Inspection Procedure 5: Engine does not start (cranking is not performed).


caution Before replacing the ECU, ensure that the power supply circuit, the earth circuit and the communication circuit are normal.

COMMENTS ON TROUBLE SYMPTOM



PROBABLE CAUSES



  • Malfunction of battery
  • Damaged wiring harness or connector (open circuit in STOE line)
  • Error in engine starting circuit system
  • Stop lamp switch malfunction
  • Malfunction of the CAN bus line
  • Malfunction of OSS-ECU
  • Malfunction of AS&G-ECU
  • Engine-ECU malfunction
  • ETACS-ECU malfunction

PROBABLE CAUSES


STEP 1. Battery check



Q. Is the check result normal?





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



Q. Is the diagnosis code set?





STEP 3. M.U.T.-III data list




  • Operate the brake pedal.
Operation state
 Item No.
 Check item
 Display
Brake pedal is depressed
 3
 Stop lamp switch
 ON
Brake pedal released
 OFF
OK: Operation state and data list display agree with each other.

Q. Is the check result normal?





STEP 4. Stop Lamp Switch Check



Q. Is the check result normal?





STEP 5. Voltage measurement at ETACS-ECU connector (STOE terminal)


(1)With the ETACS-ECU connector kept connected, measure by backprobing.
(2)Using the M.U.T.-III, set the forced power supply output to other than "IG-ST".(Refer to .)
(3)Measure the voltage between the ETACS-ECU connector (STOE terminal) and body earth.
OK: 1 V or less
(4)Using the M.U.T.-III, set the forced power supply output to "IG-ST".(Refer to .)
(5)Measure the voltage between the ETACS-ECU connector (STOE terminal) and body earth.
OK: System voltage

Q. Is the check result normal?





STEP 6. M.U.T.-III other system data list



(1)Using the M.U.T.-III, set the forced power supply output to "IG-ST".(Refer to .)
(2)Check the engine-ECU data list.
Item No.
 Check item
 Display
79
 Cranking signal
(Ignition switch-ST)
 ON
OK: Operation state and data list display agree with each other.
(3)Using the M.U.T.-III, set the forced power supply output to other than "IG-ST".(Refer to .)
(4)Check the engine-ECU data list.
Item No.
 Check item
 Display
79
 Cranking signal
(Ignition switch-ST)
 OFF
OK: Operation state and data list display agree with each other.

Q. Is the check result normal?





STEP 7. Check of open circuit in STOE line between ETACS-ECU connector and engine-ECU connector


Q. Is the check result normal?





STEP 8. Check of the troubles



Q. Is the check result normal?