I recently got the yellow warning light with "SUSPENSION FAULT" message. All four shocks went to "stiff" mode. I disconnected the multi-plug to the Suspension Control Module and used a multimeter to test continuity on all four corners; all showed 8 ohm resistance. I re-connected the plug, let the car sit for a few days, and then drove about 150 miles with no warning message and the CATS operating normally. Got home, turned the car off. Started it again and had "SUSPENSION FAULT" with all four shocks stiff. I again checked continuity and all four corners showed 8 ohms. Unfortunately, the warning didn't go away this time and all four shocks are stuck in stiff mode. Am I correct in assuming, based on testing continuity, that the problem is NOT with my shocks or with the wiring from the shocks to the control module? That would seem to imply that there's a problem with the control module itself. Should I take it to the dealer for further testing (at additional cost) or just swap out the module?

 

l would be willing to bet a replacement module would cost considerably less than a dealer visit. Can't say for sure if it would fix the problem but again, neither might the dealer.

 

You can also get the Suspension Fault message if there is a wiring fault to one of the three sensor, so it would be worth checking for shorts or open circuit to those also.. You can do some basic checks with a voltmeter to see if they are outputting sensible signals. See the attached PDF for some more details.

 

I was wondering about that. In the document you attached, the Connector Pin Identity Chart shows pins 20 through 23 as the input signals for Lateral Accelerometer, Front Vertical Accelerometer, and Rear Vertical Accelerometer, respectively. Should I measure the resistance between each of these and pin 25 (Power Output +5 V to Supply Accelerometers)? Also, can a Suspension Fault message be caused by a problem with the Road Speed Input (pin 24) or Brake Pedal Input (pin 26) signals? If so, how would I test them?

Thank, in advance, for your help!

 

Yes, I think I would measure the resistance for each of the accelerometer inputs in turn against ground (pin 18) and +5v (pin 25) to check for shorts to either. If the resistance values are similar for all three with no dead shorts, I think that would eliminate the wiring.

With a suitable code reader you can also read the module to get the error code which will tell you what the system thinks the fault is - there is no code for road speed or brake input so I doubt that is causing the problem. Once you have eliminated the wiring fire up the parts cannon and swap the CATS module out - at the very least you will have a spare module.

On mine I ended up replacing the accelerometer in the ECU compartment - there was no fault message being displayed, but the CATs wasn't working properly on roundabouts etc - a second hand accelerometer fixed the problem.

 

All of the wiring seemed fine, so I installed a used module I picked up on eBay and that fixed the problem. No more "SUSPENSION FAULT".