Test sequence

• Connect V.A.G 1551/1552 (Connecting scan tool and selecting engine electronics control module; see VAG 1551 SCAN TOOL, CONNECTING .)
• Run engine at idle speed and press buttons -0- and -1- to select "Engine electronics" address word 01.

  Indicated on display

  Fig 1: Scan Tool Display - Checking Diesel Injection Timing Control Range (1 Of 4)

  Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.
• Press buttons -0- and -4- to select "Basic setting" function 04 and confirm entry with -Q- button.

  Indicated on display

  Fig 2: Scan Tool Display - Checking Diesel Injection Timing Control Range (2 Of 4)

  Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.
• Press buttons -0-, -0- and -4- to select "Display group number 4" and confirm entry with -Q- button.

  Indicated on display

  Fig 3: Scan Tool Display - Checking Diesel Injection Timing Control Range (3 Of 4)

  Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.
  • Specified value in display field: 3: 7.0 to 9.0° BTDC

  After approx. 10 seconds the spray adjuster is moved to the retarded (late) position.

  Indicated on display

  Fig 4: Scan Tool Display - Checking Diesel Injection Timing Control Range (4 Of 4)

  Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.
  • Specified value in display field 3: 3.0 to 5.0° BTDC
• Press the --> button
• Press buttons -0- and -6- to select "End output" function 06 and confirm entry with -Q- button.
• Switch ignition off.

If the specifications are not obtained:

• Check cold start injector as follows:
• Disconnect the10-pin connector for the cold start injector (connector to injection pump) (arrow).
Fig 5: Disconnecting 10-Pin Connector For Cold Start Injector (Connector To Injection Pump)
Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.
• Measure resistance between connector terminals 9 + 10.
  • Specification: 12.0 to 20.0 Ω
Fig 6: Identifying 10-Pin Connector Terminals
Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.

If the specification is not obtained:

• Replace Cold Start Injector -N108-, see item  17.
• Check DTC memory and, if necessary, repair any malfunctions and then erase. See DIAGNOSTIC TROUBLE CODE (DTC) MEMORY, CHECKING AND ERASING .
• Read readiness code, see READINESS CODE, DISPLAYING .

  If the DTC memory has been erased or the engine control module was disconnected from permanent battery positive (B+), the readiness code must be generated again. See READINESS CODE, SETTING .

If the specification is obtained:

• Remove wiper arms and plenum cover.

  See Plenum Cover Emoval & Installation

• Connect test box VAG 1598/22 (through my 1999) or VAG 1598/31 (from my 2000) to control module wiring harness.
  Fig 7: Connect Test Box Vag 1598/22 Or Vag 1598/31 To Control Module Wiring Harness

  Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.
• Check wiring between test box and 10 -pin connector for open circuit according to wiring diagram.
  Fig 8: Identifying 10-Pin Harness Connector Terminals

  Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.
  10-PIN HARNESS CONNECTOR TERMINAL SPECIFICATION (COLD START INJECTOR)
  
  

  	Test box socket no.
  Terminal	Through MY 1999	From MY 2000
  9	79	114
  10	2	1
  10	28	2

  • Wire resistance: max. 1.5 Ω
• Check wires for short to one another, to vehicle earth and to battery positive.
  • Specification: INFINITY Ω
• If wiring and the resistance measurement values are OK, Replace engine control module, see DIESEL DIRECT FUEL INJECTION (DFI) ENGINE CONTROL MODULE (ECM) -J248-, REPLACING .