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DTC P0480

DTC P0480  : RFC System Malfunction

NOTE: Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information .
DTC Description Confirmed DTC Pending DTC Freeze Frame
P0480 RFC System Malfunction      

DTC (PGM-FI)

  1. DTC Check

    -1. Turn the vehicle to the ON mode.

    -2. Clear the DTC with the HDS, and wait for 3 minutes or more.

    -3. Check for Pending or Confirmed DTCs with the HDS.

    DTC Description Confirmed DTC Pending DTC Freeze Frame
    P0480 RFC System Malfunction      

    Is DTC P0480 indicated?

    YES 

    Go to step 3.

    NO 

    Go to step 2.

  2. Problem verification

    -1. Select RADIATOR FAN in the INSPECTION MENU with the HDS.

    RADIATOR FAN

    Check for Pending or Confirmed DTCs with the HDS.

    DTC Description Confirmed DTC Pending DTC Freeze Frame
    P0480 RFC System Malfunction      

    Is DTC P0480 indicated?

    YES 

    Go to step 3.

    NO 

    Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the RFC unit, the RFC unit relay, the radiator fan motor, the condenser fan motor, and the PCM.

  3. Radiator fan and condenser fan visual check

    -1. Check for these conditions at the radiator fan and the condenser fan:

    • Interference with fan shroud
    • Debris in the fan
    • Ice on the fan blades

    Are both fans OK?

    YES 

    Go to step 4.

    NO 

    Repair or replace the damaged parts, then do the repair verification.

  4. Radiator fan and condenser fan operation check (with HDS)

    -1. Select RADIATOR FAN in the INSPECTION MENU with the HDS.

    RADIATOR FAN

    Check the radiator fan and the condenser fan operation.

    Does one fan operate and another stop?

    YES 

    Replace the motor that is not operating, then do the repair verification.

    NO 

    Go to step 5.

  5. Radiator fan and condenser fan operation check (idling)

    -1. Turn the vehicle to the OFF (LOCK) mode.

    -2. Let the engine cool until the coolant temperature is low.

    -3. Turn the vehicle to the ON mode, and wait 3 minutes or more.

    -4. Confirm that the A/C is not switched on

    -5. Check the radiator fan and the condenser fan operation.

    Do both fans keep running?

    YES 

    Go to step 11.

    NO 

    Go to step 6.

  6. Fuse check

    -1. Turn the vehicle to the OFF (LOCK) mode.

    -2. Check the following fuse.

    Fuse No. C28 (7.5 A)
    Location Under-hood fuse/relay box

    Is the fuse OK?

    YES 

    Go to step 7.

    NO 

    Repair a short in the IGP2 SUB wire between the RFC unit relay and the No. C28 (7.5 A) fuse. Also replace the No. C28 (7.5 A) fuse, then do the repair verification.

  7. Fuse check 2

    -1. Check the following fuse.

    Fuse No. B2-4 (50 A)
    Location Main under-hood fuse box

    Is the fuse OK?

    YES 

    Go to step 8.

    NO 

    Go to step 13.

  8. Determine possible failure area (short in FAN CONTROL line, others)

    -1. Disconnect the following connector.

    RFC unit connector A (1P)

    -2. Turn the vehicle to the ON mode, and wait 3 minutes or more.

    -3. Measure the voltage between test points 1 and 2.

    Test condition Vehicle ON mode
    RFC unit connector A (1P): disconnected
    Test circuit MAIN FAN MOTOR
    Test point 1 RFC unit connector A (1P) No. 1 (WHT)
    Test point 2 Body ground
    GHH344887Courtesy of HONDA, U.S.A., INC.

    Is there battery voltage?

    YES 

    Go to step 9.

    NO 

    Go to step 17.

  9. Shorted wire check (FAN CONTROL line)

    -1. Turn the vehicle to the OFF (LOCK) mode.

    -2. Jump the SCS line with the HDS.

    SCS short

    -3. Disconnect the following connectors.

