DTC B1017: Collision Detection Signal Input

DTC detecting condition  :

Detected when error occurred in the collision detection signal.

Time needed for diagnosis  :

3 s or more

Trouble symptom  :

The auto door lock or auto door unlock does not operate.

Wiring diagram  :

Airbag system Ref. to WIRING SYSTEM>AIRBAG SYSTEM>WIRING DIAGRAM .

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1. CHECK DTC  .
   1. Turn the ignition switch to ON.
   2. Read the DTC of [Body Control] using the Subaru Select Monitor. Ref. to BODY CONTROL (DIAGNOSTICS)>DIAGNOSTIC TROUBLE CODE (DTC) .

   Is DTC B1017 displayed? (Current code)

   Yes:  Go to  2.

   No:  Even if DTC is displayed, the circuit has returned to a normal condition at this time. Reproduce the failure, and then perform the diagnosis again.

   NOTE: In this case, temporary poor contact of connector, temporary open or short circuit of harness may be the cause.
2. CHECK DTC  .

   Read the DTC of [Airbag] using the Subaru Select Monitor. Ref. to AIRBAG (DIAGNOSTICS)>DIAGNOSTIC TROUBLE CODE (DTC) .

   Are any DTCs displayed? (Current code)

   Yes:  Perform the diagnosis for the displayed DTCs of airbag. Ref. to AIRBAG (DIAGNOSTICS)>DIAGNOSTIC TROUBLE CODE (DTC)>LIST .

   No:  Go to  3.

3. CHECK COLLISION DETECTION SIGNAL WAVEFORM  .
   1. Turn the ignition switch to ON (engine OFF).
   2. Read the collision detection signal waveform using an oscilloscope.
      NOTE: Measure waveform with the connector of body integrated unit connected.
   3. Compare the measured waveform with the standard one.

      Connector & terminal 

      (i83) No. 31 (+) - Chassis ground (-):

      • Standard waveform

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      • Abnormal waveform

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   If the read waveform matches the standard one, go to  A.

   If the read waveform matches the abnormal one, go to  B.

   If the read waveform is the one other than the above, go to  C.

   1. Replace the body integrated unit. Ref. to BODY CONTROL/COMMUNICATION SYSTEM>BODY INTEGRATED UNIT .
   2. Replace the airbag control module. Ref. to AIRBAG SYSTEM>AIRBAG CONTROL MODULE>REMOVAL .
   3. Go to  4.
4. CHECK HARNESS (OPEN CIRCUIT)  .
   1. Turn the ignition switch to OFF, and wait for 60 seconds or more after disconnecting the ground terminal from the battery sensor. Ref. to REPAIR CONTENTS>NOTE>BATTERY .
   2. Disconnect the connectors (AB41, AB42, AB43) from airbag control module.
   3. Connect the connector (1BF) in the test harness BF to the connectors (AB41, AB42, AB43).
   4. Disconnect the connector from body integrated unit.
   5. Using a tester, measure the resistance between connector (2BF) in test harness BF and body integrated unit connector.
   CAUTION: To measure the voltage and resistance of airbag system component, be sure to use the specified test harness. Ref. to AIRBAG (DIAGNOSTICS)>GENERAL DESCRIPTION .

   Connector & terminal 

   (i83) No. 31 - (2BF) No. 8:

   Is the resistance less than 10 Ω?

   Yes:  Go to  5.

   No:  Repair or replace the open circuit of harness.

5. CHECK HARNESS (GROUND SHORT CIRCUIT)  .

   Measure the resistance between body integrated unit connector and chassis ground using tester.

   Connector & terminal 

   (i83) No. 31 - Chassis ground:

   Is the resistance 1 MΩ or more?

   Yes:  Go to  6.

   No:  Repair or replace the short circuit of the harness.

6. CHECK HARNESS (SHORT CIRCUIT TO POWER SUPPLY)  .
   1. Connect the ground terminal to battery sensor. Ref. to REPAIR CONTENTS>NOTE>BATTERY .
   2. Measure the voltage between body integrated unit connector and chassis ground using tester.

      Connector & terminal 

      (i83) No. 31 (+) - Chassis ground (-):

   Is the voltage less than 1 V?

   Yes:  Go to  7.

   No:  Repair or replace the short circuit of the harness.

7. CHECK BODY INTEGRATED UNIT  .
   1. Connect the connector of body integrated unit.
   2. Turn the ignition switch to ON.
   3. Using a tester, measure the voltage between connector (2BF) in test harness BF and chassis ground.
   CAUTION: To measure the voltage and resistance of airbag system component, be sure to use the specified test harness. Ref. to AIRBAG (DIAGNOSTICS)>GENERAL DESCRIPTION .

   Connector & terminal 

   (2BF) No. 8 (+) - Chassis ground (-):

   Is the voltage 4.5 - 5.5 V?

   Yes:  Replace the airbag control module. Ref. to AIRBAG SYSTEM>AIRBAG CONTROL MODULE>REMOVAL .

   No:  Replace the body integrated unit. Ref. to BODY CONTROL/COMMUNICATION SYSTEM>BODY INTEGRATED UNIT .