Toyota CH-R Service Manual: Double Locking ECU Communication Stop (B1249)

Toyota CH-R Service Manual / Networking / Lin Communication System / Double Locking ECU Communication Stop (B1249)

DESCRIPTION

The main body ECU (multiplex network body ECU) stores this DTC when communication with the double lock door control relay assembly stops for 10 seconds or more.

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

B1249

Double Locking ECU Communication Stop

No communication between double lock door control relay assembly and main body ECU (multiplex network body ECU) for 10 seconds or more
  • Double lock door control relay assembly
  • Main body ECU (multiplex network body ECU)
  • Instrument panel junction block assembly
  • Wire harness or connector
  • DOOR DBL/L fuse
  • ECU-DCC NO. 2 fuse

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

  • Inspect the fuses for circuits related to this system before performing the following procedure.
  • If the main body ECU (multiplex network body ECU) is replaced, refer to Registration.*1

    Click here

    • *1: w/ Smart Key System

PROCEDURE

1.

INSPECT INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY

(a) Remove the instrument panel junction block assembly.

Click here

*a

Component without harness connected (Instrument Panel Junction Block Assembly)

-

-

(b) Remove the main body ECU (multiplex network body ECU) from the instrument panel junction block assembly.

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

HINT:

This inspection is to check the LIN communication line in the instrument panel junction block assembly that connects the wire harness to the built-in main body ECU (multiplex network body ECU).

Standard Resistance:

Tester Connection

Condition

Specified Condition

3D-17 - MB-16 (LIN2)

Always

Below 1 Ω
NG

REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY

OK

2.

CHECK HARNESS AND CONNECTOR (MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) - DOUBLE LOCK DOOR CONTROL RELAY ASSEMBLY)

(a) Disconnect the F14 double lock door control relay assembly connector.

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

NOTICE:

Make sure that each ECU is in sleep mode before performing the inspection. To enter sleep mode, turn the ignition switch from ON to off and wait for 180 seconds or more without operating any switches.

Standard Resistance:

Tester Connection

Switch Condition

Specified Condition

3D-17 - F14-9 (LIN)

Ignition switch off

Below 1 Ω

F14-9 (LIN) or 3D-17 - Body ground

Ignition switch off

10 kΩ or higher
NG

REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

3.

CHECK HARNESS AND CONNECTOR (DOUBLE LOCK DOOR CONTROL RELAY ASSEMBLY - BATTERY, BODY GROUND)

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

Standard Voltage:

Tester Connection

Condition

Specified Condition

F14-12 (+B) - F14-7 (GND)

Always

11 to 14 V

F14-11 (CPUB) - F14-7 (GND)

Always

11 to 14 V

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

F14-7 (GND) - Body ground

Always

Below 1 Ω
NG

REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

4.

REPLACE DOUBLE LOCK DOOR CONTROL RELAY ASSEMBLY

(a) Replace the double lock door control relay assembly.

Click here

NEXT

5.

CHECK FOR DTC

(a) Clear the DTCs.

Click here

Body Electrical > Main Body > Clear DTCs

(b) Recheck for DTCs.

Body Electrical > Main Body > Trouble Codes

OK:

DTC B1249 is not output.

OK

END (DOUBLE LOCK DOOR CONTROL RELAY ASSEMBLY WAS DEFECTIVE)
NG

REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)

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