4g15 to 4g93 electrical

Aaronjn.18

Aaronjn.18

New Member
Ok hi all. I am chasing some advice as i have an electrical priblem that is doing my head in. Have a little old 96 mirage for the missus with 4g15 engine was getting tired and picked up a 1.8 lancer cheap. Swapped motor, loom, box, ecu didnt realise they had immobilizer so went and got a matching set from wreckers everything should be good but.
I have no power to crank sensor or fuel pump and less important no power to horn and constant power to wipers with ignition on. I know it runs as i have had it running by hard wiring pump and crank sensor. I am thinking ecu and immobilizer may be my problem but not sure and dont have another 120 to throw at wreckers. Something ive missed maybe? Any thoughts or ideas would be appreciated.
 
This has been covered dozens of times before;
The imob cuts fuel injection. If you have a Check Engine Light that stays on the cluster for more than about 10 seconds, then its an imob issue. The key must match the imob; the ECU only needs to be from a manual (or auto) 1.8, as long as the ecu matches the original engine/gbox type.

No power to the crank sensor sounds like a different issue, or an issue that is causing no starting, maybe not the imob.
 
Iknow ive read all the other threads i could find thats where my trouble shooting started and i found out about the immobilizer issues. Ok so i should be good with original key and immo from mirage with lancer ecu i have a matching set anyway any ideas why no power to crank sensor. I thought its power came from ecu and no crank sensor equals no spark or injectors. I have no check engime light till i hard wire crank sensor then it just stays on. Have checked all fuses and relays all seem fine im drawimg a blank it should work
 
Aaronjn.18 said:
Iknow ive read all the other threads i could find thats where my trouble shooting started and i found out about the immobilizer issues. Ok so i should be good with original key and immo from mirage with lancer ecu i have a matching set anyway any ideas
Click to expand...
Correct, as long as the key and imob match.

Aaronjn.18 said:
why no power to crank sensor. I thought its power came from ecu and no crank sensor equals no spark or injectors. I have no check engime light till i hard wire crank sensor then it just stays on. Have checked all fuses and relays all seem fine im drawimg a blank it should work
Click to expand...
Good question. I'd presume a break in the wiring or a faulty sensor, a couple guys on here have had issues where the crank wire gets worn through and the engine no longer works. You'll need to confirm the exact code/flashes the CEL brings up, and then we'd be able to help a bit more.
 
Ill try again on the cel tommorow havenr been able to pull any codes yet. My cheapo obd wont read on this car giessing its too old? Crank sensor itself should be fime as it runs when hard wired? In conjuction with fuel pump it ran perfect ill give the cel another crack tommorow with crank hard wired.... havent tried that yet.
 
I don't know how you can hardwire a sensor in place when its generally power, signal and a ground reference point, but anyway:

Its the obd2 standard plug which is why ebay readers will fit, the date being sent to the plug is Mitsubishi's own encoding so not everything is visible.

Short out pins 1 and 4, and the CEL will flash any error codes. It'll start with slow flashes, which are groups of 10 (e.g three slow flashes mean 30), and then fast flashes (single units, so four quick flashes is 4, so it'd be error code 34).
 
So just got home and tried the cel again.
By hardwired all i mean is i run power direct from battery to power on the crank sensor wiring.
As for cel nothing without hardwire on crank sensor and with the hard wire i got 5 sec solid then constant quick flashes. Counted to 50 before i gave up and disconnected and reconnected everything and tried again to be sure.
 
power to crank sensor is on a 20amp fused circuit and controled by the engine control relay.
check it. it is fuse 11 in the engine bay fusebox. multimeter at the fuse. so you know whether there is voltage received at the fuse.
on the left side of the head unit tucked on the bracket are two relays. one is fuel pump. one is engine control.
engine control relay switches power to crank sensor, injectors, idle motor, cam sensor, map sensor.
No power to this is a bigger problem.
Maybe you fudged the wiring during the swap. Maybe forgot to plug in some important plugs. Maybe the engine harness to the body harness has a bad connection or not positively plugged in.

There is absolutely no reason to throw parts at it. just troubleshoot it.
 
Also i dont think i mentioned no check engine light at all without hardwiring the crank sensor and it is on solid when i do hardwire it. Dunno if that helps for any ideas lol this has done my head in
 
Ive had clowns wire up brake light power circuit. It had a blown fused. I tore out a bucket of wiring and replaced the fuse.
Anyway read my reply above.
Rip out the bullshit hard wiring of the sensor. Check the circuit properly. If you have voltage at the fuse means go to the relay and check. ECU will switch the relay to provide power to all the things i mentioned.
Relays do fail.
 
And i have been looking for those relays hens they are not where they should be and i didnt remove them off either car and traced wires for both as far as i could and lost them both in the fuse boxes so assumed they were in there. It probably is something simple but i cant find it ill look some more and see if i can find them relays for sure.
 
if its not bolted down on the bracket means it wiring is hanging down around there. it is part of the engines harness.
If you did the swap and did it as factory there is not one reason why the relay should be disconnected let alone unclipped from its bracket.
Most swapped cars i come across are butchered. Nothing looks factory. All clips broken for no reason.
 
I have two loose loom olugs down there but they run down to where the srs ecu would be. Didnt think this would have any effect so didnt bother getting one as neither car had it is there maybe something different in the dash loom from 96 mirage to 00 lancer but i have no loose plugs anywhere i cam find and they all seem to fit only one place. As for the no horn constant power to wipers etc in conjuction with the bigger issues i was hoping there was just a plug wrong but i cant bloody find it
 
Well i feel like an idiot haha found where those relays are meant to be and went and grabbed them off the 4g15 loom still nothing. I tested relays with power and both clicked and car runs perfect shorting the plugs with paper clip. Both plugs have 12v to bottom pins with ignition on. Quoted 150 bucks for new relays from bursons so wanna check anything else before i spend that sort of money as im pretty sure they are fine.
 
Aaronjn.18 said:
Well i feel like an idiot haha found where those relays are meant to be and went and grabbed them off the 4g15 loom still nothing. I tested relays with power and both clicked and car runs perfect shorting the plugs with paper clip. Both plugs have 12v to bottom pins with ignition on. Quoted 150 bucks for new relays from bursons so wanna check anything else before i spend that sort of money as im pretty sure they are fine.
Click to expand...
got it running yet?
 
You must log in or register to reply here.
Back
Top