Code No. U1102: ASTC-ECU time-out



caution If Diagnosis Code U1102 is output from engine-A/T-ECU surely perform CAN busline diagnosis.
caution Replace ECU after certainly confirming that the communication circuits are normal.

TROUBLE JUDGMENT


Check Conditions
Judgment Criterion

COMMENT ON TROUBLE SYMPTOM


Current malfunction
Past malfunction

PROBABLE CAUSES




DIAGNOSIS PROCEDURE


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



  • Using M.U.T.-III, perform CAN busline diagnosis.

Q. Is the check result normal?

Go to Step 2 .
Correct CAN busline (Refer to GROUP54D - Diagnosis - Can Bus Diagnosis Table ), and then go to Step 6 .

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



  • Confirm whether the diagnosis codes are output from ASTC-ECU.

Q. Are the diagnosis codes set?

Perform the troubleshooting of ASTC (Refer to GROUP 35C - Inspection Chart For Diagnosis Code ).
Go to Step 3 .

STEP 3. M.U.T.-III other system diagnosis codes



  • Confirm whether Diagnosis Code U1102: ASTC-ECU time-out is output from the following ECU having CAN communication with ASTC-ECU

    1. Combination meter

Q. Is the diagnosis code set?

Go to Step 4 .
Go to Step 5 .

STEP 4. M.U.T.-III diagnosis code



  • Reconfirm whether the diagnosis codes are output from engine-A/T-ECU.

    1. Erase the diagnosis codes being output.
    2. Ignition switch: "LOCK" (OFF) to ON
    3. Confirm whether the diagnosis codes are output.

Q. Are the diagnosis codes set?

Replace the ASTC-ECU. Then go to Step 6 .
Intermittent malfunction in CAN busline between engine-A/T-ECU (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions ).

STEP 5. M.U.T.-III diagnosis code



  • Reconfirm whether the diagnosis codes are output from engine-A/T-ECU.

    1. Erase the diagnosis codes being output.
    2. Ignition switch: "LOCK" (OFF) to ON
    3. Confirm whether the diagnosis codes are output.

Q. Are the diagnosis codes set?

Replace the engine-A/T-ECU. Then go to Step 6 .
Intermittent malfunction in CAN busline between engine-A/T-ECU and ASTC-ECU (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions ).

STEP 6. M.U.T.-III diagnosis code



  • Reconfirm whether the diagnosis codes are output from engine-A/T-ECU.

    1. Erase the diagnosis codes being output.
    2. Ignition switch: "LOCK" (OFF) to ON
    3. Confirm whether the diagnosis codes are output.

Q. Are the diagnosis codes set?

Go to step 1 .
Check end.