Terrible intermittent starting issues

[5seriesguy]

Hello all, I've got a terrible issue with my 05 645

The car sometimes doesn't start. I turn the keys and everything lights up normally, but absolutely no turning of the engine. 15-60 minutes later it starts like brand new.

ICOM gives me a power management code. Nothing else just power management.

New alternator and no change. Starter is good. Battery is new. These three components are 100% okay. Key is also brand new.

There are no retrofittings.

Idk what else it could be. I change the relay as well. I checked all connections and wiring and everything is okay. All software is up to date on the car.

I turn the key trying to get it to luckily start and eventually it works , sometimes I do it too many times and anti theft preventive manipulation kicks in and I have to realign the DME and CAS for it to work.

I've never seen anything like this.
Anyone have a similar problem?

[5seriesguy]

Update: I have an AHL code. And IHKA.

Whatever it is, it is causing engine immobilization because the DME thinks the voltage is low when it's not.

The integrated supply module, according to the wiring diagrams, has a START INHIBIT relay. Could my ISM module be bad?

[jclausen]

Ivm module

[Charles645ci]

Ivm module

I have a similar problem and I took it to the dealer and I am also replacing the IVM module. Fixed!