DTC 15
Part 1 Of 2:
Part 2 Of 2:
DTC 15: Wheel Speed Sensor (Abnormal Output Signal)
CIRCUIT OPERATION
^ A toothed ABS rotor generates a voltage pulse as it moves across the pickup field of each wheel speed sensor.
^ The amount of voltage generated at each wheel is determined by the clearance between the ABS rotor teeth and the wheel speed sensor, and by the speed of rotation.
^ The wheel speed sensors transmit the frequency of the voltage pulses and the amount of voltage generated by each pulse to the ABS-ECU.
^ The ABS hydraulic unit modulates the amount of braking force individually applied to each wheel cylinder.
ABS DTC SET CONDITIONS
^ DTC 15 is output when output signal produced by any of wheel speed sensor is abnormal (excluding short and open-circuits).
TROUBLESHOOTING HINTS (The most likely causes for this DTC is to set are:)
^ improper installation of the wheel speed sensor
^ Malfunction of the wheel speed sensor
^ Damaged wiring harness or connector
^ Malfunction of the ABS rotor
^ Malfunction of the wheel bearing
DIAGNOSIS
Required Special Tools:
^ MB991223: Harness Set
^ MB991502: Scan Tool (MUT-II)
^ MB991529: Diagnostic Trouble Code Check Harness
STEP 1. Check the wheel speed sensor installation.
Q: Are the wheel speed sensors bolted securely in place at the front knuckle or the rear knuckle?
YES: Go to Step 2.
NO: Install it properly. Then go to Step 8.
STEP 2. Check the harness wires between the ABS-ECU connector A-02 (terminals 6 and 7) and the wheel speed sensor
NOTE: After inspecting the intermediate connector C-06, inspect the wires. If the intermediate connector C-06 is damaged, repair or replace it. If the connector has been repaired or replaced, go to Step 8.
Q: Is any of the harness wires between the ABS-ECU connector A-02 (terminals 6 and 7) and the wheel speed sensor
YES: Repair it and go to Step 8.
NO: Go to Step 3.
STEP 3. Check the harness wires between the ABS-ECU connector A-02 (terminals 4 and 5) and the wheel speed sensor
Q: Is any of the harness wires between the ABS-ECU connector A-02 (terminals 4 and 5) and the wheel speed sensor
YES: Repair it and then go to Step 8.
NO: Go to Step 4.
STEP 4. Check the harness wires between the ABS-ECU connector A-02 (terminals 1, 3, 8, and 9) and the wheel speed sensor connector D-08
NOTE: After inspecting the intermediate connectors C-90, C-94 and D-16, inspect the wires. If the intermediate connector C-90, C-94 or D-16 is damaged, repair or replace it. If the connector has been repaired or replaced, go to Step 8.
Q: Is any of the harness wires between the ABS-ECU connector A-02 (terminals 1, 3, 8, and 9) and the wheel speed sensor connector D-08 Rear RH> (terminals 1 and 2) or D-O9 Wear LH> (terminals 1 and 2) damaged?
YES: Repair it and then go to Step 8.
NO: Go to Step 5
STEP 5. Check each wheel speed sensor output voltage
Output Voltage
^ When measured with a voltmeter 42 mV or more
^ When measured with oscilloscope (maximum voltage) 200 mV or more
Q: Does the voltage meet the specification?
YES: Replace the hydraulic unit (integrated with ABS-ECU) and then go to Step 8.
NO: Go to Step 6
STEP 6. Check the wheel speed sensors or ABS rotors.
If there is a damage in any of the following check items, replace the wheel speed sensor or the ABS rotor.
Check items
^ Wheel speed sensor internal resistance
Standard value 1.28 - 1.92 k Ohms
^ Insulation between the wheel speed sensor body and the connector terminals
^ Toothed ABS rotor
Q: Is any of the wheel speed sensors or ABS rotors damaged?
YES: Replace the faulty part and then go to Step 8.
NO: Go to Step 7
STEP 7. Check the wheel bearings.
Refer to Front Hub Assembly Rear Axle Hub.
Q: Is any of the wheel bearings damaged?
YES: Replace it and then go to Step 8.
NO: Go to Step8.
STEP 8. Check the diagnostic trouble codes.
Q: Do the diagnostic trouble code 15 reset?
YES: Go to Step 1.
NO: This diagnosis is complete.