POWER DOOR LOCK CONTROL SYSTEM Power Source Circuit

DTC Code DTC Name
Power Source Circuit

DESCRIPTION

The main power source for the main body ECU (instrument panel junction block assembly) is supplied via the door control battery.

WIRING DIAGRAM

B409278E05

CAUTION / NOTICE / HINT

Note:

  • As the door control battery is installed between the vehicle battery and main body ECU (instrument panel junction block assembly), first perform the inspections in On-Vehicle Inspection to confirm that there are no malfunctions in the power source circuit for the main body ECU (instrument panel junction block assembly) before performing this troubleshooting procedure (Click here).

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

PROCEDURE

  1. CHECK HARNESS AND CONNECTOR (DOOR CONTROL BATTERY - BATTERY AND BODY GROUND)

    1. U184667E02

      Disconnect the door control battery connector.

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

      Standard Resistance

      Tester Connection

      Condition

      Specified Condition

      H129-2 (GND1) - Body ground

      Always

      Below 1 Ω

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

      Standard Voltage

      Tester Connection

      Condition

      Specified Condition

      H129-4 (BECU) - Body ground

      Always

      11 to 14 V
    Table 1. Text in Illustration

    *a

    Front view of wire harness connector

    (to Door Control Battery)

    REPAIR OR REPLACE HARNESS OR CONNECTOR

  2. CHECK HARNESS AND CONNECTOR (DOOR CONTROL BATTERY - MAIN BODY ECU [INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY])

    1. Disconnect the H129 door control battery connector.

    2. Disconnect the DH main body ECU (instrument panel junction block assembly) connector.

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

      Standard Resistance

      Tester Connection

      Condition

      Specified Condition

      H129-3 (EDOR) - DH-12

      Always

      Below 1 Ω

      H129-3 (EDOR) or DH-12 - Body ground

      Always

      10. kΩ or higher

    REPAIR OR REPLACE HARNESS OR CONNECTOR

  3. CHECK DOOR CONTROL BATTERY (POWER OUTPUT)

    1. Turn the ignition switch off.

    2. Remove the ECU-B fuse from the No. 1 engine room relay block (*A).

    3. Leave the vehicle as is for 30 minutes (wait until the door control battery is discharged) (*B).

      Tip:

      Discharge time is reduced when the door control battery is not fully charged.

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

      Standard Voltage

      Tester Connection

      Switch Condition

      Specified Condition

      H129-3 (EDOR) - Body ground

      Ignition switch off (*A → *B)

      11 to 14 V (*A) → Below 2 V (*B)

    5. Install the ECU-B fuse to the No. 1 engine room relay block.

    6. Leave the vehicle as is for 90 seconds (wait until the door control battery is charged).

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

      Standard Voltage

      Tester Connection

      Switch Condition

      Specified Condition

      H129-3 (EDOR) - Body ground

      Ignition switch off

      11 to 14 V

    REPLACE MAIN BODY ECU (INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY)

    REPLACE DOOR CONTROL BATTERY

    (Click here)