184000615 - Z63 SPEED SENSORS ERROR PLAUSIBILITY ERROR

The diagnostic equipment signals one or more of the following errors: C1041 Right front speed sensor, plausibility error, C1036 Left front speed sensor, plausibility error, C1051 Right rear speed sensor, plausibility error and/or C1046 Left rear speed sensor, plausibility error
This error is signalled if the control unit does not detect electrical type problems, but the speed of one of the wheels (transmitted by the sensor) is not felt to be plausible
Results of the tests
1SENSOR CHECKAll OKProblems encounteredOperation
Visually inspect the state of the sensors affected by the error (front and/or rear, right and/or left).

In particular, check:

  • that there are no metal shavings in the flywheel magentic tracks
  • that the sensor involved is correctly fitted
  • that the sensor involved shows no signs of abrasion or distortion
Position the vehicle on a lift and check the condition of the flywheel, removing the wheel, if necessary. In particular, check that there are no metal shavings in the flywheel magnetic tracks		Move on to Step 2Sensor fitting faultyRefit correctly.Move on to Step 2
Front sensor faultyReplace the sensor Op. Op. 3340A30 RPM SENSOR (ONE) OF ONE L/H OR R/H FRONT WHEEL - R+RMove on to Step 2
Rear sensor faultyReplace the sensor Op.    Op. 3340A34 RPM SENSOR (ONE) OF ONE L/H OR R/H REAR WHEEL - R+RMove on to Step 2
Phonic wheel damagedReplace the flywheel
2CONTROL UNIT CONNECTOR CHECKAll OKProblems encounteredOperation
Check that the control unit connector is not faulty at the pins (on both the wiring side and the control unit side) by carrying out a visual inspection.

In particular, check that:

  • They are not oxidized
  • They are not distorted or broken
Move on to Step 3Wiring side connector faultyReplace the wiring Op. 5505C28 INTERGRATED ENGINE BAY AND ABS SYSTEM WIRING - R R
Control unit side side connector faultyReplace the electronic control unit    Op. 3340A12 ABS HYDRAULIC AND ELECTRONIC CONTROL UNIT
3SENSOR RPM SIGNAL CHECKAll OKProblems encounteredOperation
Rotate the wheel and see whether the Examiner displays the wheel rpm figure. (See procedure A.1)Move on to Step 4The speed of the wheel cannot be evaluated using the ExaminerMove on to Step 4
4SENSOR WIRING CONTINUITY CHECKAll OKProblems encounteredOperation
Check the continuity of the wiring from the control unit to the intermediate connector for the wheel rpm sensor wiringMove on to Step 5Wiring defectiveReplace the wiring from the control unit to the connector
Sensor defectiveReplace the sensor
5WHEEL SPEED CORRECT VALUE CHECKAll OKProblems encounteredOperation
Position the vehicle on a roller bench, set the speed at between 4 and 6 km/h and evaluate the wheel speed using the ExaminerMove on to Step 6Wheel sensor defective (the Examiner shows a different speed to the one setReplace the faulty wheel sensor
End section of wiring from the wheel sensor to the connector defectiveReplace the end section of the wiring from the wheel sensor to the connector
6CHECK ON CORRECT OPERATIONAll OKProblems encounteredOperation
Delete the errors using the diagnostic equipment.Carry out the road test See Test    See Test 3340OA A.B.S. SYSTEM ACTUATION CHECKto ensure that the control unit checks whether there are any errors still present.Return to the workshop and check that the fault is no longer present using the diagnostic equipmentEnd of diagnosisThe fault persistsMove on to Step 1