Sub Heated Oxygen Sensor Testing

1. INSPECT OPERATION OF SUB HEATED OXYGEN SENSOR.
(a) Cancel diagnostic trouble code.
Refer to "Clearing Diagnostic Trouble Codes" under the testing procedures for Computers and Control Systems.
Testing and Inspection
(b) Allow the engine to warm up to normal operating temperature.
(c) Drive for 5 minutes or more between 80 km/h (50 mph) and 100 km/h, (62 mph) in 4th or 5th gear/D range.
(d) Following the conditions in step (c), press fully on the accelerator pedal for 2 seconds or more.
NOTICE: Do not exceed 100 km/h (62 mph), or diagnostic code will be cancelled.
(e) Stop the vehicle, and turn the ignition switch to OFF.
(f) Carry out steps (b), (c) and (d) again to test acceleration.
^ If DTC 27 reappears, check the oxygen sensor circuit.
^ If the circuit is normal, replace the oxygen sensor.

2. INSPECT HEATER RESISTANCE OF SUB HEATED OXYGEN SENSOR.



(a) Remove the driver's seat.
(b) Take out the console box side of the floor carpet.
(c) Disconnect the oxygen sensor connector.



(d) Using an ohmmeter, measure the resistance between the terminals +B and HT.
Resistance: 11 - 16 Ohms @ 20°C (68°F)
^ If the resistance is not as specified, replace the sensor.
(e) Reconnect the oxygen sensor connector.
(f) Reinstall the floor carpet.
(g) Reinstall the driver's seat.