To perform the test, manually rotate the left front wheel at a speed of approx. 2 - 3 km/h (observe display in the Tester screen).
Slowly increase the speed and simultaneously observe the speed increase (display).
Nominal values/required display
Speed steps of approx. 0.06 km/h. First display at 1.81 km/h.
This means: From the value measured last, the next value must be 0.06 km/h higher or, if the wheel is rotating slower, must be 0.06 km/h lower.
The Tester rounds the value down to 0.05 km/h or up to 0.07 km/h in some cases.
Example
First measured value = 1.81 km/h
Second nominal value = 1.87 km/h
Third nominal value = 1.93 km/h
etc.
Further to test 2
Display all four wheels in the Tester display.
Drive straight ahead at a uniform speed of approx. 2-4 km/h and have a second person observe the Tester display.
Required display: Deviation between the wheel speeds of the four wheels max. 1 km/h.
Further details about tests 1 and 2 are given under "Actual values menu" on P. 45 - D 38.
Possible faults (cause in the event of deviation)
- Air gap between speed sensor and gear wheel (pulse wheel) too large or, due to wear (chip formation), too small (check installation).
- Pulse wheel defective or corroded.
- Wheel bearing damage (wheel bearing not adjustable).
- Plug connection in wiring from the speed sensor to the control module or PIN on the control module connector not OK.
Test Point 3
Test point 3
Front right speed sensor, signal implausible
DTC 4201
General procedure as for test point 2/diagnostic trouble code 4206 (check speed sensor signal with the Porsche System Tester 2).
- Speed sensor signal: Go to the Actual values menu. There, select the front right wheel speed.
Test Point 4
Test point 4
Rear right speed signal, signal implausible
DTC 4211
General procedure as for test point 2/diagnostic trouble code 4206 (check speed sensor signal with the Porsche System Tester 2).
- Speed sensor signal: Go to the Actual values menu. There, select the rear right wheel speed.
Test Point 5
Test point 5
Rear left speed signal, signal implausible
DTC 4216
General procedure as for test point 2/diagnostic trouble code 4206 (check speed sensor with the Porsche System Tester 2).
- Speed sensor signal: Go to the Actual values menu. There, select the rear left wheel speed.