BMW DTC P1804 – Shift Solenoid ‘D’ Circuit Low
DTC P1804 meaning on BMW
DTC P1804 indicates a fault with the Shift Solenoid ‘D’ Circuit in a BMW vehicle. This fault code specifically points to a low voltage condition in the circuit associated with the Shift Solenoid ‘D’.
BMW DTC P1804 symptoms
Symptoms of DTC P1804 in a BMW may include harsh shifting, delayed shifting, transmission slipping, or the transmission not shifting at all. The vehicle may also experience decreased fuel efficiency and overall performance issues.
BMW DTC P1804 causes
The common causes of DTC P1804 in a BMW include a faulty shift solenoid ‘D’, damaged wiring or connectors in the circuit, low transmission fluid level, or a malfunctioning transmission control module (TCM).
BMW DTC P1804 seriousness
DTC P1804 should be addressed promptly as it can lead to further damage to the transmission system if left unresolved. Ignoring this fault code may result in more severe transmission issues and potentially costly repairs.
How to diagnose DTC P1804 on BMW
To diagnose DTC P1804 on a BMW, a mechanic would typically start by using a diagnostic scanner to retrieve the fault code and perform a thorough inspection of the shift solenoid ‘D’, wiring, connectors, and transmission fluid level. Testing the circuit for continuity and voltage, as well as checking the TCM for any faults, can help pinpoint the exact cause of the issue.
How to fix DTC P1804 on BMW
Fixing DTC P1804 on a BMW may involve replacing the faulty shift solenoid ‘D’, repairing any damaged wiring or connectors, ensuring the transmission fluid level is correct, and addressing any issues with the TCM. It is recommended to follow the manufacturer’s repair procedures and use genuine parts to ensure a proper fix.
How to erase DTC P1804 on BMW
Once the underlying issue causing DTC P1804 has been resolved, the fault code can be erased using a diagnostic scanner. By clearing the code, the vehicle’s onboard computer will reset the transmission system’s parameters and monitor for any recurring faults.
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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