ECD SYSTEM(for CCo) 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 of 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 plug relay and permits the current to flow through the glow plug based on the time calculated by the ECM. The glow plug is then heated, and enhances fuel combustion with a cold engine.

A004RLHE18

Tech Tips


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

  • After the engine is started, the ECM performs "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.

A004SXKE14

WIRING DIAGRAM

A004SF7E06
*a GLOW
*b FL MAIN
*c Glow Plug
*d Battery

CAUTION / NOTICE / HINT

Note


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

  • After replacing the ECM, the new ECM needs registration (See page ) and initialization Click here.

PROCEDURE


  1. CHECK TERMINAL VOLTAGE (GLOW PLUG RELAY)


    1. A004POFE03
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Glow Plug Relay)

      Remove the glow plug relay.

    2. Measure the voltage according to the value(s) in the table below.

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      A51-4 - Body ground Ignition switch ON 11 to 14 V

    3. Reinstall the glow plug relay.


    NG

    REPAIR OR REPLACE HARNESS AND CONNECTOR (GLOW PLUG RELAY - BATTERY)

    OK

  2. INSPECT GLOW PLUG RELAY


    1. A004Q3CE07

      Remove the glow plug relay.

    2. Measure the resistance of the relay.

      Standard Resistance
      Tester Connection Condition Specified Condition
      3 - 4 When battery voltage is not applied to terminals 1 and 2 10 kΩ or higher
      3 - 4 When battery voltage is applied to terminals 1 and 2 Below 1 Ω

    3. Reinstall the glow plug relay.


    NG

    REPLACE GLOW PLUG RELAY

    OK

  3. INSPECT GLOW PLUG ASSEMBLY (RESISTANCE)


    1. A004RRC

      Disconnect the glow plug wire.

    2. Measure the resistance of the glow plugs.

      Standard Resistance
      Tester Connection Condition Specified Condition
      Glow plug terminal - Body ground 20°C (68°F) Approximately 1.0 Ω

      Tech Tips

      If any of the glow plugs has an open circuit, the engine power will be 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 terminal and Bakelite washer 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 ASSEMBLY Click here

    OK

  4. CHECK GLOW PLUG ASSEMBLY (INSTALLATION)


    1. Check the glow plug installation.

      OK
      Glow plugs are installed securely.
      Torque:
      12.3 N*m  { 125 kgf*cm, 9 ft.*lbf }

    NG

    TIGHTEN GLOW PLUG

    OK

  5. CHECK WIRE HARNESS (GLOW PLUG - GLOW PLUG RELAY - BODY GROUND)


    1. A004OAYE03
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Glow Plug Relay)
      *2

      Front view of wire harness connector

      (to Glow Plug)

      Remove the glow plug relay.

    2. Disconnect the glow plug connector.

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

      Standard Resistance (Check for Open)
      Tester Connection Condition Specified Condition
      A51-3 - B59-1 Always Below 1 Ω
      A51-1 - Body ground Always Below 1 Ω
      Standard Resistance (Check for Short)
      Tester Connection Condition Specified Condition
      A51-3 or B59-1 - Body ground Always 10 kΩ or higher

    4. Reinstall the glow plug relay.

    5. Reconnect the glow plug connector.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  6. CHECK WIRE HARNESS (GLOW PLUG RELAY - ECM AND BODY GROUND)


    1. A004RBDE02
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Glow Plug Relay)
      *2

      Front view of wire harness connector

      (to ECM)

      Remove the glow plug relay.

    2. Disconnect the ECM connector.

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

      Standard Resistance (Check for Open)
      Tester Connection Condition Specified Condition
      A51-2 - B39-58 (GREL) Always Below 1 Ω
      Standard Resistance (Check for Short)
      Tester Connection Condition Specified Condition
      A51-2 or B39-58 (GREL) - Body ground Always 10 kΩ or higher

    4. Reinstall the glow plug relay.

    5. Reconnect the ECM connector.


    OK

    REPLACE ECM Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR