ABS (DIAGNOSTICS) > Diagnostic Procedure with Diagnostic Trouble Code (DTC)

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

DTC DETECTING CONDITION:

• Defective ABS wheel speed sensor signal (noise, abnormal signal, etc.)

• Defective magnetic encoder

• When a wheel is turned freely for a long time

TROUBLE SYMPTOM:

• ABS does not operate.

• EBD does not operate.

NOTE:

Brake warning light comes on as well as the ABS warning light.

WIRING DIAGRAM:

• LHD model

• RHD model

STEPCHECKYESNO

1.WHETHER A WHEEL TURNED FREELY OR NOT.

Did the wheels turn freely for more than one minute, such as when the vehicle is jacked-up, under full-lock cornering or when the wheels are not in contact with road surface?

ABS is normal. Erase the memory.

NOTE:

This diagnostic trouble code may sometimes occur if the wheels turn freely for a long time, for example when the vehicle is towed or jacked-up, or when steering wheel is continuously turned all the way.

2.CHECK TIRE SPECIFICATIONS.

Turn the ignition switch to OFF.

Are the tire specifications correct?

Replace the tire.

3.CHECK WEAR OF TIRE.

Is the tire worn excessively?

Replace the tire.

4.CHECK TIRE PRESSURE.

Is the tire pressure correct?

Adjust the tire pressure.

5.CHECK INSTALLATION OF ABS WHEEL SPEED SENSOR.

Is the ABS wheel speed sensor installation bolt tightened to 33 N·m (3.4 kgf-m, 25 ft-lb)?

Tighten the ABS wheel speed sensor installation bolts.

6.CHECK ABS WHEEL SPEED SENSOR GAP.

Measure the gap between the ABS wheel speed sensor protrusion and tone wheel.

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

Adjust the gap.

NOTE:

Adjust the gap using spacers (Part No. 26755AA000). If spacers cannot correct the gap, replace the worn sensor or worn tone wheel.

7.PREPARE OSCILLOSCOPE.

Is an oscilloscope available?

8.CHECK ABS WHEEL SPEED SENSOR SIGNAL.

1) Lift up the vehicle.

2) Turn the ignition switch to OFF.

3) Connect the oscilloscope according to the DTC.

4) Turn the ignition switch to ON.

5) Start the wheel, and measure the voltage at the specified frequency.

NOTE:

When this inspection is completed, ABSCM&H/U may record DTC 29.

Connector & terminal

Front RH

LHD model

(B6) No. 1 (+) — No. 2 (−):

RHD model

(F95) No. 1 (+) — No. 2 (−):

Front LH

(F94) No. 1 (+) — No. 2 (−):

Rear RH

LHD model

(B98) No. 6 (+) — No. 19 (−):

RHD model

(B98) No. 28 (+) — No. 29 (−):

Rear LH

LHD model

(B98) No. 18 (+) — No. 17 (−):

RHD model

(B98) No. 25 (+) — No. 26 (−):

Is the oscilloscope pattern the same voltage as shown in the table?

9.CHECK CONTAMINATION OF ABS WHEEL SPEED SENSOR OR TONE WHEEL.

Remove the disc rotor or drum from the hub.

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

Thoroughly remove dirt or other foreign matter.

10.CHECK DAMAGE OF ABS WHEEL SPEED SENSOR OR TONE WHEEL.

Are there cracked or damaged teeth in the protrusion of the ABS wheel speed sensor or the tone wheel?

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

11.CHECK TONE WHEEL RUNOUT.

Measure the tone wheel runout.

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

Replace the tone wheel. Front: Rear:

12.CHECK ABSCM&H/U.

1) Turn the ignition switch to OFF.

2) Connect all connectors.

3) Erase the memory.

4) Perform the Inspection Mode.

5) Read the DTC.

Is the same DTC still output?

Replace the ABSCM only.

13.CHECK OTHER DTC DETECTION.

Is there any other DTC detected?

Perform the diagnosis according to DTC.

Temporary poor contact occurs.