42B-B1168 ACC system fail

DTC B1168: ACC system fail

caution

If DTC B1168 is set, always diagnose the CAN bus lines.
Before replacing ECU, ensure that the communication circuit is normal.

DTC SET CONDITION

If the output power supply status is different from the engine switch status information received from ETACS-ECU via CAN, KOS&OSS-ECU sets DTC B1168. At the same time, KOS&OSS-ECU displays the power supply system error warning to the combination meter, and flashes the indicator of engine switch in orange.

TECHNICAL DESCRIPTION (COMMENT)

Check Conditions

The terminal voltage of IOD and +B is between 10 and 16 V.

Judgment Criterion

Any of the following conditions is met, and 2 seconds or more have elapsed.

The engine switch status information received from ETACS-ECU is "ACC" when the power supply mode is at OFF.
The engine switch status information received from ETACS-ECU is "OFF" when the power supply mode is at ACC.

TROUBLESHOOTING HINTS

Malfunction of the CAN bus line
Damaged wiring harness or connector (short to ground, short to power supply, or open circuit in ACC line)
Malfunction of ACC relay
Malfunction of KOS&OSS-ECU
Malfunction of ETACS-ECU
Commercial electric products that are connected to the accessory socket
note Be sure to remove the commercial electric products that are connected to the accessory socket before troubleshooting. Otherwise troubleshooting cannot be performed correctly.

DIAGNOSIS

STEP 1. Using scan tool (M.U.T.-III), diagnose the CAN bus line.

(1)

caution

To prevent damage to scan tool (M.U.T.-III), always turn the power supply mode of the engine switch to the "OFF" position before connecting or disconnecting scan tool (M.U.T.-III).

Connect scan tool (M.U.T.-III) [Refer to "How to connect scan tool (M.U.T.-III)

"].

(2) Turn the power supply mode of the engine switch to "ON".

(3) Diagnose the CAN bus line.

(4) Turn the power supply mode of the engine switch to "OFF".

Is the CAN bus line found to be normal?

Go to Step 2

Repair the CAN bus line (Refer to GROUP 54C, Diagnosis

STEP 2. ACC relay check.

Check that the ACC relay works normally (Refer to

Is the check result normal?

Go to Step 3

Replace the ACC relay.

STEP 3. Voltage measurement at ACC relay connector (ACC line).

(1) Disconnect the connector, and measure at the wiring harness side.

(2) Turn the power supply mode of the power supply mode of the engine switch from "LOCK" (OFF) position to "ON" position.

(3) Measure the voltage between the ACC relay connector (ACC line) and the body ground.

OK: System voltage

(4) Turn the power supply mode of the power supply mode of the engine switch from "ON" position to "LOCK" (OFF) position.

(5) Measure the voltage between the ACC relay connector (ACC line) and the body ground.

OK: 1 V or less

Is the check result normal?

Go to Step 5

Go to Step 4

STEP 4. Check of short to power supply, short to ground or open circuit in ACC line between the KOS&OSS-ECU connector and the ACC relay connector.

Is the check result normal?

Intermittent malfunction (Refer to GROUP 00, How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunction

Repair the connector(s) or wiring harness.

STEP 5. Check of open circuit in ground line between the ACC relay connector and the body ground.

Is the check result normal?

Go to Step 6

Repair the wiring harness.

STEP 6. Voltage measurement at ACC relay connector (ACC line).

(1) Disconnect the connector, and measure at the wiring harness side.

(2) Measure the voltage between the ACC relay connector (power supply line) and the body ground.

OK: System voltage

Is the check result normal?

Go to Step 8

Go to Step 7

STEP 7. Check of short to ground or open circuit in power supply line between the fusible link connector and the ACC relay connector.

Is the check result normal?

Intermittent malfunction (Refer to GROUP 00, How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunction

Repair the connector(s) or wiring harness.

STEP 8. Voltage measurement at ETACS-ECU connector (ACCI line).

(1) Disconnect the connector, and measure at the wiring harness side.

(2) Turn the power supply mode of the engine switch from "LOCK" (OFF) position to "ON" position.

(3) Measure the voltage between the ETACS-ECU connector (ACCI line) and the body ground.

OK: System voltage

(4) Turn the power supply mode of the engine switch from "ON" position to "LOCK" (OFF) position.

(5) Measure the voltage between the ETACS-ECU connector (ACCI line) and the body ground.

OK: 1 V or less

Is the check result normal?

Go to Step 9

Repair the wiring harness, ACCI line between the ETACS-ECU connector and the fusible link.

STEP 9. Using scan tool (M.U.T.-III), check data list.

(1)

caution

To prevent damage to scan tool (M.U.T.-III), always turn the power supply mode of the engine switch to the OFF position before connecting or disconnecting scan tool (M.U.T.-III).

Connect scan tool (M.U.T.-III) [Refer to "How to connect the Scan Tool (M.U.T.-III)

"].

(2) Turn the power supply mode of the engine switch to "OFF".

(3) Operate the engine switch to change the power supply mode, and check that the data list display of ETACS-ECU is changed.

When power supply mode is "OFF".

ETACS-ECU data list
Item No.	Item name	Normal condition
29	Ignition switch(ACC)	OFF

When power supply mode is "ACC".

ETACS-ECU data list
Item No.	Item name	Normal condition
29	Ignition switch(ACC)	ON

When power supply mode is "ON".

ETACS-ECU data list
Item No.	Item name	Normal condition
29	Ignition switch(ACC)	ON

OK: Normal conditions are displayed for all the items.

Is the check result normal?

Go to Step 10

Go to Step 11

STEP 10. Recheck for diagnostic trouble code.

Check again if the DTC is set in the KOS&OSS-ECU.

(1) Erase the DTC.

(2) Turn the power supply mode of the engine switch from "LOCK" (OFF) position to "ON" position.

(3) On completion, check that the DTC is set again.

Is the DTC set?

Replace the ETACS-ECU (Refer to GROUP 54A, ETACS-ECU

Intermittent malfunction is suspected (Refer to GROUP 00, How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions

STEP 11. Recheck for diagnostic trouble code.

Check again if the DTC is set in the KOS&OSS-ECU.

(1) Erase the DTC.

(2) Turn the power supply mode of the engine switch from "LOCK" (OFF) position to "ON" position.

(3) On completion, check that the DTC is not set again.

Is the DTC set?

Replace the KOS&OSS-ECU and register the VIN (Refer to

Intermittent malfunction is suspected (Refer to GROUP 00, How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions