DTC B1142:13 [ELECTRICAL SUPPLY UNIT (ESU)]


id0902ff061000

Description

Ignition switch status mismatch

Detection condition
•  The electrical supply unit (ESU) detects the following mismatches.
―  Ignition switch status determined from power supply condition in BCM received from BCM via LIN communication
―  Ignition switch status determined from power supply input condition of electrical supply unit (ESU) power supply circuit (IG1)
Fail-safe
Not applicable
Possible cause
•  BCM connector or terminal malfunction
•  Electrical supply unit (ESU) connector or terminal malfunction
•  BCM power supply circuit (IG1) malfunction
―  Short to ground in the wiring harness between METER1 10 A fuse and BCM terminal 3O
―  METER1 10 A fuse malfunction
―  Open circuit in wiring harness between IG1 relay and BCM terminal 3O
•  Electrical supply unit (ESU) power supply circuit (IG1) malfunction
―  Short to ground in the wiring harness between METER1 10 A fuse and electrical supply unit (ESU) terminal 1H
―  METER1 10 A fuse malfunction
―  Open circuit in wiring harness between IG1 relay and electrical supply unit (ESU) terminal 1H
•  Short to ground in wiring harness between BCM terminal 2Y and electrical supply unit (ESU) terminal 2I
•  Short to power supply in wiring harness between BCM terminal 2Y and electrical supply unit (ESU) terminal 2I
•  Open circuit in wiring harness between BCM terminal 2Y and electrical supply unit (ESU) terminal 2I
•  BCM malfunction
•  Electrical supply unit (ESU) malfunction

