With Manufacturer's Scan Tool

Fuel injectors, checking

WARNING!
Fire hazard! Do not smoke, work near heaters or open flame, or have anything nearby that could ignite fuel. The fuel system is under pressure. Before opening, cover connections with a rag, and open carefully to release pressure.

Special tools and equipment
- VAG1551 or VAG1552 Scan Tool (ST) with VAG1551/3 adapter cable
- VAG1598/22 test box
- Multimeter US1119 (Fluke 83 or equivalent)
- VAG1348/3A remote control with adapter cable VAG1348/32
- VAG1527B LED voltage tester
- VW1594 connector test kit
- VAG1602 measuring glass from calibration tester
- Wiring diagram

Checking conditions
- Engine Speed (RPM) Sensor OK.
- Fuel pump relay OK



- Fuse 34 OK


Checking
- Conduct output Diagnostic Test Mode (DTM) actuating fuel injectors. [1][2][3]Output Diagnostic Test Mode (DTM) (Function 03)

If one or more fuel injectors do not click:
- Check actuation of fuel injectors.




- Disconnect 5-pin harness connector -1- from ignition coil -2-.




- Disconnect harness connectors -1- from all fuel injectors -2-.
- Connect VAG1527B LED voltage tester to connector terminals for cylinder / fuel injector using adapter cables from VW1594 connector test kit.
- Operate starter and check voltage supply for cylinder 1 fuel injector.
- LED must flicker.
- Repeat test for fuel injectors for cylinders 2-6.
- Switch ignition off.

If the LED does not flicker on any cylinder:



- Connect VAG1527B LED voltage tester to cylinder 1 harness connector terminal 1 and Ground.
- Operate starter.
- LED must light.

If the LED does not light up:
- Switch ignition off.
- Check wire between 2-pin connector terminal 1 and fuel pump relay -J17- for open circuit using wiring diagram.
- Specified value: max. 1.5 Ohms

If the LED flickers on one or several cylinders:



- Connect VAG1598/22 test box to ECM harness connector.
- Check wiring for open circuits between ECM/test box and fuel injector harness connectors:
- Cyl. 1 fuel injector terminal 2 to ECM/test box socket 73
- Cyl. 2 fuel injector terminal 2 to ECM/test box socket 80
- Cyl. 3 fuel injector terminal 2 to ECM/test box socket 58
- Cyl. 4 fuel injector terminal 2 to ECM/test box socket 65
- Cyl. 5 fuel injector terminal 2 to ECM/test box socket 72
- Cyl. 6 fuel injector terminal 2 to ECM/test box socket 79
- Specified value: max. 1.5 Ohms
- Check wiring for short circuits between wires and connector terminals.
Specified value: Infinity Ohms
- Check wiring between connector terminal 1 of all fuel injectors for open circuit.
- Specified value: max. 1.5 Ohms


Fuel injector resistance, checking




- Check resistance of individual fuel injectors.
Specified value: 13.5-15.5 Ohms

If resistance is NOT OK:
- Replace affected fuel injector. Service and Repair