BMW DTC P0748 – Pressure Control Solenoid ‘A’ Electrical
DTC P0748 meaning on BMW
DTC P0748 indicates a fault with the Pressure Control Solenoid ‘A’ electrical circuit in a BMW vehicle. The Powertrain Control Module (PCM) monitors this circuit to ensure proper operation of the solenoid that controls the transmission fluid pressure. When the PCM detects an electrical issue with the solenoid, it triggers the P0748 diagnostic trouble code.
BMW DTC P0748 symptoms
Symptoms of DTC P0748 in a BMW may include harsh shifting, delayed shifting, transmission slipping, decreased fuel efficiency, and in some cases, the transmission may go into a fail-safe or limp mode. The Check Engine Light may also illuminate on the dashboard.
BMW DTC P0748 causes
The common causes of DTC P0748 in a BMW include a faulty pressure control solenoid ‘A’, damaged wiring or connectors in the solenoid circuit, low transmission fluid level or dirty fluid, or a malfunctioning PCM.
BMW DTC P0748 seriousness
Ignoring DTC P0748 in a BMW can lead to further transmission issues, potentially causing damage to the transmission components over time. It is important to address this code promptly to prevent more severe problems and ensure the vehicle’s drivability.
How to diagnose DTC P0748 on BMW
To diagnose DTC P0748 on a BMW, a mechanic would typically start by using a scan tool to retrieve the fault codes stored in the PCM. They would then inspect the pressure control solenoid ‘A’ and its electrical connections for any visible damage. Testing the solenoid’s resistance and checking the wiring for continuity can help pinpoint the issue.
How to fix DTC P0748 on BMW
Fixing DTC P0748 on a BMW may involve replacing the pressure control solenoid ‘A’ if it is found to be faulty. Additionally, repairing or replacing any damaged wiring or connectors in the circuit is essential. Ensuring the transmission fluid is at the correct level and in good condition is also important for proper operation.
How to erase DTC P0748 on BMW
After addressing the underlying issue causing DTC P0748 on a BMW, the diagnostic trouble code can be cleared using a scan tool. This will reset the Check Engine Light and allow the PCM to monitor the system for any new faults. It is important to verify that the issue has been resolved before clearing the code.
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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