Operation CHARM: Car repair manuals for everyone.

Confirmation Engine Racing Pattern





CONFIRMATION ENGINE RACING PATTERN
a. Connect the TOYOTA hand-held tester to the DLC3, or connect the probe of the oscilloscope between terminals OX1, OX2 and E1 of ECM.
b. Start engine and warm it up with all accessories switched OFF until water temp. is stable.
c. Race the engine at 2,500 - 3,000 rpm for about 3 min.
d. After confirming that the waveforms of the heated oxygen sensor, bank 1 sensor 1 (OX 1), oscillate around 0.5 V during feedback to the ECM, check the waveform of the heated oxygen sensor, bank 1 sensor 2 (OX2).






HINT: If there is a malfunction in the system, the waveform of the heated oxygen sensor, bank 1 sensor 2 (OX2), is almost the same as that of the heated oxygen sensor, bank 1 sensor 1 (OX1), on the left.
There are some cases where, even though a malfunction exists, the MIL may either light up or not light up.