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Home >> Mazda >> 2017 >> 6 Sport, Automatic Trans >> Repair and Diagnosis (Single Page) >> Accessories & Equipment >> Communication Devices >> On-Board Diagnostic - Front Body Control Module (FBCM) >> DTC B11DB-86; Error Signal Received From Current Sensor >> Diagnostic Procedure
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Diagnostic Procedure

DIAGNOSTIC PROCEDURE

Step Inspection Action
1 VERIFY FRONT BODY CONTROL MODULE (FBCM) DTCs AGAIN Yes Go to the next step.
No Go to Step 9.
2 INSPECT CURRENT SENSOR CONNECTOR
  • Switch the ignition to off.
  • Disconnect the negative battery cable. (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION [SKYACTIV-G 2.5] .)
  • Disconnect the current sensor connector.
  • Inspect the connector engagement and connection condition and inspect the terminals for damage, deformation, corrosion, or disconnection.
  • Is the connector normal?
Yes Go to the next step.
No Repair or replace the connector, then go to Step 8.
3 INSPECT FRONT BODY CONTROL MODULE (FBCM) CONNECTOR
  • 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?
Yes Go to the next step.
No Repair or replace the connector, then go to Step 8.
4 INSPECT FOR SHORT TO GROUND IN CURRENT SENSOR CIRCUIT
  • Verify that the current sensor and front body control module (FBCM) connectors are disconnected.
  • Inspect for continuity between front body control module (FBCM) terminal 2E (wiring harness-side) and body ground.
  • Is there continuity?
Yes Refer to the wiring diagram and verify whether or not there is a common connector between current sensor terminal B and front body control module (FBCM) terminal 2E.
If there is a common connector:
  • Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for a short to ground.
  • Repair or replace the malfunctioning part.

    If there is no common connector:

  • Repair or replace the wiring harness which has a short to ground.

Go to Step 8.
No Go to the next step.
5 INSPECT FOR SHORT TO POWER SUPPLY IN CURRENT SENSOR CIRCUIT
  • Verify that the current sensor and front body control module (FBCM) connectors are disconnected.
  • Reconnect the negative battery cable. (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION [SKYACTIV-G 2.5] .)
  • Switch the ignition ON (engine off or on).
  • Measure the voltage at the front body control module (FBCM) terminal 2E (wiring harness-side).
  • Is the voltage 0 V?
Yes Go to the next step.
No Refer to the wiring diagram and verify whether or not there is a common connector between current sensor terminal B and front body control module (FBCM) terminal 2E.
If there is a common connector:
  • Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for a short to power supply.
  • Repair or replace the malfunctioning part.

    If there is no common connector:

  • Repair or replace the wiring harness which has a short to power supply.

Go to Step 8.
6 INSPECT FOR OPEN CIRCUIT IN CURRENT SENSOR CIRCUIT
  • Verify that the current sensor and front body control module (FBCM) connectors are disconnected.
  • Switch the ignition to off.
  • Disconnect the negative battery cable. (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION [SKYACTIV-G 2.5] .)
  • Inspect the wiring harness for continuity between current sensor terminal B (wiring harness-side) and front body control module (FBCM) terminal 2E (wiring harness-side).
  • Is there continuity?
Yes Go to the next step.
No Refer to the wiring diagram and verify whether or not there is a common connector between current sensor terminal B and front body control module (FBCM) terminal 2E.
If there is a common connector:
  • Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for an open circuit.
  • Repair or replace the malfunctioning part.

    If there is no common connector:

  • Repair or replace the wiring harness which has an open circuit.

Go to Step 8.
7 INSPECT CURRENT SENSOR Yes Go to the next step.
No Replace the current sensor, then go to the next step.
(See CURRENT SENSOR REMOVAL/INSTALLATION [SKYACTIV-G 2.5] .)
8 VERIFY THAT REPAIRS HAVE BEEN COMPLETED Yes Repeat the inspection from Step 1.
Go to the next step.
No Go to the next step.
9 VERIFY IF OTHER DTCs DISPLAYED
  • Are any other DTCs displayed?
Yes Repair or replace the malfunctioning part according to the applicable DTC troubleshooting.
(See DTC TABLE [FRONT BODY CONTROL MODULE (FBCM)] .)
No DTC troubleshooting completed.