September 19, 2019 by dave
A Land Rover Discovery 4 made 2012 3.0T with 100 thousands kilometers,the owner drived his Land Rover Discovery 4 to our garage due to the air suspension trouble.Here I share the progress of repairing Land Rover Discovery 4 C1131/C1A20 Air Suspension Trouble.And for Land Rover parts,you can check here:Land Rover EPC Spare Catalogue
Our technicians after testing,found that the engine can be started correctly.Operated the swith on the interface of terrain response system ,the air suspension pump work normally at beginning.But after awhile,air suspension warning light on in the instrument cluster,and terranin response system was disabled.Restart the engine,found the symptom as above.Air suspension pump worked normally at beginning,but after awhile it was disabled.
Technicians connected JLR SDD to the vehicle,read out below trouble codes:
C1131-92:Air Spring Air Supply Unable to pressurize gallery
C1A20-64:Pressure increases too slow when filling reservoir
Newest JLR SDD V154 Software Free Download
Use the diagnostic tool to detect the pressure of air suspension found that the air pump stoped working when pressure inscread from 300 kPa to 800 kPa.According to the above inspection results to determine the reason of the failure may be:
1. Air supply line failure
2. Air pump failure
In accordance with the principle of simple to complex diagnostic criteria for the suspicious of the above failure:
1. Lift the vehicle,check the pipeline of the air suspension.No leakage failure and the pipelin was not pressed or folded.
2. Check the pump dry bottle and exhaust valve,they are normal.
3. Immersed the gas tank into the water for check leaking,no leakage phenomenon.
4. And repalced the air pump,but the failure still existed.
Only the air intake pipeline of the air pump had not been checked.
1. Remove the intake pipeline of air pump
2. Start the engine and turn on air suspension,found the air suspension can rise slowly.
3. Detect the pressure of air suspension with JLR SDD,the presure can reach about 1400 kPa.
4. Repeated test the air suspension of vehcile again and again,the air suspension can work normally.
We can make conclusion:air intake pipeline trouble result in air suspension system failure.
When check the intake pipeline fo the air pump,found the air filter was blocked.And after cleanning the air filter,the air suspension system work normally.
The fault is caused by air filter inlet blockage of the air pump.It should be noted that the air filter of air suspension system air pump is a consumables,it should be cleaned or replaced termly.
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