Before Opening High Pressure Fuel Injection System

Before Opening High Pressure Fuel Injection System

• The fuel injection system is separated into a high-pressure section (max. approximately 120 bar) and a low-pressure section (approximately 6 bar).

• Before opening high pressure area, fuel pressure must be reduced to a residual pressure of approximately 6 bar. The procedure for this is as follows.

Special tools, testers and auxiliary items required

• Vehicle diagnostic, testing, and information system (VAS 5051B)

Procedure

Proceed as follows:

- Connect vehicle diagnosis, testing and information system (VAS 5051B) while ignition is switched off.





Display on (VAS 5051B):





- Press Vehicle Self-Diagnosis button - 1 - in the selection.

Display on (VAS 5051B):





- In selection - 1 -, press "01 - Engine electronics " vehicle system and continue by pressing -> button.

Display on (VAS 5051B):





- In selection - 1 -, press the diagnostic function " 006 - Basic setting" and continue by pressing -> button.

Display on (VAS 5051B):





- In button field - 1 -, press the 1 4 0 buttons for "Display group 140" and confirm entry by pressing Q button.

Display on (VAS 5051B):





Example:

1. 42%

2. 39.76 bar

3. 40.63 bar

4. Inactive

- Press button A to activate basic setting.





Display on (VAS 5051B):

Example:

1. 0%

2. 0 bar

3. 5.46 bar

4. lower

The fuel rail will continue to be filled with fuel, but it will no longer be under high pressure.

Now components or lines can be opened.

- Lay clean cloths around connectors and catch escaping fuel.

Final procedures

- Start "Guided Functions" operating mode.

- Generate readiness code in ECM.