ecu wont turn on
 

my ecu refuses to turn itself on more than once a day. as in, ill wake up, start my car. drive it. turn it off. car wont turn back on for another 12+ hours. power should be good. wiring is correct (recently started acting up) and i dont know wat to do anymore.. i really need help because this poses a pretty big issue since its my DD

Why did you make a new thread??...anyway

Have you checked the Pink wire? Is it running to a good ignition source?

keep a multimeter with you.
when you wake up.
go to your microtech and check if pink and red have power. then check using continuity test wheter your brown wires are earthed correctly.

now start the car up.
drive it to were ever you normally go.
switch it off. and try to start it.
if the microtech dosnt switch on.
do the above test again and see what it tells you. if all the 3 above wires are doign what they are meant to be doing and it still dosnt switch on. microtech needs to be sent back for repairs.

Make sure all you connections are secure, and all grounds are proper. I'd go with what he^ said and use a DMM to trace the problem. Sounds to me like your aged and worn chassis wiring is on it's last legs.

Have you replaced the relay?

I'm haveing a simular problem,..
New install, LT10s in a S5 GTU w/ TII swap.

The car will turn over, but the microtech dosn't turn on.

I kept the driver's side wire harness in place, but there's no power to the coils when I turn on the ignition,
..so my pink wire isn't turning the microtech on either, since it's tapped into the Black & white going to the coil.
-There are no lights illuminated on the microtech.

(If I jumper a wire from the + battery to the where my pink wire intersects the coil wire,
The microtech will turn on & it shows a green light.)

Why arn't my coils getting power when I turn on the ignition?
Any idea's on what I did wrong?

Thanks,
-Chris

Chris, did you disconnect anything off the coils when you were doing the installation? I seem to remember there being 2 connectors under them.

Hey Ben,.

I kept the coils pluged in to the body harness.
I cut the brown & Blue Wires on the body harness that lead to the Pink & white wires on the trailing coil,
and connected the grey/white & grey/green ign output wires from the MT to them.

I left the other two yellow blue & blue green wires from the coil plug the way the were, still hooked up to the trailing coil.

For the leading coil,
I cut the Green/Yellow wire on the body harness wich leads to the Pink wire on the leading coil, and connected the grey/red ign output wire from the MT to it.
I left the other wires connected as the were.


I have the "pink Ign On" wire T-ed into the Black wire/white stripe on the body harnes, which leads to the tan wire on the trailing coil.
I did not cut the black/white wire from the body harness.

Is this right?

or should I get my switched IGN on from somewhere else?
+ I don't see why I don't have power to the coils.

firstly mate. You should make your own thread as your problem is different but since you posted here ill answer your question.

THIS IS WHAT YOU NEED TO TEST TO FIND OUT WHAT YOUR EXACT PROBLEM IS.

Disconnect your loom from your computer(lt10s).
grab a multi-meter. test for 11-12v at the RED wire. (this should be all the time).
Switch your IGN on, and test the RED wire again and it should still have power.
now check that the PINK wire has power on ignition.

Now get someone to crank the car and check that you have at least 9+V on the PINK wire AND on the RED wire.

Now put your multi-meter into continuity mode and test your brown wires to make sure they are all earthed.

THIS IS ALL THAT IS NEEDED to make a microtech power up. it has nothing to do with your coil packs.

Once your microtech starts switching on, we can then concentrate on the other reasons as to why your car isnt starting.

Check this and post back here on the results.

Thanks, I appreciate the help.
I have no power to the pink wire,
Where should I connect the pink IGN On wire to get switched 12v?

I thought it was supposed to go to the black/white wire that powers the trailing coil?..
was I wrong about that?

well thats why the computer aint powering up.
i like to be on the safe side and steer clear of factory wiring.

Off the back of the ignition barrel. IGN 1.

I ran two wires from that IGN 1 wire.

One goes to the pink wire which should only be feeding the FUEL PUMP relay and the microtech it self.
the other way coming from the barrel should go to a relay which will power the coil packs.

If you dont know how to wire up relay. i can detail that.

If your interested in finding out why your black/white wire isnt working. check your engine fuse. see if its blown.

thanks, I don't know what I was thinking with that..lol,

anyways, I found switched 12v at a black/green wire on a relay by the trailing coil, and now have the pink ign on pink wire hooked to that.
The MT powers up & shows a green light now. :icon_tup:


Now, When I turn the ignition to the On position, the Fuel Pump starts running.
I'm not cranking yet or anything,.. just in the accesory on position.
Is it supposed to to do this?

I have the fuel pump relay hooked up like this:

85- green wire
86- pink wire
87- batt via fuse
30- fuel pump

Am I still mixed up by these two pink wires?

The pink wire is split into two leads, I have one connected to the switched 12v,
and the other one connected to the fuel pump relay, wired as listed above^.
Is this correct?

Why is my fuel pump running when the car is not firing?


-Thanks for the Help!

if you leave your ignition for long enough, the fuel pump will switch off. this is very normal.
it means you did it right. GOOD STUFF!.
the fuel pump relay is hooked up correctly.

Crank it up and fire it up.

Chris, glad you got everything figured out.

And yes your fuel pump should prime for about 6-10 seconds(that I've noticed).

You can either crank right away or wait for it to finish.

Good luck and I hope I can stop by, I arrive in anchorage at 3pm. I'll give you a ring.

Can you expand on this please? I have rewired the entire vehicle harness, and am checking these threads to confirm i have not left anything out....this might be of some concern!

Cheers,
John

a relay is easy..


relay has 4 pins that mean something to you

85
86
87
30

85 and 86 are your triggers.
87 is your main power feed
30 goes to the device you are trying to feed power to.

so for example..
fuel pump.
85 goes to ignition(pink), 86 goes to your ecu fuel pump trigger(which is green on microtech)
87 goes to your battery or anywere that has 12v live power.
30 goes to your fuel pump.

Hi thanks for your reply, although you answered the wrong part! You wrote:

''the other way coming from the barrel should go to a relay which will power the coil packs.''

Could you expand on this please?

Regards
John

what i meant their. IS when you are wiring your coil packs. You get your IGN wire from IGN 1 and you feed it into the 85 or 86 pin on your relay, and then give direct power to your relay and hook your relay up to the coil pack.

So just incase ive confused you again.
this is what i am saying.



30 Goes to power on coil packs
85 goes to ignition So IGN 1 on barrel
86 goes to earth
87 goes to battery.

Make sense?

Check for loose crimps+main relay thick red wire sould be connected to hotside of starter [big bolt] with 15amp fuse.

I have the same issue as above. However I am getting 8 Volts from my red wire, eerything is wired right and it worked this morning, but ecu won't turn on now. Any ideas? Cranks fine and all electrics work

I also get 12v from my pink wire but 8 from my red

So an update, full power came back to the ecu and even though I had a charged battery a jumped started her. Guess she needed an extra kick

Mine did what yours did. You just updates the software and it kicked back on??