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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.
 
 
 
 
TECHNICAL DESCRIPTION (COMMENT)
When the engine does not start (cranking is not performed), the battery malfunction, stop light switch malfunction, engine starting circuit malfunction, or KOS&OSS-ECU malfunction may be present.
 
 
TROUBLESHOOTING HINTS
  • Malfunction of battery
  • Damaged wiring harness or connector (open circuit in ST line)
  • Error in engine starting circuit system
  • Stop light switch malfunction
  • Malfunction of the CAN bus line
  • Malfunction of KOS&OSS-ECU
  • Engine control module malfunction
 
 
DIAGNOSIS
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. Using scan tool (M.U.T.-III), communicates with this system.
Check that the communication with scan tool (M.U.T.-III) is possible.
noteIf ETACS-ECU is not active, KOS&OSS-ECU cannot communicate with the scan tool (M.U.T.-III).
(1)
cautionTo prevent damage to scan tool (M.U.T.-III), always turn the power supply mode of the engine switch to the "OFF" position before connecting or disconnecting scan tool (M.U.T.-III).
Connect scan tool (M.U.T.-III) [Refer to "How to connect scan tool (M.U.T.-III) "].
(2) Turn the power supply mode of the engine switch to "ON".
(3) Turn on and off any of the door switches several times, or open any of the doors.
(4) Check that KOS&OSS-ECU can communicate with the scan tool (M.U.T.-III).
(5) Turn the power supply mode of the engine switch to "OFF".
Is the check result normal?
Go to Step 3.
Carry out the troubleshooting of KOS&OSS-ECU power supply or ground circuit malfunction (Refer to ).
 
STEP 3. Using scan tool (M.U.T.-III), read the diagnostic trouble code.
(1)
cautionTo prevent damage to scan tool (M.U.T.-III), always turn the power supply mode of the engine switch to the "OFF" position before connecting or disconnecting scan tool (M.U.T.-III).
Connect scan tool (M.U.T.-III) [Refer to "How to connect scan tool (M.U.T.-III) "].
(2) Turn the power supply mode of the engine switch to "ON".
(3) Check if the diagnosis trouble code is set in the KOS&OSS-ECU.
(4) Turn the power supply mode of the engine switch to "OFF".
Is the DTC set?
Refer to diagnostic trouble code chart .
Go to Step 4.
 
STEP 4. Using scan tool (M.U.T.-III), check data list.
(1)
cautionTo prevent damage to scan tool (M.U.T.-III), always turn the power supply mode of the engine switch to the "OFF" position before connecting or disconnecting scan tool (MB991958).
Connect scan tool (M.U.T.-III) [Refer to "How to connect the Scan Tool (M.U.T.-III) "]
(2) Turn the power supply mode of the engine switch to "OFF".
(3) Check the KOS&OSS-ECU data list.
  • Operate the brake pedal.
 
Item No.Check itemOperation stateDisplay
22Stop 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. Stop Light Switch Check
Remove the stop light switch (Refer to GROUP 35A, Brake Pedal ).
Is the check result normal?
Go to Step 6.
Replace the stop light switch.
 
STEP 6. Using scan tool (M.U.T.-III), other system data list.
(1)
cautionTo prevent damage to scan tool (M.U.T.-III), always turn the power supply mode of the engine switch to the "OFF" position before connecting or disconnecting scan tool (MB991958).
Connect scan tool (M.U.T.-III) [Refer to "How to connect the Scan Tool (M.U.T.-III) "].
(2) Turn the power supply mode of the engine switch to "OFF".
(3) Using the scan tool (M.U.T.-III), set the forced power supply output to "IG-ST" (Refer to ).
(4) Check the engine control module data list.
 
Item No.Check itemDisplay
79Cranking signal
(Ignition switch-ST)
ON
OK: Operation state and data list display agree with each other.
(5) Using the scan tool (M.U.T.-III), set the forced power supply output to other than "IG-ST" (Refer to ).
(6) Check the engine control module data list.
 
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, and open circuit in ST line between KOS&OSS-ECU connector and engine control module connector
Is the check result normal?
Replace the KOS&OSS-ECU and register the VIN (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 engine control module. Carry out the troubleshooting relevant to the engine starting circuit system (Refer to GROUP 13A, Troubleshooting ).