    RFC unit connector B (3P)
    PCM connector A (51P)

    -4. Check for continuity between test points 1 and 2.

    Test condition Vehicle OFF (LOCK) mode
    RFC unit connector A (1P): disconnected
      RFC unit connector B (3P): disconnected
      PCM connector A (51P): disconnected
    Test circuit FAN CONTROL
    Test point 1 PCM connector A (51P) No. 5 (ORN)
    Test point 2 Body ground
    GHH344888Courtesy of HONDA, U.S.A., INC.

    Is there continuity?

    YES 

    Repair a short in the FAN CONTROL wire between the PCM (A5) and the RFC unit, then do the repair verification.

    NO 

    Go to step 10.

  10. RFC unit internal circuit check

    -1. Reconnect the following connector.

    RFC unit connector B (3P)

    -2. Check for continuity between test points 1 and 2.

    Test condition Vehicle OFF (LOCK) mode
    RFC unit connector A (1P): disconnected
      PCM connector A (51P): disconnected
    Test circuit FAN CONTROL
    Test point 1 PCM connector A (51P) No. 5 (ORN)
    Test point 2 Body ground
    GHH344889Courtesy of HONDA, U.S.A., INC.

    Is there continuity?

    YES 

    Substitute a known-good RFC unit , then recheck. If the DTC P0480 goes away and the RFC unit was substituted, replace the original RFC unit , then do the repair verification.

    NO 

    Update the PCM if it does not have the latest software, or substitute a known-good PCM , then do the repair verification.

  11. Determine possible failure area (PCM, others)

    -1. Turn the vehicle to the OFF (LOCK) mode.

    -2. Jump the SCS line with the HDS.

    -3. Disconnect the following connectors.

    PCM connector A (51P)
    RFC unit connector B (3P)

    -4. Check for continuity between test points 1 and 2.

    Test condition Vehicle OFF (LOCK) mode
    PCM connector A (51P): disconnected
    RFC unit connector B (3P) No. 3 (ORN)
    Test circuit FAN CONTROL
    Test point 1 RFC unit connector B (3P) No. 3 (ORN)
    Test point 2 PCM connector A (51P) No. 5 (ORN)
    GHH344890Courtesy of HONDA, U.S.A., INC.

    Is there continuity?

    YES 

    Update the PCM if it does not have the latest software, or substitute a known-good PCM , then do the repair verification.

    NO 

    Go to step 12.

  12. Open wire check (FAN CONTROL line)

    -1. Connect terminals A and B with a jumper wire.

    Terminal A RFC unit connector B (3P) No. 3 (ORN)
    Terminal B Body ground
    GHH344891Courtesy of HONDA, U.S.A., INC.

    -2. Check for continuity between test points 1 and 2.

    Test condition Vehicle OFF (LOCK) mode
      PCM connector A (51P): disconnected
      RFC unit connector B (3P): disconnected
      RFC unit connector B (3P) No. 3: jumped to body ground
    Test circuit FAN CONTROL
    Test point 1 PCM connector A (51P) No. 5 (ORN)
    Test point 2 Body ground
    GHH344892Courtesy of HONDA, U.S.A., INC.

    Is there continuity?

    YES 

    Substitute a known-good RFC unit , then recheck. If DTC P0480 goes away and the RFC unit was substituted, replace the original RFC unit , then do the repair verification.

    NO 

    Repair an open in the FAN CONTROL wire between the PCM (A5) and the RFC unit, then do the repair verification.

  13. Shorted wire check (+B RFC line)

    -1. Remove the RFC unit relay (A) from the auxiliary under-hood relay box.

    GHH344893Courtesy of HONDA, U.S.A., INC.

    -2. Check for continuity between test points 1 and 2.

    Test condition Vehicle OFF (LOCK) mode
    RFC unit relay: disconnected
    Test circuit +B RFC
    Test point 1 RFC unit relay 4P socket No. 2
    Test point 2 Body ground
    GHH344894Courtesy of HONDA, U.S.A., INC.

