97 Lumina, Randomly wont crank,

[aleekat]

Originally Posted by jeffcoslacker

Another way to defeat the Passkey is to read the resistor in the key with a meter, buy a resistor of the same value and solder it in between the two white wires going to those contacts in the ignition cylinder...fools the system and VATS will never trouble you again...

DITTO. 95 olds. Same issue. Ohmed the key, radio shack resistor(pack of 4 $1.00) Under drivers side knees. 2 small wire connector. First I just jumpered the resistor before soldering.

[wcshort]

OK, So I replaced the Neutral/park safety switch... Did not solve the problem.

To Recap: Intermittent problem, Wont crank, Silence when attempting crank.
-No viable security light indication. (Passkey)
-Replaced: Ignition Switch, Neutral/Park Safety Switch
-Checked: Starter Solenoid (12v lamp to solenoid power, lights when engine cranks, not when problem occurs, attached to small post on starter, not large)
-Tried: other set of keys, no effect

I'm all ears.

Tech II, You mentioned checking the "starter enable relay" as a possible solution, could you please explain to me how to do this?

[Tech II]

There is no SECURITY light in the dash?

I'm not sure on this vehicle, where the starter enable relay is......

[wcshort]

There is a security light in the instrument cluster. It does not flash or stay on longer than normal. If I'm correct in understanding this would mean that there is no indicated problem with the passkey system reading the resistor pellet in the key.

I have found some posts on other forums that point toward the "enable starter relay" aka "theft deterrent relay" but I'm not sure where to look or how to even test it.

[gmtech1]

I found some info on a Haynes online bulliten talking about the relay being behind right side of the dash, behind the glove box. This rings a bell for me also, it's been MANY years, but thats where I remember it being.

[wcshort]

Thank you. I think I know where to look for it. Any idea what I should do when I get there?

[gmtech1]

Not really, I don't have access to a schematic right now. I guess you could just pull it and try a match one. If I get time tomorrow I'll try and find a diagram.

[wcshort]

Thanks, That would be a great help.

[Tech II]

If the SECURITY light goes out normally, and the vehicle doesn't crank, then the starter enable relay is where you begin......this system doesn't have diagnostics to know if the relay is working or not.......could have been done easily with a feedback signal to the PassKey module, but wasn't done or thought of....

Basically, find the relay......if there is another relay with the same number, swap it and see if this takes care of the problem, like GMtech1 said.....

If that doesn't take care of it, you need a schematic, to test the control circuit, and the controlled circuit....

[gmtech1]

[gmtech1]

Hope it's not too confusing, there were two different diagrams, the theft system looks pretty much the same though.

[Tech II]

Well, the first thing to do is find the starter enable relay, or in this case, the theft deterrant relay....

Have you tried another relay?

If no, remove relay and attach a test light to terminals C2 and A1......turn key to crank.....does it light? If no, check for power on yellow wire(C2) with key in crank position.....if ok, then theft module or wire to it is problem....

If yes, install a jumper from A2 to C1......turn key to crank.....does engine crank over?

If yes, you need relay.....if no, check for power on yellow wire(A2) with key in crank position.....if ok, check circuit #6, especially terminal B3 in connector C100.....

[wcshort]

Thanks for the info. I will have to wait until the problem is repeated to check it. I may just replace the relay and see if it happens again. I will keep you guys posted.

[wcshort]

Out of curiosity, is there any way to completely disable the theft deterrent relay? Maybe a permanent jumper?

[Tech II]

Here's the problem...it's a safety feature......if you jumper it out, if for some reason you had the shifter in reverse or drive, and that key is turned to crank, LOOK OUT!!!!!!!!!!!!!!!!!!!!!!