BMW DTC P0135 – O2 Sensor Heater Circuit (Bank 1 Sensor 1)
DTC P0135 meaning on BMW
DTC P0135 on a BMW indicates an issue with the O2 sensor heater circuit for Bank 1 Sensor 1. This fault code specifically points to a malfunction in the heating element of the oxygen sensor located in the exhaust system before the catalytic converter on the bank 1 side of the engine.
BMW DTC P0135 symptoms
Symptoms of DTC P0135 on a BMW may include poor fuel economy, rough idling, engine hesitation, stalling, increased emissions, and in some cases, the illumination of the Check Engine Light on the dashboard.
BMW DTC P0135 causes
The common causes of DTC P0135 on a BMW include a faulty O2 sensor heater, damaged wiring or connectors in the sensor circuit, a blown fuse related to the O2 sensor heater, or issues with the engine control module (ECM).
BMW DTC P0135 seriousness
While DTC P0135 may not cause immediate drivability issues, it can lead to decreased fuel efficiency and increased emissions. Ignoring this fault code can potentially cause damage to the catalytic converter over time, resulting in more costly repairs.
How to diagnose DTC P0135 on BMW
To diagnose DTC P0135 on a BMW, a mechanic would typically use a scan tool to retrieve the fault code and then perform a visual inspection of the O2 sensor and its wiring. Testing the O2 sensor heater circuit for continuity and checking the fuse related to the sensor heater are common diagnostic steps.
How to fix DTC P0135 on BMW
Fixing DTC P0135 on a BMW usually involves replacing the faulty O2 sensor heater, repairing any damaged wiring or connectors in the sensor circuit, and ensuring that the fuse related to the O2 sensor heater is intact. Once the issue is resolved, clearing the fault code and resetting the Check Engine Light is necessary.
How to erase DTC P0135 on BMW
To erase DTC P0135 on a BMW, a scan tool capable of clearing fault codes is required. After the underlying issue causing the fault code has been fixed, the scan tool can be used to clear the code and reset the Check Engine Light. It is important to ensure that the repair has been successful before clearing the fault code.
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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