Preparation for test 1. Check, and correct, if necessary oil level in reservoir. 2. Remove plastic cover over hydraulic unit. If reservoir was empty, bleed the supply pump as follows: Disconnect the high pressure hose (P) from the steel line. With the engine running, hold the hose in a container until the oil contains no more bubbles. Note: Testing oil supply pump: SMS Level control Models 124, 201, Job No. 32-0530

Test step DTC	Test scope	Test connection	Test condition	Nominal value	Possible cause/Remedy
1.0 only vehicles up to 04/91	Service valve System pressure	Service valve in "TEST" position 250 bar gauge connected to service valve connection "MO". (Figure 1, 2)	Engine: at idle Service valve in operating position.	25 - 36 bar	Pressure < 25 bar: Oil supply pump, Service valve. Pressure > 36 bar: hydraulic unit. For testing vehicles with level control, refer to SMS Level control, Models 124, 201, Job No. 32-0530.
2.0	Pressure accumulator Gas charge pressure System pressure	Vehicles up to 04/91 Service valve in "TEST" position 250 bar gauge connected to service valve connection "MO" (Figure 1, 2) Vehicles starting 05/91 Release accumulator pressure at screw plug (16, Fig. 3) 250 bar gauge connected to service valve connection "M". (Figure 2, 3)	Perform routinely only on vehicles with > 30,000 miles. Engine: at idle Service valve in operating position or switch (S7/3) in "FUNKTION" position.	Rapid pressure increase to 10 - 22 bar, followed by slow pressure increase to 36 bar.	Rapid pressure increase to 36 bar: Pressure accumulator Pressure < 25 bar: Oil supply pump Pressure > 36 bar: Hydraulic unit. For testing vehicles with level control, refer to SMS Level control, Models 124, 201, Job No. 32-0530.