3wire?
> Is the magic Nissan "1v titania" sensor with a red wire? No such
> thing, they are Zirconia, the red wire is to fool the trade.
>
> white wire is signal 0-1v
> red wire is heater +12v from ignition switch.
> black wire is heater ground. ECU uses a transistor to switch the
> ground on and off. It only heats the sensor during warm up, idle, low
> load, lift off (throttle idle switch on) to stop it cooling off. >
> If engine is properly warm for 2000rpm test the lack of a heater won't
> affect it. Just delays how long it's takes to go into closed loop from > idle. >
> Look for an air leak.
> Check AFM connection, disconnect ACC and wiggle AFM connector, if revs
> change it's a poor connection.
> --
> Peter Hill
> Spamtrap reply domain as per NNTP-Posting-Host in header
> Can of worms - what every fisherman wants.
> Can of worms - what every PC owner gets!
Yep, this is the original 3 wire Zirconia sensor with a red wire. 12V supply tests OK. I'll test both the signal and ground at 2000 rpm at op temp. Having ground controlled by a transistor in the ECM makes sense, surprising that the factory manual did not say to test when at operating temp. It further says to check the ground points if an open circuit found, so there is a mistake in the diagnostic.
AFM= Air Fuel Meter. What component to you mean by ACC? I can't find a reference to it. Do you mean IAC= Idle Air Controller?