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Inspection Procedure 3: 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 <CVT vehicle>, clutch interlock switch malfunction <M/T vehicle>, engine starting circuit malfunction, or 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 <CVT vehicle>
  • Clutch interlock switch malfunction <M/T vehicle>
  • Malfunction of the CAN bus line
  • Malfunction of 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), 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 stored in the OSS-ECU.
(4) Turn the power supply mode of the engine switch to OFF.
Is the DTC stored?
Refer to diagnostic trouble code chart .
<CVT vehicle> : Go to Step 3.
<M/T vehicle> : Go to Step 6.
 
STEP 3. 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 (M.U.T.-III).
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 OSS-ECU data list.
  • Operate the brake pedal.
 
Item No.Check itemOperation stateDisplay
3Stop 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 12.
Go to Step 4.
 
STEP 4. Stop Light Switch Check
(1) Remove the stop light switch (Refer to GROUP 35A - Brake Pedal ).
(2) Check continuity when the stop light switch is operated to position (Refer to GROUP 35A - Brake Pedal ).
 
Check conditionTerminal connector of testerNormal condition
At free position1 - 2 (for stop light switch)Continuity exists
(2 Ω or less)
3 - 4 (for brake monitoring switch)No continuity
Press the plunger from the edge of the outer case by the dimension shown in the figure.1 - 2 (for stop light switch)No continuity
3 - 4 (for brake monitoring switch)Continuity exists
(2 Ω or less)
Is the check result normal?
Go to Step 5.
Replace the stop light switch.
 
STEP 5. Check of short to power supply, short to ground, and open circuit in STP1 line between OSS-ECU connector and stop light switch connector
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 ).
Repair the connector(s) or wiring harness.
 
STEP 6. Using scan tool (M.U.T.-III), read other system 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 diagnostic trouble code is stored in the engine control module.
(4) Turn the power supply mode of the engine switch to OFF.
Is the DTC stored?
Diagnose the engine control module. Refer to GROUP 13A - Troubleshooting .
Go to Step 7.
 
STEP 7. Clutch interlock switch (For starter relay) check
(1) Remove the clutch interlock switch (Refer to GROUP 21A - Clutch Pedal ).
(2) Continuity check of clutch interlock switch (For starter relay) (Refer to GROUP 21A - Clutch Pedal .)
 
Check conditionTerminal connector of testerNormal condition
At free position1 - 2No continuity
Press the plunger from the edge of the outer case by the dimension shown in the figure.1 - 2Continuity exists
(2 ohms or less)
Is the check result normal?
Go to Step 8.
Replace the clutch interlock switch (For starter relay).
 
STEP 8. Voltage measurement at clutch interlock switch (For starter relay) connector (STRL line)
(1) Disconnect the connector, and measure at the wiring harness side.
(2) Check the voltage between the clutch interlock switch (For starter relay) connector (STRL line) and body ground.
OK: System voltage
Is the check result normal?
Go to Step 10.
Go to Step 9.
 
STEP 9. Check of short to power supply, short to ground, and open circuit in STRL line between engine control module connector and clutch interlock switch (For starter relay) connector
Is the check result normal?
Go to Step 11.
Repair the connector(s) or wiring harness.
 
STEP 10. Check of short to power supply, short to ground, and open circuit in power supply line between starter relay connector and clutch interlock switch (For starter relay) connector
Is the check result normal?
Go to Step 11.
Repair the connector(s) or wiring harness.
 
STEP 11. Check of the troubles
When the power supply mode is OFF, operate the engine switch twice while fully depressing the clutch pedal.
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 ).
Carry out the troubleshooting relevant to the engine starting circuit system. (Refer to GROUP 13A - Troubleshooting .)
 
STEP 12. Voltage measurement at engine control module connector (ST line)
(1) With the engine control module connector kept connected, measure by backprobing.
(2) Using the scan tool (M.U.T.-III), set the forced power supply output to other than "IG-ST".(Refer to .)
(3) Measure the voltage between the engine control module connector (ST line) and body ground.
OK: 1 V or less
(4) Using the scan tool (M.U.T.-III), set the forced power supply output to "IG-ST".(Refer to .)
(5) Measure the voltage between the engine control module connector (ST line) and body ground.
OK: System voltage
Is the check result normal?
Go to Step 14.
Go to Step 13.
 
STEP 13. Check of short to power supply, short to ground, and open circuit in ST line between OSS-ECU connector and engine control module connector
Is the check result normal?
Replace the OSS-ECU and register the VIN (Refer to ).
Repair the connector(s) or wiring harness.
 
STEP 14. 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 (M.U.T.-III).
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 15.
Replace the engine control module and register the VIN and key codes (Refer to GROUP 00 - How to Perform VIN Writing ).
 
STEP 15. 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 .)