Description

ACC relay circuit malfunction

Detection condition

• Start stop unit detects that the ACC monitor voltage of 2.5 V or more for 5 s or more with the ignition switched off.

Fail-safe

Not applicable.

Possible cause

• Malfunction in accessory part installed to accessory socket

• ACC relay malfunction

• Start stop unit connector or terminal malfunction

• Short to power supply in wiring harness between ACC relay terminal C and start stop unit terminal 1E

• Start stop unit malfunction

Step

Inspection

Action

1

• Verify if the accessory part is installed to the accessory socket.

• Is an accessory part installed to the accessory socket?

Yes

Go to the next step.

No

Go to Step 3.

2

• Switch the ignition off.

• Disconnect the negative battery cable.

  (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION.)

• Remove the accessory part installed to the accessory socket.

• 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].)

• Switch the ignition off and wait for 5 s or more.

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

  (See DTC INSPECTION [START STOP UNIT].)

• Is the same DTC displayed?

Yes

Go to the next step.

No

System is normal. (Explain to the customer that the malfunction occurred due to an accessory installed to the vehicle.)

Go to Step 7.

3

• Switch the ignition off.

• Disconnect the negative battery cable.

  (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION.)

• Remove the ACC relay.

  (See RELAY LOCATION.)

• Inspect the ACC relay.

  (See RELAY INSPECTION.)

• Is the ACC relay normal?

Yes

Go to the next step.

No

Replace the ACC relay, then go to Step 6.

(See RELAY LOCATION.)

4

• 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.

5

• Always reconnect all disconnected connectors.

• Connect the negative battery cable.

  (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION.)

• Measure the voltage at the start stop unit terminal 1E (wiring harness-side).

• Is the voltage 2.5 V or more?

Yes

Refer to the wiring diagram and verify whether or not there is a common connector between ACC relay terminal C and start stop unit terminal 1E.

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.

No

Go to the next step.

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].)

• Switch the ignition off and wait for 5 s or more.

• 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.