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Home >> Acura >> 2018 >> RLX Base >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System - DTC Diagnostics (2 Of 6) (Except Hybrid) >> DTC Troubleshooting >> DTC P0203

DTC P0203

DTC P0203  : No. 3 Cylinder Injector Circuit 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
P0203 No. 3 Cylinder Injector Circuit Malfunction      

DTC (PGM-FI)

  1. Problem verification

    -1. Turn the vehicle to the ON mode.

    -2. Clear the DTC with the HDS.

    -3. Start the engine.

    NOTE: If the engine does not start, keep cranking for 10 seconds.

    -4. Check for Pending or Confirmed DTCs with the HDS.

    DTC Description Confirmed DTC Pending DTC Freeze Frame
    P0203 No. 3 Cylinder Injector Circuit Malfunction      

    Is DTC P0203 indicated?

    YES 

    Go to step 2.

    NO 

    Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the injector relay, the injector control module, the injector, and the PCM.

  2. Engine starting check

    -1. Check the result in step 1

    Did the engine start?

    YES 

    Go to step 11.

    NO 

    Go to step 3.

  3. Relay check

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

    -2. Remove the injector relay (A) from the under-hood fuse/relay box.

    GHH344535Courtesy of HONDA, U.S.A., INC.

    -3. Test the injector relay .

    Is the relay OK?

    YES 

    Go to step 4.

    NO 

    Replace the injector relay.

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

    -1. Turn the vehicle to the ON mode.

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

    Test condition Vehicle ON mode
    Injector relay: disconnected
    Test circuit FI MAIN RLY OUT
    Test point 1 Injector relay 4P socket No. 3
    Test point 2 Body ground
    GHH344536Courtesy of HONDA, U.S.A., INC.

    Is there battery voltage?

    YES 

    Go to step 5.

    NO 

    Repair an open in the FI MAIN RLY OUT wire between PGM-FI main relay 1 and the injector relay.

  5. Open wire check (+B INJ line)

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

    Test condition Vehicle ON mode
    Injector relay: disconnected
    Test circuit +B INJ
    Test point 1 Injector relay 4P socket No. 1
    Test point 2 Body ground
    GHH344537Courtesy of HONDA, U.S.A., INC.

    Is there battery voltage?

    YES 

    Go to step 7.

    NO 

    Go to step 6.

  6. Fuse check

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

    -2. Check the following fuse.

    Fuse No. B7 (20 A)
    Location Main under-hood fuse box

    Is the fuse OK?

    YES 

    Repair an open in the +B INJ wire between the No. B7 (20 A) fuse and the injector relay.

    NO 

    Repair a short in the +B INJ wire between the No. B7 (20 A) fuse and the injector relay. Also replace the No. B7 (20 A) fuse.

  7. Determine possible failure area (INJ RLY CL- line, others)

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

    Test condition Vehicle ON mode
    Injector relay: disconnected
    Test circuit FI MAIN RLY OUT, INJ RLY CL-
    Test point 1 Injector relay 4P socket No. 3
    Test point 2 Injector relay 4P socket No. 4
    GHH344538Courtesy of HONDA, U.S.A., INC.

    Is there battery voltage?

    YES 

    Go to step 9.

    NO 

    Go to step 8.

  8. Open wire check (INJ RLY CL- line)

    -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)

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

    Test condition Vehicle OFF (LOCK) mode
    Injector relay: disconnected
    PCM connector A (51P): disconnected
    Test circuit INJ RLY CL-
    Test point 1 Injector relay 4P socket No. 4
    Test point 2 PCM connector A (51P) No. 17 (BRN)
    GHH344539Courtesy of HONDA, U.S.A., INC.

    Is there continuity?

    YES 

    The INJ RLY CL- wire is OK. Check for poor connections or loose terminals at the injector relay, the injector control module, the injector, and the PCM. Update the PCM if it does not have the latest software, or substitute a known-good PCM , then recheck. If DTC P0203 goes away and the PCM was updated, troubleshooting is complete. If DTC P0203 goes away and the PCM was substituted, replace the original PCM .

    NO 

    Repair an open in the INJ RLY CL- wire between the PCM (A17) and the injector relay.

