ECD SYSTEM (w/o DPF) Pre-heating Control Circuit

DESCRIPTION

The glow plug is mounted inside the engine combustion chamber. To ensure efficient engine starting with a cold engine, the ECM calculates a time interval for the current that needs to flow through the glow plug depending on the starting engine coolant temperature when the ignition switch is turned to ON. The ECM then turns on the GLOW relay and permits the current to flow through the glow plug based on the ECM's calculated time. The glow plug is then heated, and enhances fuel combustion with a cold engine.

This DTC will be set if the glow plug or the circuit is open.

A01BDH7E02

Tech Tips


  • These troubleshooting procedures are for the following conditions: 1) difficulty starting the engine in cold weather, and 2) difficulty driving the vehicle or vehicle malfunctions in cold weather immediately after engine is started.

  • After the engine is started, the ECM performs an "after-glow" for a certain period of time. In proportion to the actual engine coolant temperature, the time period varies. The after-glow reduces diesel engine knocking, white smoke emissions and engine noises when the engine is cold.

A01BA5WE01

WIRING DIAGRAM

A01BBO2E02

INSPECTION PROCEDURE

Note


  • After replacing the ECM, the new ECM needs registration Click here and initialization Click here.

  • Inspect the fuses of circuits related to this system before performing the following inspection procedure.

PROCEDURE


  1. INSPECT GLOW RELAY


    1. A01BF57E01

      Remove the GLOW relay from the No. 1 engine room R/B and J/B.

    2. Measure the GLOW relay resistance.

      Standard Resistance
      Tester Connection Condition Specified Condition
      3 - 5 When battery voltage is not applied to terminals 1 and 2 10 kΩ or higher
      3 - 5 When battery voltage is applied to terminals 1 and 2 Below 1 Ω

    3. Reinstall the GLOW relay.


    NG

    REPLACE GLOW RELAY

    OK

  2. INSPECT GLOW PLUG (RESISTANCE)


    1. A01BAU1E02

      Disconnect the glow plug wire.

    2. Measure the resistance of the glow plugs.

      Standard Resistance
      Tester Connection Specified Condition
      Glow plug terminal - Body ground

      Approximately 0.95 Ω

      at 20°C (68°F)

      Tech Tips

      If any of the glow plugs has an open malfunction, the engine power is insufficient only when the engine is cold.

      Note


      • Exercise extreme care not to damage the glow plug pipes. Damaging them could cause an open circuit, or shorten the life of the glow plugs.

      • Keep the glow plugs free of oil and fuel while cleaning.

      • Wipe any oil off of the glow plug terminals with a clean, dry cloth during inspection.

      • Do not apply more than 11 V to the glow plugs as it may cause an open circuit.

    3. Reconnect the glow plug wire.


    NG

    REPLACE GLOW PLUG

    OK

  3. CHECK GLOW PLUG INSTALLATION


    1. Check the glow plug installation.

      OK
      Glow plugs are installed securely.
      Torque:
      13 N*m  { 130 kgf*cm, 10 ft.*lbf }

    NG

    SECURELY REINSTALL GLOW PLUG

    OK

  4. CHECK HARNESS AND CONNECTOR (GLOW RELAY - ECM, GLOW RELAY - BODY GROUND)


    1. Disconnect the D75 ECM connector.

    2. Remove the GLOW relay from the No. 1 engine room R/B and J/B.

    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance (Check for Open)
      Tester Connection Condition Specified Condition
      GLOW relay terminal - 2 - D75-19 (GREL) Always Below 1 Ω
      GLOW relay terminal - 1 - Body ground Always Below 1 Ω
      Standard Resistance (Check for Short)
      Tester Connection Condition Specified Condition
      D75-19 (GREL) - Body ground Always 10 kΩ or higher

    4. Reinstall the GLOW relay.

    5. Reconnect the ECM connector.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  5. CHECK HARNESS AND CONNECTOR (GLOW RELAY - GLOW PLUG, GLOW RELAY - BATTERY)


    1. Remove the GLOW relay from the No. 1 engine room R/B and J/B.

    2. Disconnect the D53 glow plug wire.

    3. Disconnect the battery negative terminal.

    4. Disconnect the battery positive terminal.

    5. Measure the resistance according to the value(s) in the table below.

      Standard Resistance (Check for Open)
      Tester Connection Condition Specified Condition
      GLOW relay terminal - 3 - D53-1 Always Below 1 Ω
      GLOW relay terminal - 5 - Battery positive terminal Always Below 1 Ω

    6. Reconnect the battery positive terminal.

    7. Reconnect the glow plug wire.

    8. Reconnect the battery negative terminal.

    9. Reinstall the GLOW relay.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  6. CHECK ECM (GREL VOLTAGE)


    1. A01BF7WE55
      Text in Illustration
      *a

      Component with harness connected

      (ECM)

      Start the engine.

    2. Measure the voltage of the ECM connectors.

      Standard Voltage
      Tester Connection Condition Specified Condition
      D75-19 (GREL) - D70-1 (E1) Engine coolant temperature 40°C (104°F) or less 11 to 14 V

    NG

    REPLACE ECM

    OK

  7. CHECK ECM (BATT VOLTAGE)


    1. A01BF7WE56
      Text in Illustration
      *a

      Component with harness connected

      (ECM)

      Measure the voltage of the ECM connectors.

      Standard Voltage
      Tester Connection Condition Specified Condition
      B48-23 (BATT) - D70-1 (E1) Always 11 to 14 V

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

    CHECK FOR INTERMITTENT PROBLEMS