Code No.U15A2 Vehicle speed information lost


caution
  • If the diagnosis code No. U15A2 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 vehicle speed signal from the engine-ECU for 2.5 seconds or more, it will store diagnosis code No. U15A2.

JUDGEMENT CRITERIA


When the LDW-ECU receives no vehicle speed signal from the engine-ECU 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 diagnosis


Use M.U.T.-III to diagnose the CAN bus lines.

Q. Is the check result normal?

Go to Step 2

Repair the CAN bus lines (Refer to GROUP 54C - CAN Bus Diagnostics Table ). On completion, go to Step 2.

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


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

Q. Is the diagnosis code set?

Troubleshoot the engine (Refer to GROUP 13A - Diagnosis Code Chart ).

Go to Step 3

STEP 3. 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 the "LOCK" (OFF) position to the "ON" position.
(3)Check if the diagnosis code is set.

Q. Is the diagnosis code set?

Replace the LDW-ECU, and then go to Step 4.

Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/How to Cope with Intermittent Malfunctions ).

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 the "LOCK" (OFF) position to the "ON" position.
(3)Check if the diagnosis code is set.

Q. Is the diagnosis code set?

Return to Step 1.

This diagnosis is complete.