DTC B112A:12 [START STOP UNIT]
id0902p6020500
System malfunction location |
IG2 relay circuit malfunction |
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Detection condition
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• With the ignition switched off or to ACC, the start stop unit detects IG2 relay circuit voltage of 2.5 V or more for 0.5 s or more.
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Fail-safe
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—
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Possible cause
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• Front body control module (FBCM) connector or terminal malfunction
• Start stop unit connector or terminal malfunction
• Short to power supply in wiring harness between start stop unit terminal 2D and front body control module (FBCM) terminal 2U
• Front body control module (FBCM) malfunction
• Start stop unit malfunction
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Diagnostic Procedure
Step |
Inspection |
Action |
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1
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INSPECT FRONT BODY CONTROL MODULE (FBCM) CONNECTOR CONDITION
• Switch the ignition to off.
• Disconnect the negative battery cable.
• Disconnect the front body control module (FBCM) connector.
• Inspect the connector engagement and connection condition and inspect the terminals for damage, deformation, corrosion, or disconnection.
• Is the connector normal?
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Yes
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Go to the next step.
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No
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Repair or replace the connector, then go to Step 5.
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2
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INSPECT START STOP UNIT CONNECTOR CONDITION
• Disconnect the start stop unit connector.
• Inspect the connector engagement and connection condition and inspect the terminals for damage, deformation, corrosion, or disconnection.
• Is the connector normal?
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Yes
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Go to the next step.
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No
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Repair or replace the connector, then go to Step 5.
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3
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INSPECT IG2 RELAY CIRCUIT FOR SHORT TO POWER SUPPLY
• Reconnect all the disconnected connectors.
• Connect the negative battery cable.
• Measure the voltage at front body control module (FBCM) terminal 2U (vehicle wiring harness side).
• Is the voltage 2.5 V or more?
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Yes
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Repair or replace the wiring harness which is shorted to power supply, then go to Step 5.
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No
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Go to the next step.
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4
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PERFORM DTC INSPECTION AND VERIFY IF IG2 RELAY IS MALFUNCTIONING PART
• Clear DTC for the start stop unit using the M-MDS.
• Switch the ignition to off or to ACC, and wait for 0.5 s or more.
• Perform the DTC inspection for the start stop unit using the M-MDS.
• Is DTC B112A:12 displayed?
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Yes
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Replace the front body control module (FBCM), then go to the next step.
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No
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Go to Step 6.
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5
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VERIFY THAT REPAIRS HAVE BEEN COMPLETED
• Reconnect all the disconnected connectors.
• Reconnect the disconnected negative battery cable.
• Clear DTC for the start stop unit using the M-MDS.
• Switch the ignition to off or to ACC, and wait for 0.5 s or more.
• Perform the DTC inspection for the start stop unit using the M-MDS.
• Is DTC B112A:12 displayed?
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Yes
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Repeat the inspection from Step 1.
• If the malfunction recurs, replace the start stop unit, then go to the next step.
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No
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Go to the next step.
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6
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VERIFY IF OTHER DTCs DISPLAYED
• Are any other DTCs displayed?
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Yes
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Repair the malfunctioning part according to the applicable DTC troubleshooting.
(See DTC TABLE [START STOP UNIT].)
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No
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DTC troubleshooting completed.
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