With Manufacturer's Scan Tool
Fuel Injectors, Checking
Special tools, workshop equipment, testers, measuring instruments and auxiliary items required
- VAG 1526 Hand multimeter or VAG 1715 multimeter
- VAG 1527 LED test light
- VAG 1594 Adapter set
- VAG 1598/31 test box
- Electrical Wiring Diagrams
Test prerequisites
- The fuses must be OK.
- The battery voltage must be at least 11.5 V.
- All electrical accessories, e.g. lights and rear window heating must be switched off.
- If the vehicle is equipped with air conditioning, it must be turned off.
- Selector lever must be in position "P" or "N" on vehicles with an automatic transmission.
- Fuel Pump (FP) Relay -J17- must be OK., checking:
Checking activation
- First check activation of fuel injectors via Output Diagnosis Test Mode (DTM)
[1][2][3]Output Diagnostic Test Mode (DTM) (Function 03)
If activation is OK.:
- Remove intake manifold:
NOTE: Seal the intake ports in the intake manifold or in the cylinder head with a clean cloth.
- Pull connector off all fuel injectors.
Checking resistance of fuel injectors
- Check resistance of fuel injectors between terminals.
Specification: 13.0 to 19.0 ohms
NOTE The resistance value is valid when measured at approx. 20 degrees C. The resistance value increases at higher temperatures.
If the specification is not obtained:
- Replace faulty fuel injector, item 7. Refer to "Fuel Delivery and Air Induction/Fuel Rail",
Service and Repair
Observe the following when installing fuel injectors:
- Replace O-rings on all fuel injectors and moisten then lightly with clean engine oil.
- Insert fuel injectors vertically and in the correct position into the fuel rail and secure with retaining clips.
- Set fuel rail with secured fuel injectors on cylinder head and press in evenly.
- The connectors must audibly engage in the fuel injectors when pushed on.
- Check DTC memory, repair malfunctions if necessary and then erase DTC memory.
Reading Diagnostic Trouble Codes
- Erase learned values and adapt Motronic Engine Control Module (ECM) -J220- again.
- Read readiness code. If the DTC memory has been erased or the Motronic Engine Control Module (ECM) -J220- was disconnected from battery positive (B+), the readiness code must be generated again.
Monitors, Trips, Drive Cycles and Readiness Codes
Monitors, Trips, Drive Cycles and Readiness Codes
Checking voltage supply
- Connect VAG 1527 LED test light to terminal 1 and ground (GND) of relevant fuel injector connector using adapter cables from VAG 1594.
- Operate the starter and check the voltage supply for the fuel injector. The LED must light up
- Switch off ignition.
If the LED does not light up:
- Check wire for open circuit between 2-pin connector terminal 1 and Fuel Pump (FP) Relay -J17- referring to Electrical Wiring Diagrams.
Wire resistance: max. 1.5 ohms
Checking activation and voltage supply
- Connect VAG 1527 LED test light to connector terminals of fuel injector to be tested using cables from VAG 1594.
- Operate starter and check the activation for the fuel injector.
The LED must flicker
- Switch off ignition.
The LED does not flicker:
- Remove wiper arms and cowl panel:
- Connect VAG 1598/31 test box to control module wiring harness. The Motronic Engine Control Module (ECM) -J220- remains disconnected.
- Check wiring for open circuit between test box and the 2-pin connector for fuel injectors referring to Electrical Wiring Diagrams.
Fuel injector 1: Terminal 2 and socket 96
Fuel injector 2: Terminal 2 and socket 112
Fuel injector 3: Terminal 2 and socket 88
Fuel injector 4: Terminal 2 and socket 113
Fuel injector 5: Terminal 2 and socket 97
Fuel injector 6: Terminal 2 and socket 89
Wire resistance: max. 1.5 ohms
- Additionally check wiring for short to one another, to vehicle ground (GND) and to battery positive.
Specification: infinity ohms
If there is no Diagnostic Trouble Code (DTC) in the wiring and the resistance measurement values are OK.:
- Replace Motronic Engine Control Module (ECM) -J220-.
- Check DTC memory, repair malfunctions if necessary and then erase DTC memory.
Reading Diagnostic Trouble Codes
- Erase learned values and adapt Motronic Engine Control Module (ECM) -J220- again.
- Read readiness code. If the DTC memory has been erased or the Motronic Engine Control Module (ECM) -J220- was disconnected from battery positive (B+), the readiness code must be generated again.
Monitors, Trips, Drive Cycles and Readiness Codes
Monitors, Trips, Drive Cycles and Readiness Codes