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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, OSS-ECU sets the DTC B1135, and displays the power supply system error warning screen to the multi information display of the combination meter.
 
 
DTC SET CONDITION
Check Conditions
  • After OSS-ECU activation
Judgment Criterion
  • 3 seconds or more have elapsed since the unmatch between the SW1 and SW2 of engine switch is detected
 
 
TROUBLESHOOTING HINTS
  • 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)
  • Malfunction of OSS-ECU
 
 
DIAGNOSIS
STEP 1. Engine switch check
(1) Remove the engine switch (Refer to ).
(2) Check continuity when the engine switch is operated to "Press" or "Release" position.
 
Switch operationTerminal numberNormal conditions
Press1 - 2Continuity exists (2 ohms or less)
8 - 6
Release1 - 2No continuity
8 - 6
Is the engine switch normal?
Go to Step 2.
Replace the engine switch.
 
STEP 2. Using scan tool MB991958, check data list.
Check the OSS-ECU data list.
  • Operate the engine switch.
 
Operation stateItem No.Check itemDisplay
When the engine switch is pressed1Engine switch(1)ON
2Engine switch(2)ON
When the engine switch is not pressed1Engine switch(1)OFF
2Engine switch(2)OFF
OK: Operation state and data list display agree with each other.
Are the check result normal?
Normal conditions are displayed for all the items. : Go to Step 5.
Normal condition is not displayed for item No.1 : Go to Step 3.
Normal condition is not displayed for item No. 2. : Go to Step 4.
 
STEP 3. Check of short to power supply, short to ground, and open circuit in SW1 line between OSS-ECU connector and engine switch connector
Is the check result normal?
Go to Step 5.
Repair the connector(s) or wiring harness.
 
STEP 4. Check of short to power supply, short to ground, and open circuit in SW2 line between 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 OSS-ECU connector and engine switch connector, be sure to use the oscilloscope. (Outputs the sawtooth waveform of 0 to 5 V with intervals of 10 ms.)
Is the check result normal?
Go to Step 5.
Repair the connector(s) or wiring harness.
 
STEP 5. Check whether the DTC is reset.
Is the DTC set?
Replace the OSS-ECU and register the VIN (Refer to ).
Intermittent malfunction is suspected (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunction ).