With Manufacturer's Scan Tool

Fuel Injectors, Checking


WARNING!
Fire hazard. Do NOT have anything in the area that can ignite gasoline!


Special tools, workshop equipment, testers, measuring instruments and auxiliary items required

- VAG 1551/1552 Scan Tool using VAG 1551/3 Adaptor cable
- VAG 1598/22 Test Box
- VAG 1527B Voltage Tester
- Fluke 83 multimeter
- VW 1594 Adaptor kit
- Wiring diagram

Requirements
- Engine Speed sensor must be OK. Engine Speed (RPM) Sensor, Checking
- Fuel pump relay must be OK







- Fuse 32 must be OK.


WARNING!
Fuel system is under pressure! Before opening the system place a cloth around the connection. Then release pressure by carefully loosening the connection.


Test sequence
- Check activation of fuel injectors using Function 03: Output Diagnostic Test Mode (DTM). [1][2][3]Output Diagnostic Test Mode (DTM) (Function 03)

If one or more injectors do not click:

Activation, checking







- Disconnect 5-pin harness connector -1- from ignition coil power output stage -2-.
- Disconnect harness connector -1- from connection on all fuel injectors.
- Connect VAG 1527B Voltage tester to cyl. 1 connector terminals using jumper wires from VW 1594 adaptor kit.
- Operate starter and check Voltage supply for cyl. 1 injector.
- LED must flicker
- Repeat check at fuel injector connectors for cyls. 2 to 4.
- Switch OFF ignition.

If LED does not flicker with any cylinder







- Connect Voltage tester to cyl. 1 fuel injector connector between terminal 1 and Ground.
- Operate starter.
- LED must light up

If LED does not light up
- Switch OFF ignition.
- Check for open circuit between 2-pin harness connector terminal 1 and fuel pump relay J17 using Wiring diagram.
- Wire resistance: 1.5 Ohms maximum

If LED flickers on one or several cylinders







- Connect VAG 1598/22 Test Box to ECM wiring harness.
- Check wiring between Test Box and connector for open circuit using Wiring diagram.
Injector 1: Terminal 2 + socket 73
Injector 2: Terminal 2 + socket 80
Injector 3: Terminal 2 + socket 58
Injector 4: Terminal 2 + socket 65
Wire resistance: 1.5 Ohms maximum

- Also check wires for short to one another.
- Specification: Infinity Ohms

- Check wiring for open circuit between fuel injector connector terminals -1-.
- Wire resistance: 1.5 Ohms maximum

Fuel injector resistance, checking







- Check fuel injector resistance between terminals.
- Specification: 13.5 to 15.5 Ohms

If specification not obtained
- Replace faulty fuel injector.