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PCM Power And Ground Circuit Troubleshooting (2014 2015)

PCM Power and Ground Circuit Troubleshooting 

  1. Engine starting check

    -1. Enter the maintenance mode, then start the engine.

    Does the engine start and idle smoothly?

    YES 

    Go to step 2.

    NO 

    Go to step 3.

  2. CAN gateway system DTC check

    -1. Check for CAN gateway system DTCs with the HDS.

    DTC Description DTC
    U0029-00 CAN Gateway F-CAN ch A Bus Off  
    U0047-00 CAN Gateway F-CAN ch B Bus Off  
    U0056-00 CAN Gateway F-CAN ch C Bus Off  
    U3000-49 CAN Gateway Internal Failure  

    DTC (CAN GATEWAY)

    Is DTC U0029-00, U0047-00, U0056-00, and/or U3000-49 indicated?

    YES 

    Go to the indicated DTC's troubleshooting for CAN gateway system. - Refer to: Communication Systems DTC Troubleshooting Index (2014), or Communication Systems DTC Troubleshooting Index (2015), or Communication Systems DTC Troubleshooting Index (2017) ?

    NO 

    Intermittent failure. The system is OK at this time. Check for poor connections or terminals at the PCM.

  3. Fuse check

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

    - 2. Check the following fuse.

    Fuse No. A4 (15 A)
    Location Under-hood fuse/relay box

    Is the fuse OK?

    YES 

    Go to step 7.

    NO 

    Go to step 4.

  4. Determine possible failure area (+B FI MAIN line, others)

    -1. Remove the blown No. A4 (15 A) fuse from the under-hood fuse/relay box.

    - 2. Remove PGM-FI main relay 1 (A) from the under-hood fuse/relay box.

    GHH259322Courtesy of HONDA, U.S.A., INC.

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

    Test condition Vehicle OFF (LOCK) mode
      PGM-FI main relay 1: disconnected
    Test circuit +B FI MAIN
    Test point 1 PGM-FI main relay 1 4P socket No. 1
    Test point 2 Body ground
    GHH259323Courtesy of HONDA, U.S.A., INC.

    Is there continuity?

    YES 

    Repair a short in the +B FI MAIN wire between PGM-FI main relay 1 and the No. A4 (15 A) fuse. If the wire is OK, replace the under-hood fuse/relay box . Also replace the No. A4 (15 A) fuse.

    NO 

    Go to step 5.

  5. Part(s) internal circuit check (short in FI MAIN RLY OUT line)

    -1. Jump the SCS line with the HDS.

    - 2. Disconnect each of the parts or connectors below, one at a time, then check for continuity between test points 1 and 2.

    • PGM-FI main relay 2
    • PCM connector A (51P)
    • Each injector 2P connector
    • CMP sensor A 3P connector
    • CMP sensor B 3P connector
    • CKP sensor 3P connector
    • Electronic throttle control system (ETCS) control relay
    Test condition Vehicle OFF (LOCK) mode
    Test circuit FI MAIN RLY OUT
    Test point 1 PGM-FI main relay 1 4P socket No. 2
    Test point 2 Body ground
    GHH259324Courtesy of HONDA, U.S.A., INC.

    Does continuity go away when one of the above components is disconnected?

    YES 

    Replace the part that made the short to body ground go away when it was disconnected. If the part is the PCM, update the PCM  if it does not have the latest software, or substitute a known-good PCM - Refer to: PCM Removal and Installation (2014 2015),  or PCM Removal and Installation (2017) , then recheck. If the symptom/indication goes away and the PCM was updated, troubleshooting is complete. If the symptom/indication goes away and the PCM was substituted, replace the original PCM - Refer to: PCM Removal and Installation (2014 2015),  or PCM Removal and Installation (2017) . Also replace the No. A4 (15 A) fuse in the under-hood fuse/relay box.

    NO 

    Parts are OK. Go to step 6.

