Confirmation Engine Racing Pattern
- Connect the hand-held tester to the DLC3, or connect the probe of the oscilloscope between terminals OX1A, OX1B, OX2A, OX2B and E1 of ECM connectors.
- Start the engine and warm it up with all the accessories switched OFF until engine coolant temperature is stable.
- Race the engine at 2,500 to 3,000 RPM for about 3 min.
- After confirming that the waveform of the heated oxygen sensor (bank 1, 2 sensor 1 (OX1A, OX2A)), oscillate around 0.5 V during feedback to the ECM, check the waveform of the heated oxygen sensor (bank 1, 2 sensor 2 (OX1B, OX2B)).
HINT:
If there is a malfunction in the system, the waveform of the heated oxygen sensor (bank 1, 2 sensor 2 (OX1B, OX2B)) is almost the same as that of the heated oxygen sensor (bank 1, 2 sensor 1 (OX1A, OX2A)) on the left.
There are some cases where, even though a malfunction exists, the MIL may either light up or not light up.