P0141 · blink 27 – OXYGEN SENSOR HEATER CIRCUIT MALFUNCTION(BANK1 SENSOR2)

System: EFI 3ZZ-FE
Dashboard light: Malfunction indicator lamp (Check Engine)
Check-engine blink code: 27
Applies to: 3ZZ-FE 1.6 (PK SE Saloon 1.6 2002-05 ZZE121)
Description: OXYGEN SENSOR HEATER CIRCUIT MALFUNCTION(BANK1 SENSOR2)
Detection / symptoms: Detection: S When the heater operates, heater current exceeds 2 A (2 trip detection logic) S Heater current of 0.2 A or less when the heater operates (2 trip detection logic)
Possible causes: Open or short in heater circuit of oxygen sensor; Oxygen sensor heater; Engine ECU
What to check: Workshop check order (RM821E): INSPECT ECU -> CHECK OXYGEN SENSOR(OXYGEN SENSOR HEATER) -> CHECK HARNESS AND CONNECTOR(ENGINE ECU−OXYGEN SENSOR) -> CHECK ENGINE ECU POWER SOURCE CIRCUIT -> CHECK HARNESS AND CONNECTOR(E.F.I.MAIN RELAY−OXYGEN SENSOR)(See
Confidence: high (official Toyota RM821E)

From the factory service material. Clear the code and test-drive to confirm it returns. Search all fault codes · Common problems · Warning lights