Code No. C143F: Interlock system abnormality

OPERATION

The transfer-ECU requests the A/T-ECU to reduce the transfer input friction (interlock control) when the transfer is switched between "high" and "low". To do this, the A/T-ECU engages the transmission neutral gear.

DIAGNOSIS CODE SET CONDITIONS

The interlock status, which the system receives from the A/T-ECU via CAN signal, remains "FAIL" for 1.5 seconds after the ignition switch is turned ON with the battery voltage at 10 -16 V.

PROBABLE CAUSES

Damaged wiring harness or connector
Malfunction of A/T-ECU
Malfunction of the transfer-ECU

DIAGNOSIS PROCEDURE

STEP 1. M.U.T.-III CAN bus diagnostics

Using M.U.T.-III, perform CAN bus line diagnosis.

Q. Is the check result normal?

	Go to Step 2.

	Repair the CAN bus line (Refer to GROUP 54C - Troubleshooting ). and then go to Step 4.

STEP 2. M.U.T.-III other system diagnosis codes

Check whether the automatic transmission diagnosis codes are set or not.

Q. Is the diagnosis code set?

	YES : Diagnose the automatic transmission (Refer to ).

	Go to Step 3.

STEP 3. M.U.T.-III diagnosis code

Reconfirm whether the diagnosis codes are set in the transfer-ECU.

(1)Erase the diagnosis code.

(2)Check if the diagnosis code is set.

Q. Is the diagnosis code set?

	Go to Step 4.

	Intermittent malfunction in CAN bus line between A/T-ECU and transfer-ECU (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunction ).

STEP 4. Replace the A/T-ECU

After replacing the A/T-ECU (Refer to

), re-check the transfer-ECU diagnosis code output.

Q. Is the diagnosis code set?

	Replace the transfer-ECU (Refer to ).

	The check is end.