Pug 307 2.0 HSI - Fault Code P1621- and error lights -Please Help - gaffer1974


I have a 307 02 plate 2.0 HSI.

Last Sunday my alarm went crazy and went off and i could not de activate it. After 10 minutes ti stopped but then the car would not even turn over, Check the battery and it was low / dead ! Jumped started the car, but then lost all central locking on the key so could not re arm.

After that I got the Anti Pollution alert pop. That alert comes and goes so does ESR/ADS, brake faulire ! the engine light comes on sometimes with the anti pollution alert, but its not all the time

The car has trouble starting in the morning and evenings when its not been used much, so im guessing battery ?
The fault code we got was P1621. (
P1621 Control module Long term memory performance / Immobiliser code words Not matched) what does that mean ??

Can anyone tell me if im guessing right and the battery has not enough power hence all the warnings are coming up?

your help is greatly appreciated

Pug 307 2.0 HSI - Fault Code P1621- and error lights -Please Help - Railroad.

Well to replace the battery would be a good place to start. Electronic control units do need a stable battery voltage otherwise all sorts of strange occurances can happen. In extreme cases ECUs can become damaged by voltage spikes produced by the car's charging system if the battery is unstable. As a matter of priority I would have your battery checked and replaced if unserviceble. Also I would check to make sure you have a good connection between the engine block, chassis and battery negative, also known as the engine earth. A fault here will also give very strange symptoms.....


Value my car