Gents,

I replaced my upper shock mounts and lower shock bushings yesterday. Everything went eerily smooth. Now that everything is back together, my Transmission Fault light is on. I checked the connections on top of the shocks, cleaned them, and even tried some di-electric grease as a last resort...to no avail. The car does ride much better with the new parts, but I assume the CATS is stuck on the default firm setting. Of course, Torque doesn't read suspension codes and my local Jag dealer charges $140 just to read the codes! Any ideas of what the issue could be?

 

try a hard reset. take the battery cables off at the battery and hold them together for 10 or 15 seconds I think it is then put then back on the battery. After this you may have to reset you windows and and things that you set in memory (mirror and seat, etc).

 

No harm in trying...

 

Well, that didn't work. Any other suggestions?

 

Note sure off the top of my head which fuse it is so check that, it defaults to 'firm' when not active.

 

The unit has to send an error signal to the instrument cluster to show the fault message, so if the unit is powered down, there are no error messages. That's why unplugging it works as a way to disable the system.

You could try cleaning the connection to the controller in the boot.

Barring that, it's a guessing game. Could be one of the shocks or any of the accelerometers that make the system work.

Don't suppose there is someone near you with a WDS or SDD that could read the real codes?

 

I've called around and couldn't find an indy with a WDS. Local Jag dealer wants $140 to pull the code. Can't imagine the module connector is dirty (but haven't tried cleaning). The Suspension Fault Light appeared directly after replacing the upper shock mounts and lower shock bushings. Seems unrelated to a dirty connection in the boot.

Yes, I've disconnected the module and that does disable the fault light, but doesn't resolve the issue...just makes me forget about it when I'm driving.

 

another reason not to by a XKR, more stuff to go out and the normal XK* is bad enough.

 

If the nut at the top of the shock is not tightened down enough then the electrical plug for the shock may not be making contact. I am assuming you used an allen wrench to hold the shock tube from turning and then tightened the outer nut.


There is a tread on the XJ 308 forum where someone removed and tightened the nut with an impact wrench and that internally broke the wires inside the shock(s).




Hopefully it is just your top connector

 

Thanks. An impact was used used to remove and tighten the nut. I bet the wires broke. I'll do a resistance test later.

Do you know the part number for the top connector?

 

FWIW:
This is what I did a couple of years ago. After the hard reboot, nothing cleared, so I drove it out in my driveway and stabbed the brake pedal while it was rolling. Next, turned the ignition off (for about 20 seconds if that makes any difference). Then I cranked it up and everything was cleared and good to go.
If the above does not work, I suggest checking the +12volt connections to the transmission module. A voltmeter may show that you have 12v at the module when in reality, a goodly portion of that voltage may be dropped across a bad connection. In my case, it was a connection on the bottom side of the left side (under hood - bonnet) fuse box. I went ahead and cleaned every connection on that box and have had no problems with that box since (years).

 

You said you're getting a transmission fault in the orig post. If it were ADCM issue you'd be getting this:
In the event of failure of the Adaptive Damping System, the damping units automatically revert to the Firm setting, ensuring that the vehicle remains safe to drive under all circumstances. The driver will be alerted to such a failure by illumination of a 'SUSPENSION FAULT' warning on the fascia message center and the amber warning light in the instrument cluster.

I doubt the error is coming from the suspension,

So did they 'bang' something around when changing the components or just happen to be something new?

 

Oops...I meant SUSPENSION FAULT. Not sure why or how I did that but thanks for pointing it out. The ADCM was not touched. Only the upper shock mounts and lower shock bushings were replaced. The nut was removed and tightened with an impact, which, according to rocklandjag's post, can cause damage to the connectors. I'm hoping that's what happened. I didn't get a chance to test them yesterday. I assume that reading the resistance (ohms) will be a good indicator?

 

Not sure why they'd use a impact to reinstall the nut, if I recall the torque for the nut is surprisingly light Nut - shock absorber upper stud (adaptive damping)16-18 nm

The setting is either stiff or soft, nothing in between. I did quickly measure the harness connector on both fronts 55K ohms, I didn't have probes that would reach the pins on the shock to give me a proper reading, sorry but perhaps it's been documented in another thread.

More from JTIS if u delve into it deeper.
Three accelerometers sense vehicle body movement and generate an analogue voltage (+5V max.) output, which is proportional to the vehicle body movement. These voltages are supplied to the Adaptive Damping Control Module (ADCM).At 0g. (no movement of the body) each vertical accelerometer outputs approximately 2.5V steady voltage. The lateral accelerometer outputs approximately 1.5V. The voltage output due to body movement is proportional to acceleration in the acceleration axis, up to approximately 4.5V and down to approximately 0.5V.The ADCM is hardwired to the Instrument Cluster. Should a fault occur, the ADCM grounds the System Error line which switches on the amber warning lamp and displays the message SUSPENSION FAILURE on the message centre.

Here's the pinout of the adcm, perhaps you can measure there for consistency.

 

Hi Guys. Was this ever solved? I'm in exactly the same position. Changed shock mounts and bushes. Suspension made bad banging noise immediately after I did this no error codes though. Replaced RH adaptive shock. Noise completely gone but get suspension fault message on the dash.
Weirdly if I unplug the new shock and plug connector back into the old shock the error message goes away...! New shock was bilstein #20-070816. Car is 03 xkr.
Can anybody think what may be causing this? It's making me grow old very quickly...