chazten

i looked around some and couldnt find a definitive test to check if an ignitor chip is working. So i just dove in with logic and a multimeter. So when the car is on i touch the multi meter to any one of the four pins coming from the ecu, all four have 11.5-12v of power. Then i plugged my q45 ignitor chip into that and touched the pins coming from the chip to the coilpacks. All read .01 Im no mechanic but im going to assume this definitely means its the ignitor chip.
The only reason im hesitant to assume is because 3 weeks ago i left a light on over night and it drained my battery down. When we went to jump it off it wasnt getting spark to coilpacks and the reason was in the ecu, something had shorted, we soldered it and all was well. now It has started and ran since then until i swapped out my old nasty engine harness for a nice clean new one with q45 plugs. So either its the chip, or the soldering job on the ecu has shorted out once again. What do you guys think?

chazten

Also the the two q45 chips were found at a junkyard, so its very likely there to old/corroded/dirty to function but its weird that both arent working.

OnTheChip

The coilpack pins are switched to ground so they won't read any voltage unless plugged into the coils and the coils are powered.

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NismotronicSA - Speed-Density Tuning for Nissans

chazten

What? I think you misunderstood me, Why would I be touching the coil pack plug? I meant after checking the plug that goes in the ignitor chip I tested the pins on the other side of the ignitor chip once I plugged it in.does that make anymore sense? I need pictures I'll take some tomorrow if this isn't resolved

chazten

Like you know how both ends of the ignitor chip has spots for plugs? After testing the 4 pin plug from the ecu I plugged in the ignitor chip itself and tested the opposite end that would be plugged into the 5 pin side.

OnTheChip

Right, I understand what you're saying. On the 5 wire side, 4 go to the coil packs and the 5th goes to ground. The ECU triggers transistors that switch to ground completing the primary coil winding side circuit. Without the coil packs plugged in, you won't see any voltage on those pins.

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NismotronicSA - Speed-Density Tuning for Nissans

chazten

So then how do i test the ignitor chip itself?

OnTheChip

There is a power transistor (ignitor chip) diagnostic procedure in the S14 SR20DET FSM on pdf page 337 (EC-202).

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NismotronicSA - Speed-Density Tuning for Nissans

chazten

Do I test all the pins or is this thing like a fuse and if some current is coming through it's good to go?

OnTheChip

You should test all of the pins in order to test all of the transistors in the ignitor chip. It contains 4 power transistors that are turned on individually by the signals from the ECU to complete the individual primary coil winding circuits.

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NismotronicSA - Speed-Density Tuning for Nissans

chazten

if the circuit is only completed by ecu input how is it possible to test the resistance if the chip is not plugged into the harness? The ecu has no way to tell the chip to close the gap right? Maybe my understanding of what your saying is wrong, do you get what i'm saying?

OnTheChip

Follow the diagnostic procedure in the FSM, which is a simple continuity test.

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NismotronicSA - Speed-Density Tuning for Nissans