BMW DTC P1109 – Manifold Air Pressure Too High in Deceleration
DTC P1109 meaning on BMW
The DTC P1109 on a BMW indicates that the Manifold Air Pressure is too high during deceleration. This means that the pressure in the intake manifold is exceeding the expected values when the vehicle is slowing down.
BMW DTC P1109 symptoms
Symptoms of the DTC P1109 on a BMW may include rough idling, engine stalling, decreased fuel efficiency, and potentially even engine misfires. The Check Engine Light may also illuminate on the dashboard.
BMW DTC P1109 causes
The high manifold air pressure during deceleration in a BMW can be caused by issues such as a faulty MAP (Manifold Absolute Pressure) sensor, a vacuum leak in the intake system, a clogged air filter, or a malfunctioning EGR (Exhaust Gas Recirculation) system.
BMW DTC P1109 seriousness
While the DTC P1109 may not cause immediate harm to the vehicle, it can lead to poor engine performance and decreased fuel efficiency. Ignoring this issue can potentially cause further damage to the engine over time.
How to diagnose DTC P1109 on BMW
To diagnose the DTC P1109 on a BMW, a mechanic would typically start by using a diagnostic scanner to retrieve the trouble codes. They would then inspect the MAP sensor, check for any vacuum leaks, examine the air filter, and test the EGR system to pinpoint the exact cause of the high manifold air pressure.
How to fix DTC P1109 on BMW
Fixing the DTC P1109 on a BMW involves addressing the root cause of the high manifold air pressure. This may include replacing a faulty MAP sensor, repairing any vacuum leaks, replacing the air filter if necessary, or fixing issues with the EGR system. Once the underlying problem is resolved, the trouble code should be cleared.
How to erase DTC P1109 on BMW
To erase the DTC P1109 on a BMW, the diagnostic trouble codes can be cleared using a diagnostic scanner. After the underlying issue has been fixed and the repairs have been made, the trouble code can be reset to turn off the Check Engine Light and ensure that the vehicle is running smoothly.
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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