Bought a '02 SC430 project car for my son and I with no keys and a blown engine. Just finished replacing the engine and sent my ECU to Sewell and had it flashed and bought one master key from them. Installed in car and cannot get security light to stop flashing with new key installed. Spent the last week reading the posts on here. The only thing I can find is a couple references that say I need three master keys not just one after a flash of the ECU in order for the reflashed ECU to complete it's programming and recognize the keys.
1. Has anyone else been in the same situation?
2. Do I need three master keys after the flash?

Thanks.