ECD SYSTEM (w/ EGR Cooler) 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 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.

A01E1HLE03

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.

A01DY24E03

WIRING DIAGRAM

A01DWCNE01

INSPECTION PROCEDURE

Note

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

PROCEDURE


  1. INSPECT GLOW RELAY (Marking: GLOW)


    1. A01DXU5E14

      Remove the glow relay from the engine room relay block.

    2. Measure the resistance of the relay.

      Standard resistance
      Tester Connection Specified Condition
      3 - 5 10 kΩ or higher
      3 - 5

      Below 1 Ω

      (when battery voltage is applied to terminals 1 and 2)

    NG

    REPLACE GLOW RELAY

    OK

  2. INSPECT GLOW FUSE


    1. A01E1QXE02

      Remove the GLOW H-fuse from the engine room junction block.

    2. Measure the resistance of the H-fuse.

      Standard resistance
      Below 1 Ω

    NG

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

    OK

  3. INSPECT GLOW PLUG ASSEMBLY (RESISTANCE)


    1. A01DWEGE02

      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 0.95 Ω

      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 WIRE HARNESS (GLOW RELAY (Marking: GLOW) - ECM AND BODY GROUND)


    1. A01DXGCE04

      Disconnect the E5 ECM connector.

    2. Remove the glow relay from the engine room relay block.

    3. Measure the resistance of the wire harness side connectors.

      Standard resistance (Check for open)
      Tester Connection Specified Condition
      E5-15 (GREL) - Relay block glow relay terminal 2 Below 1 Ω
      Relay block glow relay terminal 1 - Body ground Below 1 Ω
      Standard resistance (Check for short)
      Tester Connection Specified Condition
      E5-15 (GREL) - Body ground 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS AND CONNECTOR

    OK

  6. CHECK WIRE HARNESS (GLOW RELAY (Marking: GLOW) - GLOW PLUG AND BATTERY)


    1. A01DY2EE03

      Remove the GLOW relay from the engine room relay block.

    2. Disconnect the G1 glow plug connector.

    3. Measure the resistance of the wire harness side connectors.

      Standard resistance (Check for open)
      Tester Connection Specified Condition
      R/B GLOW relay terminal 3 - Glow plug wire connector Below 1 Ω
      R/B GLOW relay terminal 5 - Positive (+) battery terminal cable Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS AND CONNECTOR

    OK

  7. CHECK ECM (GREL VOLTAGE)


    1. A01DZAPE13

      Start the engine.

    2. Measure the voltage of the ECM connectors.

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

    NG

    REPLACE ECM

    OK

  8. CHECK ECM (BATT VOLTAGE)


    1. A01DV1IE07

      Measure the voltage of the ECM connectors.

      Standard voltage
      Tester Connection Specified Condition
      E6-2 (BATT) - E7-7 (E1) 11 to 14 V

    NG

    REPAIR OR REPLACE HARNESS AND CONNECTOR

    OK

    CHECK FOR INTERMITTENT PROBLEMS