DTC 28
TROUBLE CODE 28
- FAULTY A.B.S. SENSOR (WHEN THERE IS NO OPEN CIRCUIT OR SPEED SIGNAL INPUT.)-
DIAGNOSIS:
- Faulty A.B.S. sensor/harness
- Faulty tone wheel
- Faulty A.B.S. control module
TROUBLE SYMPTOM:
- A.B.S. does not operate.
NOTE: The A.B.S. control module will sense that the A.B.S. sensor circuit is "open" due to increased resistance but this trouble code will appear when the speed signal is not present or when it suddenly disappears while driving.
1. CHECK INPUT SIGNAL OF A.B.S. SENSOR TO A.B.S. CONTROL MODULE SIDE.
1) Raise all four wheels of ground.
2) Turn ignition switch OFF.
3) Disconnect connector from A.B.S. control module.
4) Disconnect connector cover from connector.
5) Connect connector to A.B.S. control module.
6) Connect the oscilloscope to the A.B.S. control module connector in accordance with the trouble code.
7) Turn ignition switch ON.
8) Rotate wheels and measure voltage at specified frequency.
NOTE: When this inspection is completed, the A.B.S. control module sometimes memorizes the trouble code 29.
TROUBLE CODE / Connector & terminal:
21 / (P4) No.23 - No.21
23 / (P4) No.22 - No.4: AWD
23 / (P4) No.5 - No.4: FWD
25 / (P4) No.24 - No.26
27 / (P4) No.8 - No.9
Specified voltage: 0.12 - 1 V (When it is 20 Hz)
2. CHECK RESISTANCE OF A.B.S. SENSOR.
1) Turn ignition switch OFF.
2) Disconnect connector from A.B.S. sensor.
3) Measure resistance between A.B.S. sensor connector terminals.
TROUBLE CODE / Connector & terminal:
21 / (B6) No.1 - No.2
23 / (B11) No.1 - No.2
25 / (P5) No.1 - No.2
27 / (P12) No.1 - No.2
Specified resistance: 0.8 - 1.3 kohms
3. CHECK A.B.S. SENSOR MECHANICAL TROUBLE.
1) Discount brake as outlined in manual to gain access to A.B.S. sensor and tone wheel for inspection.
2) Check pole piece and tone wheel for accumulation of foreign particles. If necessary, remove foreign particles and clean.
3) Check tone wheel teeth for cracks for deformities. If necessary, replace tone wheel (No. of teeth: 44) with a new one.
4) Check tone wheel for looseness.
Tightening torque:
10 - 16 Nm (1 - 1.6 kg-m, 7 - 12 ft-Ib.)
5) Measure tone wheel-to-pole piece gap over entire perimeter of the wheel.
If measurements check out "Not OK", adjust the gap using spacers (Part No. 26755AA000). If spacers cannot correct the gap, replace worn sensor or worn tone wheel.
6) Check hub runout.
Specifications 0.05 mm (0.0020 in)