Passlock SL2 V2 flashing 5 times when tring to program. Truck starts then dies. Security light flashing.

Question

Hi all,
I have a 1998 Chevrolet k1500 with a EvoStart E400 and Passlock SL2 V2.
The remote start was working fine for years (installed in 2016) and after sitting for a long time without a battery it is not working anymore.

Using the remote, the truck starts but dies almost instantly, with the "security" light flashing in the cluster.

Truck starts fine with the key, "security" light turns off, no issue.

I looked at the wiring diagram, the current wiring match the PASSLOCK1 schema.
I tried to reprogram the Passlock SL2 multiple times, but everytime the LED flashes 5 times.

Any idea?

Thank you