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DTC B1135 Engine switch
 
 
cautionWhen replacing the ECU, always check that the communication circuit is normal.
 
 
DIAGNOSTIC FUNCTION
When an abnormality is detected for 3 seconds or more with either of the SW1 or SW2 of engine switch, KOS&OSS-ECU sets DTC B1135, and displays the power supply system error warning to the combination meter, and flashes the indicator of engine switch in amber.
 
 
JUDGMENT CRITERIA
Check Conditions
  • After KOS&OSS-ECU activation
Judgment Criterion
  • 3 seconds or more have elapsed since the unmatch between the SW1 and SW2 of engine switch is detected
 
 
PROBABLE CAUSES
  • Engine switch malfunction (ON/OFF seizure of SW1 or SW2)
  • Damaged wiring harness or connector (short to power supply, short to ground, or open circuit in SW1 or SW2 line)
  • Blown out fuse
  • Malfunction of KOS&OSS-ECU
 
 
DIAGNOSIS
STEP 1. Engine switch check.
Refer to .
Is the check result normal?
Go to Step 2.
Replace the engine switch.
 
STEP 2. Using scan tool (M.U.T.-IIISE), check the data list
Check the KOS&OSS-ECU data list.
  • Operate the engine switch.
 
Item No.Check itemOperation stateDisplay
3Engine switch (SW1)When the engine switch is pressedON
4Engine switch (SW2)ON
3Engine switch (SW1)When the engine switch is not pressedOFF
4Engine switch (SW2)OFF
Item No.Check itemOperation stateDisplay
3Engine switch (SW1)When the engine switch is pressedON
4Engine switch (SW2)ON
3Engine switch (SW1)When the engine switch is not pressedOFF
4Engine switch (SW2)OFF
OK: Normal values are displayed for all the items
Are the check result normal?
: Go to Step 7.
: Go to Step 3.
: Go to Step 5.
 
STEP 3. Check of short to power supply, short to ground or open circuit in SW1 line between KOS&OSS-ECU connector and engine switch connector.
Is the check result normal?
Go to Step 4.
Repair the connector(s) or wiring harness.
 
STEP 4. Check of short to ground or open circuit between relay box (fuse) connector and engine switch connector.
Is the check result normal?
Go to Step 7.
Repair the connector(s), wiring harness or fuse.
 
STEP 5. Check of open circuit between engine switch connector and body ground.
Is the check result normal?
Go to Step 6.
Repair the connector(s) or wiring harness.
 
STEP 6. Check of short to power supply, short to ground or open circuit in SW2 line between KOS&OSS-ECU connector and engine switch connector.
noteBecause the conformity cannot be determined even when the digital tester is used to measure the voltage of SW2 line between the KOS&OSS-ECU connector and engine switch connector, be sure to use the oscilloscope (Outputs the sawtooth waveform of 0 to 5 volts with intervals of 10 ms.).
Is the check result normal?
Go to Step 7.
Repair the connector(s) or wiring harness.
 
STEP 7. Check whether the DTC is set again.
Is the DTC set?
Replace the KOS&OSS-ECU and register the ID codes (Refer to ).
Intermittent malfunction is suspected (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunction ).