Use JLR Mangoose Pro Diagnostic Cable to Learn Jaguar XJ Air Suspension Behavior

Vehicle: Jaguar XJ X350 (Other XJ cars will do too)

Tool: JLR Mangoose Pro V139 cable

JLR SDD V139 software


Remove the electric connectors, unscrew the air lines and undo the two bolts of the valve block to the frame.

Ran the compressor to vent the air line to the block, fitted the line, then I expected the valve to the reservoir would open but it did not.

First the two valve going to the rear suspension open en the car is lifted from the rear.

When the car is raised enough these valves close and both the front ones open to lift the car at the front. The way of filling is also described in the workshop manual.

After (unexpectedly) leveling the car first before filling the reservoir I then expected the filling of the reservoir would then be the final step but the reservoir valve did not open at all!

Plug JLR Mangoose SDD cable to the car and do some testing just to check if the valve is good and if it switches alright.

An interesting observation I made when measuring the pressure with the SDD is that you see the pressure going up (apron 12-13 bar) when the compressor is running and going down again to a remaining pressure of approximately 1,6 bar. All this time the reservoir was not connected at all. So the pressure you measure through the SDD is the pressure in the valve block and not necessary the pressure that is in the reservoir.

At the end you see the same pressure peak as before, probably another speed bump again.

Got some fittings today and some 6mm air line, still need to buy the pressure gauges before I can pressure test the air bags themselves. That is for next time.


PS A bit of Dutch translation 😉

Schakelgedrag luchtvering = switch behavior air suspension

Druk = Pressure

Compressor = Yep

Reservoirsolenoid = Reservoir solenoid/valve

Uitlaatsolenoid = Exhaust solenoid/valve

Vering voor = Front airbag solenoids