Test Step	Test scope	Test connection			Test condition	Nominal value	Possible cause/Remedy
1.0	Delivery capacity	4 2	N16 N16	2 1	Ignition: OFF Connect special tool fitting, part no. 000 589 01 91 00, and fuel hose (056) to diaphragm pressure regulator instead of fuel return line ( 35 , Figure 1 or 2). Place other end of fuel hose (056) in measuring glass. Ignition: ON Engine systems control module (N16) unplugged. End test after maximum of 40 seconds	11 - 14 V (indicated only briefly) 1 liter after max. 40 seconds, current draw 6 - 10 A	Check battery voltage Check strainer in fuel inlet fitting of fuel distributor for restrictions, clean or replace fuel inlet fitting. Check fuel lines for restrictions (kinks and dents). Repair as required. Pinch leak-off line between fuel accumulator and suction damper with clamp. repeat fuel delivery test. If correct delivery is attained, replace fuel accumulator. Replace fuel filter. 2.0.
2.0	Fuel pressure between fuel pump 1 and 2	1	N16	2	Unscrew cap on fuel pump 1 (M3m1), connect adaptor (045) and pressure gauge (043). Engine systems control module (N16) unplugged. Read fuel pressure. Dissconnect pressure gauge (043) and adaptor (045) and check for leaks.	2 - 4 bar	Fuel pressure < 2 bar, replace fuel pump 1 (M3m1). Fuel pressure > 4 bar, replace fuel pump 2 (M3m2).

Bosch no./MB no.		0 580 254 951/002 091 88 01
Measurement specification	with engine stopped and voltage at the fuel pump min. V	11.5
Delivery capacity	Measurement location: at the fuel line after the diaphragm pressure regulator. min. l/s Fuel tank at least half full.	1/40
Current draw	Amps	6 - 10