Description

Brake switch (No.1 signal) circuit malfunction

Detection condition

• Start stop unit detects that the brake switch No.1 signal is in the on condition for 3 s or more continuously for a continuous 5 times even though brake switch No.2 signal changes with the ignition switched ON (engine off or on).

Fail-safe function

• Determined by brake switch (No.2 signal) with the brake pedal depressed.

Possible cause

• Brake switch connector or terminal malfunction

• Brake switch (No.1 signal) malfunction

• Start stop unit connector or terminal malfunction

• Short to power supply in wiring harness between brake switch terminal D and start stop unit terminal 1C

• Start stop unit malfunction

Step

Inspection

Action

1

• Switch the ignition off.

• Disconnect the negative battery cable.

  (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION [SKYACTIV-G 2.5].)

• Disconnect the brake switch 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 5.

2

• Inspect the brake switch (No.1 signal).

  (See BRAKE SWITCH INSPECTION.)

• Is the brake switch (No.1 signal) normal?

Yes

Go to the next step.

No

Replace the brake switch, then go to Step 5.

(See BRAKE PEDAL REMOVAL/INSTALLATION.)

3

• 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 5.

4

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

• Reconnect the negative battery cable.

  (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION [SKYACTIV-G 2.5].)

• Switch the ignition ON (engine off or on).

• Measure the voltages at brake switch terminal D (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 brake switch terminal D and start stop unit terminal 1C.

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 the next step.

5

• Always reconnect all disconnected connectors.

• Reconnect the negative battery cable.

  (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION [SKYACTIV-G 2.5].)

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

  (See CLEARING DTC [START STOP UNIT].)

• Perform the work of depressing the brake pedal for 3 s or more and then releasing it for 5 times or more with the ignition switched ON (engine off or on).

• 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.

6

• 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.