    Is there continuity?

    YES 

    Repair a short in the +B RFC wire between the RFC unit relay and the No. B2-4 (50 A) fuse in the main under-hood fuse box. Also replace the No. B2-4 (50 A) fuse, then do the repair verification.

    NO 

    Go to step 14.

  14. Shorted wire check (MAIN FAN MOTOR line)

    -1. Disconnect the following connector.

    RFC unit connector A (1P)

    -2. Check for continuity between test points 1 and 2.

    Test condition Vehicle OFF (LOCK) mode
    RFC unit relay: disconnected
    RFC unit connector A (1P): disconnected
    Test circuit MAIN FAN MOTOR
    Test point 1 RFC unit connector A (1P) No. 1 (WHT)
    Test point 2 Body ground
    GHH344895Courtesy of HONDA, U.S.A., INC.

    Is there continuity?

    YES 

    Repair a short in the MAIN FAN MOTOR wire between the RFC unit relay and the RFC unit. Also replace the No. B2-4 (50 A) fuse in the main under-hood fuse box, then do the repair verification.

    NO 

    Go to step 15.

  15. Shorted wire check (M+(M) line)

    -1. Disconnect the following connector.

    RFC unit connector C (2P)

    -2. Check for continuity between test points 1 and 2.

    Test condition Vehicle OFF (LOCK) mode
    RFC unit relay: disconnected
    RFC unit connector A (1P): disconnected
    RFC unit connector C (2P): disconnected
    Test circuit M+(M)
    Test point 1 RFC unit connector C (2P) No. 1
    Test point 2 Body ground
    GHH344896Courtesy of HONDA, U.S.A., INC.

    Is there continuity?

    YES 

    Replace the radiator fan motor . Also replace the No. B2-4 (50 A) fuse, then do the repair verification.

    NO 

    Go to step 16.

  16. Shorted wire check (M+(S) line)

    -1. Disconnect the following connectors.

    RFC unit connector D (2P)

    -2. Check for continuity between test points 1 and 2.

    Test condition Vehicle OFF (LOCK) mode
    RFC unit relay: disconnected
    RFC unit connector A (1P): disconnected
    RFC unit connector C (2P): disconnected
    RFC unit connector D (2P): disconnected
    Test circuit M+(S)
    Test point 1 RFC unit connector D (2P) No. 1
    Test point 2 Body ground
    GHH344897Courtesy of HONDA, U.S.A., INC.

    Is there continuity?

    YES 

    Replace the A/C condenser fan motor . Also replace the No. B2-4 (50 A) fuse, then do the repair verification.

    NO 

    Substitute a known-good RFC unit , then recheck. If DTC P0480 goes away and the RFC unit was substituted, replace the original RFC unit , then do the repair verification.

  17. Relay check

    -1. Turn the vehicle to the OFF (LOCK) mode.

    -2. Remove the RFC unit relay (A) from the auxiliary under-hood relay box.

    GHH344898Courtesy of HONDA, U.S.A., INC.

    -3. Test the RFC unit relay .

    Is the relay OK?

    YES 

    Go to step 18.

    NO 

    Replace the RFC unit relay, then do the repair verification.

  18. Open wire check (+B RFC line)

    -1. Turn the vehicle to the ON mode.

    -2. Measure the voltage between test points 1 and 2.

    Test condition Vehicle ON mode
    RFC unit connector A (1P): disconnected
    RFC unit relay: disconnected
    Test circuit +B RFC
    Test point 1 RFC unit relay 4P socket No. 2
    Test point 2 Body ground
    GHH344899Courtesy of HONDA, U.S.A., INC.

    Is there battery voltage?

    YES 

    Go to step 19.

    NO 

    Repair an open in the +B RFC wire between the RFC unit relay and the No. B2-4 (50 A) fuse in the main under-hood fuse box, then do the repair verification.