  9. Open wire check (INJ RLY OUT/IG(EDU)1 line)

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

    -2. Disconnect the following connector.

    Injector control module connector D (4P)

    -3. Connect terminals A and B with a jumper wire.

    Terminal A Injector relay 4P socket No. 1
    Terminal B Injector relay 4P socket No. 2
    GHH344540Courtesy of HONDA, U.S.A., INC.

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

    Test condition Vehicle OFF (LOCK) mode
    Injector relay: disconnected
    Injector control module connector D (4P): disconnected
    Injector relay 4P socket No. 1 and No. 2: jumped
    Test circuit IG(EDU)1
    Test point 1 Injector control module connector D (4P) No. 1 (WHT)
    Test point 2 Body ground
    GHH344541Courtesy of HONDA, U.S.A., INC.

    Is there any voltage?

    YES 

    Go to step 10.

    NO 

    Repair an open in the INJ RLY OUT/IG(EDU)1 wire between the injector relay and the injector control module.

  10. Open wire check (INJ RLY OUT/IG(EDU)2 line)

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

    Test condition Vehicle OFF (LOCK) mode
    Injector relay: disconnected
    Injector control module connector D (4P): disconnected
    Injector relay 4P socket No. 1 and No. 2: jumped
    Test circuit IG(EDU)2
    Test point 1 Injector control module connector D (4P) No. 2 (GRY)
    Test point 2 Body ground
    GHH344542Courtesy of HONDA, U.S.A., INC.

    Is there any voltage?

    YES 

    Go to step 11.

    NO 

    Repair an open in the INJ RLY OUT/IG(EDU)2 wire between the injector relay and the injector control module.

  11. Open wire check (INJ Ti 3 line)

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

    -2. If needed, remove the jumper wire from the injector relay 4P socket, then reinstall the injector relay.

    -3. If needed, reconnect the following connector.

    Injector control module connector D (4P)

    -4. Jump the SCS line with the HDS.

    -5. Disconnect the following connectors.

    Injector control module connector C (12P)
    PCM connector B (51P)

    -6. Check for continuity between test points 1 and 2.

    Test condition Vehicle OFF (LOCK) mode
    Injector control module connector C (12P): disconnected
    PCM connector B (51P): disconnected
    Test circuit INJ Ti 3
    Test point 1 Injector control module connector C (12P) No. 11 (BLU)
    Test point 2 PCM connector B (51P) No. 16 (BLU)
    GHH344543Courtesy of HONDA, U.S.A., INC.

    Is there continuity?

    YES 

    Go to step 12.

    NO 

    Repair an open in the INJ Ti 3 wire between the PCM (B16) and the injector control module.

  12. Open wire check (IJF2 line)

    -1. Disconnect the following connector.

    PCM connector C (51P)

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

    Test condition Vehicle OFF (LOCK) mode
    Injector control module connector C (12P): disconnected
    PCM connector B (51P): disconnected
    PCM connector C (51P): disconnected
    Test circuit IJF2
    Test point 1 Injector control module connector C (12P) No. 5 (GRY)
    Test point 2 PCM connector C (51P) No. 18 (GRY)
    GHH344544Courtesy of HONDA, U.S.A., INC.

    Is there continuity?

    YES 

    Go to step 13.

    NO 

    Repair an open in the IJF2 wire between the PCM (C18) and the injector control module.

  13. Determine possible failure area (open in INJ HS3 line or INJ LS3 line, others)

    -1. Disconnect the following connector.

    Injector control module connector A (6P)

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

    Test condition Vehicle OFF (LOCK) mode
    Injector control module connector C (12P): disconnected
    PCM connector B (51P): disconnected
    PCM connector C (51P): disconnected
    Injector control module connector A (6P): disconnected
    Test circuit INJ HS3, INJ LS3
    Test point 1 Injector control module connector A (6P) No. 1 (BRN)
    Test point 2 Injector control module connector A (6P) No. 4 (GRN)
    GHH344545Courtesy of HONDA, U.S.A., INC.

    Is there continuity?

    YES 

    Go to step 16.

    NO 

    Go to step 14.

  14. Open wire check (INJ HS3 line)

    -1. Disconnect the following connector.

