P0135 — 02 Sensor Heater Circuit Malfunction (Bank 1 Sensor 1)
Category: Powertrain Severity: Medium
Updated:
DTC code P0135 means: 02 Sensor Heater Circuit Malfunction (Bank 1 Sensor 1). It falls under the "Powertrain" category, with an estimated severity of Medium. Common causes include faulty O2 sensor heater, blown fuse and wiring/connector issue; it's worth confirming the diagnosis before replacing parts.
Possible causes
- Faulty O2 sensor heater
- Blown fuse
- Wiring/connector issue
- Faulty ECM
Symptoms
- Loss of power when accelerating
- Unstable idle
- Higher fuel consumption
- Jerking while driving
How to diagnose it step by step
- Check the O2 heater fuse.
- Measure the upstream sensor heater resistance.
- Check for 12 V with the key on.
- Replace the sensor if the heater is open.
How to fix it
Clean or replace the MAF/MAP sensor and check for intake leaks.
Estimated repair cost
Sensor installed: $100–300.
Frequently asked questions
What does DTC code P0135 mean?
02 Sensor Heater Circuit Malfunction (Bank 1 Sensor 1).
Is code P0135 serious?
Severity Medium. Not urgent, but worth diagnosing to avoid bigger damage.
Can I keep driving with code P0135?
Yes, it is safe to drive.
Related codes
P0134 P0136 P0133 P0137 P0132 P0138 P0131 P0139 P0130 P0140
Refine by car make
- Audi P0135: O2 sensor or its fuse.
- BMW P0135: O2 sensor (bank 1, sensor 1).
- Citroën P0135: O2 sensor or its fuse.
- Dacia P0135: MAF/MAP sensor.
- Fiat P0135: MAF/MAP sensor.
- Ford P0135: Heater fuse or O2 sensor.
- Honda P0135: Upstream O2 sensor.
- Hyundai P0135: Upstream O2 sensor.
- Kia P0135: Upstream O2 sensor.
- Mazda P0135: MAF sensor.
- Mercedes-Benz P0135: Upstream O2 sensor.
- Nissan P0135: Upstream O2 sensor.
- Opel P0135: O2 sensor or fuse.
- Peugeot P0135: O2 sensor or its fuse.
- Renault P0135: Upstream O2 sensor.
- Toyota P0135: Upstream O2 sensor.
- Volkswagen P0135: O2 sensor or its fuse.
- Volvo P0135: MAF sensor.
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