ECD SYSTEM 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 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 relay 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.

A01KE8YE04

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.

A01KIAKE05

WIRING DIAGRAM

A01KFIOE01

INSPECTION PROCEDURE

Note

If the ECM is replaced, the new ECM needs initialization Click here.

PROCEDURE


  1. INSPECT GLOW MAIN RELAY


    1. A01KH01E01

      Remove the GLOW MAIN relay from the R/B No.2.

    2. Check the GLOW MAIN relay resistance.

      Standard resistance
      Tester Connection Specified Condition
      1 -2 10 kΩ or higher
      1 -2

      Below 1 Ω

      (when battery voltage is applied to terminals 3 and 4)

    3. Reinstall the GLOW MAIN relay.


    NG

    REPLACE GLOW MAIN RELAY

    OK

  2. INSPECT FUSE (GLOW)


    1. A01KGZVE02
      Text in Illustration
      *1 R/B No. 2
      *2 GLOW Fuse

      Remove the GLOW fuse from the R/B No. 2.

    2. Check the GLOW fuse resistance.

      Standard resistance
      Below 1 Ω

    3. Reinstall the GLOW fuse.


    NG

    CHECK FOR SHORT IN ALL HARNESS AND COMPONENTS CONNECTED TO FUSE, AND REPLACE FUSE

    OK

  3. INSPECT GLOW PLUG ASSEMBLY (RESISTANCE)


    1. A01KGI8E04
      Text in Illustration
      *1 Glow Plug Assembly

      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 0.7 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 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.


    NG

    REPLACE GLOW PLUG ASSEMBLY

    OK

  4. CHECK GLOW PLUG ASSEMBLY (INSTALLATION)


    1. Check the glow plug installation.

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

    NG

    TIGHTEN GLOW PLUG

    OK

  5. CHECK HARNESS AND CONNECTOR (GLOW MAIN RELAY - ECM)


    1. A01KHGLE03
      Text in Illustration
      *1 R/B No. 2
      *2 GLOW Relay
      *3 ECM Connector
      *a Wire Harness Side

      Disconnect the E7 ECM connector.

    2. Remove the GLOW MAIN relay from the R/B No.2

    3. Check the resistance.

      Standard resistance (Check for open)
      Tester Connection Specified Condition
      Relay block glow main relay terminal 3 - E7-15 (GREL) Below 1 Ω
      Standard resistance (Check for short)
      Tester Connection Specified Condition
      Relay block glow main relay terminal 3 or E7-15 (GREL) - Body ground 10 kΩ or higher

    4. Reconnect the ECM connector.

    5. Reinstall the GLOW MAIN relay.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  6. CHECK HARNESS AND CONNECTOR (GLOW MAIN RELAY - GLOW PLUG AND BATTERY)


    1. A01KIBWE03
      Text in Illustration
      *1 R/B No. 2
      *2 GLOW Relay
      *3 GLOW Plug Wire
      *a Wire Harness Side

      Remove the GLOW MAIN relay from the R/B No. 2.

    2. Disconnect the G1 glow plug wire.

    3. Check the resistance.

      Standard resistance
      Tester Connection Specified Condition
      Relay block glow main relay terminal 2 - Glow plug wire connector Below 1 Ω
      Relay block glow main relay terminal 1 - Positive (+) battery terminal cable Below 1 Ω
      Relay block glow main relay terminal 4 - Body ground Below 1 Ω

    4. Reinstall the GLOW MAIN relay.

    5. Reconnect the glow plug wire.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  7. INSPECT ECM TERMINAL VOLTAGE (GREL TERMINAL)


    1. A01KIKQE13
      Text in Illustration
      *1 ECM Connector

      Start the engine.

    2. Measure the voltage of the ECM connectors.

      Standard resistance
      Tester Connection Condition Specified Condition
      E7-15 (GREL) - E5-7 (E1) Engine coolant temperature 40°C (104°F) or less 11 to 14 V

    NG

    REPLACE ECM

    OK

  8. INSPECT ECM TERMINAL VOLTAGE (BATT TERMINAL)


    1. A01KIKQE14
      Text in Illustration
      *1 ECM Connector

      Measure the voltage of the ECM connectors.

      Standard voltage
      Tester Connection Specified Condition
      E8-2 (BATT) - E5-7 (E1) 11 to 14 V

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

    CHECK FOR INTERMITTENT PROBLEMS