BMW DTC P0140 – O2 Sensor Circuit No Activity Detected (Bank 1 Sensor 2)
DTC P0140 meaning on BMW
The Diagnostic Trouble Code (DTC) P0140 for BMW indicates that the O2 sensor circuit for Bank 1 Sensor 2 is not showing any activity. This sensor is located downstream of the catalytic converter and is responsible for monitoring the oxygen levels in the exhaust gases.
BMW DTC P0140 symptoms
Symptoms of a P0140 DTC on a BMW may include poor fuel economy, rough idling, hesitation during acceleration, and an illuminated Check Engine Light on the dashboard.
BMW DTC P0140 causes
The most common causes of a P0140 DTC on a BMW are a faulty O2 sensor, damaged wiring or connectors in the sensor circuit, or a problem with the engine control module (ECM).
BMW DTC P0140 seriousness
While a P0140 DTC may not cause immediate drivability issues, it can lead to decreased fuel efficiency and increased emissions. Ignoring this code can potentially cause damage to the catalytic converter over time.
How to diagnose DTC P0140 on BMW
To diagnose a P0140 DTC on a BMW, a mechanic would typically use a scan tool to retrieve the code and then perform a visual inspection of the O2 sensor and its wiring. They may also test the sensor’s voltage output and resistance to determine if it is functioning correctly.
How to fix DTC P0140 on BMW
Fixing a P0140 DTC on a BMW usually involves replacing the faulty O2 sensor. The sensor should be tested before replacement to confirm the diagnosis. Additionally, any damaged wiring or connectors should be repaired or replaced as needed.
How to erase DTC P0140 on BMW
Once the underlying issue causing the P0140 DTC on a BMW has been resolved, the code can be cleared using a scan tool. This will reset the Check Engine Light and allow the vehicle’s ECM to 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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