L322 TD6 towing caravan

[sandrotag]

We are just back from a 3 months trip up north towing a 23ft caravan.
All went well until on the way back close to home after we hitched we got the message AIR SUSPENSION INACT followed later on by SELF LEVEL INACT.
We got home ok, and yesterday our trusted specialist cleared the message and all is ok now. The fault was.. Too much energy required....
Is there a certain procedure to follow when connecting the van?
We usually hitch up the van and when the electric is connected, turn the ignition key to on, the car levels (rear up and front down) then turn the engine on and go.
When plugged in and key on the message ck trailer lights appears and goes after we do that, the rear parking sensors stop working, the suspension lock light turns on and while travelling the car seems to hold gears a bit longer.
I wonder of I should start the engine immediately to give more power to the compressor?
When the fault happend the van was flat and the car was on an a rear uphill slope when we hitched.
The van is 2.6t with a ball weight of 240kg.
Thank you

[rar110]

I would start the motor to level it up so there's less drain on the battery.

I would also buy some kind of diagnostic tool to clear and diagnose faults. There is a group buy on at the moment for an IID tool. About 30% off from memory.

[chaybra]

The car should not raise without the engine running, leave the car idle when hitching.

[sandrotag]

Thank you for the replies!
Can I plug the electric in while the engine is running?
Yes, I will look for a Diagnostic tool to clear/read the fault.
Thanks