DTC U1673: Lin Communication Bus Error Body Control Module: Wiring diagram

Power rear gate system Ref. to WIRING SYSTEM>POWER REAR GATE SYSTEM>WIRING DIAGRAM .

Courtesy of SUBARU OF AMERICA, INC.

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

CHECK DTC .
1. Turn the ignition switch to OFF.
2. Turn the ignition switch to ON.
3. Wait for 5 seconds.
4. Read the DTC of [Body Control] using the Subaru Select Monitor. Ref. to BODY CONTROL (DIAGNOSTICS)>DIAGNOSTIC TROUBLE CODE (DTC) .
  Is DTC U1673 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 then 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 CONTROL MODULE .
1. Turn the ignition switch to OFF.
2. Disconnect the power rear gate Control Module connector.
3. Turn the ignition switch to ON.
4. Wait for 5 seconds.
5. Read the DTC of [Body Control] using the Subaru Select Monitor, Ref. to BODY CONTROL (DIAGNOSTICS)>DIAGNOSTIC TROUBLE CODE (DTC) .
  Is DTC U1673 displayed? (Current malfunction)
  
  Yes : Go to 3 .
  
  No : Replace the power rear gate Control Module. Ref. to POWER REAR GATE SYSTEM>POWER REAR GATE CONTROL MODULE .
CHECK CONTROL MODULE .
1. Turn the ignition switch to OFF.
2. Disconnect the sunroof unit connector.
3. Turn the ignition switch to ON.
4. Wait for 5 seconds.
5. Read the DTC of [Body Control] using the Subaru Select Monitor. Ref. to BODY CONTROL (DIAGNOSTICS)>DIAGNOSTIC TROUBLE CODE (DTC) .
  Is DTC U1673 displayed? (Current malfunction)
  
  Yes : Go to 4 .
  
  No : Replace the sunroof unit. Ref. to SUNROOF/T-TOP/CONVERTIBLE TOP (SUNROOF)>SUNROOF MOTOR .
CHECK HARNESS (OPEN CIRCUIT) .
1. Turn the ignition switch to OFF.
2. Disconnect the body integrated unit connector.
3. Measure the resistance between body integrated unit connector and each unit connector.
  Connector & terminal
  
  (i81) No. 18 - (R422) No. 14:
  
  (i81) No. 18 - (R55) No. 7:
  
  Is the resistance less than 10 Ω?
  
  Yes : Go to 5 .
  
  No : Repair the open circuit of harness.
CHECK HARNESS (SHORT CIRCUIT TO POWER SUPPLY) .
1. Turn the ignition switch to ON.
2. Measure the voltage between each unit connector and chassis ground.
  Connector & terminal
  
  (R55) No. 7 (+) - Chassis ground (-):
  
  (R422) No. 14 (+) - Chassis ground (-):
  
  Is the voltage less than 1 V?
  
  Yes : Go to 6 .
  
  No : Repair the short circuit to power supply in harness.
CHECK HARNESS (GROUND SHORT CIRCUIT) .
1. Turn the ignition switch to OFF.
2. Measure the resistance between each unit connector and chassis ground.
  Connector & terminal
  
  (R55) No. 7 - Chassis ground:
  
  (R422) No. 14 - Chassis ground:
  
  Is the voltage 1 MΩ or more?
  
  Yes : Replace the body integrated unit, Ref. to SECURITY AND LOCKS>BODY INTEGRATED UNIT .
  
  No : Repair the ground short circuit of harness.