Maxima SE V6-3.0L (VQ30DE) (1998)
ON BOARD DIAGNOSIS LOGIC
The rear heated oxygen sensor has a much longer switching time between rich and lean than the front heated oxygen sensor. The oxygen storage capacity
before the three way catalyst causes the longer switching time. To judge the malfunctions of rear heated oxygen sensor, ECM monitors whether or not
the voltage is too high during the various driving condition such as fuel-cut.
DIAGNOSTIC TROUBLE CODE CONFIRMATION PROCEDURE
CAUTION: Always drive vehicle at a sate speed.
NOTE: If "DIAGNOSTIC TROUBLE CODE CONFIRMATION PROCEDURE" has been previously conducted, always turn ignition switch "OFF"
and wait at least 5 seconds before conducting the next test.
OVERALL FUNCTION CHECK
Use this procedure to check the overall function of the rear heated oxygen sensor circuit. During this check, a 1st trip DTC might not be confirmed.
Without TOOLS
(1) Start engine and warm it up to normal operating temperature.
(2) Set voltmeter probes between ECM terminals (56) (sensor signal) and (25) (engine ground).
(3) Check the voltage after racing up to 4,000 rpm under no load at least 10 times.
(Depress and release accelerator pedal as soon as possible.)
The voltage should be below 2V during this procedure.