Actual Values (Abs And Abs/Tc); Further To Speed - Porsche Boxster Technical Manual

Boxster Anti-lock brake system, diagnosis 45
e
Actual values (ABS and ABS/TC) Procedure
Two tests are possible to determine the speed-
The following actual values can be checked with sensor signal.
this menu (with this function):
-Speed (wheel speed / test possible up to Test 1 with the vehicle raised.
18 km/h) (Swapping the speed sensors and checking the
quality of the speed sensor signal.)
Speed, front left , ,
S
d
f
t ' ht Test 2 when driving straight ahead at approx.
pee, ron rig 2 -4 km/h.
Speed, rear left
(
'
I I
' ,
f h ' d' '
d I h I S d ' ht signa qua Itles 0 t e In IVI ua w ee s are com-
pee rear rig "
J pared with each other). Test 2 IS a better
measure of the signal quality than is test 1.
e -Engine rpm (not present with Solo ASS)
Further to test 1
Further to speed: In order to perform the test, manually turn the
left front wheel at a uniform speed of approx.
Se.'ect, activate and call up the desired wheel 2 -3 km/h (observe display in the Tester
usIng the arrow k~ys., , screen). Slowly increase the speed while simulta-
The wheel speed IS dIsplayed according to the neously observing the speed increase (display).
wheel rpm.
All four wheels are displayed if all speeds are acti- Nominal values/required display
vated and called up. 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
Example (front left wheel) 0.06 km/h higher or, if rotating slower, must be
0.06 km/h lower. The Tester rounds the value
Speed, front left 15.00 km/h down to 0.05 km/h or up to 0.07 km/h in some
e cases.
Example
Example (all wheels)
Speed, front left 15.00 km/h First measured value = 1.81 km/h
Second nominal value = 1.87 km/h
Speed, front right 15.00 km/h Third nominal value = 1.93 km/h
etc.
Speed, rear left 15.00 km/h
Speed, rear right 15.00 km/h
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45 02 Diagnosis/troubleshooting, anti-lock brake system 45 -D 39
Printed in Germany -3, 1996 986D451
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