DTC Troubleshooting: P0615 (K20C2) - Honda Civic FC/FK 2016-2021

DTC Troubleshooting: P0615

DTC P0615: Starter Cut Relay Diagnosis Circuit Malfunction

NOTE: Before you troubleshoot, review the general troubleshooting information.

DTC Description	Confirmed DTC	Pending DTC
P0615 Starter Cut Relay Diagnosis Circuit Malfunction

Problem verification:

Problem verification

?1.	Turn the vehicle to the ON mode.

?2.	Clear the DTC with the HDS.

?3.	Try to start the engine.

?4.

Check for Pending or Confirmed DTCs with the HDS.

DTC Description	Confirmed DTC	Pending DTC
P0615 Starter Cut Relay Diagnosis Circuit Malfunction

Is DTC P0615 indicated?


	YES

The failure is duplicated. Go to step 2.


	NO

Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the relay circuit board 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.?

DTC check:

DTC check

?1.

Check for Pending or Confirmed DTCs with the HDS.

DTC Description	Confirmed DTC	Pending DTC
P16F3 Starter Cut Relay 1 Control Circuit Low Voltage
P16F4 Starter Cut Relay 2 Control Circuit Low Voltage

Are DTC P16F3 and P16F4 indicated?


	YES

Go to the troubleshooting for DTC P16F3 and P16F4.?


	NO

Go to step 3.

Determine possible failure area (ST RLY 1 TO 2 line, others):

Determine possible failure area (ST RLY 1 TO 2 line, others)

?1.	Turn the vehicle to the ON mode.

?2.	Clear the DTC with the HDS.

?3.	Try to start the engine.

Does the engine start?


	YES

Go to step 4.


	NO

Go to step 5.

Open wire check (ST RLY 1 TO 2 line):

Open wire check (ST RLY 1 TO 2 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 connectors.

PCM connector A (50P)

Relay circuit board connector A (8P)

?4.

Check for continuity between test points 1 and 2.

Test condition	Vehicle OFF (LOCK) mode
	PCM connector A (50P): disconnected
	Relay circuit board connector A (8P): disconnected
Test point 1	Relay circuit board connector A (8P) No. 8
Test point 2	PCM connector A (50P) No. 19

Is there continuity?


	YES

The ST RLY 1 TO 2 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 P0615 goes away and the PCM was substituted, replace the original PCM.?


	NO

Repair an open in the ST RLY 1 TO 2 wire between the PCM (A19) and the relay circuit board.?

Fuse check:

Fuse check

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

?2.

Check the following fuse.

Fuse	No. B21 (10 A)
Location	Under-dash fuse/relay box

Is the fuse OK?


	YES

Go to step 6.


	NO

Check for a short in the IG1 ACG wire between the No. B21 (10 A) fuse and the relay circuit board. If the wire is OK, replace the under-dash fuse/relay box. Also replace the No. B21 (10 A) fuse.?

Open wire check (IG1 ACG line):

Open wire check (IG1 ACG line)

?1.

Disconnect the following connectors.

Relay circuit board connector B (6P)

Under-dash fuse/relay box connector C (27P)

?2.

Connect terminals A and B with a jumper wire.

Terminal A	Under-dash fuse/relay box connector C (27P) No. 6
Terminal B	Body ground

?3.

Check for continuity between test points 1 and 2.

Test condition	Vehicle OFF (LOCK) mode
Test condition	Relay circuit board connector B (6P): disconnected
	Under-dash fuse/relay box connector C (27P): disconnected
	Under-dash fuse/relay box connector C (27P) No. 6: jumped to body ground
Test point 1	Relay circuit board connector B (6P) No. 4
Test point 2	Body ground

Is there continuity?


	YES

Go to step 7.


	NO

Repair an open in the IG1 ACG wire between the relay circuit board and the under-dash fuse/relay box.?

Relay circuit board check:

Relay circuit board check

?1.	Remove and test the relay circuit board.

Is the relay circuit board OK?


	YES

Replace the under-dash fuse/relay box.?


	NO

Replace the relay circuit board.?