I have a 2002 Dodge grand Caravan that for some reason goes into Security mode when I install the key. It will not great at all. It just makes noise and dash lights them a bit. Here's the freaky thing. when I put my diagnostic machine in its place, the car cranks. What do I need to do to get this to work correctly? Is it the key or the ECM?

 

So.....provide some background. Are you the original owner? Has this always happened? Just started out of the blue? You just bough the vehicle and this happened? You lost a key and had a new one made? We are not mind readers.

 

First of all, thank you for your reply. Let me be more descriptive as you have requested.

I am the second owner of the vehicle (dodge grand caravan, 2002). I had a small fender bender in which the vehicle was repaired. I drove the van for about two weeks before I have the cranking problem. I had starter issues before the accident and needed to change out the starter. I did so. When I tried to start the vehicle, the system would go into the security mode and would not crank the car. I tested the fuses and the ASD relay and it clicked for about 5 minutes. I then placed my diagnostic reader on the port and tried to crank it and it cranked fine. Several times it cranked with no issue. When I removed the diagnostic machine, it went back to the security mode and would not crank. I tested for ground and all was fine, I got continunity. I could not figure out the issue. This is the reason for my asking if someone thought it could be the key or the ECM? Hope this is a bit clearer? I am trying to go the least expensive route, but I am unsure how to proceed.

 

"Here's the freaky thing. when I put my diagnostic machine in its place, the car cranks"

Does that mean the car cranks and starts or just cranks?

Here's a link to someone who had a very similar problem especially in regards to the scanner letting you start the van. Turned out to be a grounding issue at the battery: https://bobistheoilguy.com/forums/ub...h_scan_tool_pl

 

The PCM is under the LEFT fender behind the headlamp. I see damaged wires all the time from this.

 

I will look into this as soon as I have a moment. Thank you again for those who eplied. It has really helped me.