Ignition - Page 2

jeffcoslacker · #16 06-14-2005, 11:12 PM

If you unplug the sensor, and probe the wiring harness with a test light, you should get a light on one of the wires when someone cranks the motor. That will be your supply, so the other should be your signal. Once you know which is signal, follow it to the IM, and probe that wire as the motor is cranked with the sensor plugged in, and see if you get a variable signal at the IM.

If you have no power supply to the CPS, you'll have to work back from there and see why. Seems like I read where somebody had a problem like that, and rather than find the problem, they just ran a 12v wire fused to the ignition power at the fusebox, and the car ran.

Take a look at your wiring to the ECM, make sure you don't have something fused or melted.

orkan · #17 06-14-2005, 11:31 PM

Why it would give 12V only if crank the motor? Why it will not give 12V if just ignition would be on?
If someone cranks the motor - the signal wire shoulg give impulses... but should power be present all the time?
I can check resistance -> there is coil. I don't get at all how it works...
+12V-----3__ground
+Sig ___3
3 - is coil =)
So signal is basically the same 12V, but since crank is rotating, it will decrease 12V to 0 at some point because of moving magnetic field. Am I correct?
So if so - there should be no difference where to plug +12V, cause other wire will always become signal wire? Or there is some chip in the sensor, that needs power?
I will do testing tomorrow... and we'll see what result it'll bring...
Thanx for help!
Serg.

jeffcoslacker · #18 06-14-2005, 11:41 PM

Quote:

Originally Posted by orkan

Why it would give 12V only if crank the motor? Why it will not give 12V if just ignition would be on?
If someone cranks the motor - the signal wire shoulg give impulses... but should power be present all the time?
I can check resistance -> there is coil. I don't get at all how it works...
+12V-----3__ground
+Sig ___3
3 - is coil =)
So signal is basically the same 12V, but since crank is rotating, it will decrease 12V to 0 at some point because of moving magnetic field. Am I correct?
So if so - there should be no difference where to plug +12V, cause other wire will always become signal wire? Or there is some chip in the sensor, that needs power?
I will do testing tomorrow... and we'll see what result it'll bring...
Thanx for help!
Serg.

It may be 12v all the time with the ignition on, but just to be sure, I suggested cranking, as it HAS to be on then.

Here is what I am wondering. Do both wires go back to the IM?

I'm wondering if the IM sends power through the sensor, and reads the change in resistance, or if the sensor actually produces a voltage signal of it's own. It seems if you only have two wires, that might be the way it works.

I'm getting tired too. Not thinking clearly. I'll think about it some more, hopefully someone who really knows the theory will jump in. I can always figure it out when it's right in front of me, but sometimes it's hard to think through it when you can't see it.

orkan · #19 06-14-2005, 11:51 PM

Sensor has 2 wires, that goes to IM.
One wire is +12V, other one is +Signal.
IM has 3 pins on connector, but it's ok, since IM-side sensor connector has 3 pins also. midle pin is grounded inside the module, and also inside the sensor. It matches specs.
In the repair manual there was a direction to give +12V to the sensor and then crank the motor, measuring voltage on signal wire. Sensor does not change resistance, but changes voltage. if the module does not output +12V to the sensor. How come, if it's new... Even if so - why it sometimes works and sometimes not?
Anyways, need to check =)
I've checked manual, and it tells that if the computer is faulty - car would still run, because all systems will go to "back-up" mode, functioning with basic setup. So computer cannot be the problem here, I suppose...
Anyways... I'll test more tomorrow in the morning. And let you know.
thanx for help!
Serg.

orkan · #20 06-16-2005, 02:26 PM

Check it out...
Yesterday.. I've disconnected the wire that connects ICM and sensor, and connected back. And engine started, worked nicely...
Until I was driving back home, and run over the bump. Engine stopped that very moment. I supposed just wiring on crank sensor, cause I have bad connector there.
I waited engine to cool, detached crank sensor wire, and plugged back in. and engine started. =)
I drove to repair area (we have special area in community for repairs) it was ok..
So I disconnected sensor, and replaced it with old one.
Started again nicely, but worked only one minute, and stopped and never started again, even if I unplug and plug wires back in.
BTW, auto parts stores do not have this wire or connector =(
So, I've replaced sensor with new one, plugged everything back in, but still no luck: engine doesn't start.
Checked all coils, power to ICM, etc - everything OK.
So now I can suppose - the reason is the wires, that goes around crank sensor, may be somewhere in there sonnectors loose also, and that makes engine to stop, and start back again when I move them?
So my question: where do those wires go? =)) Can it be connected with ignition somehow?
I'll go now and check them... but it's so hard to do anything, without jack stands... to little space to crawl deep under the car..
Anyways... =) I'll be back soon.
If you have any ideas - let me know
THANX!!!

jeffcoslacker · #21 06-16-2005, 07:36 PM

Drive the car up on a block of wood or something so you have more room. Have somebody crank the motor while you move the wiring around, and see if it starts suddenly.

If the problem seems to be in the connector, go cut one off a car at the junkyard. Or your neighbor's car

orkan · #22 06-16-2005, 07:40 PM

Just above the crank sensor I can see some connector, and it's not good connected.
There is just one blue wire, and the thing under that connector is round... but connector seems to be flat.
I'm confused. What is that thing? And there should be one wire? Or I have senond somewhere?
I just took an image of this strange thing....
If this will help:

Wire that goes from there is blue =)
What is that?
thanx.

orkan · #23 06-16-2005, 08:28 PM

Also... I'm not able to unplug it... =(
At least I'm afraid to break something... Should I try harder? =)

jeffcoslacker · #24 06-16-2005, 09:48 PM

Looks like an oil pressure sensor. It goes into the motor, right?

orkan · #25 06-16-2005, 10:10 PM

Well, crank sensor is lower than this thing... so it goes in the engine.
Ok.. then this sensor is OK, cause I see oil pressure lamp, on dash, and when I try to start the motor, it disapears (pressure is up when starter working..)
Damn... it should be some small wiring problem....

cadgear · #26 06-16-2005, 10:45 PM

Looks more like the KS than an oil sensor, iirc the oil pressure sensor is a two-wire sensor as well. Either way it wouldn't have the effect you describe on the engine.

orkan · #27 06-18-2005, 02:33 PM

Hm... check this out...
Yesterday I was absolutely sure that I found the problem - in fuse (!!!) But it was not just blown fuse... DIS 10A fuse was replaced with 20A fuse, and to that socket (where fuse should be inserted) cooling fan +12V wire was inserted. But it made bad contact, and with time melt the fuse and the socket due to heating. I removed that wire, cleaned socket contacts, installed fuse - and engine started. Put old module and sensor - and still engine starts and runs ok...
But...
Today Already 2 times engine just stopped in the middle of the road. But I was lucky enough to start it again immediately. Both times was when I was not pushing Accelerator pedal, in fact, when I just removed foot from accelerator...
Any ideas? =(

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