Diagnostic Procedure

Step

Inspection

Action

1
INSPECT BCM CONNECTOR CONDITION
•  Switch the ignition off.
•  Disconnect the negative battery cable.
•  Disconnect the BCM connector.
•  Inspect the connector engagement and connection condition and inspect the terminals for damage, deformation, corrosion, or disconnection.
•  Is the connector normal?
Yes
Go to the next step.
No
Repair or replace the connector, then go to Step 9.
2
INSPECT ELECTRICAL SUPPLY UNIT (ESU) CONNECTOR CONDITION
•  Disconnect the electrical supply unit (ESU) connector.
•  Inspect the connector engagement and connection condition and inspect the terminals for damage, deformation, corrosion, or disconnection.
•  Is the connector normal?
Yes
Go to the next step.
No
Repair or replace the connector, then go to Step 9.
3
VERIFY BCM POWER SUPPLY (IG1) VOLTAGE
•  Connect the negative battery cable.
•  Switch the ignition ON (engine off or on).
•  Measure the voltage at the BCM terminal 3O (wiring harness-side).
•  Is the voltage B+?
Yes
Go to Step 8.
No
Inspect the METER1 10 A fuse.
•  If the fuse is blown:
―  Refer to the wiring diagram and verify whether or not there is a common connector between METER1 10 A fuse and BCM terminal 3O.
If there is a common connector:
•  Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for a short to ground.
•  Repair or replace the malfunctioning part.
If there is no common connector:
•  Repair or replace the wiring harness which has a short to ground.
•  Replace the fuse.
•  If the fuse is damaged:
―  Replace the fuse.
•  If the fuse is normal:
―  Refer to the wiring diagram and verify whether or not there is a common connector between IG1 relay and BCM terminal 3O.
If there is a common connector:
•  Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for an open circuit.
•  Repair or replace the malfunctioning part.
If there is no common connector:
•  Repair or replace the wiring harness which has an open circuit.
Go to Step 9.
4
VERIFY ELECTRICAL SUPPLY UNIT (ESU) POWER SUPPLY (IG1) VOLTAGE
•  Measure the voltage at the electrical supply unit (ESU) terminal 1H (wiring harness-side).
•  Is the voltage B+?
Yes
Go to Step 8.
No
Inspect the METER1 10 A fuse.
•  If the fuse is blown:
―  Refer to the wiring diagram and verify whether or not there is a common connector between METER1 10 A fuse and electrical supply unit (ESU) terminal 1H.
If there is a common connector:
•  Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for a short to ground.
•  Repair or replace the malfunctioning part.
If there is no common connector:
•  Repair or replace the wiring harness which has a short to ground.
•  Replace the fuse.
•  If the fuse is damaged:
―  Replace the fuse.
•  If the fuse is normal:
―  Refer to the wiring diagram and verify whether or not there is a common connector between IG1 relay and electrical supply unit (ESU) terminal 1H.
If there is a common connector:
•  Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for an open circuit.
•  Repair or replace the malfunctioning part.
If there is no common connector:
•  Repair or replace the wiring harness which has an open circuit.
Go to Step 9.
5
INSPECT LIN COMMUNICATION CIRCUIT BETWEEN BCM AND ELECTRICAL SUPPLY UNIT (ESU) FOR SHORT TO GROUND
•  Switch the ignition off.
•  Disconnect the negative battery cable.
•  Verify that the BCM and electrical supply unit (ESU) connectors are disconnected.
•  Inspect for continuity between BCM terminal 2Y (wiring harness-side) and body ground.
•  Is there continuity?
Yes
Refer to the wiring diagram and verify whether or not there is a common connector between BCM terminal 2Y and electrical supply unit (ESU) terminal 2I.
If there is a common connector:
•  Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for a short to ground.
•  Repair or replace the malfunctioning part.
If there is no common connector:
•  Repair or replace the wiring harness which has a short to ground.
Go to Step 9.
No
Go to the next step.
6
INSPECT LIN COMMUNICATION CIRCUIT BETWEEN BCM AND ELECTRICAL SUPPLY UNIT (ESU) FOR SHORT TO POWER SUPPLY
•  Verify that the BCM and electrical supply unit (ESU) connectors are disconnected.
•  Connect the negative battery cable.
•  Switch the ignition ON (engine off or on).
•  Measure the voltage at the BCM terminal 2Y (wiring harness-side).
•  Is the voltage 0 V?
Yes
Go to the next step.
No
Refer to the wiring diagram and verify whether or not there is a common connector between BCM terminal 2Y and electrical supply unit (ESU) terminal 2I.
If there is a common connector:
•  Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for a short to power supply.
•  Repair or replace the malfunctioning part.
If there is no common connector:
•  Repair or replace the wiring harness which has a short to power supply.
Go to Step 9.
7
INSPECT LIN COMMUNICATION CIRCUIT BETWEEN BCM AND ELECTRICAL SUPPLY UNIT (ESU) FOR OPEN CIRCUIT
•  Switch the ignition off.
•  Disconnect the negative battery cable.
•  Verify that the BCM and electrical supply unit (ESU) connectors are disconnected.
•  Inspect the wiring harness for continuity between BCM terminal 2Y (wiring harness-side) and electrical supply unit (ESU) terminal 2I (wiring harness-side).
•  Is there continuity?
Yes
Go to the next step.
No
Refer to the wiring diagram and verify whether or not there is a common connector between BCM terminal 2Y and electrical supply unit (ESU) terminal 2I.
If there is a common connector:
•  Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for an open circuit.
•  Repair or replace the malfunctioning part.
If there is no common connector:
•  Repair or replace the wiring harness which has an open circuit.
Go to Step 9.
8
VERIFY IF MALFUNCTIONING LOCATION IS BCM DEPENDING ON REPEATABILITY
•  Always reconnect all disconnected connectors.
•  Connect the negative battery cable.
•  Clear the DTC for the electrical supply unit (ESU) using the M-MDS.
•  Retrieve the electrical supply unit (ESU) DTCs using the M-MDS.
•  Is the same DTC displayed?
Yes
Replace the BCM, then go to the next step.
No
Go to Step 10.
9
VERIFY THAT REPAIRS HAVE BEEN COMPLETED
•  Always reconnect all disconnected connectors.
•  Connect the negative battery cable.
•  Clear the DTC for the electrical supply unit (ESU) using the M-MDS.
•  Retrieve the electrical supply unit (ESU) DTCs using the M-MDS.
•  Is the same DTC displayed?
Yes
Repeat the inspection from Step 1.
•  If the malfunction recurs, replace the electrical supply unit (ESU).
Go to the next step.
No
Go to the next step.
10
VERIFY IF OTHER DTCs DISPLAYED
•  Are any other DTCs displayed?
Yes
Repair or replace the malfunctioning part according to the applicable DTC troubleshooting.
No
DTC troubleshooting completed.