    No. 3 cylinder injector 2P connector

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

    Test condition Vehicle OFF (LOCK) mode
    Injector control module connector C (12P): disconnected
    PCM connector B (51P): disconnected
    PCM connector C (51P): disconnected
    Injector control module connector A (6P): disconnected
    No. 3 cylinder injector 2P connector: disconnected
    Test circuit INJ HS3
    Test point 1 No. 3 cylinder injector 2P connector No. 2 (BRN)
    Test point 2 Injector control module connector A (6P) No. 1 (BRN)
    GHH344546Courtesy of HONDA, U.S.A., INC.

    Is there continuity?

    YES 

    The INJ HS3 wire is OK. Go to step 15.

    NO 

    Repair an open in the INJ HS3 wire between the No. 3 cylinder injector and the injector control module.

  15. Open wire check (INJ LS3 line)

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

    Test condition Vehicle OFF (LOCK) mode
    Injector control module connector C (12P): disconnected
    PCM connector B (51P): disconnected
    PCM connector C (51P): disconnected
    Injector control module connector A (6P): disconnected
    No. 3 cylinder injector 2P connector: disconnected
    Test circuit INJ LS3
    Test point 1 No. 3 cylinder injector 2P connector No. 1 (GRN)
    Test point 2 Injector control module connector A (6P) No. 4 (GRN)
    GHH344547Courtesy of HONDA, U.S.A., INC.

    Is there continuity?

    YES 

    Replace the No. 3 cylinder injector .

    NO 

    Repair an open in the INJ LS3 wire between the No. 3 cylinder injector and the injector control module.

  16. Shorted wire check (INJ Ti 3 line to power)

    -1. Turn the vehicle to the ON mode.

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

    Test condition Vehicle ON mode
    Injector control module connector C (12P): disconnected
    PCM connector B (51P): disconnected
    PCM connector C (51P): disconnected
    Injector control module connector A (6P): disconnected
    Test circuit INJ Ti 3
    Test point 1 Injector control module connector C (12P) No. 11 (BLU)
    Test point 2 Body ground
    GHH344548Courtesy of HONDA, U.S.A., INC.

    Is there any voltage?

    YES 

    Repair a short to power in the INJ Ti 3 wire between the PCM (B16) and the injector control module.

    NO 

    Go to step 17

  17. Shorted wire check (IJF2 line to power)

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

    Test condition Vehicle ON mode
    Injector control module connector C (12P): disconnected
    PCM connector B (51P): disconnected
    PCM connector C (51P): disconnected
    Injector control module connector A (6P): disconnected
    Test circuit IJF2
    Test point 1 Injector control module connector C (12P) No. 5 (GRY)
    Test point 2 Body ground
    GHH344549Courtesy of HONDA, U.S.A., INC.

    Is there any voltage?

    YES 

    Repair a short to power in the IJF2 wire between the PCM (C18) and the injector control module.

    NO 

    Go to step 18.

  18. Shorted wire check (INJ HS3 line to power)

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

    -2. Disconnect the following connector.

    No. 3 cylinder injector 2P connector

    -3. Turn the vehicle to the ON mode.

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

    Test condition Vehicle ON mode
    Injector control module connector C (12P): disconnected
    PCM connector B (51P): disconnected
    PCM connector C (51P): disconnected
    Injector control module connector A (6P): disconnected
    No. 3 cylinder injector 2P connector: disconnected
    Test circuit INJ HS3
    Test point 1 Injector control module connector A (6P) No. 1 (BRN)
    Test point 2 Body ground
    GHH344550Courtesy of HONDA, U.S.A., INC.

    Is there any voltage?

    YES 

    Repair a short to power in the INJ HS3 wire between the No. 3 cylinder injector and the injector control module.

    NO 

    Go to step 19

  19. Shorted wire check (INJ LS3 line to power)

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

    Test condition Vehicle ON mode
    Injector control module connector C (12P): disconnected
    PCM connector B (51P): disconnected
    PCM connector C (51P): disconnected
    Injector control module connector A (6P): disconnected
    No. 3 cylinder injector 2P connector: disconnected
    Test circuit INJ LS3
    Test point 1 Injector control module connector A (6P) No. 4 (GRN)
    Test point 2 Body ground
    GHH344551Courtesy of HONDA, U.S.A., INC.

