AVS EX Series Electric Cassette Steps (EXE600/750/1000/1200)

Overview

AVS EX Series steps are electric cassette steps — the tread slides out of a slim enclosed case mounted under the entry door, driven by a controller that learns its end positions by calibration rather than by adjustable mechanical limit switches. Sizing follows the model number (EXE600 through EXE1200, roughly the tread width in millimetres). The controller adds two protections worth knowing before diagnosing: a sensitive edge on the tread that stops and reverses deployment if the step meets an obstruction (or a leg), and a dirt-detection function that raises an error when the mechanism binds from road grime — AVS's standard prescription for most step errors is bluntly practical: check for obstructions and jet-wash the step.

Control box LEDs (on the step controller)

The control box carries five indicator positions:

• LED 1 flashing green — step is moving.
• LED 2 green — step fully deployed; flashing — step is neither fully stowed nor fully deployed (mid-travel or lost position); off — step fully stowed.
• LED 4 flashing — the step has logged an error; read the blink code on the dash LED (below).
• LED 5 green — calibrated and idle: the normal state with the step stowed.
• LED 5 red with LED 2 flashing — controller is in calibration mode.

Dash LED behaviour and blink codes

The green dash LED (built into the step switch) flashes while the step moves, stays on solid when deployed, and is off when stowed. If it keeps flashing when the step should be at rest in either end position, the controller has lost its calibration — recalibrate.

When the controller detects a problem it flashes the dash LED red in a repeating burst-then-pause pattern. Codes reported with the step fully stowed:

• 3 blinks — the stow switch did not activate when expected. Check the step for obstructions and jet-wash it.
• 4 blinks — the deploy switch did not activate when expected. Same remedy: clear obstructions, jet-wash.
• 5 blinks — the step has become excessively dirty (drive effort out of range). Clear obstructions and jet-wash the mechanism.

If a code returns immediately after cleaning and recalibration, look for physical damage — bent arms, kerb strikes, or a failing drive — rather than repeating the wash.

Recalibration procedure

1. With a small screwdriver or pen, press the recessed calibration button on the control box. LED 5 turns red and LED 2 flashes green — calibration mode.
2. Fully cycle the step out and in three complete times using the normal switch. The dash light flashes throughout.
3. After the third cycle LED 5 turns green — the step is calibrated.
4. Close the door and confirm the step stows fully (dash LED off, LED 2 off).
5. Sensitive-edge check: with caution, place a leg in front of the tread and deploy. When the edge triggers, the switch LED turns from green to red and blinks — the step should stop/retract rather than push through.

Emergency stow — step failed in the OUT position

Applies to EXE600, EXE750 and EXE1000HZ. If the step stops deployed and will not power in, the tread can be freed from its drive arms and pushed home by hand:

1. Under the step, find the two drive arms attached to the aluminium tread.
2. Pull out the R-clips securing the arms — keep them, they are reused.
3. Remove the steel and nylon washers from the arm pins.
4. Detach the arms from the tread and fold them in under the step — the arms need to be crossed over each other to stow fully inside the case.
5. Push the tread fully in by hand.
6. Insert the R-clips through the holes in the underside of the case on both sides, pushing each fully through — the clip pins pass through the case and capture the tread, holding it stowed.

This is a temporary get-you-home fix only. The step is mechanically pinned, not latched by its drive, and must go to a service agent for proper repair as soon as possible. Note the safety consequence for an occupied coach: with the tread pinned, the entry step is out of service — crews should place a portable step at that entrance until repaired.

Service notes

Because the EX Series self-protects on drive effort, most nuisance faults trace to dirt, ice or gravel in the cassette rather than electrical failure. Make jet-washing the cassette interior and a recalibration the first service action for codes 3, 4 and 5 before replacing parts. After any wash, cycle the step several times to redistribute lubricant and confirm the dash LED reaches steady states at both ends of travel. AVS Steps support: Deeside Industrial Park, UK — +44 1244 833 790, sales@avssteps.co.uk.