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DTC 29 ABNORMAL ABS WHEEL SPEED SENSOR SIGNAL ON ANY ONE OF FOUR SENSOR

DTC 29 ABNORMAL ABS WHEEL SPEED SENSOR SIGNAL ON ANY ONE OF FOUR SENSOR

DIAGNOSIS:


• Faulty ABS wheel speed sensor signal (noise, irregular signal, etc.)

• Faulty tone wheel

• Wheels turning freely for a long time


TROUBLE SYMPTOM:


• ABS does not operate.

• EBD does not operate.

Note

In addition to the ABS warning light, brake warning light illuminates.



WIRING DIAGRAM:


CHECK IF THE WHEELS HAVE TURNED FREELY FOR A LONG TIME.

Is the wheels have been turned freely for more than one minute, such as when vehicle is jacked-up, under full-lock cornering or the tires not in contact with road surface?

Yes


No

• The ABS is normal. Erase the DTC.

•
Note

When the wheels turn freely for a long time, such as when vehicle is towed or jacked-up, or when steering wheel is continuously turned all way, this DTC may sometimes occur.



CHECK TIRE SPECIFICATIONS.

Turn the ignition switch to OFF.

Are the tire specifications correct?

Yes


No

Replace the tire.


CHECK WEAR OF TIRE.

Is the tire worn excessively?

Yes

Replace the tire.


No


CHECK TIRE PRESSURE.

Is the tire pressure correct?

Yes


No

Adjust the tire pressure.


CHECK INSTALLATION OF ABS WHEEL SPEED SENSOR.

Are the ABS wheel speed sensor installation bolts tightened 33 Nm (3.3 kgf-m, 24 ft-lb)?

Yes


No

Tighten the ABS wheel speed sensor installation bolts securely.


CHECK ABS WHEEL SPEED SENSOR GAP.

Measure the tone wheel to ABS wheel speed sensor piece gap over entire perimeter of the wheel.

Is the gap as following value? Front wheel: 0.3 — 0.8 mm (0.012 — 0.031 in) Rear wheel: 0.7 — 1.2 mm (0.028 — 0.047 in)

Yes


No

• Adjust the gap.

•
Note

Adjust the gap using spacer (Part No. 32009555). If the spacers cannot correct gap, replace worn sensor or worn tone wheel.



PREPARE OSCILLOSCOPE.

Is an oscilloscope available?

Yes


No


CHECK ABS WHEEL SPEED SENSOR SIGNAL.

Raise all four wheels off ground.

Turn the ignition switch to OFF.

Connect the oscilloscope to the connector.

Turn the ignition switch to ON.

Rotate the wheels and measure voltage at specified frequency.

Note

When this inspection is completed, ABSCM& H/U sometimes stores the DTC 29.


Connector & terminal

Front RH

(B15) No. 1 (+) — No. 2 (−):

Front LH

(B62) No. 20 (+) — No. 24 (−):

Rear RH

(B99) No. 10 (+) — No. 9 (−):

Rear LH

(B99) No. 5 (+) — No. 4 (−):

Is the waveform pattern on oscilloscope as shown in the figure?

Yes


No


CHECK CONTAMINATION OF ABS WHEEL SPEED SENSOR OR TONE WHEEL.

Remove the disc rotor or drum from hub.

Is the ABS wheel speed sensor piece or tone wheel contaminated by dirt or other foreign matter?

Yes

Thoroughly remove dirt or other foreign matter.


No


CHECK DAMAGE OF ABS WHEEL SPEED SENSOR OR TONE WHEEL.

Are there broken or damaged teeth in the ABS wheel speed sensor piece or tone wheel?

Yes

Replace the ABS wheel speed sensor or tone wheel. Front: Rear: and Front: Rear:


No


CHECK TONE WHEEL RUNOUT.

Measure the tone wheel runout.

Is the runout less than 0.05 mm (0.0020 in)?

Yes


No

Replace the tone wheel. Front: Rear:


CHECK ABSCM&H/U.

Turn the ignition switch to OFF.

Connect all connectors.

Erase the memory.

Perform the inspection mode.

Read out the DTC.

Is the same DTC as in the current diagnosis still being output?

Yes

Replace the ABSCM&H/U.


No


CHECK ANY OTHER DTC APPEARANCE.

Are other DTCs being output?

Yes

Proceed with the diagnosis corresponding to DTC.


No

A temporary poor contact.