Test sequence
Checking the function of the injection timing control range is accomplished in function 04 (Basic settings). Using this procedure, the cold start injector is pulsed so that the range of values for the advanced and retarded positions of the injection timing device can be read in display field 3.
- Connect Scan Tool VAG1551 ( VAG1552 ) and select engine electronics control unit with the "Address word" 01. When doing this the engine must be running at idling speed. (Connecting Scan Tool and selecting engine electronics control unit → Scan Tool VAG1551 , connecting .)
Indicated on display:
| Rapid data transfer HELP Select function XX |
- Press buttons 0 and 4 to select "Basic setting" function 04 and confirm entry with Q button.
Indicated on display:
| Basic setting HELP Input display group number XXX |
- Press buttons 0 , 0 and 4 for "Display group number 4" and confirm entry with Q button.
Indicated on display:
| System in basic setting 4 → 880 rpm advanced 7.9 ° BTDC 66 % |
Specification in display field 3: advanced 7.0 to 9.0 ° BTDC
After approx. 10 seconds the timing device is moved to the retarded (late) position.
Indicated on display:
| System in basic setting 4 → 880 rpm retarded 3.9 ° BTDC 74 % |
Specification in display field 3: retarded 3.0 to 5.0 ° BTDC
If specifications are not obtained:
- Check commencement of injection valve as follows:
- Press → button.
- Press buttons 0 and 6 to select "End output" and confirm entry with the Q button.
- Switch off ignition.
- Disconnect the 10-pin connector for the quantity adjuster (connector to quantity adjuster in injection pump) - arrow -.
- Measure resistance between connector contacts 9+10.
Specification: 12 to 20 Ω
If specification is not obtained:
- Replace Cold Start Injector N108.
- Check DTC memory and, if necessary, repair any malfunctions and then erase → Diagnostic Trouble Code (DTC) memory, checking and erasing .
- Read-out the readiness code → Reading readiness code . If the DTC memory has been erased, the readiness code must be generated again → Readiness code, setting .
If specification is obtained:
- Remove wiper arms and plenum cover: → 92 WINDSHIELD WIPER & WASHER SYSTEM
- Connect test box VAG1598/31 to control unit wiring harness.
- Check wiring between test box and 10-pin connector for open circuit according to wiring diagram.
Terminal 9+ socket 114
Terminal 10+ sockets 1 and 2
Wire resistance: max. 1.5 Ω
- Check wires for short to one another, to vehicle Ground and to battery positive (B+).
Specification: ∞Ω
If no fault is detected in the wiring:
- Replace Diesel Direct Fuel Injection (DFI) Engine Control Module (ECM) J248 → Diesel Direct Fuel Injection (DFI) Engine Control Module (ECM) J248 , replacing .