Code No.C1396: Engine-ECU malfunction



caution If there is any problem in the CAN bus lines, an incorrect diagnosis code may be set. Diagnose the CAN bus lines before the diagnosis codes (Refer to GROUP 54C, CAN bus-line diagnostic flow ).

OPERATION


The hydraulic unit (integrated with ASTC-ECU) communicates with the engine-ECU via the CAN bus line. ASTC-ECU sends the command to the engine-ECU to reduce the engine power at the ASC or ATC operation.

DIAGNOSIS CODE SET CONDITION


This diagnosis code is set when the ASTC-ECU power supply voltage is normal but the engine-ECU is abnormal after the engine is started.

PROBABLE CAUSES


The most likely causes for this diagnosis code to set are:


DIAGNOSIS


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




caution Before connecting or disconnecting the M.U.T.-III, turn the ignition switch to the "LOCK" (OFF) position.
(1)Connect M.U.T.-III to the 16-pin diagnosis connector.
(2)Turn the ignition switch to the "ON" position.
(3)Diagnose the CAN bus line.
(4)Turn the ignition switch to the "LOCK" (OFF) position.

Q. Is the check result?

Go to Step 3.

Repair the CAN bus line (Refer to GROUP 54C, CAN bus line Diagnostic flow ). Then go to Step 2.

STEP 2. Check whether the diagnosis code is reset.




caution Before connecting or disconnecting the M.U.T.-III, turn the ignition switch to the "LOCK" (OFF) position.
(1)Turn the ignition switch to the "ON" position.
(2)Erase the diagnosis code.
(3)Turn the ignition switch to the "LOCK" (OFF) position.
(4)Turn the ignition switch to the "ON" position.
(5)Check if the diagnosis code is set.
(6)Turn the ignition switch to the "LOCK" (OFF) position.

Q. Is code No.C1396 set?

Check if a diagnosis code is set by the engine-ECU. (Refer to 13A, check chart for diagnosis codes .)Then go to Step 3.

The procedure is complete.

STEP 3. Check whether the diagnosis code is reset.




Check again if the diagnosis code is set.
(1)Turn the ignition switch to the "ON" position.
(2)Erase the diagnosis code.
(3)Turn the ignition switch to the "LOCK" (OFF) position.
(4)Turn the ignition switch to the "ON" position.
(5)Check if the diagnosis code is set.
(6)Turn the ignition switch to the "LOCK" (OFF) position.

Q. Is code No.C1396 set?

Replace the hydraulic unit assembly (integrated with ASTC-ECU). Then go to Step 4.

It can be assumed that this malfunction is intermittent. Refer to GROUP 00, How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunction .

STEP 4. Check whether the diagnosis code is reset.




Check again if the diagnosis code is set.
(1)Turn the ignition switch to the "ON" position.
(2)Erase the diagnosis code.
(3)Turn the ignition switch to the "LOCK" (OFF) position.
(4)Turn the ignition switch to the "ON" position.
(5)Check if the diagnosis code is set.
(6)Turn the ignition switch to the "LOCK" (OFF) position.

Q. Is code No.C1396 set?

Go to Step 1.

The procedure is complete.