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Saturn and the bypass signal
Posted: Wed Aug 09, 2006 6:50 pm
by tebriel
Blue, yes if the ground was strong and I hooked it into the relay, it would keep the fan on whenever power was going to the unit. Lance, it's not that the grounding of pin 30 on the db37 is reversed, just that it's constant. It's always grounded. I don't think I would've had the chance to reverse the polarity, I had this harness working with the MS1 for 2 years, and then I just plugged it in, and added a wire for pin 30. But I will look and see if I have extra transistors and replace q3 and q5 and see if that helps. It's very odd because the software is behaving correctly, but whether the port is on or off, the wire is always grounded :/ there's no shorts on the connector either, it's a solderless connector. thanks guys, teb
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Posted: Mon Aug 14, 2006 2:46 pm
by chrispel
Ok I want to hook up the bypass to my saturn. I 'm already using Fidle for the fans and it rocks. I want to use Spr1 on Pin 3 and PM4 the accel LED to trigger it. How do I get the 5V to it? DO I just take the 5V of the proto and where does it wire to?
Posted: Tue Aug 15, 2006 7:38 am
by S.Bretz
I think I just used the 5 volt off the PCM's tps power wire, or maybe it was the MS's tps power.
Hook the timing wire up to the EST signal wire on the PCM you are good to go.
Posted: Tue Aug 15, 2006 8:10 pm
by tebriel
do you have a link to the diagram of the ICM crispel? it shows the bypass wire on there. You know, i've never needed to switch the 5v off. it starts fine with it supplied, with the MS supplying the power. Maybe obd2 is different or something? but the only thing it's done for me is have me forget to switch the switch back on while driving, and having the car run like poop for a while and me trying to figure out why. Then I look down at the switch
Also, back to my FIdle circuit. I looked it over earlier, and noticed that I could have a cold joint on R19 I think. so I added some solder to that and it worked!!
On the 95, take pin 30 on the db37 out to A3 on the smaller pcm connector, it's green, not green/white as the stupid fsm says. The green/white wire is A4, and is the cannister solenoid thing. Which will click if you supply a ground to it

So my fan control works perfectly now!!
-teb
Posted: Wed Aug 16, 2006 12:20 pm
by bluetrepidation
Having a fan is nice. You running a knock sensor yet?
A.J.
Posted: Wed Aug 16, 2006 2:20 pm
by S.Bretz
Nah. The saturn knock sensor is different from the ones listed....plus the ones listed in the mega manual also need some type of signal conditioning device. All that stuff is inside the SATURN pcm, so its not like we can just use it or pull it off a certain year s-car in a yard. The conditioner that the manual shows is something I have never seen or payed notice to, so I don't know where to look for it on the cars at the yards...I'm probably just gonna buy a knock senor and conditioner new for Advanced Discout Auto or autozone.
Posted: Wed Aug 16, 2006 3:11 pm
by chrispel
Teb I'm going to be ditching the PCM once the add on board comes out so I can drive my stock gauges thats why I need the ms configured to run the bypass.
Posted: Wed Aug 16, 2006 6:16 pm
by bluetrepidation
chrispel wrote:Teb I'm going to be ditching the PCM once the add on board comes out so I can drive my stock gauges thats why I need the ms configured to run the bypass.
Follow this to setup the physical circuit:
http://megasquirt.sourceforge.net/extra ... gmdis.html
The generic port settings are easy enough to figure out. Just let it kick the output on after the engine hits 400 RPM.
A.J.
Posted: Wed Aug 16, 2006 6:19 pm
by bluetrepidation
S.Bretz wrote:Nah. The saturn knock sensor is different from the ones listed....plus the ones listed in the mega manual also need some type of signal conditioning device. All that stuff is inside the SATURN pcm, so its not like we can just use it or pull it off a certain year s-car in a yard. The conditioner that the manual shows is something I have never seen or payed notice to, so I don't know where to look for it on the cars at the yards...I'm probably just gonna buy a knock senor and conditioner new for Advanced Discout Auto or autozone.
It would be a good idea to keep using the stock knock sensor and just hook up a conditioner seeing that the stock unit has its resonance matched to the resonance of the block and crank.
A.J.
Posted: Thu Aug 17, 2006 7:05 am
by tebriel
Good point AJ. We'll have to figure something out.