Hi all

This is my first post, apart from the presentation, on this fabulous forum.

I have a 2003 XJ6 which has developed an air suspension error. I was on a somewhat lengthy drive when suddenly "Air suspension fault" appeared in the display and the ride got very coarse/hard. When I stepped out of the car I could see the rear had raised, probably closer to 2 inches/10 cm.

When I arrived at home I ran diagnostics (iCarsoft LR II) and it said I had a short circuit in the rear left shock (I can't remember the code). I swapped the relay and the error disappeared. When I put the (most probably) faulty relay back in I got a different error saying the relay was bad. I know have a new relay in place but the back of the car is still very high and I still have a C2302 Leveling plausibility error.

Also the car is about 3/4" lower on the left side, both front and rear.

I have recorded the height of the car today and will be checking tomorrow if there's any change.

Could it be the compressor, or should I look elsewhere? Any tips would be appreciated. Thanks.

 

Compressor normally throws C2303 Reservoir plausibility error. No matter what code you get for suspension issues, the ASM always sets the shocks to "Hard" hence your hard ride. It does sound as if you might have something wrong in the leveling equipment, like a duff height detector or something. Early cars had one height detector per wheel, but later ones had one for the front pair and one each for the rear wheels. Has anything been done to the car recently, or anything happened that might have caused damage to the detectors and their wiring ?

 

Thanks for replying.

Mine is an early model with 4 height sensors/detectors.

I did have the shocks out to replace the bushings a few weeks before the error. I guess I'd driven around 700km/440miles after the work was done when the error occurred.

 

C2302 refers to the height sensors.

Check the wiring to the sensors for breaks or damage also

check that a sensor is not seized or has been knocked when the vehicle was worked on.

 

Thanks. I'll have a look at the sensors when I get access to a lift. Hopefully early next week.

 

Is it possible that a height calibration can cure the problem? Could it have been "thrown off" when the relay went bad. As I mentioned in my first post I had an error that said short circuit in the rear left damper. This is gone after I replaced the relay

Also, it seems like it tries to self level, sort of. When I park on uneven surface it sometimes will drop on one side and then stay that way for a while. Then it will rise up way too hight again.

I should mention that the light and message in the display in the dashboard goes away everytime I stop the care and will come back again after I've driven about a mile

So, what do you guys think, can a height calibration cure the problem, and more importantly, can I do anything wrong if I try to calibrate while I have a C2302 error?

 

The brackets holding the sensors in place are prone to corrosion, this happened to mine - caused my O/S rear corner to sag. Worth checking your brackets, cheap & easy fix.
I would check/fix this if needed first. If this is the problem you'll need to recalibrate afterwards.

 

I've had a look at the height sensors and brackets and they look ok visually. I haven't had them off the car yet though as I still don't have access to a lift. Hopefully I will next week.

 

Turned out the rear RH side height sensor that was the culprit. It's been replaced and all is good. Thanks to those who replied.

 

Glad to hear. Just out of curiosity did you calibrate as well or did it work without calibration?

 

I haven't calibrated yet, I just ran the pre-geometry program which left it with the left front wheel a few millimeters lower than the rest. Maybe I'll have a go at calibrating later.

 

How did you find out that was bad?
There should be a separate error code for each ride height sensor?
Did you find any additional code in addition to P2302?
.
.
.

 

I bought the IDS SDD diagnostics package and checked status on all sensor when deflating and the rear one at the RH side showed the same height all the way.

It would definitely be nice with separate error codes for each sensor. I can't remember if I had any other error codes.