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Re: Sync loss during warmup with SW0205

PostPosted: Fri Dec 22, 2017 2:04 pm
by snowrx
Here's files, starting from 27 F, might not be representative as the car started after just a few tries.
"Cold" files are as I first cranked, others are at a cold idle

Re: Sync loss during warmup with SW0205

PostPosted: Fri Dec 22, 2017 2:07 pm
by snowrx
Rest of files. TunerStudio recorded 32 seperate tiny .msl files while I idled a bit. Started a new.msl with every synch loss, you could string them together and view as a whole. I assume this is because I am triggering the SD with RPM>300, and synch loss = no RPM,

Looks like I am still set on Wasted COP from earlier cam diagnosis.

Re: Sync loss during warmup with SW0205

PostPosted: Tue Dec 26, 2017 1:55 pm
by snowrx
Snugged up pin sockets on both cam and crank sensors, then tried one cold start each with a hot air pre-heat of cam then crank sensors. No joy.
Won't have new sensors to test for a bit, not sure what else could be temperature (or time?) sensitive to give me the synch loss on the 32-2-2-2 code.

Datalog is a 29 F start with preheated crank sensor, a couple of start attempts, then cold idle with synch losses until time= 34 seconds, then all is well.

Re: Sync loss during warmup with SW0205

PostPosted: Wed Jan 03, 2018 2:30 pm
by snowrx
Replaced cam sensor and did a couple cold starts, looks like it helped, now getting synch loss only with initial cranking (or when I stall it engaging clutch on cold tranny)
Hopefully this will now start with two tries rather than 6 or 8 or 10, and quit the stalling. Not sure why the sensor could fail cold, but warm to working temperature in 30 seconds, as it's sensing the back of the cam pulley in air. Perhaps a vibration component as well? Time will tell.

Crank sensor came in today, I'll try that next. It's in the crank oil and I would expect it to warm up faster than the cam sensor.

Re: Sync loss during warmup with SW0205

PostPosted: Thu Jan 04, 2018 6:30 am
by Matt Cramer
It wouldn't be the first time I've seen a sensor have a temperature dependent failure with VR sensors. I'm not sure if it is due to thermal effects on the magnet or some sort of expansion / contraction changing the air gap just enough to make trouble.

Re: Sync loss during warmup with SW0205

PostPosted: Sat Jan 06, 2018 6:27 pm
by snowrx
Hoping that the cam sensor took care of the issue- still a drop or two while cranking, but not the continuing missing and stalls I had before. Coincidental that it expressed with the swap to the SW0205?

Just cause there are a trillion settings combinations for cold start, don't assume it's a software settings issue until you check the hardware. :roll:

Now on to why my first crank never registers a good AFR on the preheated O2 sensor.....

Re: Sync loss during warmup with SW0205

PostPosted: Mon Jan 08, 2018 8:46 am
by Matt Cramer
snowrx wrote:Hoping that the cam sensor took care of the issue- still a drop or two while cranking, but not the continuing missing and stalls I had before. Coincidental that it expressed with the swap to the SW0205?


We don't have quite the same opportunity OEMs have for putting in testing our ECUs with worn, marginal, or partially failed sensors. So the stock Subaru ECU may have had some sort of hardware or software features to compensate for a sensor that was beginning to fail that our system didn't.

Just cause there are a trillion settings combinations for cold start, don't assume it's a software settings issue until you check the hardware. :roll:

Now on to why my first crank never registers a good AFR on the preheated O2 sensor.....


The tune has a 40 second delay after start for applying the AFR readings. It is also possible that the supply voltage to the sensor drops far enough to make the controller reset while cranking; many wideband controllers also have a built in delay before they start sending a signal.

Re: Sync loss during warmup with SW0205

PostPosted: Mon Jan 08, 2018 10:05 am
by snowrx
Thanks again Matt, I'll look at those O2 thoughts