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

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DTC Code DTC Name
  Pre-heating Control Circuit
A015A7ZE16
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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 engine switch is turned on (IG). The ECM then turns on the glow relay and permits current to flow through the glow plug based on the ECM calculated time. The glow plug is then heated, and enhances fuel combustion with a cold engine.

A DTC will be stored if the glow plug or the circuit is open.

Tip:

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

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WIRING DIAGRAM

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INSPECTION PROCEDURE

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 (Click here) and initialization (Click here).

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PROCEDURE


  1. Click here

    CHECK ECM TERMINAL VOLTAGE (GREL TERMINAL)


    1. A0157ZSE01

      Remove the GLOW 1 relay from the engine room relay block.

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

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      GLOW 1 relay (2) - Body ground Engine switch on (IG) 11 to 14 V
      GLOW 2 relay (2) - Body ground Engine switch on (IG) 11 to 14 V

  2. Click here

    INSPECT GLOW RELAY (GLOW 1 or 2)


    1. Inspect the GLOW 1 relay (Click here).

    2. Inspect the GLOW 2 relay (Click here).


  3. Click here

    INSPECT FUSE (GLOW 1 and GLOW 2)


    1. Remove the GLOW 1 and GLOW 2 fuses from the engine room relay block.

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

      Standard Resistance
      Component Condition Specified Condition
      GLOW 1 H-fuse Always Below 1 Ω
      GLOW 2 H-fuse Always Below 1 Ω

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    INSPECT GLOW PLUG ASSEMBLY (RESISTANCE)


    1. Inspect the glow plug assembly (Click here).


  5. Click here

    CHECK GLOW PLUG ASSEMBLY (INSTALLATION)


    1. Check the glow plug installation (Click here).

      OK
      Glow plugs are installed securely.

  6. Click here

    CHECK HARNESS AND CONNECTOR (GLOW PLUG RELAY - GLOW PLUG - BATTERY AND BODY GROUND)


    1. A015ARKE01

      Remove the GLOW 1 relay from the engine room relay block.

    2. Disconnect the C77 glow plug connector.

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

      Standard Resistance (Check for Open)
      Table 1. No. 1
      Tester Connection Condition Specified Condition
      GLOW 1 relay (3) - C77-1 Always Below 1 Ω
      GLOW 1 relay (5) - Positive (+) battery terminal cable Always Below 1 Ω
      GLOW 1 relay (1) - Body ground Always Below 1 Ω

    4. Remove the GLOW 2 relay from the engine room relay block.

    5. Disconnect the C78 glow plug connector.

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

      Standard Resistance (Check for Open)
      Table 2. No. 2
      Tester Connection Condition Specified Condition
      GLOW 2 relay (3) - C78-1 Always Below 1 Ω
      GLOW 2 relay (5) - Positive (+) battery terminal cable Always Below 1 Ω
      GLOW 2 relay (1) - Body ground Always Below 1 Ω

  7. Click here

    CHECK HARNESS AND CONNECTOR (GLOW PLUG RELAY - ECM AND BODY GROUND)


    1. A0155X5E01

      Remove the GLOW 1 relay from the engine room relay block.

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

    3. Disconnect the ECM connector.

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

      Standard Resistance
      Table 3. for LHD
      Tester Connection Condition Specified Condition
      GLOW 1 relay (2) - A38-12 (GREL) Always Below 1 Ω
      GLOW 2 relay (2) - A38-23 (GRL2) Always Below 1 Ω
      GLOW 1 relay (2) or A38-12 (GREL) - Body ground Always 10 kΩ or higher
      GLOW 2 relay (2) or A38-23 (GRL2) - Body ground Always 10 kΩ or higher
      Table 4. for RHD
      Tester Connection Condition Specified Condition
      GLOW 1 relay (2) - A52-12 (GREL) Always Below 1 Ω
      GLOW 2 relay (2) - A52-23 (GRL2) Always Below 1 Ω
      GLOW 1 relay (2) or A52-12 (GREL) - Body ground Always 10 kΩ or higher
      GLOW 2 relay (2) or A52-23 (GRL2) - Body ground Always 10 kΩ or higher

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    REPLACE GLOW RELAY (GLOW 1 or 2)

  9. Click here

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

  10. Click here

    REPLACE GLOW PLUG ASSEMBLYClick here

  11. Click here

    TIGHTEN GLOW PLUGClick here

  12. Click here

    REPAIR OR REPLACE HARNESS OR CONNECTOR

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    REPAIR OR REPLACE HARNESS OR CONNECTOR

  14. Click here

    CHECK FOR INTERMITTENT PROBLEMSClick here

  15. Click here

    REPLACE ECMClick here