Braun NUVL855R Under-Vehicle Wheelchair Lift (UVL)

Overview

The NUVL855R is Braun's commercial 'public use' under-vehicle lift (UVL). Instead of folding up inside the doorway, the whole platform carriage lives in a steel cassette housing bolted under the vehicle floor. On deploy, a chain-driven carriage rolls the platform out of the cassette on horizontal arms; hydraulic cylinders then raise it to floor level or lower it to the ground. Rated capacity is 750 lb. It is ADA and FMVSS 403/404 compliant and intended for attendant operation via a four-button hand pendant: DOOR, STOW, DOWN, UP.

Two safety edges frame the platform: an automatic inner roll stop that doubles as the bridge plate to the vehicle floor, and a two-stage outer barrier (a spring-loaded tall barrier plus an actuator-driven short barrier that becomes the ground-level ramp). Both are weight-sensing — the lift refuses to move if either barrier or the platform threshold is occupied, and the platform will not raise unless the barriers are up. A visual and audible threshold alarm fires if someone stands in the doorway threshold while the platform is an inch or more below floor level.

Interlocks — why the lift 'randomly' won't run

NUVL lifts are wired through vehicle interlocks: the lift is dead unless the vehicle is parked and secured (a +12 V 'vehicle secure' signal on pin 6 of the 9-pin pump-module plug), and the vehicle is prevented from moving unless the lift is stowed (lift-stowed signal on pin 7). On Ford E-Series buses this job is done by an InPower ITM126 interlock module — see the section at the end. When diagnosing a completely dead lift, always verify the interlock chain before condemning the lift.

Maintenance and lubrication

The control board has a built-in cycle counter (LCD display). The green 'Lift Ready' LED on the pump cover turns yellow every 750 cycles as a service reminder; after servicing, hold the CYCLE button below the LCD until it returns to green (this clears the since-service count, not the lifetime count). Service intervals run at 750 / 1,500 / 4,500 cycles and then repeat every 750. Use LPS2 penetrating oil where light oil is called out, Door-Ease stick on the lifting-arm slots, and Mobiltemp SHC32 synthetic grease on the chain release latch. The hydraulic system uses Braun 87010R (MIL-5606 aviation fluid) — never top up with Dexron III or other fluids. Check level with the platform fully lowered; if the reservoir decal is missing, correct level is 7/8" down from the bottom of the fill tube.

Manual backup operation

Everything needed lives at the pump module: a T-handle release cable and a manual hand pump with a release valve. The inner roll stop functions automatically during manual operation.

To extend the platform (power failure, lift stuck in cassette)

1. Pull the T-handle and turn it to lock the release in the pulled position — this disengages the carriage drive chain.
2. Pull the platform out of the housing by hand.
3. Turn the T-handle back and push it fully in.
4. Grasp the outer barrier and jog the platform in and out until you feel the release mechanism re-engage and lock.

Warning: the T-handle must be pushed fully in and the platform positively locked before the vehicle moves — an unlocked carriage can eject the platform while driving. If not locked, the platform can also creep during hand-pump raising and lowering.

To raise / lower the platform by hand pump

1. Lower: open the hand-pump release valve counterclockwise — 1/2 turn only.
2. Raise: close the valve clockwise (once it seats, tighten 15–30 inch-pounds — snug, never wrenched), insert the pump handle and stroke.
3. Close the release valve securely before returning to powered operation.

Outer barrier and handrails

The tall outer barrier folds manually: remove the hairpin cotter, pull the detent pin, rotate the barrier, then reinstall pin and cotter. Handrails are likewise secured with detent pins that must be pulled to fold/unfold and reinserted afterward. Fold handrails down onto the barrier before stowing the lift. After any manual work, push the platform fully into the housing before resuming powered operation so the limit switches see the correct state.

Factory troubleshooting sequence

Braun's NUVL troubleshooting procedure isolates board vs. harness/motor problems in nine steps: confirm power-up (pendant lights, LCD cycle count, green interlock LED, 12 V on the gray/red interlock wire; reset by unplugging main power at the left of the board); with the manual release pulled check drive-chain tension (slack here causes many faults — adjust if it sags 1/2" or more); run the board-mounted override switches — if overrides work both directions the board and hydraulics are fine and the problem is switch/pendant side; check all fuses along the bottom of the board with a meter on both tabs; hand-stow and deploy the platform with the release pulled — travel should be smooth, and powered in/out current at the fuse should stay under 8 A; at a dead motor plug, both wires should read ground at rest and one should go to 12 V when the matching override is pressed; put the LCD in diagnostic mode ('diag' button) and compare each limit-switch state to the chart; verify every limit switch gets full, smooth plunger depression centered on its cam (critical on the full-out switch); finally recalibrate stow (platform) sense and ground sense.

Board calibrations

Platform sense (50 lb occupied threshold): place 20 lb at platform center, raise 3" above stow level, hold the 50# CAL button while pressing pendant STOW; release CAL when the platform starts moving inward. Ground sense: hold pendant DOWN at full ground level, tap the O_BAR/GROUND LVL button, release DOWN. Outer-barrier occupied: with barrier fully unfolded at ground, hold O_BAR/GROUND LVL while raising the barrier with pendant UP, releasing the button at half travel. A stubborn 'pump runs but won't lift' fault is often a stuck valve — flush it by pressing the UP and DOWN overrides together for 4–5 seconds, several times.

InPower ITM126 lift interlock (Ford E-Series)

The ITM126 / ITM126-E21 is the dash-mounted interlock module used with Braun (also Ricon/Maxon) public-use lifts in 2009+ and 2021+ Ford E-Series vans and cutaways. It provides the FMVSS 403/404 logic: with the ignition on, shifter in Park and the parking brake set, opening the lift door flashes the DOOR AJAR indicator, locks the shifter (via a T-cable at the shift-lock solenoid), and turns on the Lift Enable output — +12 V at 1.8 A feeding the lift's vehicle-secure input. Releasing the parking brake mid-cycle kills Lift Enable. Troubleshooting: confirm +12 V on the red power wire (module grounds through the shift-lock circuit, pin 6 of P1); a sticking lift-door switch is the most common failure and leaves the cycle incomplete; check for +12 V on the Lift Enable output (J1 pin 4) when all conditions are met. Never back-feed 12 V into the Lift Enable wire while it is still connected to the module — it trips an internal breaker (self-resetting once the external source is removed). Disconnect the wire from the module first if you need to hot-wire the lift for testing. Replacement parts: control/display module ITM126-MODULE; chassis harness 7201.044 (2009–2019) or 7201.070 (2021+).