DTC B2606: Power Seat Position Sensor Circuit Low

DTC detecting condition:

When the short circuit in the pulse sensor circuit is detected during the motor operation.

Trouble symptom:

Seat memory does not operate.
Seat operation stops immediately in manual operation.

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. Using the Subaru Select Monitor, perform the clear memory of [Power Seat Memory]. Ref. to COMMON (DIAGNOSTICS)>CLEAR MEMORY .
3. Turn the ignition switch to OFF.
4. Disconnect Power Seat & Remote Control Mirror Control Module connector and reconnect it.
5. Turn the ignition switch to ON.
6. Move the power seat.
7. Read the DTC of [Power Seat Memory] using the Subaru Select Monitor. Ref. to POWER SEAT MEMORY (DIAGNOSTICS)>DIAGNOSTIC TROUBLE CODE (DTC) .
Is DTC B2606 displayed? (Current malfunction)

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 perform the diagnosis again.

NOTE: In this case, temporary poor contact of connector, temporary open or short circuit of harness may be the cause.
CHECK HARNESS (GROUND SHORT CIRCUIT) .
1. Turn the ignition switch to OFF.
2. Disconnect the Power Seat & Remote Control Mirror Control Module connector.
3. Disconnect the connectors of all motors (slide/tilt/lifter/reclining).
4. Measure the resistance between Power Seat & Remote Control Mirror Control Module connector and chassis ground.
  Connector & terminal
  
  (R504) No. 22 - Chassis ground:
Is the resistance 1 MΩ or more?

Yes: Go to 3.

No: Repair or replace the short circuit to ground in harness between Power Seat & Remote Control Mirror Control Module connector and motor connector.
CHECK SLIDE MOTOR .
1. Connect the slide motor connector.
2. Using a tester, measure the resistance between Power Seat & Remote Control Mirror Control Module connector and chassis ground.
  Connector & terminal
  
  (R504) No. 22 - Chassis ground:
Is the resistance 1 MΩ or more?

Yes: Go to 4.

No: Replace the seat cushion frame assembly. Ref. to SEATS>FRONT SEAT .
CHECK TILT MOTOR .
1. Disconnect the slide motor connector.
2. Connect the tilt motor connector.
3. Using a tester, measure the resistance between Power Seat & Remote Control Mirror Control Module connector and chassis ground.
  Connector & terminal
  
  (R504) No. 22 - Chassis ground:
Is the resistance 1 MΩ or more?

Yes: Go to 5.

No: Replace the seat cushion frame assembly. Ref. to SEATS>FRONT SEAT .
CHECK LIFTER MOTOR .
1. Disconnect the tilt motor connector.
2. Connect the lifter motor connector.
3. Using a tester, measure the resistance between Power Seat & Remote Control Mirror Control Module connector and chassis ground.
  Connector & terminal
  
  (R504) No. 22 - Chassis ground:
Is the resistance 1 MΩ or more?

Yes: Go to 6.

No: Replace the seat cushion frame assembly. Ref. to SEATS>FRONT SEAT .
CHECK RECLINING MOTOR .
1. Disconnect the lifter motor connector.
2. Connect the reclining motor connector.
3. Using a tester, measure the resistance between Power Seat & Remote Control Mirror Control Module connector and chassis ground.
  Connector & terminal
  
  (R504) No. 22 - Chassis ground:
Is the resistance 1 MΩ or more?

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

No: Replace the backrest frame assembly. Ref. to SEATS>FRONT SEAT .