E90 - Unable to communicate with multiple modules ISTA

[husaindindar]

Hi Everyone.

So I'm having issues with my E90 320d.

I have a loss of low down boost. Aircon seems to not work on drivers side (blows normal air). Other than that everything works just fine.
Car starts and everything else works just fine.

When I connect to Ista, I cannot get communication to multiple modules. I've checked Relay 30G, and it seems to be fine.





Anyone have an idea on what to look out for?
Could the EKPS module be causing some comms issues?



Thanks!

 

[husaindindar]

Hi guys.

Does anyone know why the EGS, FRM and KOMBI modules show as grey?

 

[Solo Man]

I know that the E90's have a problem with the FRM module. It causes certain things to fail when it is faulty but low boost i have not heard of. Iirc., the windows will not work, i think the cluster shows some lights to light up and i think the speedo will not work. Not sure though as it was not my car but a friends. I removed the FRM and sent it to Gert at OBDWorx in Benoni for repairs. Was R1500 at the time to fix it.

 

[husaindindar]

I know that the E90's have a problem with the FRM module. It causes certain things to fail when it is faulty but low boost i have not heard of. Iirc., the windows will not work, i think the cluster shows some lights to light up and i think the speedo will not work. Not sure though as it was not my car but a friends. I removed the FRM and sent it to Gert at OBDWorx in Benoni for repairs. Was R1500 at the time to fix it.

I was thinking FRM, but all my electrics work just fine. Also suspected alternator or battery, but that also tested fine. I suspect EKP module as it's the only one on the PT CAN line that's not responding. The one thing that's also common is JBE.

Really stumped on this one!!!

 

[Solo Man]

When you test the alternator you should keep the mulimeter on for about two or three minutes. On my ex 120d the alternator would show 14,2 volts but after a short while it would dip to 9 volts and immediately go back to 14,2 V. Iirc., the voltage regulator or rectifier or something to that effect was faulty. i replaced the alternator (a Valeo) with an aftermarket one and the car never had any problems afterwards.