DTC B1131: START setting circuit: Diagnosis

WARNING: This page is about a different car, the 2014 Mitsubishi Outlander. However, it is still accessible from the selected car via links, so may be relevant.

STEP 1. Check of short to power supply, short to ground, 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?
1. YES: Go to Step 2
2. NO: Repair the connector(s) or wiring harness.
STEP 2. Check of short to power supply, short to ground, and open circuit in ST2 line between ETACS-ECU connector and engine control module connector
Q: Is the check result normal?
1. YES: Go to Step 3
2. NO: Repair the connector(s) or wiring harness.
STEP 3. Voltage measurement at engine control module connector (ST2 terminal)
1. Disconnect the engine control module connector, and measure at the wiring harness side.
2. Using the scan tool (M.U.T.-III), set the forced power supply output to other than "IG-ST" (Refer to FORCED POWER SUPPLY OUTPUT PROCEDURE ).
3. Measure the voltage between the engine control module connector (ST2 terminal) and body ground.
  OK: 1 V or less
4. Using the scan tool (M.U.T.-III), set the forced power supply output to "IG-ST" (Refer to FORCED POWER SUPPLY OUTPUT PROCEDURE ).
5. Measure the voltage between the engine control module connector (ST2 terminal) and body ground.
  OK: System voltage
Q: Is the check result normal?
1. YES: Go to Step 4
2. NO: Go to Step 5

STEP 4. Using scan tool (M.U.T.-III), check data list.

Check the OSS-ECU data list.

CAUTION: To prevent damage to scan tool (M.U.T.-III), always turn the power supply mode of the engine switch to the OFF position before connecting or disconnecting scan tool (M.U.T.-III).

Connect scan tool (M.U.T.-III). Refer to "HOW TO CONNECT THE SCAN TOOL (M.U.T.-III) ."
Turn the power supply mode of the engine switch to OFF.
Disconnect the engine control module connector.

Using the scan tool (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	13	Cranking signal output (monitor)	OFF

OK: Depending on the state of forced power supply output, the display is turned ON/OFF.

Q: Is the check result normal?

YES: Replace the engine control module and register the VIN and key codes (Refer to HOW TO PERFORM VIN WRITING ).
NO: Replace the OSS-ECU and register the VIN (Refer to REGISTRATION WHEN REPLACING OSS-ECU ).

STEP 5. Voltage measurement at ETACS-ECU connector (ST2 terminal)
1. Measure the ETACS-ECU connector side by backprobing.
2. Using the scan tool (M.U.T.-III), set the forced power supply output to other than "IG-ST". (Refer to FORCED POWER SUPPLY OUTPUT PROCEDURE .)
3. Measure the voltage between the ETACS-ECU connector (ST2 terminal) and body ground.
  OK: 1 V or less
4. Using the scan tool (M.U.T.-III), set the forced power supply output to "IG-ST". (Refer to FORCED POWER SUPPLY OUTPUT PROCEDURE .)
5. Measure the voltage between the ETACS-ECU connector (ST2 terminal) and body ground.
  OK: System voltage
Q: Is the check result normal?
1. YES: Go to Step 6
2. NO: Replace the OSS-ECU and register the chassis number (Refer to REGISTRATION WHEN REPLACING OSS-ECU ). Then go to Step 6
STEP 6. Recheck for diagnostic trouble code
1. Erase the DTC.
2. Turn the power supply mode of the engine switch from OFF to ON.
3. Check if DTC is stored.
4. Turn the power supply mode of the engine switch from ON to OFF.
Q: Is the DTC stored?
1. YES: Replace the ETACS-ECU.
2. NO: Intermittent malfunction is suspected (Refer to HOW TO COPE WITH INTERMITTENT MALFUNCTION ).