Code No.B1131 Starter setting circuit fail



caution
  • Use caution that the cooling fan becomes activated when the forced power supply output of M.U.T.-III is performed while the engine-ECU connector is disconnected. (Fail-safe for ETACS-ECU)
  • When replacing the ECU, always check that the communication circuit is normal.

DIAGNOSTIC FUNCTION


When a short circuit (short to power supply, short to earth) of starter setting circuit system is detected, OSS-ECU sets the diagnosis code No.B1131. At the same time, OSS-ECU displays the power supply system error warning screen to the multi information display of the combination meter, and flashes the indicator of engine switch in orange.

JUDGEMENT CRITERIA


Check Conditions
Judgment Criterion
  1. When the starter setting signal is ON, the starter setting circuit voltage is less than 1.5 V.
  2. When the starter setting signal is OFF, the circuit voltage is 3.5 V or more.

PROBABLE CAUSES




DIAGNOSIS PROCEDURE


STEP 1. Check of short to power supply, short to earth, and open circuit in ST, STO line between OSS-ECU connector and ETACS-ECU connector


note Before the wiring harness check, check the joint connector, and repair if necessary.

Q. Is the check result normal?

Go to Step 2
Repair the connector(s) or wiring harness.

STEP 2. Check of short to power supply, short to earth, and open circuit in STOE line between ETACS-ECU connector and engine-ECU connector


Q. Is the check result normal?

Go to Step 3
NO : Repair the connector(s) or wiring harness.

STEP 3. Voltage measurement at engine-ECU connector (STOE terminal)


(1)Disconnect the engine-ECU connector, and measure at the wiring harness side.
(2)Using the M.U.T.-III, set the forced power supply output to other than "IG-ST".(Refer to .)
(3)Measure the voltage between the engine-ECU connector (STOE terminal) and body earth.
OK: 1 V or less
(4)Using the M.U.T.-III, set the forced power supply output to "IG-ST".(Refer to .)
(5)Measure the voltage between the engine-ECU connector (STOE terminal) and body earth.
OK: System voltage

Q. Is the check result normal?

Go to Step 4
NO :

STEP 4. M.U.T.-III data list


Check the OSS-ECU data list.
(1)Disconnect the engine-ECU connector.
(2)Using the M.U.T.-III, perform the forced power supply output.
State of forced power supply output
Item No.
Check item
Display
IG-ST
13
Cranking signal output(monitor)
ON
Other than IG-ST
OFF
OK: Depending on the state of forced power supply output, the display is turned ON/OFF.

Q. Is the check result normal?

Replace the engine-ECU and register the chassis number and key codes [Refer to GROUP 00 - How to Perform Chassis Number (Chassis No.) Writing ].
Replace the OSS-ECU and register the chassis number (Refer to ).

STEP 5. Voltage measurement at ETACS-ECU connector (STOE terminal)


(1)Measure the ETACS-ECU connector side by backprobing.
(2)Using the M.U.T.-III, set the forced power supply output to other than "IG-ST".(Refer to .)
(3)Measure the voltage between the ETACS-ECU connector (STOE terminal) and body earth.
OK: 1 V or less
(4)Using the M.U.T.-III, set the forced power supply output to "IG-ST".(Refer to .)
(5)Measure the voltage between the ETACS-ECU connector (STOE terminal) and body earth.
OK: System voltage

Q. Is the check result normal?

Go to Step 6
Replace the OSS-ECU and register the chassis number (Refer to ). Then go to Step 6

STEP 6. Check whether the diagnosis code is reset.


Q. Is the diagnosis code set?

Replace the ETACS-ECU.
Intermittent malfunction is suspected (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunction ).