BMW DTC P1904 – Pressure Control Solenoid ‘E’ Shift Progress Too Low
DTC P1904 meaning on BMW
The Diagnostic Trouble Code (DTC) P1904 for BMW indicates an issue with the Pressure Control Solenoid ‘E’ 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 operating within the expected parameters.
BMW DTC P1904 symptoms
Symptoms of DTC P1904 on a BMW may include harsh or delayed shifting, erratic shifting behavior, transmission slipping, or the transmission going into limp mode. The vehicle may also exhibit poor acceleration and reduced fuel efficiency.
BMW DTC P1904 causes
The common causes of DTC P1904 on a BMW include a faulty pressure control solenoid ‘E’, low transmission fluid level or dirty fluid, wiring issues, or a malfunctioning transmission control module. Additionally, mechanical problems within the transmission itself can also trigger this fault code.
BMW DTC P1904 seriousness
Ignoring DTC P1904 on a BMW can lead to further damage to the transmission system, potentially resulting in costly repairs. Continued driving with this fault can cause additional stress on the transmission components and may lead to a complete transmission failure.
How to diagnose DTC P1904 on BMW
To diagnose DTC P1904 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 components, check the transmission fluid level and condition, and inspect the wiring harness connected to the pressure control solenoid ‘E’. Further testing may involve checking the solenoid’s resistance and functionality.
How to fix DTC P1904 on BMW
Fixing DTC P1904 on a BMW usually involves replacing the faulty pressure control solenoid ‘E’. Additionally, the transmission fluid should be inspected and replaced if necessary. Any damaged wiring should be repaired, and the transmission control module may need to be reprogrammed or replaced if deemed faulty. It is essential to address the root cause of the issue to prevent future occurrences.
How to erase DTC P1904 on BMW
After the necessary repairs have been made to address DTC P1904 on a BMW, the fault codes can be cleared using a diagnostic scanner. This will reset the vehicle’s computer and turn off the Check Engine Light. It is important to ensure that the underlying issue has been resolved before clearing the fault codes to prevent the code from reappearing.
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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