Code No.U1401 Dynamic range error


caution If diagnosis code No.U1401 is set in the ETACS-ECU, diagnose the CAN main bus line.
caution Whenever the ECU is replaced, ensure that the communication circuit is normal.


TROUBLE JUDGMENT


This code is set when an abnormality is present in the signal from the ambient temperature sensor.

PROBABLE CAUSE



  • Damaged wiring harness or connectors
  • Malfunction of the combination meter
  • Malfunction of the ETACS-ECU

DIAGNOSIS PROCEDURE


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


warning Since the radiator fan rotates during CAN bus line diagnostics, make sure that no one is servicing the engine compartment before diagnosing the CAN bus line. Since the CAN communication stops when diagnosing the CAN bus line, the ETACS-ECU detects the time-out of the engine-ECU, and activates the radiator fan to prevent overheating as fail-safe.
Use the M.U.T.-III to diagnose the CAN bus lines.

Q. Is the check result normal?

Go to Step 2
Repair the CAN bus line (Refer to GROUP 54C, Troubleshooting ).

STEP 2. M.U.T.-III other systems diagnosis code


Check again if the diagnosis code is set to the combination meter.

Q. Is the diagnosis code set?

Diagnose the combination meter. Refer to GROUP 54A, combination meter <COLT>, <COLT CZ3>.
Go to Step 3

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


Check if a diagnosis code, which relates to CAN communication-linked systems below, is set.

  • A/C-ECU
    U1401: Dynamic range error

Q. Is the diagnosis code set?

Go to Step 4
Go to Step 5

STEP 4. Check whether the diagnosis code is reset.


Recheck if the diagnosis code is set.
(1)Erase the diagnosis code.
(2)Ignition switch: LOCK (OFF) position to ON
(3)Check if the diagnosis code is set.

Q. Is the diagnosis code set?

Replace the combination meter.
A poor connection, open circuit or other intermittent malfunction is present in the CAN bus lines between the combination meter and the ETACS-ECU (Refer to GROUP 00, How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunction ).

STEP 5. Check whether the diagnosis code is reset.


Recheck if the diagnosis code is set.
(1)Erase the diagnosis code.
(2)Ignition switch: LOCK (OFF) position to ON
(3)Check if the diagnosis code is set.

Q. Is the diagnosis code set?

Replace the ETACS-ECU.
A poor connection, open circuit or other intermittent malfunction is present in the CAN bus lines between the combination meter and the ETACS-ECU (Refer to GROUP 00, How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunction ).