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



JUDGEMENT CRITERIA


Check Conditions
  • After OSS-ECU activation
Judgment Criterion
  • When the following conditions are met:

  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



  • Damaged wiring harness or connector (short to earth or short to power supply in ST line, STO line or STOE line)
  • Malfunction of OSS-ECU
  • ETACS-ECU malfunction
  • Malfunction of engine-ECU

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 ).