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Home › Subaru › 1996 › Legacy Outback, 2.2 4 › Repair and Diagnosis › Brakes › Traction Control › Anti-Lock Brake System - With 5.3 Abs › Testing › Test 2 - Wheel Sensor Short Circuit

Test 2 - Wheel Sensor Short Circuit

  1. Ensure sensor bolts are tight. Ensure tone wheel bolts are tight.
  2. Check sensor to tone wheel air gap around entire wheel. Gap should be .035-.055" (.9-1.1 mm) front and .028-.047" (.7-1.2 mm) rear. If gap is too small, use Spacer (26755AA000) to increase gap to specification. If gap exceeds specification, remove spacer(s) or replace tone wheel or faulty wheel speed sensor. When gap is set, go to next step.
  3. If an oscilloscope is not available, go to next step. If an oscilloscope is available, raise and support vehicle with wheels off of ground. Turn ignition off. Disconnect ABS control module connector, remove cover and reinstall connector. Turn ignition on. Backprobe ABS control unit connector with oscilloscope test probes while rotating each wheel depending on trouble code. See Figure. See WHEEL SENSOR INPUT VOLTAGE table. Voltage should be .12-1.00 volt (AC waveform). If input voltage is not as specified or waveform is erratic, go to next step. If input voltage and waveform is as specified, go to step 6). This test procedure may set DTC 29.
    CHECKING WHEEL SENSOR INPUT VOLTAGE

    DTC (1) Terminals No.
    22 14 & 15
    24 49 & 19
    26 18 & 46
    28 16 & 17
    (1) Second terminal listed should be connected to oscilloscope ground lead.
  4. Check sensor and tone wheel for damage or contamination. Clean, repair or replace as needed. Go to next step.
  5. Check hub runout. If runout is less than .002" (.05 mm), go to next step. If runout is .002" (.05 mm) or more, replace hub.
  6. Turn ignition off. Depending on specific trouble code, disconnect appropriate ABS wheel sensor connector. Measure resistance between wheel sensor terminals. If resistance is 800-1200 ohms, go to next step. If resistance is not 800-1200 ohms, replace wheel sensor.
  7. Check continuity between sensor terminal and ground. If continuity exists, replace sensor. If continuity does not exist, go to next step.
  8. Reconnect sensor connector. Disconnect ABS control module connector. Check resistance of sensor circuit at ABS control module connector. See ABS CONNECTOR WHEEL SENSOR TERMINAL RESISTANCE table. If resistance is 800-1200 ohms, go to next step. If resistance is not 800-1200 ohms, repair wiring between sensor and ABS control module.
    ABS CONNECTOR WHEEL SENSOR TERMINAL RESISTANCE

    DTC Terminals No.
    22 14 & 15
    24 49 & 19
    26 18 & 46
    28 16 & 17
  9. Check continuity between sensor circuit and ground, at ABS control module connector. If continuity exists, repair wiring. If continuity does not exist, go to next step.
  10. Check resistance between ground and ABS control module connector terminal No. 1 and No. 55. If resistance is less than .5 ohm, go to next step. If resistance is .5 ohm or more, repair wiring.
  11. Check ABS control unit connector and wheel sensor connector contacts. If connector contacts are poor, repair contacts. If contacts are okay, go to next step.
  12. Ensure car telephone or wireless transmitter are properly installed and routed away from sensor harness. Go to next step.
  13. Reconnect all connectors. Check resistance between shield connector terminals and ground. See ABS WHEEL SENSOR SHIELD CONNECTOR TERMINAL table. If resistance is less than .5 ohm, go to next step. If resistance is .5 ohm or more, repair shield harness.
    ABS WHEEL SENSOR SHIELD CONNECTOR TERMINAL

    DTC Terminal No.
    22 11
    24 2
    26 8
    28 3
  14. Reconnect all connectors. Erase memory. Recheck trouble codes. If same trouble code returns, replace ABS control unit. If other trouble codes exist, go to proper test procedure. If no trouble codes exist, problem was a temporary poor contact. Recheck harness and connectors.
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