Suspension Issues

[101RRS]

Its been a few years since I rebuilt my Hitachi air compressor and all has been good.

Until yesterday - started the car and got an orange suspension fault but the system still worked OK able to raise and lower with no cascading issues. As it was getting dark I left the issue and had a look this morning. The car had dropped to access height with the back passenger wheel on the bump stops. Hmmm [bigsad]

Putting the code reader on it I got C1A74 (Rear Left Sensor), C1A05 (Rear Left Height Sensor out of Range) - there were a few other error codes but mainly the sort you get when codes have not been cleared for a long while.

So it would seem the rear left height sensor was out of range and the system lowered it to where it thought it should be (on the stops) or there was a small hole, and then the system lowered the other three bags to try and match it.

After reading the codes, I cleared them started and rechecked - nothing came back and I have had not issues today.

Now I have had my car long enough to know that there types of faults are early warning of possible failing issues in the future so for what ever reason I may have height sensor on the way out - either sensor itself or the wiring to it.

I have not had to deal with these suspension issues before so I intend to get a new sensor in anticipation of it failing before too long.

Any tricks for new players on replacing these?

Thanks

Garry

[Graeme]

As the system is meant to maintain height with only 3 height sensors working, albeit without fine adjustments, I wonder if the out of range condition occurred after the suspension lowered rather than triggering the lowering and therefore the air-spring or the corner valve could be leaking. Have you sprayed soapy water all around the air-spring? As leaks mostly occur at the folds, raising to off-road height before spraying is indicated.

PS Theoretically the heights should be recalibrated after fitting a new sensor or even just refitting after removal but its not critical if not calibrated.

[101RRS]

Thanks Graeme - the initial fault showed up on the dash when the car was still up at onroad height and driving it there was no issue with the fault. I should have read the codes then but was too lazy.

It dropped overnight so I guess we will see what happens tonight. No, I have no checked for a leak at this stage but if it drops again I will have to do so. The bags are now 16 years old and covered 225,000km so I am expecting things like air bags, another compressor rebuild and wheel bearings to pop up before too long.

Cheers

Garry

[Graeme]

The rear springs in my D4 had serious cracks on the inside of the top folds at 90K kms so I replaced them shortly afterwards as I didn't expect them to last until the new shocks needed replacing in another 80-90K.

[scarry]

You have done very well out of the bags.

i had three replaced under 6yrs old,then the corner valves decided they would play up intermittently,over the next few years.

One left rear bag was replaced under warranty,the others replaced were the fronts.

[101RRS]

The car did not drop overnight and the fault has come back but I will know it will. So no leak at the moment.

Time to save the pennies for new shocks, airbags and air compressor rebuild.

[101RRS]

So the issue as not re-appeared so maybe just a one off - am I being optimistic [bighmmm]