Have a '95 TS executive suddenly won't even crank over (checked starter motor/fuses/battery/all the usual things OK) Suspect the immobilizer is not sending code, will check wiring etc, but I've read on these forums that the factory immo won't stop the motor cranking. Does it just kill the ignition & the fuel?
It's well cared for and was running like a dream on the day it died!

lol
The TS doesn't have an immobiliser as such, ie there is no chip in the key nor is there a key reader in the ignition barrel.
In fact there was no immobiliser of any sort on the TR or the early TSs.
Later ones had a simple system - covered in a few threads on here.

If yours has an immobiliser and it has been activated (kills both crank & start) the test is real easy.
Just put the key in on ACC, wait 30 minutes, then try starting. If it now cranks and fires, you know the immobiliser is the problem.
Otherwise, look for other problems.

What you have read is probably about the third gen cars, which have a totally different immobiliser setup.

Yes, mine has no reader in the ignition barrel, so I guess I can now look elsewhere, (I've a lot of experience tracing electrical faults, so logic should prevail here) I just had no idea whether I had to eliminate the immo first. It has an aftermarket immo which gave trouble some time ago, and I jumped that out (just fuel & crankover). The car ran fine for weeks after that.
Maybe one clue is that while driving once, both indicators started flashing (about 10 secs) then stopped. I assumed the old immo (which still opens the doors & flashes the indicators) was getting senile, but I knew it couldn't disable the car.
Thanks for that, incidentally would you know - is this flashing I spoke of a possible warning something is wrong? Seems you're familiar with that model.

The immobiliser - if you have one - is easy to recognise. You will find a white plastic device on the very end of the ignition barrel with 4 thin wires coming from it.

If there isn't one, you have no immobiliser at all.

More likely to be the ignition switch itself, battery or starter motor.

Pull out the actual ignition switch - also at the end of the ignition barrel, some heavy wiring coming off that - and have a look. They can come apart or burn the inside contacts.

Have you tried to test the battery and starter by bypassing everything else? Connect a wire from battery positive to the small spade terminal on the starter, just a quick touch and see if the starter kicks into life - a longer touch should spin the motor. If not, the starter or battery are at fault.

As for your old immobiliser - sounds like it is still in the car. I'd remove it completely or at least check the wiring. They are usually spliced into the wiring from the ignition switch and there may be a bad connection there. First thing I did when I bought my 95 TS was to rip out the aftermarket immobiliser - one less source of potential problems to deal with. The splicing on the wiring was so makeshift I had to go to the wreckers to get another ignition switch.

The 30 minute Acc On worked. The car has an immo cct, but it's wired into the starting system.
Now all I need to know is why that activated. I've found all the chassis points to check, it's all in the wiring diag.
It doesn't have an immo on the ing barrel, just a "key present " switch. Maybe that's buggy!
Very grateful for that advice! Saved me hours of grovelling.
So . . . I'll keep you posted as I find out stuff.

The "wait patiently for 30 minutes" trick worked and it started?

A previous poster a long time ago had the same problem. I suggested she leave a key in the ignition switch permanently, cover it with a towel, then lock the car with a second key! lol

A quick and free workaround, anyway.

Now that you mention the "key present switch", I don't know if there is one, but I did discover by accident that the steering lock needs to make a really solid "clunk" when you pull the key out, otherwise it won't start next time. Maybe that is the problem?
All I did was lubricate the whole thing to get a reliable and solid "clunk" each time the key was pulled out. Fixed the problem but I didn't look into the presence of some sort of "key present" detection system.

OK - I found out what my 4-wired-plug does. It goes to a chip which send the number code. I got out the 'scope &
looked at the signals. There's ground, power (5V), two data lines (one is clock, the other is data). When you
turn on the ignition, on comes the power, out goes the number.
And it all looks good, but I'm still stuck with no certain reason why it stopped working on me.
I will solder out the crappy little plug altogether, (it's contacts are from one side of the pin only which
isn't that reliable), check the ECU for leaky caps, and other things this forum has suggested to me.
Will I keep you informed here? (don't wanna be a bore) but I take pictures, make notes, and am rather thorough.
I just like to bloody know.
It would make a good case study especially if I find something definite.
So, initially I was wrong, there is no key present switch, no radio link to anywhere either.
I'll keep you posted, over & out,
-= Sherlock=-

OK - I found out what my 4-wired-plug does.


If these are thin wires this is actually the immobilizer unit. If so, it doesn't send any number to the ECU, it isn't that sophisticated! It works totally differently.

