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Home >> Mazda >> 2012 >> 6 i Touring >> Repair and Diagnosis >> External Pages >> Different car >> Section 611 (On-Board Diagnostic [Body Control System)) >> DTC B1178:11 [BCM] >> Diagnostic Procedure

Diagnostic Procedure

WARNING: This page is about a different car, the 2009 Mazda 6. However, it is still accessible from the selected car via links, so may be relevant.
Step Inspection Action
1 PERFORM DTC INSPECTION 
  • Clear the DTC using the M-MDS. (See CLEARING DTC [BCM] )
  • Perform the BCM DTC inspection using the M-MDS with the trunk closed (trunk lid latch switch off) (See DTC INSPECTION [BCM] .)
  • Is the same DTC present?
Yes Go to the next step.
No Go to Step 7.
2 INSPECT TRUNK LID LATCH SWITCH CONNECTOR CONDITION 
  • Switch the ignition to off.
  • Disconnect the negative battery cable
  • Disconnect the trunk lid latch switch connector.
  • Inspect the connector and terminals (corrosion, damage, pin disconnection).
  • Is there any malfunction?
Yes Repair or replace the connector or terminals, then go to Step 6
No Go to the next step.
3 INSPECT TRUNK LID LATCH SWITCH  Yes Replace the trunk lid latch switch, then go to Step 6. (See TRUNK LID LATCH AND RELEASE ACTUATOR REMOVAL/INSTALLATION .)
No Go to the next step.
4 INSPECT BCM CONNECTOR CONDITION 
  • Disconnect the BCM connector
  • Inspect the connector and terminals (corrosion, damage, pin disconnection)
  • Is there any malfunction?
Yes Repair or replace the connector or terminals, then go to Step 6.
No Go to the next step.
5 INSPECT TRUNK LID LATCH SWITCH CIRCUIT FOR SHORT TO GROUND 
  • Inspect for continuity between trunk lid latch switch terminal C (wiring harness-side) and body ground
  • Is there continuity?
Yes Repair or replace the wiring harness for a possible short to ground, then go to the next step.
No Go to the next step
6 VERIFY TROUBLESHOOTING COMPLETED 
  • Make sure to reconnect the disconnected connectors.
  • Reconnect the negative battery cable
  • Clear the DTC using the M-MDS (See CLEARING DTC [BCM] )
  • Perform the BCM DTC inspection using the M-MDS with the trunk closed (trunk lid latch switch off). (See DTC INSPECTION [BCM] )
  • Is the same DTC present?
Yes Repeat the inspection from Step 1
If the malfunction recurs, replace the BCM, then go to the next step (See BODY CONTROL MODULE (BCM) REMOVAL/INSTALLATION )
No Go to the next step.
7 VERIFY THAT NO OTHER DTCs ARE PRESENT 
  • Are any DTCs present?
Yes Go to the applicable DTC inspection (See DTC TABLE [BCM] .)
No DTC troubleshooting completed.