Code U1000, Security light stays on when I try to crank the engine?

DESHANIA BUNCH

MEMBER
2005 NISSAN MAXIMA
6 CYL
2WD
AUTOMATIC
178,600 MILES

Okay, so, I stopped at a store left my car running when I came out the car was off, I had to get it towed. Now my security light stays on when I try to crank my car. I had a mechanic to come look the code that popped up was U1000 then it said can communicate circuit changed the BCM and the ECM still the red light pulled off the cover under the dash and seen that the car has had an ignition replacement at some point in time. Also, a red and blue wire that have been cut and put back together, but the red light still is on, and the cooling fan is still running while trying to crank or when the car is turned to the on position.

Monday, August 29th, 2022 AT 8:57 PM

1 Reply

KEN L

MASTER CERTIFIED MECHANIC
54,137 POSTS

Okay, we need to run a CAN scan which is easy to do. This will go over the entire car to see what codes it finds; it sounds like the BCM is not programmed correctly. Also, it could be a faulty IPDM which is common. You can get a CAN scanner from Amazon for about $30.00.

Here is a video to show you how:

https://youtu.be/u-4syLc-ifQ

Here is a scanner link:

https://amzn.to/3o41KcZ

You can try a hard reboot which is done by removing the negative side of the battery, with the cable loose from the negative side of the battery, hold it to the positive terminal for 1 minute this will discharge the memory capacitors in the BCM and PCM allowing the system to reboot. Here is how to replace the IPDM just in case you need it. Check out the diagrams (below). Please let us know what you find. We are interested to see what it is.

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