New Beetle GLS L4-1.9L DSL Turbo (ALH) (2002)
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Brake Switch (Cruise Control): Testing and Inspection
Brake Light Switch -F63- and Brake Vacuum Vent Valve Switch For Cruise Control/Diesel Fuel Injection -F47-, Checking
The Diesel injection system senses throttle pedal travel via the Throttle Position Sensor -G79-. As with any mechanical device, -G79- could be faulty.
For reasons of safety, engine speed is regulated when the brakes are applied. To accomplish this, the ECM requires signals from the Brake Light Switch
-F- and the Brake Vacuum Vent Valve Switch -F47-. This means that if the brakes are applied while the throttle pedal is depressed, engine speed will
immediately drop to an idle. An incorrectly adjusted switch could lead to unnecessary regulating action.
Special tools
-
VAG 1551/1552 Scan Tool using VAG 1551/3 Adapter cable
-
VAG 1598/22 Test Box (MY 1999)
-
VAG 1598/31 Test Box (from MY 2000)
-
Fluke 83 multimeter
-
VW 1594 Adapter kit
-
Wiring diagram
Test sequence
-
Connect VAG 1551/1552 Scan Tool.
-
Switch ON ignition but do not start engine.
-
Press 0 and 1 buttons to select Address word 01: "Engine electronics"
Display will appear as shown (example only)
038906018M 1.9l R4 EDC 00AG 1813
->
Coding 0001
WSC XXXXX
-
Press -> button.
Display will appear as shown
Rapid data transfer
HELP
Select function XX
-
Press 0 and buttons to select Function 08: "Read measuring value block".
-
Press Q button to enter input.
Display will appear as shown
Read measuring value block
HELP
Input Display group number XXX
-
Press buttons 0, 0 and 6 to select "Display group 6".
-
Press Q button to enter input.
-
Observe values in Display zone 2.
Specification: 0 0 0
Read measuring value block 6
0 km/h
0 0 0
000000 255
-
Slowly operate brake pedal.
-
Specification: 0 11
Both displays must change from 0 to 1 at same time.
Read measuring value block 6
0 km/h
0 1 1
000000 255
-
Center display = Brake Vacuum Vent Valve Switch -F47-
-
Right-hand display = Brake Light Switch -F
-
Slowly release brake pedal to rest position again.
Both displays must change from 1 to 0 again.
