Someone over here suggested maybe something to do with the ignition. Maybe a wire cut on the column or something to that effect.
The keys don't hold a code do they?
They'reabit oldfor that aren't they? (being a 1998 andbeing avery basic ex militarytruck)

Hey, thanks for the response though. If you can think of anything else or can add to whats there then anything's appreciated.

Thanks again guys

Jules.

 

Jules,

Are there any other codes? That 1631 code is:"P1631 Theft Deterrent System password Incorrect-C". Itindicates an error in the passlock system, but it doesn't indicate the cause of the problem. It could be a bad ground or cut wire in the column, a bad sensor, etc. You may need someone with a Tech 2 scanner to diagnose the problem.

 

Jules,

Are there any other codes? That 1631 code is:"P1631 Theft Deterrent System password Incorrect-C". Itindicates an error in the passlock system, but it doesn't indicate the cause of the problem. It could be a bad ground or cut wire in the column, a bad sensor, etc. You may need someone with a Tech 2 scanner to diagnose the problem.

 

This might sound kinda stupid but on some Dodge systems, when the antitheft system locks out your ignition, you can lock all the doors, then use the key to unlock them, and it clears the system.

 

Right. Still having problems with the truck.

RonH , We've changed the column for another from another truck, just incase there was a cut wire or damage to the column or somethng, but still it doesn't work.

The truck did have a large dent in the side of the bed and we were wondering if it had something to do with that. i.e. engine cuts out in case of an accident.

I tried to reply the other day, but it wouldn't allow me to post a picture, so I've uploaded 2 to my webspace for you to see.
http://homepage.ntlworld.com/jbrimfield/bed%20dent.jpg

We're really lucky that it missed the bodywork (scrape to paint) but now you can see why we're wondering if it has anything to do with this.

We've tried different ECU's incase this was the cause ( same numbers on the lid so IS for that vehicle ) but to no avail.

Also, on the column we've tried removing the little plug on the ignition barrel
http://homepage.ntlworld.com/jbrimfield/plug.jpg
to see if there's any difference there.
3 wires. yellow, orange with black tracer, red with white tracer

Now, this is whats happening........

If everything is plugged in correctly, then when we switch on the ignition, the little security word comes up on the top right of the dash and stays constant. After 5 or so seconds it starts to flash. If we try to start the truck, then you can hear it fire once then nothing and the security light still flashes on the dash, and the truck just turns over without firing.

If we remove the plug on the ignition barrel, then go through theprocess again, when we switch on the ignition, the security light is on constant again for 5 or so seconds, then goes out. If we then try to start the truck, it fires for approx 1 second then the security light comes on again flashing, the truck dies and just turns over again.

We were wondering if the security hascome on due to the accident, and if so, how do we reset it?
Little button somewhere? or can we put a paperclip between terminals 1 and 8 on the scanner plug under the column or something, or is it a complicated thing?

Anymore help would be VERY much appreciated please, as being in the UK, we haven't exactly got a chevy dealer on every street corner, and even if we did, I'm sure they wouldn't have a clue on what to do. ( trust me, our chevy's over here areNOTHING like yours LOL ).

Thanks in advance,

Jules.

 

Jules,

I know you don't have a handy dealer, but I really think you need someone with tools to find your problem. There are procedures for diagnosing your problem, but they all involve a scantool or a techline terminal or other special tool.

Maybe GM can refer you to someone who can help.

 

If that column also included a different ignition switch it won't start the truck. Theignition switch has a particular resistance value that the BCM is programmed for ... if you change the switch then the control module needs to "learn" the new switch.
When you swapped columns you should swap control modules as well.


I doubt it has anythingto do with the problem.



By doing that the security systems goes into tamper mode.
You can't disable those wires since they are the signal wires for the security system .... from the ignition switch to the control module.




No button...... no jumpering terminals with a paper clip...... needs the scantool/terminal.


Cheers.

 

jules, i asked your question in some other places. so far, i had one answer: try "relearn" process. they said to insert the key in, turn theaccessories on, let the security light do what it does, and try to start the engine. if it starts and dies, just let it sit like this, without removing the key or doing anything else,for as long as it takes for the light to reflash and go away. they said it might take up to 30 minutes for ecu to relearn the situation.

also this might help:
https://chevroletforum.com/m_1839/tm.htm