(If it is the immobilizer and you have popped the ignition barrel out of the car or just taken the immobilizer section off the end of the barrel, I know exactly what the problem is, and how to fix it. But first put up a picture to let me see where you are, to make sure we are on the same page.)

http://www.aussiemagna.com/forums/showthread.php?t=84876&page=1&highlight=ts+immobiliser

Yep, it sends a code all right. I'll send you some pics of what is happening, but basically, when you start the car, 5V is applied to the chip in the ign sw barrel. It only sends a code if it is plugged in, because the load resistors are at the other end of those wires it plugs into - cunning - , (probably in the ECU). This signal is visible if I tap into the wires, & it does not come from the car wiring, it comes from the ign barrel, I've checked the direction, and that makes sense. But the signal that you've turned the key comes from the fact that accessories has been switched on. Then the ECU (probably) applies 5V to the chip through the wiring, the chip sends the code back, & it's all GO!
So, I don't specifically have an immobilizer, but the car won't start unless -
1. It has been reset (that's the "clunk" you mentioned)
2. The key is in the lock and rotated to at least the accessories position
3. The chip successfully sends its' code.
Hope these images work -
E:\IgLock.jpg
E:\CodeSend.jpg

OK - no images. How do I send the damn things? I've been trying for 10 mins, the FAQ talks about stuff I don't have on my page . . .

You need to join a image host like photobucket.com and upload them from your computer to there and insert the url you get from there in here.

Another very easy to use image site is http://imgur.com/.
Here there is no need to join if you wish to be an anonymous uploader of the images.
Do copy & save at least the "bulletin" and "delete" URL's for the uploaded images.

The service manual shows what you describe in the wiring diagrams section. The "sender" in the ignition barrel communicates with the "immobilisation control unit" when the key is inserted. The ICU doesn't communicate with the ECU, but it does interlock the signals from the ECU that drive the fuel pump relay and ignition power transistor. If the immobiliser says that the wrong key is in the barrel or the barrel doesn't send its code, then you won't be able to fire the engine or get fuel to the injectors. Also looks like it interrupts the starter relay signal too - perhaps backing up your theory that an immobiliser fault may be preventing you from turning the engine over.

If it only interlocks FROM the ECU, then it seems possible to bypass the ICU altogether by re-routing the ECU "incoming" signals to corresponding ICU "outgoing" signals?
If so that would be an easy to defeat immobiliser!

The service manual shows what you describe in the wiring diagrams section.

This is a 95 TS we are looking at - which manual are you reading?

The big old PDF. See pages 54-3D-220 to 224.

The big old PDF. See pages 54-3D-220 to 224.

lol Forgotten how hard it is to move around that PDF to find anything!

These are the pics for what I have here -
Anyway, all's good, I'm still not sure if it's just the lock not returning fully after key withdrawl, or what, but in series with the code and including the power would be about a dozen contacts, they're all going to go, if possible. I'm adding a simple diagnostic readout since i'm in amongst all that wiring, I am determined to know what is going & what is not if it ever happens again.http://i280.photobucket.com/albums/kk162/SolarEclipse/CodeSend_zpselandwww.jpghttp://
http://i280.photobucket.com/albums/kk162/SolarEclipse/IgLock_zps4knqwycm.jpg?t=1431495945http://

Can only see one, OK -
http://i280.photobucket.com/albums/kk162/SolarEclipse/CodeSend_zpselandwww.jpg

That's nothing like the ignition barrel setup I had on my 95 TS! Definitely didn't have the extra metal bit on the barrel with the 4 wires coming out of it.
Looks like a proper code reader, which means there is a chip in the key as well.

Perhaps Mitsu did some development on the immobiliser during the life of the TS model?

Wire colours (B/W, R, Y, P) downstream of the plug you have drawn align with the wiring diagrams, although the pin designations you've given them do not. Looks like you've just labelled them 4 to 1, opposite to how the manual lists them.

Manual says:

Data = pin 1 (pink)
Clock = pin 2 (yellow)
5V Supply = pin 3 (red)
Ground = pin 4 (black/white)


Your upstream wiring between the plug and barrel (G/BN, BL/W, BN, BL/B) is not detailed in the manual, but may be omitted for clarity on Mitsubishi's part.

Either way it looks a lot like it's just the factory immobiliser circuit that's listed in the manual for the 95 model.

Unless the key has an unusually large plastic "handle" with an extra metal "knob" poking out of one edge that makes contact with the ignition barrel when it is inserted (ever seen an old Holden VT Commodore key?), the key is unlikely to contain a coded chip. What's more likely is that the barrel code sender merely looks for the insertion and twisting of a normal key. If you can get the key past the first two steps without the barrel jamming, you've evidently got a legitimate key and you're probably not trying to hotwire the car, and the code sender on the barrel tells the ICU to disable itself and allows you to start the car.

OK - I'm the originator of this thread . . .
Yeah, so to make it all clear, I traced these wires from the ig lock to the immobilizer unit which is located on the REAR of the bracket which holds the ECU to the chassis, (near front passenger legs). So, after taking out the ECU, unbolt the slightly larger mounting bracket, and on the back of that is the immo unit. The wiring goes behind the body paddding, not readily visible. On its way there it goes through another plug behind the cilmate controls/radio console. Three plugs there and back. 4 wires. No ground at the other end in the ignition barrel (I checked for that). 4 x 3 = 12 contacts. Hmmmm.
Not any more there isn't.
And, now I know what my code is.
I hope this info is useful to someone, it is to me.