BMW DTC P1237 – Secondary Upstream Manifold Air Pressure Sensor Circuit Low
DTC P1237 meaning on BMW
The Diagnostic Trouble Code (DTC) P1237 for BMW refers to the Secondary Upstream Manifold Air Pressure Sensor Circuit Low. This code indicates that there is a problem with the circuit that controls the secondary upstream manifold air pressure sensor, resulting in a low voltage signal being sent to the engine control module (ECM).
BMW DTC P1237 symptoms
Symptoms of DTC P1237 on a BMW may include:
- Check Engine Light illuminated on the dashboard
- Reduced engine performance
- Engine stalling or hesitation
- Poor fuel efficiency
BMW DTC P1237 causes
The common causes of DTC P1237 on a BMW include:
- Faulty secondary upstream manifold air pressure sensor
- Wiring or connector issues in the sensor circuit
- ECM software or hardware problems
BMW DTC P1237 seriousness
While DTC P1237 may not cause immediate harm to the vehicle, it can lead to poor engine performance and reduced fuel efficiency. Ignoring this code may result in further damage to the engine over time.
How to diagnose DTC P1237 on BMW
To diagnose DTC P1237 on a BMW, you can follow these steps:
- Use a diagnostic scanner to retrieve the fault codes stored in the ECM.
- Inspect the wiring and connectors related to the secondary upstream manifold air pressure sensor for any damage or corrosion.
- Test the sensor using a multimeter to check for proper voltage and resistance values.
- If necessary, perform a smoke test to check for any vacuum leaks in the intake system.
How to fix DTC P1237 on BMW
To fix DTC P1237 on a BMW, you can try the following solutions:
- Replace the faulty secondary upstream manifold air pressure sensor.
- Repair or replace any damaged wiring or connectors in the sensor circuit.
- If the ECM is suspected to be the issue, reflash or replace the ECM as needed.
How to erase DTC P1237 on BMW
To erase DTC P1237 on a BMW, you can use a diagnostic scanner to clear the fault codes stored in the ECM. After fixing the underlying issue causing the code, clearing the codes will reset the Check Engine Light and monitor the system for any new 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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