Ecu not receiving power signal... possiable fried #62 ecu? - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

teamsprock · 02-12-2010, 09:57 AM

I have spent the last few days searching online and working with a multimeter in the car trying to diagnose my issue, so if I missed something searching, please help direct me there and sorry for starting a new thread.

Quick background: had car running fine last year, spent the last few months working on car, new intake manifold, painted interior, and relocated lower engine harness (the one with the two black fuse boxes in the enigne bay) into the cabin. Now car won't start.

Car Specs: 89 240sx, redtop SR, #62 mines flashed ecu

Good: Fuel pump primes, all lights work, car turns over, 12v power to coilpacks.

Bad: No power going to ecu (see explanation below), when the key is turned on the ecu led blinks once then stays off, no spark signal sent (assume because ecu has no power), haven't check yet to see if injectors are firing.

Since my ecu light doesn't stay on does that mean it's done for? I read that on another forum, but to much bad info in the thread to be 100% sure.

If I check for voltage on pin 38 or 47 ("ecu power") on the ecu clip I get nothing. I assume that being the "ecu power" I should get a 12v signal?

More info: I used the clip circled in red to send a 12v signal one at a time between those 3 power sources to identify which one did what if anything. When I give power to the main ignition power the ecu led flashes once and AFC turns on. If I give power to the backup power, nothing happens (what I would expect). If I give power to the ecu power, the AFC kicks on but I don't get any thing happening with the led light.

Thanks for the help.

02-12-2010, 09:57 AM	#1
teamsprock Zilvia Addict Join Date: Sep 2006 Location: Billings Age: 42 Posts: 636 Trader Rating: (8) Feedback Score: 8 reviews	Ecu not receiving power signal... possiable fried #62 ecu? I have spent the last few days searching online and working with a multimeter in the car trying to diagnose my issue, so if I missed something searching, please help direct me there and sorry for starting a new thread. Quick background: had car running fine last year, spent the last few months working on car, new intake manifold, painted interior, and relocated lower engine harness (the one with the two black fuse boxes in the enigne bay) into the cabin. Now car won't start. Car Specs: 89 240sx, redtop SR, #62 mines flashed ecu Good: Fuel pump primes, all lights work, car turns over, 12v power to coilpacks. Bad: No power going to ecu (see explanation below), when the key is turned on the ecu led blinks once then stays off, no spark signal sent (assume because ecu has no power), haven't check yet to see if injectors are firing. Since my ecu light doesn't stay on does that mean it's done for? I read that on another forum, but to much bad info in the thread to be 100% sure. If I check for voltage on pin 38 or 47 ("ecu power") on the ecu clip I get nothing. I assume that being the "ecu power" I should get a 12v signal? More info: I used the clip circled in red to send a 12v signal one at a time between those 3 power sources to identify which one did what if anything. When I give power to the main ignition power the ecu led flashes once and AFC turns on. If I give power to the backup power, nothing happens (what I would expect). If I give power to the ecu power, the AFC kicks on but I don't get any thing happening with the led light. Thanks for the help.