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Inspection Procedure 14: Engine does not start (Cranking is not performed).
 
 
cautionBefore replacing the ECU, ensure that the power supply circuit, the ground circuit and the communication circuit are normal.
 
 
 
 
COMMENTS ON TROUBLE SYMPTOM
When the engine does not start (cranking is not performed), the battery malfunction, stoplight switch malfunction, engine starting circuit malfunction, or KOS&OSS-ECU malfunction may be present.
 
 
PROBABLE CAUSES
  • Malfunction of battery
  • Damaged wiring harness or connector (open circuit in ST line)
  • Error in engine starting circuit system
  • Stoplight switch malfunction
  • Malfunction of the CAN bus line
  • Malfunction of KOS&OSS-ECU
  • ECM malfunction
 
 
PROBABLE CAUSES
STEP 1. Battery check
Perform the battery test to check the battery status (Refer to GROUP 54A - Battery ).
Is the check result normal?
Go to Step 2.
Replace the battery.
 
STEP 2. Check that the scan tool (M.U.T.-IIISE) communicates with this system
Check that the communication with scan tool (M.U.T.-IIISE) is possible.
(1) Turn on and off any of the door switches several times, or open any of the doors.
(2) Check that KOS&OSS-ECU can communicate with the scan tool (M.U.T.-IIISE).
Is the check result normal?
Go to Step 3.
Perform troubleshooting for inspection procedure 3 "Abnormal in KOS&OSS-ECU power supply and ground circuits ."
 
STEP 3. Using scan tool (M.U.T.-IIISE), check the DTC.
Check if the DTC is set in the KOS&OSS-ECU.
Is the DTC set?
: Diagnose the KOS&OSS-ECU. Refer to .
: Go to Step 4.
 
STEP 4. Using scan tool (M.U.T.-IIISE), check the data list
Check the KOS&OSS-ECU data list.
  • Operate the brake pedal.
 
Item No.Check itemOperation stateDisplay
5Stop light switchBrake pedal is depressedON
Brake pedal releasedOFF
Item No.Check itemOperation stateDisplay
5Stop light switchBrake pedal is depressedON
Brake pedal releasedOFF
OK: Operation state and data list display agree with each other.
Is the check result normal?
: Go to Step 6.
Go to Step 5.
 
STEP 5. Stoplight switch check
Continuity check of stoplight switch (Refer to GROUP 35A - Brake Pedal ).
Is the check result normal?
Go to Step 6.
Replace the stoplight switch (Refer to GROUP 35A - Brake Pedal ).
 
STEP 6. Using scan tool (M.U.T.-IIISE), check the other system data list
Check the ECM data list.
(1) Using the scan tool (M.U.T.-IIISE), set the forced power supply output to "IG START". (Refer to .)
(2) Check the ECM data list.
 
Item No.Check itemDisplay
79Cranking signal
(Ignition switch-ST)
ON
Item No.Check itemDisplay
79Cranking signal
(Ignition switch-ST)
ON
OK: Operation state and data list display agree with each other.
(3) Using the scan tool (M.U.T.-IIISE), set the forced power supply output to other than "IG START". (Refer to .)
(4) Check the ECM data list.
 
Item No.Check itemDisplay
79Cranking signal
(Ignition switch-ST)
OFF
Item No.Check itemDisplay
79Cranking signal
(Ignition switch-ST)
OFF
OK: Operation state and data list display agree with each other.
Is the check result normal?
Go to Step 8.
Go to Step 7.
 
STEP 7. Check of short to power supply, short to ground or open circuit in ST line between KOS&OSS-ECU connector and ECM connector
Is the check result normal?
Replace the KOS&OSS-ECU and register the ID codes (Refer to ).
Repair the connector(s) or wiring harness.
 
STEP 8. Check of the troubles
Check whether the engine is started (cranking is performed).
Is the check result normal?
Intermittent malfunction is suspected (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunction ).
There is a problem with the engine starting circuit system of ECM. Carry out the troubleshooting relevant to the engine starting circuit system. (Refer to GROUP 13A - Diagnosis .)