DTC B2642: Mirror P Sensor Circuit Anomalous State

DTC detecting condition:

When the horizontal sensor value is 0 V or less and the vertical sensor value is 0 V or less.
When the horizontal sensor value is 0 V or less and the vertical sensor value is 5 V or more.
When the horizontal sensor value is 5 V or more and the vertical sensor value is 0 V or less.
When the horizontal sensor value is 5 V or more and the vertical sensor value is 5 V or more.

Trouble symptom:

Mirror surfaces do not move even when the mirror surface switch is operated.

Wiring diagram:

Remote control mirror system Ref. to WIRING SYSTEM>REMOTE CONTROL MIRROR 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 DTC B2642 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 OPERATION CONDITION OF FAILSAFE .
Operate the mirror surface switch in up/down and left/right directions for two seconds or more respectively.

Does the mirror surface operation stop during the operation?

Yes: Go to 3 .

No: Since a malfunction is presently not occurring, reproduce the failure and perform the diagnosis again.
CHECK MIRROR SURFACE SIGNAL OF POWER SEAT AND REMOTE CONTROL MIRROR 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 .
- MIR P Sensor Current Vertical Position
- MIR P Sensor Current Horizontal Position
  NOTE: Check the displayed voltages without moving the mirror surface switch.
Does each of the displayed voltages match any of the following combinations?
- [MIR P Sensor Current Vertical Position]: approx. 0 V, and [MIR P Sensor Current Horizontal Position]: approx. 0 V
- [MIR P Sensor Current Vertical Position]: approx. 5 V, and [MIR P Sensor Current Horizontal Position]: approx. 0 V
- [MIR P Sensor Current Vertical Position]: approx. 0 V, and [MIR P Sensor Current Horizontal Position]: approx. 5 V
- [MIR P Sensor Current Vertical Position]: approx. 5 V, and [MIR P Sensor Current Horizontal Position]: approx. 5 V
Yes: Go to 4 .

No: 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.
Perform the diagnosis with phenomenon for the ongoing phenomenon. Ref. to POWER SEAT MEMORY (DIAGNOSTICS)>Diagnostics with Phenomenon>LIST .
CHECK CONNECTOR .
1. Turn the ignition switch to OFF.
2. Check that the following connectors are properly connected.
  - Remote control mirror switch connector
  - Power seat and remote control mirror control module connector
  - Outer mirror assembly (passenger's seat) connector
Is there any fault in the connector or terminals? (Broken pin or poor mating of connector)

Yes: Engage the connector properly, or repair the faulty portion and check the operation.

No: Go to 5 .
CHECK OUTER MIRROR ASSEMBLY (PASSENGER'S SEAT) UNIT (MEMORY SENSOR (HORIZONTAL)) .
1. Turn the ignition switch to OFF.
2. Disconnect the connector from the outer mirror assembly (passenger's seat).
3. Operate the mirror surface of the outer mirror assembly (passenger's seat) inward → outward by hand, and measure the resistance between the following terminals.
  Connector and terminal
  
  No. 9 - No. 12:
Is the resistance between approx. 0.1 kΩ (at the maximum inward) - approx. 2.4 kΩ (at the maximum outward)?

Yes: Go to 6 .

No: Replace the outer mirror assembly (passenger's seat). Ref. to GLASS/WINDOWS/MIRRORS>OUTER MIRROR ASSEMBLY .
CHECK OUTER MIRROR ASSEMBLY (PASSENGER'S SEAT) UNIT (MEMORY SENSOR (VERTICAL)) .
1. Turn the ignition switch to OFF.
2. Disconnect the connector from the outer mirror assembly (passenger's seat).
3. Operate the mirror surface of the outer mirror assembly (passenger's seat) upward → downward by hand, and measure the resistance between the following terminals.
  Connector and terminal
  
  No. 9 - No. 11:
Is the resistance between approx. 0.1 kΩ (at the maximum upward) - approx. 2.4 kΩ (the maximum downward)?

Yes: The memory sensor is normal. Go to 7 .

No: Replace the outer mirror assembly (passenger's seat). Ref. to GLASS/WINDOWS/MIRRORS>OUTER MIRROR ASSEMBLY .
CHECK HARNESS (POWER SUPPLY CIRCUIT) .
1. Turn the ignition switch to ON.
2. Using a tester, measure the voltage between the outer mirror assembly (passenger's seat) harness connector and chassis ground.
  Connector and terminal
  
  (D15) No. 9 (+) - Chassis ground (-):
Is the voltage 4.5 V or more?

Yes: Go to 8 .

No: Check the harness between the power seat and remote control mirror control module connector and the outer mirror assembly (passenger's seat) connector.
CHECK HARNESS (GROUND CIRCUIT) .
1. Turn the ignition switch to OFF.
2. Using a tester, measure the resistance between the outer mirror assembly (passenger's seat) harness connector and chassis ground.
  Connector and terminal
  
  (D15) No. 10 - Chassis ground:
Is the resistance 1 Ω or less?

Yes: Go to 9 .

No: Check the harness between the power seat and remote control mirror control module connector and the outer mirror assembly (passenger's seat) connector.
CHECK HARNESS (OPEN CIRCUIT) .
1. Disconnect the connector from the power seat and remote control mirror control module.
2. Using a tester, measure the resistance between the outer mirror assembly (passenger's seat) harness connector and the power seat and remote control mirror control module harness connector.
  Connector and terminal
  
  (R503) No. 11 - (D15) No. 11:
  
  (R503) No. 12 - (D15) No. 12:
Is the resistance 1 Ω or less?

Yes: Go to 10 .

No: Repair the open circuit of harness between the power seat and remote control mirror control module connector and the outer mirror assembly (passenger's seat) connector.
CHECK HARNESS (SHORT CIRCUIT TO POWER SUPPLY) .
1. Turn the ignition switch to ON.
2. Using a tester, measure the voltage between the power seat and remote control mirror control module connector and chassis ground.
  Connector and terminal
  
  (R503) No. 11 (+) - Chassis ground (-):
  
  (R503) No. 12 (+) - Chassis ground (-):
  
  (R503) No. 20 (+) - Chassis ground (-):
  
  (R503) No. 21 (+) - Chassis ground (-):
Is the voltage less than 1 V?

Yes: Go to 11 .

No: Repair the short circuit to power supply in the harness between the power seat and remote control mirror control module connector and the outer mirror assembly (passenger's seat) connector.
CHECK HARNESS (GROUND SHORT CIRCUIT) .
1. Turn the ignition switch to OFF.
2. Using a tester, measure the resistance between the power seat and remote control mirror control module connector and chassis ground.
  Connector and terminal
  
  (R503) No. 11 - Chassis ground:
  
  (R503) No. 12 - Chassis ground:
  
  (R503) No. 20 - Chassis ground:
  
  (R503) No. 21 - Chassis ground:
Is the resistance 1 MΩ or more?

Yes: Replace the power seat and remote control mirror control module. Ref. to SEATS>POWER SEAT SYSTEM .

No: Repair the short circuit to ground in harness between the power seat and remote control mirror control module connector and the outer mirror assembly (passenger's seat) connector.