ECU no power... No start

ECU no power... No start
Topic Started: Jun 7 2010, 04:08 PM (161 Views)
mo_hish	Jun 7 2010, 04:08 PM Post #1
Posts: 637 Group: Members Member #154 Joined: August 8, 2009 Location: Upper Darby, PA My Ride: VGT S13.5	Drove the car this morning to the store, parked it... 5 min later came out and the car wouldn't start. Popped the hood, and found the fuse box cover off, and the ignition coil ground was off. Put the cover and ground back on and wouldn't start. What I know: CEL won't come on No spark Fuel pump wont prime Relays and fuses are good ECU only getting 1.4v at power pins (pins 47 & 38.) When I jumper 3&5 at the EGI relay, the CEL comes on and the ECU gets power (full 12v at power pins) but wont start When EGI is jumpered, fuel pump will prime when I unplug the distributor No spark with or w/o EGI relay jumpered Pin 36 (Ignition) gets 12v with key in on position Pin 34 (Start signal) gets 10v while cranking SAFC still turns on Opened the ECU and everything looks/smells fine I'm lost. I'm assuming it's a wiring problem and I'm considering getting another harness, but I don't want to get one if it's not even going to help...



mo_hish	Jun 9 2010, 05:37 PM Post #2
Posts: 637 Group: Members Member #154 Joined: August 8, 2009 Location: Upper Darby, PA My Ride: VGT S13.5	Anyone?



mo_hish	Jun 10 2010, 09:18 PM Post #3
Posts: 637 Group: Members Member #154 Joined: August 8, 2009 Location: Upper Darby, PA My Ride: VGT S13.5	Ok, so I backprobed some stuff and found a few questionables. I backprobed the EGI relay, and all 3 wires are getting 12v (with the key on) except for the black/white (power to the ECU?) wire. I'm guessing thats why when we jump the 3 & 5 pins, the ECU gets power. I'm actually pretty sure I get spark with them jumped... It's kind of hard to see, but its there. Also, I backprobed the ECU checking continuity with ground to see if there was a bare wire touching the chassis or something like that. All the ECU and various sensor grounds that go into the ECU are fine. The ones I'm not sure about are: Pin 113 (SB) - AAC Solenoid Pin 45 (G/Y) - Ambient Switch > G > B > FICD Pin 24 (R) - Check Engine Light (MIL) Pin 36 (B/R) - Ignition Switch I had my multimeter set to beep if it was a continuous circuit (1 lead on ground, and checking the pins with the other lead)... with these, it didnt beep, but would sound like static, then if I turned the key to the 'on' position, it would immediately go away. I checked the voltage with the key 'on' and all seemed fine.



1 user reading this topic (1 Guest and 0 Anonymous)


« Previous Topic · KA · Next Topic »