DTC Troubleshooting: P2623 (K20C1) - Honda Civic FC/FK 2016-2021

1.

Problem verification:

Problem verification

?1.	Turn the vehicle to the ON mode.

?2.	Clear the DTC with the HDS.

?3.	Start the engine. (If the engine does not start, crank the engine for 20 seconds.)

?4.

Check for Pending or Confirmed DTCs with the HDS.

DTC Description	Confirmed DTC	Pending DTC
P0201 No. 1 Cylinder Injector Circuit Malfunction
P0202 No. 2 Cylinder Injector Circuit Malfunction
P0203 No. 3 Cylinder Injector Circuit Malfunction
P0204 No.4 Cylinder Injector Circuit Malfunction
P2623 High Pressure Fuel Pump Spill Valve Malfunction

Are DTC P2623 and P0201, P0202, P0203, or P0204 indicated at the same time?


	YES

The failure is duplicated. Go to step 2.


	NO

The failure is duplicated. Go to step 8.


	NO

Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the high pressure fuel pump and the PCM. If the on-board snapshot of this DTC is recorded, try to reproduce the failure under the same conditions with the on-board snapshot.?

2.

Relay circuit board check:

Relay circuit board check

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

?2.	Remove and test the relay circuit board.

Is the relay circuit board OK?


	YES

Go to step 3.


	NO

Replace the relay circuit board.?

3.

Open wire check (+B IGP line):

Open wire check (+B IGP line)

?1.

Measure the voltage between test points 1 and 2.

Test condition	Vehicle OFF (LOCK) mode
Test condition	Relay circuit board: removed
Test point 1	Relay circuit board connector C (18P) (female terminals) No. 18:
Test point 2	Body ground

Is there battery voltage?


	YES

The +B IGP wire is OK. Go to step 5.


	NO

Go to step 4.

4.

Fuse check:

Fuse check

?1.

Check the following fuse.

Fuse	No. A7 (20 A)
Location	Under-hood fuse/relay box

Is the fuse OK?


	YES

Repair an open in the +B IGP wire between the No. A7 (20 A) fuse and the relay circuit board. If needed, replace the under-hood fuse/relay box.?


	NO

Repair a short in the +B IGP wire between the No. A7 (20 A) fuse and the relay circuit board. Also replace the No. A7 (20 A) fuse. If needed, replace the under-hood fuse/relay box.?

5.

Determine possible failure area (FI MAIN RLY CL- line, others):

Determine possible failure area (FI MAIN RLY CL- line, others)

?1.

Turn the vehicle to the ON mode, and measure the voltage between test points 1 and 2 momentarily.

Test condition	Momentarily after turning vehicle to ON mode
Test condition	Relay circuit board: removed
Test point 1	Relay circuit board connector C (18P) (female terminals) No. 5:
Test point 2	Relay circuit board connector C (18P) (female terminals) No. 18:

Is there battery voltage momentarily?


	YES

Go to step 7.


	NO

Go to step 6.

6.

Open wire check (FI MAIN RLY CL- line):

Open wire check (FI MAIN RLY CL- line)

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

?2.	Jump the SCS line with the HDS, and wait more than 1 minute.

?3.

Disconnect the following connector.

PCM connector No. 2 (58P)

?4.

Check for continuity between test points 1 and 2.

Test condition	Vehicle OFF (LOCK) mode
	Relay circuit board: removed
	PCM connector No. 2 (58P): disconnected
Test point 1	Relay circuit board connector C (18P) (female terminals) No. 5:
Test point 2	PCM connector No. 2 (58P) No. 26

Is there continuity?


	YES

The FI MAIN RLY CL- wire is OK. Check for any authorized service information related to the DTCs or symptoms you are troubleshooting, or substitute a known-good PCM, then recheck. If DTC P2623 goes away and the PCM was substituted, replace the original PCM.?


	NO

Repair an open in the FI MAIN RLY CL- wire between PCM connector No. 2 terminal No. 26 and the relay circuit board.?

7.

Open wire check (FI MAIN RLY OUT line):

Open wire check (FI MAIN RLY OUT line)

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

?2.	Jump the SCS line with the HDS, and wait more than 1 minute.

?3.

Disconnect the following connector.

PCM connector No. 2 (58P)

?4.

Check for continuity between test points 1 and 2.

Test condition	Vehicle OFF (LOCK) mode
	Relay circuit board: removed
	PCM connector No. 2 (58P): disconnected
Test point 1	Relay circuit board connector C (18P) (female terminals) No. 17:
Test point 2	PCM connector No. 2 (58P) No. 2, No. 4, and No. 6

Is there continuity?


	YES

The FI MAIN RLY OUT wire is OK. Go to step 8.


	NO

Repair an open in the FI MAIN RLY OUT wire between PCM connector No. 2 terminals (No. 2, No. 4, No. 6) and the relay circuit board.?

8.

Open wire check (HPUMP H line, HPUMP L line):

Open wire check (HPUMP H line, HPUMP L line)

?1.	If removed, reinstall the relay circuit board.

