Fuel Delivery and Air Induction: Service and Repair
Diesel Direct Fuel Injection System, Servicing
The following table provides quick links to all chapters in this section.
For all Diesel fuel injection system component locations, refer to => 23 Description and Operation.
For all Diesel fuel injection system removal/installation procedures and torque specifications.
Check the Technical Bulletins for information that may supersede any information included in this information.
• All manufacturers special tools as well as common tools may contain a manufacturer specific part number. These tools may be substituted with an equivalent aftermarket tool or are available for purchase through VW..
• Manufacturers special tools as well as common tools that contain a manufacturer specific part number may be referenced in the test procedure illustrations showing the tool use or installation. If the manufacturer specific tool is not being used, an equivalent aftermarket tool may be installed in the same manner as the manufacturers special tool.
• The manufacturers test box Adapter - 68 Pin (VAG1598/18) is available for purchase or rental..
Safety Precautions
To reduce the risk of personal injury and/or damage to the fuel injection and ignition system. Note the following:
CAUTION!
Fire hazard! To prevent personal injury, and damage to vehicle components. Remove all objects from the repair area that can ignite Diesel fuel.
CAUTION!
Be sure the ignition is switched OFF, when:
• Disconnecting or connecting Diesel fuel injection and glow plug system wiring or test equipment.
• Be sure the ignition is switched OFF. Failure to do so may damage the Diesel Direct Fuel Injection (DFI) Engine Control Module (ECM).
• Observe procedures for disconnecting battery. Refer to Electrical Equipment.
BEFORE cranking the engine at starting RPM (such as for compression testing)
• Disconnect the Fuel Cut-Off Valve (N109) electrical harness connector on the Diesel injection pump.
• After all repair work is completed, check and erase Diagnostic Trouble Code (DTC) memory.
Observe the following if test and measuring instruments are required during a test drive:
CAUTION!
• Test and measuring equipment must always be secured to the rear seat and be operated from there by a second person.
• If test and measuring instruments are operated from the front passenger's seat and the vehicle is involved in an accident, there is a possibility that the person sitting in this seat may receive serious injuries when the airbag is deployed.
CAUTION!
The use of nails, paper clips, or another unauthorized materials to back-probe electrical harness connectors is strictly prohibited and may cause damage to the electrical harness connectors, terminal ends or damage to a component. Use only the manufacturers test lead kit or an equivalent aftermarket test lead kit for back-probing all electrical harness connectors.
Clean Working Conditions
CAUTION!
When working on the fuel supply or Diesel injection system, always observe the following rules of cleanliness.
• Thoroughly clean fuel system line and hose connections and the surrounding area before disconnecting.
• Place removed components on a clean surface and cover. Use plastic sheet or paper. Do not use fluffy rags that leave lint!
• Carefully cover over or seal any components that have been opened if repairs are not carried out immediately.
• Install only clean parts. Do not remove replacement parts from the packaging until immediately before they are to be installed or use parts that have been stored without packaging (e.g. in toolboxes, etc.).
• When the fuel system has been opened, avoid working with compressed air whenever possible, and also avoid moving the vehicle if possible
• Do not let Diesel fuel come in contact with engine coolant hoses and, if necessary, immediately clean any hose that has been contaminated by fuel. Replace hoses if Diesel fuel has had time to soak into the hose material.
Technical Data
