Air Suspension Control System — On Air Active — CKA9001Z / CKA9002Z / CKA9006Z
Not sure which configuration fits your system? [Contact Us] — technical experts on the phone line.
Tired of watching gauges?
Every manually controlled air suspension system asks the same thing of its driver: check the pressure, adjust for the load, check again when the load changes. And every built-in automatic levelling system has a weakness — when the original ECAS (electronically controlled air suspension) unit fails, the vehicle is left without working suspension control, and the original manufacturer's replacement is often expensive, slow to source, or no longer available.
On Air Active answers both problems. It's our own automatic levelling system — fitted to new On Air kits, or as a direct replacement for a failed ECAS unit on your existing air suspension.
How It Works
A height sensor mounted at the rear axle measures ride height in real time. The control unit compares this against the target height and inflates or deflates the air springs to hold it — load the vehicle, drive, and the suspension maintains correct geometry with no driver input.
The system corrects whenever the ignition is on, but with a built-in delay — it won't chase every bump or react to a 20-second stop on a hill. This protects the valve block and compressor from constant micro-adjustment and is a deliberate part of the design.
On Air Active is fully electrically standalone — no CAN bus connection to your vehicle's electronics.
Why We Built It
On Air Active exists because of what came through our workshop: automatic levelling systems failing on motorhomes, ambulances and commercial vehicles, with replacement units costly or unobtainable. Rather than fit someone else's controller, we designed our own. The control unit is built around our own PCB fully epoxy-potted against moisture and vibration, housed in a glass-reinforced nylon enclosure produced in-house. Height sensor brackets and hardware are stainless steel. Designed, built and tested by On Air Suspension at our Ongar, Essex workshop.
What's Included
- On Air Active control unit — potted electronics, glass-reinforced nylon enclosure
- AMK compressor with intake/exhaust filter kit
- Height sensor pack with stainless steel brackets and composite linkage
- Illuminated power switch
- Two-corner valve block, wiring harness, air line, fixings, conduit and fittings
- Full operating and fitting instructions
Three Configurations
- CKA9001Z — S1.0 semi-air, no tank. For semi-air kits. The standard choice for fleet and premium motorhome semi-air installations.
- CKA9002Z — S1.1 full-air, with tank. Air tank and pressure sensor for stored air and faster response. The right choice for full-air systems using the lowering function.
- CKA9006Z — S1.0 full-air, no tank. Full-air installations where space is limited or stored air isn't required.
Unsure which fits your kit or vehicle? [Contact Us] before ordering.
Replacing a Failed Levelling System?
On Air Active is a direct replacement for failed ECAS units across motorhome, ambulance and commercial applications. We retain your existing serviceable hardware — air springs and air lines stay — and replace the control unit, wiring and cab switch. It is the system at the heart of our ambulance OE conversion kit, replacing original equipment levelling on frontline vehicles. (Not suitable for passenger-car OE air suspension systems.)
Signs your existing system has failed: a dash warning light on built-in systems; the compressor no longer kicking in, or running constantly; on full-air systems, the vehicle settling down onto the axle. Send us a photo of your existing unit and we'll identify it and confirm the replacement.
Fitting
DIY-friendly for a competent installer — full instructions included, minimal drilling. Professional fitting is available at our Ongar, Essex workshop — [Contact Us] to arrange.
FAQ
Can On Air Active replace my existing automatic levelling system?
Yes. It's a direct replacement for failed ECAS units on motorhomes, ambulances and commercial vehicles. Serviceable air springs and air lines are retained; the control unit, wiring and cab switch are replaced. It is not suitable for passenger-car OE air suspension systems.
How do I know my existing system has failed?
Built-in systems usually show a dash warning light. Otherwise look for the compressor not kicking in, running constantly, or — on full-air systems — the vehicle sitting down on the axle. Send us a photo of your unit and we'll identify it.
Can I adjust the ride height myself?
All configurations include a dump button, which fully deflates the system — useful for loading access or maintenance. On rear-only systems, ride height is otherwise maintained automatically at the target height with no driver adjustment — standard across levelling systems. The full 4-corner system adds selectable height settings: maximum inflation, standard, and lowered.
Will it constantly adjust while I'm driving?
It corrects whenever the ignition is on, but with a built-in delay — a 20-second stop on a hill won't trigger a readjustment. This prevents unnecessary wear on the valve block and compressor.
Does it connect to my vehicle's electronics?
No. On Air Active is electrically standalone with no CAN bus connection.
Does a single sensor keep the vehicle level side-to-side?
The sensor mounts to the anti-roll bar, and a single measuring point is the correct approach for rear-only levelling systems.
Can I fit it myself?
Yes, for a competent installer — full fitting instructions are included and drilling is minimal. Workshop fitting is available at Ongar, Essex.
Do I need the version with the tank?
Full-air systems using the lowering function should take the tank (CKA9002Z). Semi-air and rear-only installations generally don't need one (CKA9001Z). Call if unsure.