What this code means
P0615 may indicate that the PCM is detecting a problem in the starter cut relay diagnosis circuit.
What the vehicle may do
- The vehicle may have a no-start condition.
- The vehicle can have an intermittent starting complaint.
- A warning light may be present even if the engine starts during testing.
Possible fault areas
- Possible starter cut relay circuit wiring issue.
- Possible fuse or under-dash fuse/relay box issue.
- Possible relay circuit board issue.
- Possible connector or terminal problem at the relay circuit board or PCM.
- Possible PCM software or PCM-side concern.
Diagnostic path
Open and preparation
On this 2010 to 2017 Honda Accord with the 2.4 gas engine, P0615 may mean the PCM is seeing a problem in the starter cut relay diagnosis circuit. The customer may describe a no-start, an intermittent start concern, or a warning light with normal starting depending on when the fault shows up. Broadly, this can involve the starter cut relay circuit path, the relay circuit board, fuse or fuse box wiring, connector condition, or PCM-side control and monitoring. Before testing, save the freeze data and any on-board snapshot, then start with the basic system checks so you know whether this is a current fault or an intermittent one.
Duplicate the fault first
Start by pressing the engine start/stop button to select the ON mode. Clear the code with the HDS, then try to start the engine. After that, check for Pending or Confirmed codes with the HDS. If P0615 comes right back, the failure is duplicated and you can keep moving through the circuit checks. If it does not come back, treat it as intermittent for now. At that point, the system is OK at this time, so focus on poor connections or loose terminals at the relay circuit board and the PCM.
Sort out the diagnostic path
Next, check the HDS again for companion starter cut diagnosis codes without chasing P0615 in isolation. If those companion codes are present, handle that diagnostic path first. If they are not present, clear the code again and try to start the engine. If the engine starts, the next check is the ST RLY 1 TO 2 line. If the engine does not start, move to the fuse and ignition feed side of the circuit.
If the engine starts, check the ST RLY 1 TO 2 line
For the ST RLY 1 TO 2 open-wire check, select OFF mode, jump the SCS line with the HDS, then disconnect relay circuit board connector A, the 8P connector, and PCM connector A, the 51P connector. Jumper relay circuit board connector A No. 8, the PUR wire, to body ground. Then check continuity between PCM connector A No. 47, the PUR wire, and body ground. If there is continuity, the ST RLY 1 TO 2 wire is OK. From there, update the PCM if it does not have the latest software, or substitute a known-good PCM, then verify the repair. If there is no continuity, repair the open in the ST RLY 1 TO 2 wire between the relay circuit board and the PCM at A47, then verify the repair.
If the engine does not start, check the fuse and IG1 ACG line
If the engine did not start during the path check, select OFF mode and check fuse No. B9, rated at 20 A, in the under-dash fuse/relay box. If that fuse is not OK, repair the short in the wire between the No. B9 20 A fuse in the under-dash fuse/relay box and the appropriate initiator. Then replace the 20 A fuse and verify the repair. If the fuse is OK, continue with the IG1 ACG open-wire check. Disconnect relay circuit board connector A, the 8P connector, and under-dash fuse/relay box connector F, the 18P connector. The same connector designation applies for USA, Mexico, and Canada models. Jumper relay circuit board connector A No. 4, the PNK wire, to body ground. Then check continuity between under-dash fuse/relay box connector F No. 11, the PNK wire, and body ground. If there is no continuity, repair the open in the IG1 ACG wire between the under-dash fuse/relay box and the relay circuit board, then verify the repair. If there is continuity, the IG1 ACG wire is OK and the next decision is based on the relay circuit board test.
Relay circuit board decision
With the IG1 ACG wire confirmed OK, test the relay circuit board. If the relay circuit board is OK, replace the under-dash fuse/relay box for the applicable market version, then verify the repair. If the relay circuit board is not OK, replace the relay circuit board, then verify the repair.
Verify the repair
Keep verification separate from the circuit testing. Select OFF mode, reconnect all connectors, and exit SCS mode with the HDS. Select ON mode, reset the PCM with the HDS, and do the PCM idle learn procedure. Then check for Pending or Confirmed codes with the HDS. If P0615 is still indicated, check for poor connections or loose terminals at the relay circuit board and the PCM. If the PCM was updated, substitute a known-good PCM and recheck. If the PCM was already substituted, go back to the beginning and duplicate the fault again. If P0615 is not indicated, troubleshooting is complete. If a PCM was substituted and that resolved the concern, replace the original PCM. If any other Pending or Confirmed codes are present, check what they mean next. The takeaway is simple: prove whether P0615 is current, split the path by whether the engine starts, and let the ST RLY 1 TO 2, fuse, IG1 ACG, and relay board checks drive the repair. For more diagnostic training, visit stepdiagnostics.com.
Final check
Use the code confirmation, engine-start result, and continuity checks to narrow the fault area without guessing.
For more guided automotive diagnostics, visit STEP Diagnostics.