    Is there any voltage?

    YES 

    Repair a short to power in the INJ LS3 wire between the No. 3 cylinder injector and the injector control module.

    NO 

    Go to step 20

  20. Shorted wire check (INJ Ti 3 line to ground)

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

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

    Test condition Vehicle OFF (LOCK) mode
    Injector control module connector C (12P): disconnected
    PCM connector B (51P): disconnected
    PCM connector C (51P): disconnected
    Injector control module connector A (6P): disconnected
    No. 3 cylinder injector 2P connector: disconnected
    Test circuit INJ Ti 3
    Test point 1 Injector control module connector C (12P) No. 11 (BLU)
    Test point 2 Body ground
    GHH344552Courtesy of HONDA, U.S.A., INC.

    Is there continuity?

    YES 

    Repair a short to ground in the INJ Ti 3 wire between the PCM (B16) and the injector control module.

    NO 

    Go to step 21

  21. Shorted wire check (IJF2 line to ground)

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

    Test condition Vehicle OFF (LOCK) mode
    Injector control module connector C (12P): disconnected
    PCM connector B (51P): disconnected
    PCM connector C (51P): disconnected
    Injector control module connector A (6P): disconnected
    No. 3 cylinder injector 2P connector: disconnected
    Test circuit IJF2
    Test point 1 Injector control module connector C (12P) No. 5 (GRY)
    Test point 2 Body ground
    GHH344553Courtesy of HONDA, U.S.A., INC.

    Is there continuity?

    YES 

    Repair a short to ground in the IJF2 wire between the PCM (C18) and the injector control module.

    NO 

    Go to step 22.

  22. Shorted wire check (INJ HS3 line to ground)

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

    Test condition Vehicle OFF (LOCK) mode
    Injector control module connector C (12P): disconnected
    PCM connector B (51P): disconnected
    PCM connector C (51P): disconnected
    Injector control module connector A (6P): disconnected
    No. 3 cylinder injector 2P connector: disconnected
    Test circuit INJ HS3
    Test point 1 Injector control module connector A (6P) No. 1 (BRN)
    Test point 2 Body ground
    GHH344554Courtesy of HONDA, U.S.A., INC.

    Is there continuity?

    YES 

    Repair a short to ground in the INJ HS3 wire between the No. 3 cylinder injector and the injector control module.

    NO 

    Go to step 23

  23. Shorted wire check (INJ LS3 line to ground)

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

    Test condition Vehicle OFF (LOCK) mode
    Injector control module connector C (12P): disconnected
    PCM connector B (51P): disconnected
    PCM connector C (51P): disconnected
    Injector control module connector A (6P): disconnected
    No. 3 cylinder injector 2P connector: disconnected
    Test circuit INJ LS3
    Test point 1 Injector control module connector A (6P) No. 4 (GRN)
    Test point 2 Body ground
    GHH344555Courtesy of HONDA, U.S.A., INC.

    Is there continuity?

    YES 

    Repair a short to ground in the INJ LS3 wire between the No. 3 cylinder injector and the injector control module.

    NO 

    Go to step 24

  24. Shorted wire check (INJ HS4 line to power)

    -1. Disconnect the following connectors.

    No. 4 cylinder injector 2P connector
    Injector control module connector B (6P)

    -2. Turn the vehicle to the ON mode.

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

    Test condition Vehicle ON mode
    Injector control module connector C (12P): disconnected
    PCM connector B (51P): disconnected
    PCM connector C (51P): disconnected
    Injector control module connector A (6P): disconnected
    No. 3 cylinder injector 2P connector: disconnected
    No. 4 cylinder injector 2P connector: disconnected
    Injector control module connector B (6P): disconnected
    Test circuit INJ HS4
    Test point 1 Injector control module connector B (6P) No. 3 (BRN)
    Test point 2 Body ground
    GHH344556Courtesy of HONDA, U.S.A., INC.

    Is there any voltage?

    YES 

    Repair a short to power in the INJ HS4 wire between the No. 4 cylinder injector and the injector control module.

    NO 

    Substitute a known-good injector control module , then recheck. If the DTC P0203 goes away and the injector control module was substituted, replace the original injector control module .