1993 Subaru Justy BaseFACTORY OEM SERVICE PROCEDURE

Code 13: Top Dead Center (TDC) Sensor

NOTE: Refer to illustration for ECU connector and terminal identification. See Figure .
  1. Disconnect distributor connector. Set voltmeter to low volt AC scale. Connect voltmeter between terminals No. 3 and 4 of distributor connector. See Figure . Crank engine and ensure voltage fluctuates with RPM. If voltage fluctuates, go to next step. If voltage does not fluctuate, replace TDC sensor.
  2. Disconnect ECU connectors. Measure resistance between ECU and distributor connectors. See TDC SENSOR RESISTANCE SPECIFICATIONS  table. If resistance is as specified, go to next step. If resistance is not as specified, repair connector and/or wiring harness as necessary.
    TDC SENSOR RESISTANCE SPECIFICATIONS

    Measure Between Terminals Ohms
    No. 5 (1) & No. 3 (2) Less Than One
    No. 6 (1) & No. 4 (2) Less Than One
    No. 5 (1) & Ground Infinite
    No. 6 (1) & Ground Infinite
    (1) Measure at ECU connector F119.
    (2) Measure at distributor connector. See Figure .
  3. Reconnect ECU connectors. Measure resistance between ground and ECU connector F119, terminal No. 7. If resistance is less than 10 ohms, check ECU terminals for proper installation. If terminals are okay, replace ECU. If resistance is more than 10 ohms, repair wiring harness as necessary.
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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • • You smell fuel, burning insulation, or see smoke.
  • • Brakes feel soft, pull hard to one side, or make grinding noises.
  • • The engine overheats, stalls repeatedly, or misfires under load.
  • • You are missing required tools, torque specs, or safe lifting equipment.
  • • You are not confident in the next step or safety outcome.