Quick security light question

[Mr80Series]

Just wondering if anyone can provide a quick answer about the normal operation of the security light.

Am I correct to believe that with the vehicle off and the key out the light should flash every few seconds?

With the (proper) key in the security light should be completely out?

With the incorrect key the light will illuminate and stay on (not flashing)?

If attempting to start with an incorrect or non-programmed key the engine will not fire but will crank?

Just trying to sort out a custom vehicle with a 2UZ from a 2004 UZJ100 and any help would be appreciated. I believe I have coded the key correctly but the vehicle will only stat for about 3 seconds and then shuts off. I want to verify that the security system is the issue.

 

[96crooser]

I don't think it would start at all if the key wasn't programmed correctly and the flashing light would continue to blink it would cank and not start. But there maybe something I don't know about.

 

[Mr80Series]

Thanks, I'm in the same boat. I've never driven a hundy that was complete so not 100% sure how this system operates. Hoping someone on this forum has a bit of experience or could have a quick peek at theirs to see what normal operation is.

 

[bigredmachine]

Just wondering if anyone can provide a quick answer about the normal operation of the security light.

Am I correct to believe that with the vehicle off and the key out the light should flash every few seconds?

With the (proper) key in the security light should be completely out?

With the incorrect key the light will illuminate and stay on (not flashing)?

If attempting to start with an incorrect or non-programmed key the engine will not fire but will crank?

Just trying to sort out a custom vehicle with a 2UZ from a 2004 UZJ100 and any help would be appreciated. I believe I have coded the key correctly but the vehicle will only stat for about 3 seconds and then shuts off. I want to verify that the security system is the issue.

correct with the key out light will flash every few seconds

correct with a programed key the light will go out and the truck will be able to start

with an non-programed key I don't remember off hand if the light will stay light or will continue to flash, but it will not go out and stay out similar to if the key was programmed

if you try to start with a non-programed key the truck will crank but wont start.

double check that you have the correct key, and see what the security light does when you insert the key that you have. did the truck come with only one key or was this a second key that you had cut and programed

 

[Mr80Series]

correct with the key out light will flash every few seconds

correct with a programed key the light will go out and the truck will be able to start

with an non-programed key I don't remember off hand if the light will stay light or will continue to flash, but it will not go out and stay out similar to if the key was programmed

if you try to start with a non-programed key the truck will crank but wont start.

double check that you have the correct key, and see what the security light does when you insert the key that you have. did the truck come with only one key or was this a second key that you had cut and programed

Thanks Bigredmachine. This thing has been a bit of a headache. The engine, PCM and immob parts are all from the same vehicle. I wasn't sure about the key so I sent it to a programmer and had everything coded to match. Now it will start for about 3 seconds and then shuts off. Trying to find definitive answers on the immob systems to see if this is still the issue. Will build an led light circuit shortly to verify that the security is in fact turning off and accepting the key.

 

[costalcat]

@bigredmachine is correct but even if you sent the key off you have to program it to the ECU. If you don't it will just try to turn over and then die. The ECU can only hold so many keys so using the manual method of programming it to the ECU will not work in that case. I had the issue with a key I sent off. In the end I had a mobile key guy come by the house he cleared the ECU and then reprogrammed my 2 existing keys and then the third key I had just ordered. He also cut me a non fob key that is not programmed so I can only open the door with it. Oh and just because it acts like a master , light goes off, does not mean it will allow programming. Sometimes the cloned master will not work for programming a new key manually. You have to have a real master key to enter the ECU program mode

 

[Mr80Series]

@bigredmachine is correct but even if you sent the key off you have to program it to the ECU. If you don't it will just try to turn over and then die. The ECU can only hold so many keys so using the manual method of programming it to the ECU will not work in that case. I had the issue with a key I sent off. In the end I had a mobile key guy come by the house he cleared the ECU and then reprogrammed my 2 existing keys and then the third key I had just ordered. He also cut me a non fob key that is not programmed so I can only open the door with it. Oh and just because it acts like a master , light goes off, does not mean it will allow programming. Sometimes the cloned master will not work for programming a new key manually. You have to have a real master key to enter the ECU program mode

Thanks Coastalcat. I should have clarified. I sent the PCM away to have the key memory cleared and everything coded appropriately. Should have been starting fresh. There was a program that I was requested to follow, which I did, and the vehicle does start but only for a few seconds and then shuts down. My goal with this post is to verify what the immob light indicates in different patters so that I can continue my diagnosis. It looks like I may be beyond the immob since I do have an engine that cranks and starts with the key, just need to figure out why she shuts off now. I'll also add that this is a completely custom vehicle so lot's of areas for issues to pop up.

 

[costalcat]

Ah copy that . Good luck !!