Description

BCM power supply voltage low input

Detection condition

• The BCM detected a BCM power supply circuit (terminals 1B and 1A) voltage of less than 10 V for 10 s or more with the ignition switched ON (engine off or on).

Fail-safe

Not applicable

Possible cause

• DTCs are stored in the PCM.

• Battery malfunction

• Generator malfunction

• BCM connector or terminal malfunction

• BCM power supply circuit malfunction

• Short to ground in the wiring harness between the following:

• MAIN 200 A fuse—BCM terminal 1B

• MAIN 200 A fuse—BCM terminal 1A

• INTERIOR 15 A fuse malfunction

• ROOM 25 A fuse malfunction

• HAZARD 15 A fuse malfunction

• MAIN 200 A fuse malfunction

• Open circuit in wiring harness between the following terminals:

• Battery positive terminal—BCM terminal 1B

• Battery positive terminal—BCM terminal 1A

• BCM malfunction

Step

Inspection

Action

1

• Clear the DTC for the BCM using the M-MDS.

  (See CLEARING DTC [BCM].)

• Switch the ignition ON (engine off or on) and wait for 10 s or more.

• Retrieve the BCM DTCs using the M-MDS.

  (See DTC INSPECTION [BCM].)

• Is the same DTC displayed?

Yes

Go to the next step.

No

Go to Step 8.

2

• Retrieve the PCM DTCs using the M-MDS.

  (See ON-BOARD DIAGNOSTIC TEST [PCM (SKYACTIV-G 2.0)].)

• Are any DTCs displayed?

Yes

Repair or replace the malfunctioning part according to the applicable DTC troubleshooting.

(See DTC TABLE [PCM (SKYACTIV-G 2.0)].)

No

Go to the next step.

3

• Inspect the battery.

  (See BATTERY INSPECTION.)

• Is the battery normal?

Yes

Go to the next step.

No

Recharge or replace the battery, then go to Step 7.

(See BATTERY RECHARGING.)

(See BATTERY REMOVAL/INSTALLATION [SKYACTIV-G 2.0].)

4

• Inspect the generator.

  (See GENERATOR INSPECTION [SKYACTIV-G 2.0].)

• Is the generator normal?

Yes

Go to the next step.

No

Replace the generator, then go to Step 7.

(See GENERATOR REMOVAL/INSTALLATION [SKYACTIV-G 2.0].)

5

• Switch the ignition off.

• Disconnect the negative battery cable.

  (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION.)

• 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 7.

6

• Connect the negative battery cable.

  (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION.)

• Measure the voltage at the following terminals (wiring harness-side):

• BCM terminal 1B

• BCM terminal 1A

• Is the voltage B+?

Yes

Go to the next step.

No

Inspect the INTERIOR 15 A fuse, ROOM 25 A fuse, HAZARD 15 A fuse and MAIN 200 A fuse.

• Any fuse is blown:

• Refer to the wiring diagram and verify whether or not there is a common connector between the following:

• MAIN 200 A fuse—BCM terminal 1B

• MAIN 200 A fuse—BCM terminal 1A

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.

• Any fuse is damaged:

• Replace the fuse.

• All fuses are normal:

• Refer to the wiring diagram and verify whether or not there is a common connector between the following:

• Battery positive terminal—BCM terminal 1B

• Battery positive terminal—BCM terminal 1A

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 the next step.

7

• Always reconnect all disconnected connectors.

• Connect the negative battery cable.

  (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION.)

• Clear the DTC for the BCM using the M-MDS.

  (See CLEARING DTC [BCM].)

• Switch the ignition ON (engine off or on) and wait for 10 s or more.

• Retrieve the BCM DTCs using the M-MDS.

  (See DTC INSPECTION [BCM].)

• Is the same DTC displayed?

Yes

Repeat the inspection from Step 1.

• If the malfunction recurs, replace the BCM.

  (See BODY CONTROL MODULE (BCM) REMOVAL/INSTALLATION.)

Go to the next step.

No

Go to the next step.

8

• Are any other DTCs displayed?

Yes

Repair or replace the malfunctioning part according to the applicable DTC troubleshooting.

(See DTC TABLE [BCM].)

No

DTC troubleshooting completed.