BlownCorona Posted May 17, 2016 Author Share Posted May 17, 2016 That's entirely possible, I'll check when I get home. But if that was the case, shouldn't the pump turn on after its prime pulse, when the pump should be switched off? Quote Link to comment Share on other sites More sharing options...
BlownCorona Posted May 17, 2016 Author Share Posted May 17, 2016 I think the turning on when the key is off, is because I have the signal positive wired straight to the battery and the MS diagrams show it on 12v switched, so that's an easy fix. But I don't know why it doesn't want to earth properly when actualy turned on Quote Link to comment Share on other sites More sharing options...
downtrail Posted May 18, 2016 Share Posted May 18, 2016 Check transistor data sheet theres 2 versions of the pn2222a they have the collector and emitor backwards. But yes wire the relay coil to a ignition 12v or itll back feed through when key off and run ecu Quote Link to comment Share on other sites More sharing options...
BlownCorona Posted May 18, 2016 Author Share Posted May 18, 2016 Great info as always, will check that out Quote Link to comment Share on other sites More sharing options...
BlownCorona Posted May 18, 2016 Author Share Posted May 18, 2016 im looking at the transistors, the internet tells me Q3 is for the fuel pump? its a PN2222A-C36 but i cant really find any info on what way around it should be. also alot of sources online refer to it as a 2N2222A, same thing? all the small transistors on my board are the same unit. Edit- assembly instructions state PN2222A so thats all good Quote Link to comment Share on other sites More sharing options...
BlownCorona Posted May 19, 2016 Author Share Posted May 19, 2016 Hmm so on closer inspection, the ecu seems to work exactly as it should. Earthing the pin for a few seconds to prime, lining up with what the laptop displays. And the relay/ pump works as it should when earthing the relay manually, I've also switched the signal wire to 12v switched so no more running with key off. But when I join the relay earth to the ecu, it doesn't work as you'd expect and I don't know why this is. The laptop still displays a pump prime. But it doesn't happen Quote Link to comment Share on other sites More sharing options...
Ned Posted May 19, 2016 Share Posted May 19, 2016 Got the pump on the wrong contacts of the relay? Should be on the normally open pins Quote Link to comment Share on other sites More sharing options...
BlownCorona Posted May 19, 2016 Author Share Posted May 19, 2016 Yup relay system works. Pump turns on when signal line is grounded Quote Link to comment Share on other sites More sharing options...
Ned Posted May 19, 2016 Share Posted May 19, 2016 So everything appears to work until you plug the relay into the ECU? Can you turn the car off, and read the voltage on the ECU pin? Should be ~batt voltage. Then keep measuring while turning the car on so it primes and see what it says? Maybe increase the priming pulse to 5sec or so so the multimeter has time to settle. It should read basically 0. If it doesnt, then maybe the output driver is broken and needs replacing? Quote Link to comment Share on other sites More sharing options...
BlownCorona Posted May 19, 2016 Author Share Posted May 19, 2016 No voltage with car off. 1v during priming pulse then back to nothing Quote Link to comment Share on other sites More sharing options...
Ned Posted May 19, 2016 Share Posted May 19, 2016 Ah, yeah, that makes sense with it connected to switched 12v. Should be fine then... Maybe measure the 12V side of the relay? Should be fine if it works when you short the micro pin to ground though, so im out... Quote Link to comment Share on other sites More sharing options...
downtrail Posted May 20, 2016 Share Posted May 20, 2016 Hmmmmm replace q3 may have fried it trying to back feed ecu through it when you had relay wired to battery. Also check d7 is in the correct way may also need replacing but id start with the transistor. Quote Link to comment Share on other sites More sharing options...
h4nd Posted May 20, 2016 Share Posted May 20, 2016 Pic / cct diagram please. We can check for things like: current limiting resistors, and does the relay have a catch diode for its turn-off spike. (disclaimer, I screwed up exactly those things on a simple cct recently) Quote Link to comment Share on other sites More sharing options...
BlownCorona Posted May 20, 2016 Author Share Posted May 20, 2016 whats a cct? and i will get pics and check/replace items advised Quote Link to comment Share on other sites More sharing options...
BlownCorona Posted May 20, 2016 Author Share Posted May 20, 2016 D7 is in the correct orientation. just discovered my soldering iron is dead will have to wait till either work on monday, or till i can get a new one to replace Q3. hopefully its just that jaycar dont list a PN2222A. but they do list a 2N2222A. is this interchangeable? ive seen plenty of mention of the 2N variant on forums and a direct quote from the assembly manual; Note: Digi-Key parts kits use the ZTX450 as a drop-in replacement for the 2N2222A originally specified. i understand about checking all the pinouts etc Quote Link to comment Share on other sites More sharing options...
h4nd Posted May 21, 2016 Share Posted May 21, 2016 Sorry. Cct as abbreviation for circuit. As in circuit diagram Quote Link to comment Share on other sites More sharing options...
downtrail Posted May 21, 2016 Share Posted May 21, 2016 Will be fine just check data sheet for orientation it may be those 2 that are opposites D7 is in the correct orientation. just discovered my soldering iron is dead will have to wait till either work on monday, or till i can get a new one to replace Q3. hopefully its just that jaycar dont list a PN2222A. but they do list a 2N2222A. is this interchangeable? ive seen plenty of mention of the 2N variant on forums and a direct quote from the assembly manual; Note: Digi-Key parts kits use the ZTX450 as a drop-in replacement for the 2N2222A originally specified. i understand about checking all the pinouts etc Quote Link to comment Share on other sites More sharing options...
BlownCorona Posted May 21, 2016 Author Share Posted May 21, 2016 Will do. And I actually can't find a full circuit diagram, I guess it may be intellectual properly and not available but I'm not sure. Holiding it up to the light as far as I can see its only a diode and transistor after the cpu pin Quote Link to comment Share on other sites More sharing options...
downtrail Posted May 21, 2016 Share Posted May 21, 2016 Thats about it think theses a resistor these somewhere also. But very basic not alot to fail. Quote Link to comment Share on other sites More sharing options...
BlownCorona Posted May 21, 2016 Author Share Posted May 21, 2016 replaced Q3 and now it works perfectly. must have fried it Quote Link to comment Share on other sites More sharing options...
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