DTC P16F4 (2016 2017 2018 2019 2020 With Auto Idle Stop System)

DTC P16F4 : Starter Cut Relay 2 Control Circuit Low Voltage

NOTE: Before you troubleshoot, review the general troubleshooting information - Refer to: How to Troubleshoot the A/T System (2014 2015), or How to Troubleshoot the Fuel and Emissions Systems, or How to Troubleshoot the Brake Booster Pressure Monitoring System (2016 2017 2018 2019 2020), or How to Troubleshoot the Fuel and Emissions Systems(With Auto Idle Stop System) (2016) .

DTC Description	Confirmed DTC	Pending DTC	Freeze Frame
P16F4 Starter Cut Relay 2 Control Circuit Low Voltage

DTC (PGM-FI)

Engine starting check
-1. Try to start the engine.

Does the engine start?

YES

Go to step 2.

NO

Go to step 4.

Problem verification

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

- 2. Turn the vehicle to the ON mode.

- 3. Clear the DTC with the HDS.

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

DTC Description	Confirmed DTC	Pending DTC	Freeze Frame
P16F4 Starter Cut Relay 2 Control Circuit Low Voltage

DTC (PGM-FI)

Is DTC P16F4 indicated?

YES

The failure is duplicated. Go to step 3.

Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at starter cut relay 2 and the PCM. If the freeze data/on-board snapshot of this DTC is recorded, try to reproduce the failure under the same conditions with the freeze data/on-board snapshot.

Shorted wire check (STRLY2 line)

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

- 2. Remove starter cut relay 2 (A) from the auxiliary under-hood relay block.

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

- 3. Jump the SCS line with the HDS.

SCS short

- 4. Disconnect the following connector.

PCM connector A (51P)

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

Test condition	Vehicle OFF (LOCK) mode
	Starter cut relay 2: disconnected
	PCM connector A (51P): disconnected
Test point 1	PCM connector A (51P) No. 4 - Refer to: PCM Connector for Inputs and Outputs (2014 2015), or PCM Connector for Inputs and Outputs (2016), or PCM Connector for Inputs and Outputs (2017 2018 2019 2020)
Test point 2	Body ground

Is there continuity?

YES

Repair a short in the STRLY2 wire between the PCM (A4) and starter cut relay 2.

The STRLY2 wire 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 (2016) .

Starter system check

-1. Turn the vehicle to the ON mode.

- 2. Shift the transmission to P or N position/mode.

- 3. Check the parameter(s) below with the HDS.

Signal	Threshold		Current conditions
Signal	Values	Unit	Values	Unit
STARTER CUT CTRL RETURN	ON

Do the current condition(s) match the threshold?

YES

Go to step 5.

Go to the symptom troubleshooting for engine will not start - Refer to: Fuel and Emissions Systems Symptom Troubleshooting - Engine stalls, or Fuel and Emissions Systems Symptom Troubleshooting - Engine will not start, engine starts but stalls immediately, or engine is hard to start .

Determine possible failure area (PCM, others)

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

- 2. Jump the SCS line with the HDS.

SCS short

- 3. Disconnect the following connector.

PCM connector A (51P)

- 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
Test point 1	PCM connector A (51P) No. 4 - Refer to: PCM Connector for Inputs and Outputs (2014 2015), or PCM Connector for Inputs and Outputs (2016), or PCM Connector for Inputs and Outputs (2017 2018 2019 2020)
Test point 2	Body ground

Is there battery voltage?

YES

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 (2016) .

Go to step 6.

Open wire check (STRLY2 line)

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

- 2. Remove starter cut relay 2 (A) from the auxiliary under-hood relay block.

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

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

Test condition	Vehicle OFF (LOCK) mode
	PCM connector A (51P): disconnected
	Starter cut relay 2: disconnected
Test point 1	Starter cut relay 2 4P socket No. 4
Test point 2	PCM connector A (51P) No. 4 - Refer to: PCM Connector for Inputs and Outputs (2014 2015), or PCM Connector for Inputs and Outputs (2016), or PCM Connector for Inputs and Outputs (2017 2018 2019 2020)

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

Is there continuity?

YES

The STRLY2 wire is OK. Go to step 7.

Repair an open in the STRLY2 wire between the PCM (A4) and starter cut relay 2.

Fuse check

-1. Check the following fuse.

Fuse	No. C7 (7.5 A)
Location	Under-hood fuse/relay box

Is the fuse OK?

YES

Go to step 8.

Check for a short in the IG1 START CUT wire between the No. C7 (7.5 A) fuse and the under-hood fuse/relay box, and repair it if needed. Also replace the No. C7 (7.5 A) fuse.

Open wire check (IG1 START CUT line)

-1. Turn the vehicle to the ON mode.

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

Test condition	Vehicle ON mode
	PCM connector A (51P): disconnected
	Starter cut relay 2: disconnected
Test point 1	Starter cut relay 2 4P socket No. 3
Test point 2	Body ground

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

Is there battery voltage?

YES

Replace starter cut relay 2.

Repair an open in the IG1 START CUT wire between starter cut relay 2 and the under-hood fuse/relay box.