?2.	Jump the SCS line with the HDS, and wait more than 1 minute.

?3.

Disconnect the following connector.

PCM connector No. 1 (96P)

?4.

Check for continuity between test points 1 and 2.

Test condition	Vehicle OFF (LOCK) mode
	PCM connector No. 2 (58P): disconnected
	PCM connector No. 1 (96P): disconnected
Test point 1	PCM connector No. 1 (96P) No. 2
Test point 2	PCM connector No. 1 (96P) No. 7

Is there continuity?


	YES

The HPUMP H wire and the HPUMP L wire are not open. Go to step 11.


	NO

Go to step 9.

9.

Open wire check (HPUMP H line):

Open wire check (HPUMP H line)

?1.

Disconnect the following connector.

High pressure fuel pump 2P connector

?2.

Check for continuity between test points 1 and 2.

Test condition	Vehicle OFF (LOCK) mode
	PCM connector No. 2 (58P): disconnected
	PCM connector No. 1 (96P): disconnected
	High pressure fuel pump 2P connector: disconnected
Test point 1	High pressure fuel pump 2P connector (female terminals) No. 1:
Test point 2	PCM connector No. 1 (96P) No. 2

Is there continuity?


	YES

The HPUMP H wire is not open. Go to step 10.


	NO

Repair an open in the HPUMP H wire between PCM connector No. 1 terminal No. 2 and the high pressure fuel pump.?

10.

Open wire check (HPUMP L line):

Open wire check (HPUMP L line)

?1.

Check for continuity between test points 1 and 2.

Test condition	Vehicle OFF (LOCK) mode
	PCM connector No. 2 (58P): disconnected
	PCM connector No. 1 (96P): disconnected
	High pressure fuel pump 2P connector: disconnected
Test point 1	High pressure fuel pump 2P connector (female terminals) No. 2:
Test point 2	PCM connector No. 1 (96P) No. 7

Is there continuity?


	YES

The HPUMP L wire is OK. Replace the high pressure fuel pump.?


	NO

Repair an open in the HPUMP L wire between PCM connector No. 1 terminal No. 7 and the high pressure fuel pump.?

11.

Shorted wire check (HPUMP H line to power):

Shorted wire check (HPUMP H line to power)

?1.

Disconnect the following connector.

High pressure fuel pump 2P connector

?2.	Turn the vehicle to the ON mode.

?3.

Measure the voltage between test points 1 and 2.

Test condition	Vehicle ON mode
	PCM connector No. 2 (58P): disconnected
	PCM connector No. 1 (96P): disconnected
	High pressure fuel pump 2P connector: disconnected
Test point 1	PCM connector No. 1 (96P) No. 2
Test point 2	Body ground

Is there any voltage?


	YES

Repair a short to power in the HPUMP H wire between PCM connector No. 1 terminal No. 2 and the high pressure fuel pump.?


	NO

Go to step 12.

12.

Shorted wire check (HPUMP L line to power):

Shorted wire check (HPUMP L line to power)

?1.

Measure the voltage between test points 1 and 2.

Test condition	Vehicle ON mode
	PCM connector No. 2 (58P): disconnected
	PCM connector No. 1 (96P): disconnected
	High pressure fuel pump 2P connector: disconnected
Test point 1	PCM connector No. 1 (96P) No. 7
Test point 2	Body ground

Is there any voltage?


	YES

Repair a short to power in the HPUMP L wire between PCM connector No. 1 terminal No. 7 and the high pressure fuel pump.?


	NO

Go to step 13.

13.

Shorted wire check (HPUMP H line):

Shorted wire check (HPUMP H line)

?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
	PCM connector No. 2 (58P): disconnected
	PCM connector No. 1 (96P): disconnected
	High pressure fuel pump 2P connector: disconnected
Test point 1	PCM connector No. 1 (96P) No. 2
Test point 2	Body ground

Is there continuity?


	YES

Repair a short in the HPUMP H wire between PCM connector No. 1 terminal No. 2 and the high pressure fuel pump.?


	NO

The HPUMP H wire is OK. Go to step 14.

14.

Shorted wire check (HPUMP L line):

Shorted wire check (HPUMP L line)

?1.

Check for continuity between test points 1 and 2.

Test condition	Vehicle OFF (LOCK) mode
	PCM connector No. 2 (58P): disconnected
	PCM connector No. 1 (96P): disconnected
	High pressure fuel pump 2P connector: disconnected
Test point 1	PCM connector No. 1 (96P) No. 7
Test point 2	Body ground

Is there continuity?


	YES

Repair a short in the HPUMP L wire between PCM connector No. 1 terminal No. 7 and the high pressure fuel pump.?


	NO

The HPUMP L wire is OK. Check for any authorized service information related to the DTCs or symptoms you are troubleshooting, or substitute a known-good PCM, then recheck. If DTC P2623 goes away and the PCM was substituted, replace the original PCM.?