Engine Speed (RPM) Signal, Checking

RPM signal
- Connect VAG 1598/4 adapter harness to 26-point instrument cluster connector (green).
- Connect adapter harness to VAG 1598A test box
- Connect engine tester VW 1367 to measure RPM
- Connect signal wire (green terminal) of tester VW 1367 to socket 12 of VAG 1598A test box using connector test kit VW 1594.
- Start engine and let idle.
- Engine RPM must be displayed on VW 1367

If NOT
- Check wiring for open circuit according to wiring diagram, repair as necessary.