Powertrain codes P0700 and P1621

[robgm]

Yesterday i drove back from a camp, only about 45 minutes away. I stopped the car to drop off some people. After about 15 minutes i started it again. Check powertrain message came up, and then reduced performance message. Power felt lower for a while. I managed to drive home and power felt okay. Today i turned on again, same error but without the reduce performance message or feeling. I put the ODB2 on it, and got the following codes:
P0700: Transmission Control System, MIL request - circuit malfunction.
P1621: Control Module Long Term Memory Performance/Immobilizer Code Words Do Not Match. PCM Memory Performance; Control Module Long Term Memory Performance.

Car does start. I'm bit worried to drive it.

Any idea what is wrong here?

 

[scaredyet]

Maybe try a genuine key. I had an issue about some security and fuel cannot remember. I was also having issues starting and got check power train. I used my spare key which is genuine and thank god I have not had a problem since

 

[robgm]

Actually, the wife took my main key by accident on Friday just when i was leaving for camp weekend. So i had to use the spare key. Once i got to camp I didn’t use the car until drive back on Sunday. Now i’m using the main key, after a few start/stops, the error on dashboard has gone. Phew.

Maybe battery going flat in spare. I did change the main key battery few years ago. Does the key battery matter for immobiliser?
(Both keys are genuine, came with car)

 

[Fu Manchu]

No. When battery voltage is low, the power is supplied via the slip ring. That’s the bit around the ignition lock. The key won’t open the doors. Alarm goes off opening with the key itself. Key into the ignition. Turn. Alarm off. Car starts.