Description

Error light switch signal received from start stop unit

Detection condition

• Front body control module (FBCM) receives the CAN error signals from the start stop unit 3 times with the ignition switched ON (engine off or on).

Fail-safe function

• If DTC U0338:09 is detected when the ignition is switched ON (engine off or on), the headlight LO and the TNS are illuminated.

• If DTC U0338:09 is cleared, the headlight LO and the TNS are turned off, and the operation returns to normal.

Possible cause

• Light switch malfunction

• Start stop unit malfunction

• Front body control module (FBCM) malfunction

System wiring diagram

Not applicable

Step

Inspection

Action

1

• Clear the DTC for the front body control module (FBCM) using the M-MDS.

  (See CLEARING DTC [FRONT BODY CONTROL MODULE (FBCM)].)

• Retrieve the front body control module (FBCM) DTCs using the M-MDS.

  (See DTC INSPECTION [FRONT BODY CONTROL MODULE (FBCM)].)

• Is the same DTC displayed?

Yes

Go to the next step.

No

Go to Step 6.

2

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

  (See DTC INSPECTION [START STOP UNIT].)

• Are any DTCs displayed?

Yes

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

(See DTC TABLE [START STOP UNIT].)

No

Go to the next step.

3

• Inspect the light switch.

  (See LIGHT SWITCH INSPECTION.)

• Is the light switch normal?

Yes

Go to the next step.

No

Replace the light switch, then go to Step 5.

(See LIGHT SWITCH REMOVAL/INSTALLATION.)

4

• Clear the DTC for the front body control module (FBCM) using the M-MDS.

  (See CLEARING DTC [FRONT BODY CONTROL MODULE (FBCM)].)

• Retrieve the front body control module (FBCM) DTCs using the M-MDS.

  (See DTC INSPECTION [FRONT BODY CONTROL MODULE (FBCM)].)

• Is the same DTC displayed?

Yes

Replace the start stop unit, then go to the next step.

(See START STOP UNIT REMOVAL/INSTALLATION.)

No

Go to Step 6.

5

• Clear the DTC for the front body control module (FBCM) using the M-MDS.

  (See CLEARING DTC [FRONT BODY CONTROL MODULE (FBCM)].)

• Retrieve the front body control module (FBCM) DTCs using the M-MDS.

  (See DTC INSPECTION [FRONT BODY CONTROL MODULE (FBCM)].)

• Is the same DTC displayed?

Yes

Repeat the inspection from Step 1.

• If the malfunction recurs, replace the front body control module (FBCM).

  (See FRONT BODY CONTROL MODULE (FBCM) REMOVAL/INSTALLATION.)

Go to the next step.

No

Go to the next step.

6

• Are any other DTCs displayed?

Yes

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

(See DTC TABLE [FRONT BODY CONTROL MODULE (FBCM)].)

No

DTC troubleshooting completed.