I have to press the slide extend button twice for both my slides. Since you are getting the code 5 it is different, but here is what I have observed so it may help you.
As soon as you apply power to the coach (either plug in to shore power or turn house power switch on) you should see an error code on the slide controller.
The first time you press the slide extend/retract button it clears the error code (Lippert documentation in both the In Wall Owners Manual and In-Wall Slide-Out Troubleshooting "When an error code is present, the board needs to be reset. Energizing the extend/retract switch (Fig. 1) resets the board. Energize the extend/retract switch again for normal operation."). The interesting thing I have seen is once I clear the error, it does not reapper until the power to the coach is removed, applied, removed again and applied again (two times). The first time removing power and re-applying it does not present the error.
Both of my controllers are displaying 1 green and 9 red flashes = motor 1 Hall Power Short to Ground. Thor thinks the issue is both controllers are probably grounded to the same lug on the chassis and it is loose, the only reason it would be both controllers. The dealer has already replaced motor 1 and wiring harness on one slide which did not fix it. I also swapped the wiring harness for motor 1 and motor 2 and when I put power back it is still giving the code for motor 1 so this tells me it is not actually the motor or wiring harness.
I emailed Lippert at firstname.lastname@example.org
and described my problem and got the most helpful information from them so far within a few hours. Their suggestion for troubleshooting was this:
The best way to test this system is to operate the slide. What code is flashing? Write down that code. Swap the motor harnesses from Motor 1 to Motor 2 and Motor 2 to Motor 1. Operate the slide again. Does the code change? No? Replace the controller or check for faulty grounds. Yes? Continuity tests on harness. Does it pass? NO, replace harness. Yes? Replace the slide out motor as there is an issue with the sensor on the top of the motor or the wires pulled out of the motor.