Faulty Signal
Faulty signal
Query
Question
Question
Does the car have a DSTC system?
Yes - DSTC
No - STC
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STC - Checking the wheel sensor and pulse wheel
DSTC - DSTC
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Checking the wheel sensor and pulse wheel
- Ignition off.
- Remove the wheel for better access.
Check that the relevant wheel sensor is tightly against the shaft / hub. Check that there is no dirt between the sensor and mating surface.
Check that the relevant pulse wheel is properly secured and is not damaged (no teeth missing, not deformed or scratched etc.)
Remedy as necessary.
Other information:
- To remove and replace the front wheel sensors, see Wheel sensor, front, replacing Wheel Sensor Front, Replacing.
Was a fault detected?
Yes - Verification
No - Checking the brakes and wheel bearings
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Checking the brakes and wheel bearings
Hint: A sticking brake can block one or both wheels when the car is being driven. This will mean that the wheel sensor signal is not transmitted.
Check that the brake calipers are not sticking and blocking the wheels.
Check the wheel bearing on the relevant wheel for play and sticking.
Remedy as necessary.
Other information
- To check and replace the brake caliper, see Replacing the front brake calipers, B5244T5, B5254T2 Replacing the Front Brake Calipers.
- To replace sticking wheel bearings, see Replacing the front wheel hub Front Wheel Hub, Replacing.
Select Continue when the fault has been remedied.
Continue - Verification
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Verification
Verification
Verification
Hint: After the repair it is necessary to check that the fault has been rectified.
- Ignition off.
- Connect the connectors, install the components, etc.
- Ignition on.
- Check that the ABS warning lamp comes on and goes out after approximately 2 seconds. If the lamp does not go out, the fault is still present.
- Test-drive the car as described in Test Drive Form (ABS), description Test Drive Form (ABS), Description.
Check the ABS warning lamp during the test-drive. If the warning lamp comes on, return to the workshop and read off the diagnostic trouble codes.
Does the lamp go out and stay out?
Yes - VERIFIED
No - VERIFICATION FAILED
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VERIFIED - Fault Found
VERIFICATION FAILED - Fault-tracing information
PAPER - No Fault Found
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Fault-tracing information
Information
Fault-tracing information
The fault should have been detected and remedied. As this is not the case fault-tracing has failed.
Exit fault-tracing for this diagnostic trouble code (DTC) or make another attempt.
Do you want to exit fault-tracing?
Yes - FAULT-TRACING FAILED
No - Attempt New Test
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FAULT-TRACING FAILED - FAULT-TRACING FAILED
Attempt New Test - Checking the wheel sensor and pulse wheel
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DSTC
Signal faulty
Checking wheel sensor and sensor wheel
- Ignition off.
- Remove the wheel for better access.
Check that the relevant wheel sensor is fitted tight to the spindle/hub. There must not be any dirt between the sensor and contact surface.
Check that the relevant sensor wheel is properly tight and is free from damage (all teeth in place, no scratches, no deformations etc.).
Do the necessary corrective action.
Additional information:
- To remove/replace the front wheel sensor, see Wheel sensor, front, replacing Wheel Sensor Front, Replacing.
Is there a fault?
Yes - Verification
No - Checking the brakes and wheel bearings
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Checking the brakes and wheel bearings
Hint: A sticking brake may cause one or both wheels to be blocked during driving. This means that the wheel sensor signal has defaulted.
Check that the brake calliper is not stuck thus blocking the wheels.
Check that there is no play in the wheel bearing of the relevant wheel and that it is not stuck.
Do the necessary corrective action.
Additional information
- To check/replace the brake calliper, see Replacing the front brake calipers, B5244T5, B5254T2 Replacing the Front Brake Calipers.
- To replace sticking wheel bearings, see Replacing the front wheel hub Front Wheel Hub, Replacing.
Select Continue when the fault has been rectified.
Continue - Verification
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Verification
Verification
Verification
Hint: After the repair it is necessary to check that the fault has been rectified.
- Ignition off.
- Connect the connectors, install the components, etc.
- Ignition on.
- Check that the ABS warning lamp lights and goes out after approximately 2 seconds. If the lamp does not go out, the fault has not been rectified.
- Test-drive the car as described in Test driving Test Driving.
Check the ABS warning lamp during the test drive. If the warning lamp lights, return to the workshop and read the diagnostic trouble codes.
Does the lamp go out and stay out?
Yes - VERIFIED
No - VERIFICATION FAILED
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VERIFIED - Fault Found
VERIFICATION FAILED - Trouble-shooting information
PAPER - No Fault Found
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Trouble-shooting information
Information
FAULT-TRACING FAILED - FAULT-TRACING FAILED
Attempt New Test - Checking wheel sensor and sensor wheel
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FAULT FOUND - Fault Found
FAULT-TRACING FAILED - FAULT-TRACING FAILED
No Fault Found - No Fault Found
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