  6. Shorted wire check (FI MAIN RLY OUT line)

    -1. Disconnect the following parts:

    • PGM-FI main relay 2
    • PCM connector A (51P)
    • Injectors
    • CMP sensor A
    • CMP sensor B
    • CKP sensor
    • Electronic throttle control system (ETCS) control relay

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

    Test condition Vehicle OFF (LOCK) mode
      PGM-FI main relay 1: disconnected
    PGM-FI main relay 2: disconnected
    PCM connector A (51P): disconnected
    Each injector 2P connector: disconnected
    CMP sensor A 3P connector: disconnected
    CMP sensor B 3P connector: disconnected
    CKP sensor 3P connector: disconnected
    Electronic throttle control system (ETCS) control relay: disconnected
    Test circuit FI MAIN RLY OUT
    Test point 1 PGM-FI main relay 1 4P socket No. 2
    Test point 2 Body ground
    GHH259325Courtesy of HONDA, U.S.A., INC.

    Is there continuity?

    YES 

    Repair a short in the FI MAIN RLY OUT wire between PGM-FI main relay 1 and each part. Also replace the No. A4 (15 A) fuse in the under-hood fuse/relay box.

    NO 

    The FI MAIN RLY OUT wire is OK. Replace PGM-FI main relay 1. Also replace the No. A4 (15 A) fuse in the under-hood fuse/relay box.

  7. Fuse check 2

    -1. Check the following fuse.

    Fuse No. B9 (20 A)
    Location Under-dash fuse/relay box

    Is the fuse OK?

    YES 

    Go to step 12.

    NO 

    Go to step 8.

  8. Relay check

    -1. Remove the blown No. B9 (20 A) fuse from the under-dash fuse/relay box.

    - 2. Remove PGM-FI main relay 2 (A) from auxiliary under-hood relay box B.

    GHH259326Courtesy of HONDA, U.S.A., INC.

    - 3. Test PGM-FI main relay 2.

    Is the relay OK?

    YES 

    PGM-FI main relay 2 is OK. Go to step 9.

    NO 

    Replace PGM-FI main relay 2. Also replace the No. B9 (20 A) fuse in the under-dash fuse/relay box.

  9. Determine possible failure area (IG1 FUEL PUMP line, others)

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

    Test condition Vehicle OFF (LOCK) mode
      PGM-FI main relay 2: disconnected
    Test circuit IG1 FUEL PUMP
    Test point 1 Auxiliary under-hood relay box B 17P socket No. 2 (YEL)
    Test point 2 Body ground
    GHH259327Courtesy of HONDA, U.S.A., INC.

    Is there continuity?

    YES 

    Go to step 10.

    NO 

    Go to step 11.

  10. Shorted wire check (IG1 FUEL PUMP/IG1(F/P) line)

    -1. Jump the SCS line with the HDS.

    - 2. Disconnect the following connector.

    PCM connector B (51P) - Refer to: How to Troubleshoot the Fuel and Emissions Systems (2014 2015), or How to Troubleshoot the Gear Unit Control System, or How to Troubleshoot the Fuel and Emissions Systems (2017)

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

    Test condition Vehicle OFF (LOCK) mode
      PGM-FI main relay 2: disconnected
      PCM connector B (51P): disconnected
    Test circuit IG1(F/P)
    Test point 1 PCM connector B (51P) No. 3 (WHT)
    Test point 2 Body ground
    GHH259328Courtesy of HONDA, U.S.A., INC.

    Is there continuity?

    YES 

    Repair a short in the IG1(F/P) wire between the No. B9 (20 A) fuse and the PCM (B3), between the No. B9 (20 A) fuse and the relay circuit board. Also replace the No. B9 (20 A) fuse.

    NO 

    The IG1(F/P) wire is OK. Replace the No. B9 (20 A) fuse, and update the PCM  if it does not have the latest software, or substitute a known-good PCM - Refer to: PCM Removal and Installation (2014 2015),  or PCM Removal and Installation (2017) , then recheck. If the symptom/indication goes away and the PCM was updated, troubleshooting is complete. If the symptom/indication goes away and the PCM was substituted, replace the original PCM - Refer to: PCM Removal and Installation (2014 2015),  or PCM Removal and Installation (2017) .

  11. Shorted wire check (FUEL PUMP RLY OUT line)

    -1. Disconnect the following connector.

