Air suspension. Another of the common Land Rover Discovery 4 problems is faulty air suspension. Originally launched as a more utilitarian version of the Range Rover in the 1980s, despite the luxuries, the Discovery line still has features that make it a suitable all-terrain vehicle. One of these is the inclusion of air suspension. C1A20-64 Suspension fault. Getting the C1A20-64 fault code. I ran the GAP Tool to check the Gallery Pressure and Temperature of the compressor. You tube video link below. I also got the below messages on the dash screen. I am not sure what the normal temperature is of the compressor but I got it up to 280°F (about 138°C). 1. I replaced the air compressor (the entire assembly) with a new one. This didn't change the behavior of the vehicle at all. I was still getting an amber warning light about 50% of the time. I drove the vehicle with the new compressor for about 2 weeks. 2. Next, I replaced the front valve block with a new unit. SYMPTOM: System detects extended mode unnecessarily when lowering. POSSIBLE CAUSES: Crossed gallery and air spring pipes. Incorrect valve block installed to front or rear. Damage or blockage in air harness. ACTION: Refer to the guided diagnostic routine on the approved diagnostic system. The IIDtool shows the transmission fault as "U0416-86 (2F) Invalid Data from Vehicle Dynamics control module" * When I start moving I will also get an HDC Fault System Not Available and Cruise Control Not Allowed and the Suspension light will come on and display "Suspension Lowered". It seems to go somewhere in between Access and Normal height. Owner's Manuals. 2017 Land Rover Discovery Suspension Technical Service Bulletins. SSM75824. Date Added to File: November 7, 2022. Failing Component: Chassis control module (chcm) suspension warning on cluster. Discuss it at Forum View This TSB. SSM75779. Disconnect the positive battery terminal from the main starting battery. (I assume that you only have one battery in your 3. If not, disconnect the others as well and leave them disconnected until after all is done.) Connect the negative cable to the positive cable. Community site dedicated to Discovery 3, 4 LR3 and LR4 Owners and Enthusiasts. Totally free to join - message boards, galleries, wiki, off road events, social meetings. Advertise on DISCO3.CO.UK I noticed that my park sensors isn't always working. After checking wires again from the CJB to the ABS module, suspension ecu, transmission ecu, I found no faults. However, when I unplugged the park sensor module, the car cleared all errors! lifted, and no issues! My 60 amp suspension fuse did blow twice,, but after replacing, it all seems fine. Land Rover Discovery 4 SDV6 Suspension Fault. Thread starter Gumster; Start date Jul 8, 2020; G. Gumster New Member. Posts 3 Location Northern ireland. Jul 8, 2020 #1 AZ8mCBY.