Description

Communication error with BCM

Detection condition

• Start stop unit detects the communication error with BCM 10 times continuously.

Fail-safe

• Performs control with the driver’s side door and trunk open.

Possible cause

• BCM connector or terminal malfunction

• Start stop unit connector or terminal malfunction

• Short to ground in wiring harness between start stop unit terminal 1Q and BCM terminal 2J

• Open circuit in wiring harness between start stop unit terminal 1Q and BCM terminal 2J

• BCM malfunction

• Start stop unit malfunction

Step

Inspection

Action

1

• 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 6.

2

• Disconnect the start stop unit 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 6.

3

• Verify that the BCM and start stop unit connectors are disconnected.

• Inspect for continuity between BCM terminal 2J (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 start stop unit terminal 1Q and BCM terminal 2J.

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 6.

No

Go to the next step.

4

• Verify that the BCM and start stop unit connectors are disconnected.

• Inspect for continuity between start stop unit terminal 1Q (wiring harness-side) and BCM terminal 2J (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 start stop unit terminal 1Q and BCM terminal 2J.

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 6.

5

• Always reconnect all disconnected connectors.

• Connect the negative battery cable.

  (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION.)

• Clear the DTC for the start stop unit using the M-MDS.

  (See CLEARING DTC [START STOP UNIT].)

• Retrieve the start stop unit DTCs using the M-MDS.

  (See DTC INSPECTION [START STOP UNIT].)

• Is the same DTC displayed?

Yes

Replace the BCM, then go to the next step.

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

No

Go to Step 7.

6

• Always reconnect all disconnected connectors.

• Connect the negative battery cable.

  (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION.)

• Clear the DTC for the start stop unit using the M-MDS.

  (See CLEARING DTC [START STOP UNIT].)

• Retrieve the start stop unit DTCs using the M-MDS.

  (See DTC INSPECTION [START STOP UNIT].)

• Is the same DTC displayed?

Yes

Repeat the inspection from Step 1.

• If the malfunction recurs, replace the start stop unit.

  (See START STOP UNIT REMOVAL/INSTALLATION.)

Go to the next step.

No

Go to the next step.

7

• Are any other DTCs displayed?

Yes

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

(See DTC TABLE [START STOP UNIT].)

No

DTC troubleshooting completed.