Code No.U0126 SAS CAN timeout


caution
  • If the diagnosis code No. U0126 is set, be sure to diagnose the CAN bus line.
  • Before replacing the ECU, ensure that the power supply circuit, the earth circuit and the communication circuit are normal.

DIAGNOSTIC FUNCTION


When the LDW-ECU receives no signal from the steering wheel sensor for 2.5 seconds or more, it will store diagnosis code No. U0126.

JUDGEMENT CRITERIA


When the LDW-ECU receives no signal from the steering wheel sensor for 2.5 seconds or more, it will determine that the system is defective.

PROBABLE CAUSES



DIAGNOSIS PROCEDURE


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


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 ). On completion, go to Step 2.

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


Check if diagnosis code is set to the ASC-ECU.

Q. Is the diagnosis code set?

Troubleshoot the ASC. Refer to GROUP 35C - Troubleshooting .

Go to Step 3

STEP 3. Check the M.U.T.-III Diagnosis code for other systems


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

Q. Is the diagnosis code set?

Go to Step 4

Go to Step 5

STEP 4. Check whether the diagnosis code is reset.


Check again if the diagnosis code is set to the LDW-ECU.
(1)Erase the diagnosis code.
(2)Turn the ignition switch from "LOCK" (OFF) position to "ON" position.
(3)Check if diagnosis code is set.

Q. Is the diagnosis code set?

Replace the steering wheel sensor.

The trouble can be an intermittent malfunction such as a poor connection or open circuit in the CAN bus lines between the steering wheel sensor and the LDW-ECU (GROUP 00 - How to use Troubleshooting/inspection Service Points - How to Cope with Intermittent Malfunction ).

STEP 5. Check whether the diagnosis code is reset.


Check again if the diagnosis code is set to the LDW-ECU.
(1)Erase the diagnosis code.
(2)Turn the ignition switch from "LOCK" (OFF) position to "ON" position.
(3)Check if diagnosis code is set.

Q. Is the diagnosis code set?

Replace the LDW-ECU.

The trouble can be an intermittent malfunction such as a poor connection or open circuit in the CAN bus lines between the steering wheel sensor and the LDW-ECU (GROUP 00 - How to use Troubleshooting/inspection Service Points - How to Cope with Intermittent Malfunction ).