What Transfer Case Control does
This function lets a Nexus ECU run the all-wheel drive system on a Polaris RZR. The driver still chooses 2WD or AWD with a switch, but the ECU decides when the change is actually allowed, based on vehicle speed. That stops the front drive engaging or releasing at speeds where it could shock the driveline.
Think of the dash switch as a request. Flip it, and the ECU arms the change, then waits until speed is below your limit before operating the solenoid.
Settings
| Setting | What it does | Our advice |
|---|---|---|
| Engagement: Max Speed | With the switch armed, vehicle speed must drop below this before the ECU shifts from 2WD to AWD | Start low and conservative; raise it only if the vehicle's drivetrain handles it smoothly |
| Dis-engagement: Max Speed | With the switch turned off, speed must be below this before the ECU goes from AWD back to 2WD | Also conservative; releasing under load or at speed can be abrupt |
Because both limits rely on vehicle speed, the ECU needs a working vehicle speed signal. Check it reads correctly in NSP before you trust this function.
Wiring
Enable Output Enable to give the function an output for the transfer case engagement solenoid, then assign:
- Output: normally a high current output (HCO), since it's driving a solenoid. If none are free, a digital pulsed output (DPO) or stepper output will work, but only through a relay that carries the solenoid current.
- AWD Switch: the driver's 2WD/AWD switch, on an SPI or an AVI (analog voltage input).
Never hang a solenoid directly off a DPO or stepper output. Use a relay; our relay guide explains why.
Testing it
- With the vehicle stationary, flip the AWD switch and confirm the input changes in NSP and the solenoid engages.
- Drive slowly above your engagement limit, flip the switch, and confirm nothing happens until you slow below it.
- Repeat for disengagement.
Setting up a RZR from scratch? The Elite 1500 RZR XP 1000 Plug 'n' Play kit covers 2015-2016 models, and the Elite version of this function is covered in Elite transfer case control. Questions about your build? Get in touch.
