Code No.34: CAN Communication Error


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 54D, CAN bus-line diagnostic flow ).

OPERATION
ASTC-ECU sends or receives data from engine-A/T-ECU <3000 A/T, 3800>, engine-ECU <3000 M/T, 3200>, A/T-ECU <3200 A/T>, combination meter, G and yaw rate sensor, and steering wheel sensor via the CAN bus line.

DIAGNOSIS CODE SET CONDITIONS
This diagnosis code is set if communication errors have occurred simultaneously between the relevant ECUs and/or sensors, which are connected to the CAN bus line.

PROBABLE CAUSES
The most likely causes for these diagnosis codes to set are:

  • Damaged wiring harness or connector
  • Malfunction of the ASTC-ECU
  • Malfunction of other ECU

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 normal?
Go to Step 3.
Repair the CAN bus line (Refer to GROUP 54D, 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.34 set?
Replace the ASTC-ECU. Then go to Step 3.
The procedure is complete.

STEP 3. 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.34 set?
Repeat the troubleshooting from Step 1.
The procedure is complete.