DTC B2605: Battery Control Low

DTC detecting condition: 

When low voltage (9 V or less) or high voltage (16 V or more) continues for 10 seconds.

Trouble symptom: 

Seat operation is possible with manual operation, but the following situations may occur.

• Seat position memory registration is unable to be performed.
• Memory cannot be reloaded.

Wiring diagram: 

Power seat system Ref. to WIRING SYSTEM>POWER SEAT SYSTEM>WIRING DIAGRAM .

Courtesy of SUBARU OF AMERICA, INC.

1. CHECK DTC. 
   1. Turn the ignition switch to ON.
   2. Read the DTC of [Power Seat Memory] using the Subaru Select Monitor. Ref. to POWER SEAT MEMORY (DIAGNOSTICS)>DIAGNOSTIC TROUBLE CODE (DTC) .

   Is a DTC other than DTC B2605 displayed? (Current malfunction)

   Yes:  Perform the diagnosis for the displayed DTCs.

   No:  Go to  2.

2. CHECK DTC. 

   Make sure that DTC B2605 is not displayed as past malfunction.

   Is B2605 displayed? (Past malfunction)

   Yes:  Perform the memory recall after re-registering the memory.

   No:  Go to  3.

3. CHECK POWER SEAT CONTROL MODULE. 

   Using the Subaru Select Monitor, check the following items in the [Data monitor] of [Power Seat Memory]. Ref. to POWER SEAT MEMORY (DIAGNOSTICS)>DATA MONITOR .

   • Battery Voltage

   Is the voltage 8 - 16 V?

   Yes:  Go to  5.

   No:  Go to  4.

4. CHECK HARNESS (OPEN CIRCUIT). 
   1. Turn the ignition switch to OFF.
   2. Disconnect the Power Seat & Remote Control Mirror Control Module connector.
   3. Turn the ignition switch to ON.
   4. Using a tester, measure the voltage between Power Seat & Remote Control Mirror Control Module connector and chassis ground.

      Connector & terminal 

      (R502) No. 2 (+) - Chassis ground (-):

      (R502) No. 8 (+) - Chassis ground (-):

      (R504) No. 1 (+) - Chassis ground (-):

      (R504) No. 22 (+) - Chassis ground (-):

   Is the voltage 8 - 16 V?

   Yes:  Replace Power Seat & Remote Control Mirror Control Module. Ref. to SEATS>POWER SEAT SYSTEM .

   No:  Repair the open circuit of the harness between Power Seat & Remote Control Mirror Control Module connector and the fuse.

5. CHECK BATTERY VOLTAGE. 

   Measure the battery voltage while the power seat is in operation.

   Is the voltage 8 - 16 V?

   Yes:  Ask the user if the power window or passenger's power seat was operated or cranking was performed while the driver's power seat was in operation.

   NOTE: Even when the battery voltage is normal under ordinary circumstance, the voltage may drop to 7.5 V or less in some cases, for example at cranking.

   No:  Check the battery. Ref. to STARTING/CHARGING SYSTEMS (H4DO)>BATTERY>INSPECTION .