B1135

DTC B1135 Engine switch

CAUTION:
When 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 Engine Switch Removal and Installation).

(2)Check continuity when the engine switch is operated to "Press" or "Release" position.





Q. Is the engine switch normal?

YES Go to Step 2.
NO Replace the engine switch.
STEP 2. Using scan tool MB991958, check data list.

Check the OSS-ECU data list.

- Operate the engine switch.





OK: Operation state and data list display agree with each other.


Q. 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

Q. Is the check result normal?

YES Go to Step 5.
NO 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

NOTE:
Because 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.)

Q. Is the check result normal?

YES Go to Step 5.
NO Repair the connector(s) or wiring harness.
STEP 5. Check whether the DTC is reset.

Q. Is the DTC set?

YES Replace the OSS-ECU and register the VIN (Refer to Programming and Relearning).
NO Intermittent malfunction is suspected How to Cope With Intermittent Malfunctions).