BMW DTC P1574 – Electronic Control Module Sensor Supply B High Output
DTC P1574 meaning on BMW
DTC P1574 on a BMW indicates that the Electronic Control Module (ECM) has detected a high output signal from the sensor supply B circuit. This typically means that the voltage being supplied to the sensor is higher than the specified range, causing the ECM to trigger the fault code.
BMW DTC P1574 symptoms
Symptoms of DTC P1574 on a BMW may include:
- Check Engine Light illuminated on the dashboard
- Reduced engine performance
- Engine stalling or rough idling
- Difficulty starting the vehicle
BMW DTC P1574 causes
The common causes of DTC P1574 on a BMW include:
- Faulty sensor supply B circuit
- Short circuit or open circuit in the wiring harness
- Defective Electronic Control Module (ECM)
- Voltage regulator issues
BMW DTC P1574 seriousness
While DTC P1574 may not always result in immediate drivability issues, it is important to address the underlying problem promptly. Ignoring this fault code can lead to further damage to the vehicle’s components and potentially affect its overall performance and reliability.
How to diagnose DTC P1574 on BMW
To diagnose DTC P1574 on a BMW, you can follow these steps:
- Use a diagnostic scanner to retrieve the fault code and any related codes.
- Inspect the sensor supply B circuit for any visible damage or loose connections.
- Check the voltage output of the sensor using a multimeter to determine if it is within the specified range.
- Perform a continuity test on the wiring harness to identify any short or open circuits.
- If necessary, test the ECM and voltage regulator for proper functionality.
How to fix DTC P1574 on BMW
To fix DTC P1574 on a BMW, you can consider the following solutions:
- Repair or replace any damaged wiring in the sensor supply B circuit.
- Replace the faulty sensor if it is not providing the correct voltage output.
- If the ECM is determined to be defective, replace it with a new unit.
- Address any issues with the voltage regulator that may be causing the high output signal.
How to erase DTC P1574 on BMW
To erase DTC P1574 on a BMW, you can use a diagnostic scanner to clear the fault code from the ECM’s memory. After addressing the underlying issue that triggered the fault code, you can reset the ECM and ensure that the Check Engine Light is no longer illuminated.
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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