    Fuel tank unit 4P connector

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

    Test condition Vehicle OFF (LOCK) mode
      PGM-FI main relay 2: disconnected
      Fuel tank unit 4P connector: disconnected
    Test circuit FUEL PUMP RLY OUT
    Test point 1 Auxiliary under-hood relay box B 17P socket No. 1 (GRN)
    Test point 2 Body ground
    GHH259329Courtesy of HONDA, U.S.A., INC.

    Is there continuity?

    YES 

    Repair a short in the FUEL PUMP RLY OUT wire between PGM-FI main relay 2 and the fuel tank unit 5P connector. Also replace the No. B9 (20 A) fuse in the under-dash fuse/relay box.

    NO 

    The FUEL PUMP RLY OUT wire is OK. Check the fuel pump, and replace it if needed. Also replace the No. B9 (20 A) fuse in the under-dash fuse/relay box.

  12. Open wire check (IG1(F/P) line)

    -1. Jump the SCS line with the HDS.

    - 2. Disconnect the following connector.

    PCM connector B (51P) - Refer to: How to Troubleshoot the Fuel and Emissions Systems (2014 2015), or How to Troubleshoot the Gear Unit Control System, or How to Troubleshoot the Fuel and Emissions Systems (2017)

    - 3. Turn the vehicle to the ON mode.

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

    Test condition Vehicle ON mode
      PCM connector B (51P): disconnected
    Test circuit IG1(F/P)
    Test point 1 PCM connector B (51P) No. 3 (WHT)
    Test point 2 Body ground
    GHH259330Courtesy of HONDA, U.S.A., INC.

    Is there battery voltage?

    YES 

    The IG1 FUEL PUMP wire is OK. Go to step 13.

    NO 

    Repair an open in the IG1 FUEL PUMP wire between the No. B9 (20 A) fuse and the PCM (A3).

  13. Determine possible failure area (PGM-FI main relay 1 control circuit, others)

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

    - 2. Jump the SCS line with the HDS.

    - 3. Disconnect the following connector.

    PCM connector A (51P) - Refer to: How to Troubleshoot the Fuel and Emissions Systems (2014 2015), or How to Troubleshoot the Gear Unit Control System, or How to Troubleshoot the Fuel and Emissions Systems (2017)

    - 4. Turn the vehicle to the ON mode.

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

    Test condition Vehicle ON mode
    PCM connector A (51P): disconnected
    PCM connector B (51P): disconnected
    Test circuit FI MAIN RLY CL-
    Test point 1 PCM connector A (51P) No. 7 (ORN)
    Test point 2 Body ground
    GHH259331Courtesy of HONDA, U.S.A., INC.

    Is there battery voltage?

    YES 

    Go to step 16.

    NO 

    Go to step 14.

  14. Open wire check (+B FI MAIN line)

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

    - 2. Remove PGM-FI main relay 1 (A) from the under-hood fuse/relay box.

    GHH259332Courtesy of HONDA, U.S.A., INC.

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

    Test condition Vehicle OFF (LOCK) mode
    PCM connector A (51P): disconnected
    PCM connector B (51P): disconnected
    PGM-FI main relay 1: disconnected
    Test circuit +B FI MAIN
    Test point 1 PGM-FI main relay 1 4P socket No. 3
    Test point 2 Body ground
    GHH259333Courtesy of HONDA, U.S.A., INC.

    Is there battery voltage?

    YES 

    Go to step 15.

    NO 

    Repair an open in the +B FI MAIN wire between PGM-FI main relay 1 and the No. A4 (15 A) fuse. If the wire is OK, replace the under-hood fuse/relay box . Also replace the No. A4 (15 A) fuse.

  15. Open wire check (FI MAIN RLY CL- line)

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

    Test condition Vehicle OFF (LOCK) mode
    PCM connector A (51P): disconnected
    PCM connector B (51P): disconnected
    PGM-FI main relay 1: disconnected
    Test circuit FI MAIN RLY CL-
    Test point 1 PGM-FI main relay 1 4P socket No. 4
    Test point 2 PCM connector A (51P) No. 7 (ORN)
    GHH259334Courtesy of HONDA, U.S.A., INC.

    Is there continuity?

