For the air ride module to work in this case, this is what I think needs to be done. I think you will need to have all the solenoids and ride height sensors connected to stop a hard fault. Then the module looks at the front height first, if the front height is correct, only then will it proceed to the rear.
Depending on the height of the front springs, you might have to adjust the sensors until they show the right height. If when you first key on, the front solenoids open, and the compressor turns on, that would mean the sensors need to be adjusted to show the front end is higher.
If when you first key on, the solenoids open and the vent clicks open, that would mean the sensors need to be adjusted to show the front end is lower.
If nothing happens to raise or lower the front when needed, it will throw the check air ride message and never make it to the rear.
My CE actually has springs on just the front right now. I take my good airsprings off while I store the car over the summer. The rear needs to be pumped up a bit now, I'll test my theory on it today hopefully.