Code 77

Rear O2 Sensor Test:

Rear Heated O2 Sensor Functional Test:

REAR HEATED OXYGEN SENSOR (DTC: P0136)
1) Start engine and warm it up sufficiently.
2) Set voltmeter probes between ECM terminals (52) (sensor signal) and (43) (engine ground).
3) Check the voltage when racing up to 6,000 rpm under no load. Or check the voltage when coasting from 80 km/h (50 MPH) in 3rd gear position. The voltage should be above 0.6V at least one time.
4) Check the voltage when racing up to 4,000 rpm under no load at least 10 times. (depress and release accelerator pedal as soon as possible). Or keep vehicle at idling for 10 minutes, then check the voltage. The voltage should be below 0.55V at least one time.

NOTE: After starting the engine, the output voltage of the rear heated oxygen sensor indicates higher voltage (approx. 5V at highest) than the normal operating range for about 7 seconds. This is due to checking for open circuits in rear heated oxygen sensor by on-board diagnosis. Therefore, if you measure the voltage (at ECM terminal 52) during this diagnosis, the higher voltage will appear. (CONSULT will also show the higher voltage, GST may show approx. 0V.) This is not a malfunction even though it is out of the normal range.