Diesel Data: Automotive Repair

Oxygen Sensor: Testing and Inspection



INSPECT AIR-FUEL RATIO COMPENSATION SYSTEM

HINT: You can also check the system by choosing "DATA MONITOR", then "O2 SENSOR OUTPUT VOLTAGE" on the monitor of the hand-held tester.






a. Connect the hand-held tester to the terminal 23 (OX1A) <=> 7 (E1) and 21 (OX1B) <=> 7 (E1) of the ECM.

CAUTION: Connect test leads from the back side of the connector with the ECU connected.

b. Warm up the oxygen sensor with the engine speed at 2,500 rpm for approx. 2 minutes.
c. Confirm that the voltage changes between 0 V to 1 V with the engine speed at 2,500 rpm.

OK: The voltage changes more than 8 times in 10 seconds.

CAUTION: Perform the check immediately after the end of the warming up.
If not confirming the change of voltage, warming up the oxygen sensor again.