Code No.C1450: ASTC-ECU System (Communication Error) <Vehicles with ASTC>












OPERATION



DIAGNOSIS CODE SET CONDITIONS



PROBABLE CAUSES



  • Damaged harness wires and connectors
  • Malfunction of the ASTC system
  • Malfunction of the transfer-ECU

DIAGNOSIS PROCEDURE

STEP 1. Check the ASTC system.
Refer to GROUP 35C - Troubleshooting .

Q. Is the check result normal?
Go to Step 2.
Perform the relevant troubleshooting.

STEP 2. Measure the voltage at transfer-ECU connector D-124.
(1)Measure the voltage between terminal No.15, 16, 31, 32 and earth at the ECU side.
(2)Turn the ignition switch to the ON position.
OK: 1 V or less

Q. Is the check result normal?
Go to Step 5.
Go to Step 3.

STEP 3. Connector check: D-223 ASTC-ECU connector, D-225 intermediate connector.
Check for the contact with terminals.

Q. Is the check result normal?
Go to Step 4.
Repair the defective connector.

STEP 4. Check the harness between transfer-ECU connector D-124 terminal No.15, 16, 31, 32 and ASTC-ECU connector D-223 terminal No.72, 73, 71, 79.
Check the output line for open circuit.

Q. Is the check result normal?
Go to Step 5.
Repair the wiring harness.

STEP 5. Connector check: D-124 transfer-ECU connector.
Check for the contact with terminals.

Q. Is the check result normal?
Go to Step 6.
Repair the defective connector.

STEP 6. Replace the transfer-ECU.
(1)Replace the transfer-ECU.
(2)Test drive the vehicle.
(3)Check if the diagnosis code is set.

Q. Is diagnosis code No.C1450 set?
Go to Step 1.
The procedure is complete.