BMW DTC P0991 – Transmission Fluid Pressure Sensor/Switch ‘E’ Circuit Intermittent
DTC P0991 meaning on BMW
DTC P0991 on a BMW indicates a fault with the Transmission Fluid Pressure Sensor/Switch ‘E’ Circuit. This fault code is triggered when the powertrain control module (PCM) detects an intermittent issue with the transmission fluid pressure sensor or switch in circuit ‘E’.
BMW DTC P0991 symptoms
Symptoms of DTC P0991 on a BMW may include erratic shifting behavior, transmission slipping, harsh shifting, transmission overheating, or the transmission going into limp mode. The vehicle’s check engine light may also be illuminated.
BMW DTC P0991 causes
The common causes of DTC P0991 on a BMW include a faulty transmission fluid pressure sensor/switch, damaged wiring or connectors in the circuit, low transmission fluid level, or a malfunctioning PCM.
BMW DTC P0991 seriousness
DTC P0991 should be addressed promptly to prevent potential damage to the transmission system. Ignoring this fault code can lead to further transmission issues and potentially costly repairs.
How to diagnose DTC P0991 on BMW
To diagnose DTC P0991 on a BMW, a mechanic would typically start by using a diagnostic scanner to retrieve the fault code and any related codes. They would then inspect the transmission fluid pressure sensor/switch and its circuit for any visible damage or corrosion. Testing the sensor’s resistance and checking the wiring for continuity would also be part of the diagnostic process.
How to fix DTC P0991 on BMW
Fixing DTC P0991 on a BMW may involve replacing the faulty transmission fluid pressure sensor/switch, repairing any damaged wiring or connectors, ensuring the transmission fluid level is correct, and clearing the fault codes from the PCM. It is recommended to follow the manufacturer’s diagnostic and repair procedures to address this issue effectively.
How to erase DTC P0991 on BMW
To erase DTC P0991 on a BMW, a diagnostic scanner capable of clearing fault codes is required. Once the underlying issue has been addressed and fixed, the fault codes can be cleared from the PCM using the diagnostic tool. After clearing the fault codes, it is advisable to test drive the vehicle to ensure the issue has been resolved.
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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