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 positions cannot be memorized.
Seat operation is possible with manual operation, but not with memory function.

Wiring diagram:

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

Courtesy of SUBARU OF AMERICA, INC.

CAUTION: Before performing diagnosis, refer to "CAUTION" in "General Description". Ref. to POWER SEAT MEMORY (DIAGNOSTICS)>GENERAL DESCRIPTION>CAUTION .

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

Is DTC B2605 displayed? (Past malfunction)

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

No: Go to 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.
CHECK HARNESS (OPEN CIRCUIT) .
1. Turn the ignition switch to OFF.
2. Disconnect the seat position memory Control Module connector.
3. Turn the ignition switch to ON.
4. Using a tester, measure the voltage between the seat position memory Control Module connector and chassis ground.
  Connector & terminal
  
  (St42) No. 18 (+) - Chassis ground (-):
  
  (St42) No. 24 (+) - Chassis ground (-):
  
  (St43) No. 1 (+) - Chassis ground (-):
Is the voltage 8 - 16 V?

Yes: Replace the seat position memory Control Module. Ref. to SEATS>POWER SEAT SYSTEM .

No: Repair the open circuit of harness between the seat position memory Control Module connector and fuse.
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 . Ref. to STARTING/CHARGING SYSTEMS (H4DOTC)>BATTERY .