O2 Sensor Heater Circuit (Bank 1, Sensor 1)

Where it lives

For P0135, the sensor sits on the circuit this code reports. The description of P0135 puts it on bank 1.

Check these first

• Blown O2 sensor heater fuse
• Open or shorted heater wiring
• Failed sensor heater element
• Corroded connector
• Faulty PCM heater driver

What to do next

1. Check the sensor heater fuse and relay
2. Measure heater resistance between the sensor heater pins
3. Verify ignition power and ground at the heater circuit
4. Replace the sensor if the heater tests open or shorted
5. Repair any wiring or connector damage and clear the code

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