BMW DTC P1135 – O2 Sensor Heater Circuit Low Voltage (Bank 1 Sensor 1)
DTC P1135 meaning on BMW
DTC P1135 on a BMW indicates an issue with the O2 sensor heater circuit for Bank 1 Sensor 1. This fault code specifically points to low voltage in the O2 sensor heater circuit, which can affect the sensor’s performance and accuracy.
BMW DTC P1135 symptoms
Symptoms of DTC P1135 on a BMW may include poor fuel economy, rough idling, hesitation during acceleration, and an illuminated check engine light on the dashboard. Additionally, the vehicle may fail emissions testing due to increased emissions.
BMW DTC P1135 causes
The most common causes of DTC P1135 on a BMW are a faulty O2 sensor heater, damaged wiring or connectors in the O2 sensor circuit, or a blown fuse related to the O2 sensor heater circuit. Environmental factors such as extreme temperatures can also contribute to this issue.
BMW DTC P1135 seriousness
While DTC P1135 may not cause immediate drivability issues, it can lead to decreased fuel efficiency and increased emissions. Ignoring this fault code can potentially cause long-term damage to the vehicle’s engine and emissions system.
How to diagnose DTC P1135 on BMW
To diagnose DTC P1135 on a BMW, a mechanic will typically use a diagnostic scanner to retrieve the fault code and perform a visual inspection of the O2 sensor and its wiring. They may also test the O2 sensor heater circuit for continuity and check the fuse related to the O2 sensor heater.
How to fix DTC P1135 on BMW
Fixing DTC P1135 on a BMW usually involves replacing the faulty O2 sensor heater, repairing any damaged wiring or connectors in the O2 sensor circuit, and ensuring the fuse related to the O2 sensor heater is intact. Once the issue is resolved, the fault code should be cleared from the vehicle’s ECU.
How to erase DTC P1135 on BMW
To erase DTC P1135 on a BMW, a mechanic can use a diagnostic scanner to clear the fault code from the vehicle’s ECU. After the repair has been completed and the underlying issue causing the fault code has been resolved, clearing the code will turn off the check engine light and reset the system for proper operation.
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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