I have a 2006 LR3 HSE purchased in June of this year with 94,000 miles. The car was in good shape with no lights on the dash and seemingly well taken care of with a file full of service receipts and records. After about 2 months of ownership I engaged the DSC light when taking a corner. This light would proceed to come on and off but would never stay on permanently. Then about a month after the first fault the DSC and HDC lights came on permanently.
I have a Gap tool and have cleared the codes, but the HDC fault and Amber Brake light are still present. I know I need to replace my pads and rotors, which I believe is why the BRAKE light is illuminated. I have checked all the rear brake bulbs and none are out. I have checked the brake switch is showing ACTIVE/INACTIVE when depressed in the GAP tool and believe it is functioning properly.
I seem to get a constant body control fault and YAW rate sensor fault, C1A98-92. The Yaw rate sensor flickers between 0 & -.0400 when stationary.
I have confirmed the ABS module is opening and closing on all valves using the Gap tool. I visually removed the Rear ABS sensors to inspect for damage to the sensor or wires and they seem fine. The compressor fills fine, the voltage to each ride height sensor is fine. I am able to change the ride height but when I start driving the car lowers itself and is extremely BOUNCY.
I have confirmed the compressor and the software match. I bubble tested the central and front valve blocks and they seem to be fine. I raised the car to full height, pulled the suspension fuses and checked in the AM. Height did not change.

What I know:
- Suspension does not seem to have a leak
- Rear suspension goes up and down easily
-Front suspension is slow to raise
-Front suspension after several changes to height stops wanting to raise>? but you can hear the compressor and valve working
- steering angle is correct
- I have checked the TCM module and no signs of water intrusion
-I have checked wiring under the plastic engine cover, behind the left rear wheel, and at all Ride height sensors
- The ride height sensors do not float around the screen on NAV display

I keep getting YAW rate sensor fault but am unsure how to test this. Short of pulling the whole thing apart and replacing the sensor.
Any insight into what could be causing this would be greatly appreciated.
Thanks

 

The sensor could be he issues. Can it be calibrated with GAP? But if the live values change, I would swap it. I dont think it can be bench tested.

 

Just an update. It was in fact the Yaw Rate Sensor.
There are 2 great videos on Youtube, one on how to remove the front Passenger seat, and the other to remove the yaw rate sensor. I was able to remove it without cutting the carpet or removing the whole center console.

The codes have cleared and Suspension is back up. I am able to select all modes for driving height.

I unplugged the battery when removing the seats because of the airbags, but may have connected the battery at one point with the seats out to confirm the new sensor did work. I now have an sis and seat belt fault and am unable to clear them with GAP Tool. Does anyone know if this module has to be reset? And how one goes about doing that? Or can I do a hard reset on the battery to clear these faults?
Thanks!

Also I purchased a used but tested (with warranty) YAW rate sensor from Goldwing Saab & Rover Parts in Hastings, New York. Their prices were very reasonable and shipping was fast. Also nice to have the warranty rather than buying off eBay.