    YES 

    The FI MAIN RLY CL- wire is OK. Test PGM-FI main relay 1 . If the relay is OK, update the PCM  if it does not have the latest software, or substitute a known-good PCM - Refer to: PCM Removal and Installation (2014 2015),  or PCM Removal and Installation (2017) , then recheck. If the symptom/indication goes away and the PCM was updated, troubleshooting is complete. If the symptom/indication goes away and the PCM was substituted, replace the original PCM - Refer to: PCM Removal and Installation (2014 2015),  or PCM Removal and Installation (2017) .

    NO 

    Repair an open in the FI MAIN RLY CL- wire between the PCM (A7) and PGM-FI main relay 1.

  16. Open wire check (+B FI MAIN line)

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

    - 2. Remove PGM-FI main relay 1 (A) from the under-hood fuse/relay box.

    GHH259335Courtesy of HONDA, U.S.A., INC.

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

    Test condition Vehicle OFF (LOCK) mode
    PCM connector A (51P): disconnected
    PCM connector B (51P): disconnected
    PGM-FI main relay 1: disconnected
    Test circuit +B FI MAIN
    Test point 1 PGM-FI main relay 1 4P socket No. 1
    Test point 2 Body ground
    GHH259336Courtesy of HONDA, U.S.A., INC.

    Is there battery voltage?

    YES 

    Go to step 17.

    NO 

    Repair an open in the +B FI MAIN wire between PGM-FI main relay 1 and the No. A4 (15 A) fuse. If the wire is OK, replace the under-hood fuse/relay box . Also replace the No. A4 (15 A) fuse.

  17. Open wire check (FI MAIN RLY OUT line)

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

    Test condition Vehicle OFF (LOCK) mode
    PCM connector A (51P): disconnected
    PCM connector B (51P): disconnected
    PGM-FI main relay 1: disconnected
    Test circuit FI MAIN RLY OUT
    Test point 1 PGM-FI main relay 1 4P socket No. 2
    Test point 2 PCM connector A (51P) No. 9 (BRN)
    GHH259337Courtesy of HONDA, U.S.A., INC.

    Is there continuity?

    YES 

    The FI MAIN RLY OUT wire is OK. Go to step 18.

    NO 

    Repair an open in the FI MAIN RLY OUT wire between the PCM (A9) and PGM-FI main relay 1.

  18. Relay check

    -1. Test PGM-FI main relay 1.

    Is PGM-FI main relay 1 OK?

    YES 

    PGM-FI main relay 1 is OK. Go to step 19.

    NO 

    Replace PGM-FI main relay 1.

  19. Open wire check (GND 1, GND 3, PGM, LG lines)

    -1. Disconnect the following connectors.

    PCM connector C (51P) - Refer to: How to Troubleshoot the Fuel and Emissions Systems (2014 2015), or How to Troubleshoot the Gear Unit Control System, or How to Troubleshoot the Fuel and Emissions Systems (2017)

    - 2. Check for continuity between the following test points and body ground individually.

    Test condition Vehicle OFF (LOCK) mode
    PCM connector A (51P): disconnected
    PCM connector B (51P): disconnected
    PCM connector C (51P): disconnected
    PGM-FI main relay 1: disconnected
    Connector Test circuit Terminal
    PCM connector B (51P) GND 1 No. 1 (BLK)
    GND 3 No. 18 (BLK)
    PCM connector C (51P) PGM No. 2 (BLK)
    LG No. 20 (BRN)
    GHH259338Courtesy of HONDA, U.S.A., INC.
    GHH259339Courtesy of HONDA, U.S.A., INC.

    Is there continuity?

    YES 

    The GND 1, GND 3, PGM, and LG wires are OK. Update the PCM  if it does not have the latest software, or substitute a known-good PCM - Refer to: PCM Removal and Installation (2014 2015),  or PCM Removal and Installation (2017) , then recheck. If the symptom/indication goes away and the PCM was updated, troubleshooting is complete. If the symptom/indication goes away and the PCM was substituted, replace the original PCM - Refer to: PCM Removal and Installation (2014 2015),  or PCM Removal and Installation (2017) .

    NO 

    Repair an open in the wire between the PCM (B1, B18, C2, C20) and G101.

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