Guided Fault Finding

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Information

Always read the fault memory out first. Any fault codes must be corrected using Guided Fault Finding in PIWIS Tester .

Symptom	Fault detection	Possible causes	Solution
Gradual loss of pressure Vehicle lying to one side after a long time Longer than average regulating times No reaction to driver's request Fault memory entries Lift time exceeded Leak in pressure accumulator	Check vehicle height over a long period of time and find the leak using commercially available leak detection spray	Leak in air-spring strut/air spring bellows	Replace front air-spring strut > 433019 - REMOVING AND INSTALLING FRONT AIR-SPRING STRUT or repair it Replace rear air suspension bellows > 434319 - REMOVING AND INSTALLING AIR SUSPENSION BELLOWS > 430117 - BLEEDING AND FILLING THE LEVELLING SYSTEM
		Leak in air lines or valve unit	Check tightening torques for air line connections, check insertion depth of air lines (colour marking), replace air line

Symptom

Fault detection

Possible causes

Solution

Gradual loss of pressure

Fault memory entries

Check vehicle height over a long period of time and find the leak using commercially available leak detection spray

Leak in air-spring strut/air spring bellows

Leak in air lines or valve unit

Check tightening torques for air line connections, check insertion depth of air lines (colour marking), replace air line

Symptom	Fault detection	Possible causes	Solution
Vehicle lying to one side No leaks in the system	Carry out Guided Fault Finding using the Porsche System Tester	Level sensor faulty	Replace level sensor > 431855 - REPLACING FRONT LEVEL SENSOR > 431955 - REPLACING REAR LEVEL SENSOR
		Linkage or level sensor holder bent
		Sensor for body not installed/screwed correctly	Visual inspection of all sensors for body > 433419 - REMOVING AND INSTALLING SENSOR FOR BODY

Symptom	Fault detection	Possible causes	Solution
Vehicle is too high Vehicle cannot be lowered	1.) Check that the vehicle has sufficient ground clearance	Vehicle position is raised	Visual inspection for damage and check clearance around the air-spring struts/air springs and anti-roll bars
	2.) Check air line and line routing	Air line blocked, kinked or frozen	Replace kinked air lines; carefully clean frozen and blocked air lines using compressed air
	3.) Valve unit blocked	Dirt in valve unit	Replace valve unit > 432355 - REPLACING VALVE UNIT
	4.) Compressor/valve block blocked	Dirt in compressor/valve block	Replace compressor > 431519 - REMOVING AND INSTALLING COMPRESSOR
	5.) Carry out Guided Fault Finding using the Porsche System Tester	Check relays, plug contacts, wiring harness and fuses in the vehicle electrical system Drain valve in compressor faulty/leaking/open
		Drain valve in compressor or control valves in valve block do not work Valve unit does not work
	6.) If no faults were found after carrying out Step 5.), the compressor is faulty	Compressor faulty

Symptom	Fault detection	Possible causes	Solution
Vehicle is too low Vehicle cannot be raised or can only be raised very slowly	1.) Check that the vehicle has sufficient ground clearance	Vehicle position is raised	Visual inspection for damage and check clearance around the air-spring dampers and anti-roll bars
	2.) Check air line and line routing	Air line blocked, kinked or frozen	Replace kinked air lines; carefully blow out frozen and blocked air lines using compressed air
	3.) Valve unit blocked	Dirt in valve unit	Replace valve unit > 432355 - REPLACING VALVE UNIT
	4.) Compressor/valve block blocked	Dirt in compressor/valve block	Replace compressor > 431519 - REMOVING AND INSTALLING COMPRESSOR
	5.) Carry out Guided Fault Finding using the Porsche System Tester	Check relays, plug contacts, wiring harness and fuses in the vehicle electrical system Drain valve in compressor faulty/leaking/open
		Drain valve in compressor or control valves in valve block do not work
	6.) If no faults were found after carrying out Step 5.), the compressor is faulty	Compressor faulty

Symptom	Fault detection	Possible causes	Solution
Rapid loss of pressure	Vehicle lying to the left or right; when you try to switch to a different level, you can hear air coming from the faulty air spring	Air-spring strut/air suspension bellows faulty	Replace front air-spring strut > 433019 - REMOVING AND INSTALLING FRONT AIR-SPRING STRUT or repair it REFERENCE is missing Replace rear air suspension bellows > 434319 - REMOVING AND INSTALLING AIR SUSPENSION BELLOWS > 430117 - BLEEDING AND FILLING THE LEVELLING SYSTEM
		Air line torn off	Repair air line > 430117 - BLEEDING AND FILLING THE LEVELLING SYSTEM

Symptom	Fault detection	Possible causes	Solution
Insufficient damping	Test drive: Adjust the damping level while driving. You should feel a significant change in the damping effect when driving on uneven road surfaces. Also check for hard "knocks" (rumbling noises).	Electric connector for PASM faulty	Check electric connector for PASM and replace it if necessary
		Damping adjustment valve faulty	Replace front air-spring strut REFERENCE is missing Replace shock absorbers > 429319 - REMOVING AND INSTALLING REAR SHOCK ABSORBER If shock absorbers are worn, clean the air line system
		Shock absorbers worn