Guided Fault Finding
Component arrangement - air suspension
> Refer to the appropriate service information
| Symptom | Fault detection | Possible causes | Solution |
|---|---|---|---|
Gradual loss of pressure
|
Observe vehicle height over a long period of time and try to find the leak using commercially available leak detection spray | Leak in air-spring strut/air spring | Replace air-spring strut/air spring> WM, 433019 REMOVING AND INSTALLING FRONT SPRING STRUT (AIR SPRINGS) > 432519 REMOVING AND INSTALLING REAR SPRING STRUT (AIR SPRINGS) or carry out repairs |
| Leak in air lines or valve unit | Check tightening torques for air line connections, check insertion depth of air lines (color marking), replace air line | ||
Vehicle lying to one side
|
Carry out Guided Fault Finding using the Porsche System Tester | Vehicle level sensor faulty | Replace vehicle level sensor> WM, 431855 REPLACING FRONT LEVEL SENSOR > 431955 REPLACING REAR LEVEL SENSOR |
| Linkage or holder for vehicle level sensor is bent | |||
Vehicle is too high
|
1.) Check that the vehicle has sufficient ground clearance | Vehicle position is raised | Look for signs of 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 Air line on front axle not inserted far enough (fault code 284) |
Replace kinked air lines; carefully blow out frozen and blocked air lines using compressed air Insert air line on front axle as far as it will go; only one marking should be visible. |
|
| 3.) Levelling system: Upper/lower limit value exceeded | Compressor fuse faulty Air line on front axle not inserted far enough (fault code 284) |
Replace compressor> WM, 431519 REMOVING AND INSTALLING COMPRESSOR FOR LEVELLING SYSTEM Insert air line on front axle as far as it will go; only one marking should be visible. |
|
| 4.) Carry out Guided Fault Finding using the Porsche System Tester | Check relays, plug contacts, wire harness and fuses in the vehicle electrical system Drain valve in the compressor faulty/leaking/open |
Replace compressor> WM, 431519 REMOVING AND INSTALLING COMPRESSOR FOR LEVELLING SYSTEM | |
| Drain valve in compressor or control valves in valve block do not work Valve unit does not work |
Replace compressor> WM, 431519 REMOVING AND INSTALLING COMPRESSOR FOR LEVELLING SYSTEM | ||
| 5.) Valve unit blocked | Dirt in valve unit | Replace valve unit> WM, 430419 REMOVING AND INSTALLING VALVE BLOCK | |
| 6.) Compressor/valve block blocked | Dirt in compressor/valve block | Replace compressor> WM, 431519 REMOVING AND INSTALLING COMPRESSOR FOR LEVELLING SYSTEM | |
| 7.) If no faults were found after carrying out Step 6.), the compressor is faulty | Compressor faulty | Replace compressor> WM, 431519 REMOVING AND INSTALLING COMPRESSOR FOR LEVELLING SYSTEM | |
Vehicle is too low
|
1.) 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 |
| 2.) Valve unit blocked | Dirt in valve unit | Replace valve unit> WM, 430419 REMOVING AND INSTALLING VALVE BLOCK | |
| 3.) Compressor/valve block blocked | Dirt in compressor/valve block | Replace compressor> WM, 431519 REMOVING AND INSTALLING COMPRESSOR FOR LEVELLING SYSTEM | |
| 4.) Carry out Guided Fault Finding using the Porsche System Tester | Check relays, plug contacts, wire harness and fuses in the vehicle electrical system Drain valve in the compressor faulty/leaking/open |
Replace compressor> WM, 431519 REMOVING AND INSTALLING COMPRESSOR FOR LEVELLING SYSTEM | |
| Drain valve in compressor or control valves in valve block do not work | Replace compressor> WM, 431519 REMOVING AND INSTALLING COMPRESSOR FOR LEVELLING SYSTEM | ||
| 5.) If no faults were found after carrying out Step 4.), the compressor is faulty | Compressor faulty | Replace compressor> WM, 431519 REMOVING AND INSTALLING COMPRESSOR FOR LEVELLING SYSTEM | |
| 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 spring is faulty | Replace air-spring strut/air spring> WM, 433019 REMOVING AND INSTALLING FRONT SPRING STRUT (AIR SPRINGS) > 432519 REMOVING AND INSTALLING REAR SPRING STRUT (AIR SPRINGS) or carry out repairs > 4301IN BLEEDING AND FILLING THE LEVELLING SYSTEM |
| Air line torn off | Replace air line > 4301IN BLEEDING AND FILLING THE LEVELLING SYSTEM | ||
| Insufficient damping | Test drive: Adjust the damping level while the vehicle is in motion. You should feel a significant change in the damping effect when driving on uneven road surfaces. Also listen for "rumbling noises" | Damping adjustment valve faulty | Replace air-spring strut> WM, 433019 REMOVING AND INSTALLING FRONT SPRING STRUT (AIR SPRINGS) or replace rear shock absorber> WM, 432537 DISASSEMBLING AND ASSEMBLING REAR SPRING STRUT (AIR SPRINGS) |
| Vibration damper worn | Replace air-spring strut> WM, 433019 REMOVING AND INSTALLING FRONT SPRING STRUT (AIR SPRINGS) ; clean air line system or replace rear shock absorber> WM, 432537 DISASSEMBLING AND ASSEMBLING REAR SPRING STRUT (AIR SPRINGS) |
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| Error message "PASM failure" with significant inward/outward spring motion. The error message is gone after switching the ignition off and on again. | Fault code 322, 323, 324 or 325 stored in the fault memory. | Front level sensor holder bent. | Replace front level sensor> WM, 431855 REPLACING FRONT LEVEL SENSOR |