Mirror Heater Does Not Operate (Passenger's Seat)

Trouble causes:

Poor contact of connector
Open circuit of harness
Outer mirror assembly (passenger's seat) malfunction
Outer mirror control module (passenger's seat) malfunction
FRM (front relay control module) malfunction

CAUTION: Before performing diagnosis, refer to "CAUTION" in "General Description". Ref. to DOOR MIRROR (DIAGNOSTICS)>General Description>CAUTION .

CHECK BATTERY .
Check the battery unit. Ref. to STARTING/CHARGING SYSTEMS (H4DO)>BATTERY . Ref. to STARTING/CHARGING SYSTEMS (H4DOTC)>BATTERY .

Is the battery OK?

Yes : Go to 2 .

No : Replace or charge the battery.
CHECK FUSE .
Check the fuse. Ref. to GLASS/WINDOW/MIRRORS>RELAY AND FUSE .

Is the fuse OK?

Yes : Go to 3 .

No : Replace the fuse. When the replaced fuse is blown immediately, repair the power supply circuit.
CHECK IGNITION SWITCH .
Check the vehicle ignition switch status.

Is the ignition switch ON or ACC?

Yes : Go to 4 .

No : Turn the ignition switch to ON or ACC, and check the operation.
CHECK DTC .
1. Turn the ignition switch to ON, and wait for 20 seconds or more.
2. Using the Subaru Select Monitor, read the DTCs of [Door Mirror (Passenger)] and [Front Relay Control Module]. Ref. to Door Mirror (Diagnostics)>Diagnostic Trouble Code (DTC) . Ref. to FRONT RELAY CONTROL MODULE (DIAGNOSTICS)>DIAGNOSTIC TROUBLE CODE (DTC) .
  - Door Mirror (Passenger)
  - Front Relay Control Module
  Are any DTCs displayed? (Current malfunction)
  
  Yes : Perform the diagnosis for the displayed DTCs. Ref. to Door Mirror (Diagnostics)>Diagnostic Trouble Code (DTC) . Ref. to FRONT RELAY CONTROL MODULE (DIAGNOSTICS)>DIAGNOSTIC TROUBLE CODE (DTC) .
  
  No : Go to 5 .
CHECK INPUT SIGNAL .
Using the Subaru Select Monitor, check the following items in the [Data monitor] of [Door Mirror (Passenger)]. Ref. to Door Mirror (Diagnostics)>Data Monitor .
- Rear Defogger Relay Output Signal
Is [ON] displayed when the rear defogger switch is turned to ON?

Yes : Go to 6 .

No : Perform the diagnosis for front relay control module. Ref. to FRONT RELAY CONTROL MODULE (DIAGNOSTICS)>BASIC DIAGNOSTIC PROCEDURE .
CHECK CONNECTOR CONNECTION .
1. Turn the ignition switch to OFF.
2. Check that the following connectors are properly connected. Repair the connector if any broken pin or poor mating is detected.
  - Outer mirror control module (passenger's seat) connector
  - Outer mirror assembly (passenger's seat) connector
3. Turn the ignition switch to ON.
4. Check if the mirror heater operates when the rear defogger switch is turned to ON.
  Does the mirror heater operate?
  
  Yes : Since the poor contact of connector has repaired, the circuit condition returned to normal.
  
  No : Go to 7 .
CHECK OUTER MIRROR ASSEMBLY (PASSENGER'S SEAT) UNIT .
1. Turn the ignition switch to OFF.
2. Disconnect the outer mirror assembly (passenger's seat) connector (Df55).
3. Apply battery voltage between outer mirror assembly (passenger's seat) connector terminals, and check if the mirror heater operates.
  Connector and terminal
  
  No. 13 (+) - No. 14 (-):
  
  Does the mirror heater operate?
  
  Yes : Go to 8 .
  
  No : Replace the outer mirror assembly (passenger's seat). Ref. to GLASS/WINDOW/MIRRORS>OUTER MIRROR ASSEMBLY .
CHECK HARNESS (OPEN CIRCUIT) .
1. Confirm that the ignition switch is turned to OFF.
2. Disconnect the outer mirror control module (passenger's seat) connector.
3. Disconnect the outer mirror assembly (passenger's seat) connector.
4. Using a tester, measure the resistance between outer mirror control module (passenger's seat) connector and outer mirror assembly (passenger's seat) connector.
  Connector and terminal
  
  (Df24) No. 14 - (Df55) No. 13:
  
  Is the resistance less than 10 Ω?
  
  Yes : Replace the outer mirror control module (passenger's seat). Ref. to GLASS/WINDOW/MIRRORS>OUTER MIRROR CONTROL MODULE .
  
  No : Repair the open circuit of harness between outer mirror control module (passenger's seat) connector and outer mirror assembly (passenger's seat) connector.