Can a Teleflex AR4502RM smartstick autopilot rudder reference work on a raymarine M81188

According to a post on the Raymarine forum, this error message could indicate an issue with either the steering, the drive unit, the rudder reference unit (if fitted), or the course computer . The post suggests a few tests that you can do yourself to figure out which item is causing the issue.

I suggest that you try the following steps:

Check the connections between the ST8002 SmartPilot and the other components of your autopilot system.
Check the calibration of the ST8002 SmartPilot and the other components of your autopilot system.
Check the hydraulic fluid level and the hydraulic pump pressure.
Check the hydraulic pump motor and the hydraulic pump solenoid valve.
If none of these steps work, I recommend that you contact Raymarine customer support for further assistance.

I am not familiar with your particular model autopilot, but I do know that Raymarine autopilots can be fussy. All must have a compatible gps feeding it, of course. All must have a rudder angle indicator if your auto pilot connects to the wheel or rudder instead of directly to the tiller.

I’m happy to assist further over the phone at https://www.6ya.com/expert/bill_f6ca18ca1db028ed

Verify that it is configured for your installation. Some units can be installed either on the port or starboard side, and they have to be programmed accordingly. Verify this in the user's manual.

Check if rudder reference unit is installed as before ,it seems that the pilot sense that the rudder is turning the wrong way. check when giving +10 command the
rudder turns to increase the heading,if yes, it could be the wiring of the rudder reference unit or it was installed the wrong way after service on the rudder.
Is rudder position indicating correctly?

Check the installation manual for initial setup,if system worked before ,check rudder reference unit for broken wire loose connection or defective unit (it is a potentiometer resistance shoud change smoothly with position)

What model autopilot? If it is a Raytheon/Raymarine try switching the motor leads to see if that works.

It sounds like the rudder feedback has a dead spot in the center of it. The replacement part numbers:

Rotary (inboard engines): M81105
Linear (outboard engines): M81188

The rudder sensor works like a light dimmer, so you get 5V and ground on the outside two connections and a varying voltage between about 1 and 4 volts depending on rudder position
847-746-0100 www.technicalmarine.com

CHECK RUDDER REFERENCE UNIT FOR CONTINUITY(IT IS A POTMETER) CHECK IF MOTOR IS RUNNING IN THE CORRECT DIRECTION ,CHECK CONNECTION OF RUDDER REF UNIT.

Yep, if rudder calibration values are OK, then there is a real problem with calibration, it can be a mechanical problem or a faulty rudder feedback unit. Follow procedure at page 93 of user manual :
AP35 Autopilot Instruction Manualto troubleshoot the error, if you cannot get rid of the error message you may have to replace the rudder feedback unit or to have the unit inspected by a technician.