  19. Open wire check (IGP2 SUB)

    -1. Measure the voltage between test points 1 and 2.

    Test condition Vehicle ON mode
    RFC unit connector A (1P): disconnected
    RFC unit relay: disconnected
    Test circuit IGP2 SUB
    Test point 1 RFC unit relay 4P socket No. 3
    Test point 2 Body ground
    GHH344900Courtesy of HONDA, U.S.A., INC.

    Is there battery voltage?

    YES 

    Go to step 20.

    NO 

    Repair an open in the IGP2 SUB wire between the RFC unit relay and the No. C28 (7.5 A) fuse in the under-hood fuse/relay box, then do the repair verification.

  20. Open wire check (MAIN FAN MOTOR line)

    -1. Turn the vehicle to the OFF (LOCK) mode.

    -2. Connect terminals A and B with a jumper wire.

    Terminal A RFC unit relay 4P socket No. 1
    Terminal B Body ground
    GHH344901Courtesy of HONDA, U.S.A., INC.

    -3. Check for continuity between test points 1 and 2.

    Test condition Vehicle OFF (LOCK) mode
    RFC unit connector A (1P): disconnected
    RFC unit relay: disconnected
    RFC unit connector A (1P) No. 1: jumped to body ground
    Test circuit MAIN FAN MOTOR
    Test point 1 RFC unit connector A (1P) No. 1 (WHT)
    Test point 2 Body ground
    GHH344902Courtesy of HONDA, U.S.A., INC.

    Is there continuity?

    YES 

    Go to step 21.

    NO 

    Repair an open in the MAIN FAN MOTOR wire between the RFC unit relay and the RFC unit, then do the repair verification.

  21. Open wire check (FAN LO SIGNAL line)

    -1. Remove the jumper wire from the RFC unit relay 4P socket.

    -2. Jump the SCS line with the HDS.

    -3. Disconnect the following connector.

    PCM connector A (51P)

    -4. Connect terminals A and B with a jumper wire.

    Terminal A RFC unit relay 4P socket No. 4
    Terminal B Body ground
    GHH344903Courtesy of HONDA, U.S.A., INC.

    -5. Check for continuity between test points 1 and 2.

    Test condition Vehicle OFF (LOCK) mode
    RFC unit connector A (1P): disconnected
    RFC unit relay: disconnected
    PCM connector A (51P): disconnected
    RFC unit connector A (1P) No. 4: jumped to body ground
    Test circuit FAN LO SIGNAL
    Test point 1 PCM connector A (51P) No. 6 (PNK)
    Test point 2 Body ground
    GHH344904Courtesy of HONDA, U.S.A., INC.

    Is there continuity?

    YES 

    Update the PCM if it does not have the latest software, or substitute a known-good PCM , then do the repair verification.

    NO 

    Repair an open in the FAN LO SIGNAL wire between the PCM (A6) and the RFC unit relay, then do the repair verification.

  22. Repair verification

    -1. Turn the vehicle to the OFF (LOCK) mode.

    -2. Reconnect all connectors.

    -3. Exit the SCS mode with the HDS.

    -4. Turn the vehicle to the ON mode.

    -5. Reset the PCM with the HDS .

    Reset PCM

    -6. Do the PCM idle learn procedure.

    -7. Check for Pending or Confirmed DTCs with the HDS.

    DTC Description Confirmed DTC Pending DTC Freeze Frame
    P0480 RFC System Malfunction      

    DTC (PGM-FI)

    Is DTC P0480 indicated?

    YES 

    Check for poor connections or loose terminals at the main under-hood fuse box, the under-hood fuse/relay box, the RFC unit relay, the radiator fan motor, the condenser fan motor, and the PCM. If the PCM was updated, substitute a known-good PCM , then recheck. If the PCM was substituted, go to step 1.

    NO 

    Troubleshooting is complete. If the PCM was substituted, replace the original PCM . If any other Pending or Confirmed DTCs are indicated, go to the indicated DTC's troubleshooting.

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