|
|
TROUBLESHOOTING AUTOMATIC TRANSMISSION 23A-75 You can narrow down the possible cause of the PROBABLE CAUSES • Damaged wiring harness or connector • Malfunction of the engine-ECU • Malfunction of the A/T-ECU DIAGNOSIS PROCEDURE STEP 1. M.U.T.-III CAN bus diagnostics Q: Is the check result normal? YES : Go to Step 2. NO : Repair the CAN busline (Refer to − Can Bus Diagnostic Chart ), and then go to Step 4. STEP 2. M.U.T.-III other system diagnosis codes Q: Is the diagnosis code output? YES : Diagnose the diesel fuel system (Refer to GROUP 13A, Troubleshooting ). NO : Go to Step 3. STEP 3. M.U.T.-III diagnosis code Q: Is the diagnosis code output? YES : Go to Step 4. NO : Intermittent malfunction in CAN busline − How to Use Troubleshooting/Inspection Service Points − How to Cope with Intermittent Malfunction ). STEP 4. Replace the engine-ECU Q: Is the diagnosis code output? YES : Replace the A/T-ECU. NO : The check is end. Code No.U1073: Bus off CAUTION • If diagnosis code U1073 is set in the A/T-ECU, always diagnose the CAN main bus line. If • Whenever the ECU is replaced, ensure that the communication circuit is normal. DIAGNOSIS CODE SET CONDITIONS PROBABLE CAUSES • Damaged wiring harness or connector • Malfunction of the A/T-ECU DIAGNOSIS PROCEDURE STEP 1. M.U.T.-III CAN bus diagnostics Q: Is the check result normal? YES : Go to Step 2. NO : Repair the CAN bus line (Refer to GROUP STEP 2. M.U.T.-III diagnosis code position. (4) Turn the ignition switch to the ON position. position. Q: Is code No.U1073 set? YES : Replace the A/T-ECU. Then go to Step 3. NO : Intermittent malfunction (Refer to GROUP − How to Use Troubleshooting/ Inspection Service Points ). |