p1155
Moderate
Toyota · Sedans
Air/Fuel Sensor Heater Circuit Response Bank 2 Sensor 1
Quick Answer
Error code P1155 on your Toyota Sedans means: Air/Fuel Sensor Heater Circuit Response Bank 2 Sensor 1. This is usually fixable — see the step-by-step guide below.
Affected Models
Likely Causes
  1. Failed air/fuel ratio sensor heater element on Bank 2
  2. Blown heater circuit fuse
  3. Damaged wiring between ECM and Bank 2 Sensor 1
  4. Corroded or water-damaged sensor connector
  5. Internal ECM heater driver failure
How to Fix It
1
Check the A/F sensor heater fuse and relay in the fuse box
2
Measure the Bank 2 Sensor 1 heater element resistance and compare to specification
3
Inspect the wiring from the ECM to the Bank 2 Sensor 1 connector for opens or shorts
4
Check for water intrusion or corrosion at the sensor connector
5
Replace the air/fuel ratio sensor if heater resistance is out of range
Pro Tip
This fix requires some technical knowledge. If you're unsure about any step, consider contacting support or a qualified technician.
Parts You May Need
Air/fuel ratio sensor (Bank 2 Sensor 1)
Sensor heater fuse
Wiring harness repair connector
Dielectric grease for connector
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