Four-wheel pneumatic system, electrical check: Notes

It is necessary in vehicles in which the On Board Diagnostic (OBD) system does not provide any clues to the source of the malfunction to perform the complete electrical test.
In vehicles in which the On Board Diagnostic (OBD) system provides a direct clue to the source of the malfunction, only the test steps recommended in the DTC table need to be performed (systematic starting-point).