S-Type (X200) V8-4.2L (2005)
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10.
If no faults were found and the wheel speed sensor fault was determined to be 'permanent' in step 1, the ABS/DSC module should be replaced.
11.
If the fault is 'intermiffent' and the wheel speed sensor was verified to be OK in Step 6, replace connector pins and link harnesses, where possible,
in the wheel speed sensor circuit, as the likely root cause of the fault is an intermittent wiring or connector fault.
SIGNAL FAULT DIAGNOSTIC GUIDELINES
NOTE:
Wheel speed sensor signal faults can be caused by sensor installation issues, wiring issues, or even vehicle behavior.
NOTE:
A wheel speed sensor signal fault will clear and not return after a normal test drive if the fault was a result of either of the following situations:
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Individual wheels or pairs of wheels having been rotated independently of the others, such as when the wheels have been driven while the
vehicle is on a wheels-free ramp.
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A loss of traction on one or more wheels for extended periods.
1.
Check that the vehicle has the correct wheel and tire sizes and that the tires are properly inflated.
2.
If any discrepancies were found, correct and re-test.
3.
Visually inspect to ensure that the sensor is correctly installed and seated.
4.
If the encoder ring is visible, check that it is clean and that none of the teeth are damaged.
5.
If the encoder ring is installed in the wheel bearing, and there is no excessive play in the bearing, remove the bearing and check the encoder ring
for contamination or damage.
6.
Check the sensor lead for any signs of damage to the outer insulation.
7.
Check the sensor lead connector for damage or any signs of water ingress.
8.
If any faults were found, correct and re-test.
9.
If the diagnostic tool supports a data logging application, perform the following:
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Set up to monitor the output from all four wheel speed sensors during a road test.
NOTE:
As the vehicle speed increases from stand still, all four signals should rise simultaneously and show the same output, within an average of +/- 1.2
mph (+/- 2 kph). There should not be any random or regular signal spikes or deviations on individual signals.
^
Test drive the vehicle slowly at approximately 10 mph (16 kph) in a straight line on a smooth road.
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Check for any random spikes/deviations occurring on any individual signal that will indicate an electrical fault.
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Check for any regular spikes/deviations occurring on any individual signal that will indicate a problem with the sensor encoder ring.
10.
Perform the following integrity checks on the wiring between the sensor connector and the control module connector:
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Check for shorts to power or ground.
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Check for signs of corrosion or water ingress into the connectors.
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Check for any cuts or abrasions in the wiring insulation, where possible.
11.
Disconnect and re-connect all connectors between the ABS/DSC module and the suspect wheel speed sensor and check to see if the DTC clears.
12.
Determine if the root cause of the problem is the sensor as follows:
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Swap the left-hand and right-hand sensors on an axle.
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Test drive the vehicle above a speed of 10 mph (16 kph).
