Fuel Injectors, Checking
CAUTION!
Fire hazard! Do not smoke, work near heaters or open flame, or have anything in the area that could ignite fuel.
Checking resistance
- Disconnect harness connector from fuel injector to be checked.
- Measure fuel injector resistance using multimeter (Fluke 83 or equivalent).
- Specified value:
- Bosch: 15.0 to 17.0 ohm
- Siemens: 13.5 to 14.5 ohm
- Replace any fuel injector for which resistance measurement does not fall within specified value.
Checking voltage supply
- Fuel pump relay OK Testing and Inspection
- Fuel pump OK
- Fuse for fuel injectors OK
- Disconnect harness connector from fuel injector to be checked.
- Connect VAG 1527B voltage tester between harness connector terminal 1 and Ground (GND).
- Use scan tool "Output Diagnostic Test Mode" function 03 to trigger fuel pump relay -J17-.
- Specified value: voltage tester must light up
If voltage tester does not light up:
- Check wiring between terminal 1 and fuel injector fuse using wiring diagram.
If voltage tester does light up:
- Check fuel injector triggering.
Checking fuel injector triggering
- Disconnect harness connector from fuel injector to be checked.
- Connect VAG 1527B voltage tester between terminal 2 and battery positive voltage (B+) using jumper wires from connector test kit VW 1594.
- Operate starter for several seconds (OK for engine to turn).
- Voltage tester must flash
If tester does not flash, check wiring between terminal 2 of the respective fuel injector and the ECM as follows:
- Connect VAG 1598/19 test box to ECM harness connector.
- Check fuel injector 1 signal wire for continuity between harness connector terminal 2 and test box socket D1.
Specified value: max. 1 ohms
- Check fuel injector 2 signal wire for continuity between harness connector terminal 2 and test box socket D2.
Specified value: max. 1 ohms
- Check fuel injector 3 signal wire for continuity between harness connector terminal 2 and test box socket D4.
Specified value: max. 1 ohms
- Check fuel injector 4 signal wire for continuity between harness connector terminal 2 and test box socket D5.
Specified value: max. 1 ohms
- Check fuel injector 5 signal wire for continuity between harness connector terminal 2 and test box socket D6.
Specified value: max. 1 ohms
- Check fuel injector 6 signal wire for continuity between harness connector terminal 2 and test box socket D8.
- Specified value: max. 1 ohms
If continuity is not obtained:
- Eliminate open or short circuit between terminal 2 of respective fuel injector connector, and ECM connector.
Cylinder number Connector D terminal
(fuel injector terminal 1)
1 1
2 2
3 4
4 5
5 6
6 8
If voltage tester does not flash for each fuel injector:
- Check voltage supply for ECM.
If the voltage supply is OK:
- Replace ECM