 on BMW
Fixing DTC P1940 on a BMW may involve replacing the pressure control solenoid, cleaning out any clogged hydraulic passages, replacing the pressure sensor if faulty, or repairing/replacing the transmission pump if necessary. It is recommended to follow the manufacturer’s repair procedures and use genuine OEM parts to ensure proper functionality.
How to erase DTC P1940 on BMW
Once the underlying issue causing DTC P1940 on a BMW has been diagnosed and fixed, the fault code can be cleared using a diagnostic scanner. By clearing the code, the vehicle’s computer will reset and monitor the system for any recurring issues. It is important to ensure that the repair has been successful before clearing the fault code to prevent it from reoccurring.
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.