Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
DTC P16F5
DTC P16F5 : Starter Cut Relay 1 Control Circuit High Voltage
NOTE: Before you troubleshoot, review the general troubleshooting information .
| DTC Description | Confirmed DTC | Pending DTC | Freeze Frame |
|---|---|---|---|
| P16F5 Starter Cut Relay 1 Control Circuit High Voltage |
DTC (PGM-FI)
- 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 Freeze Frame P16F5 Starter Cut Relay 1 Control Circuit High Voltage Is DTC P16F5 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 starter cut relay 1, 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 .
- Relay check
-1. Turn the vehicle to the OFF (LOCK) mode.
-2. Remove starter cut relay 1 (A) from the under-hood fuse/relay box.
-3. Test starter cut relay 1.
Is starter cut relay 1 OK?
YES
Starter cut relay 1 is OK. Go to step 3.
NO
Replace starter cut relay 1.
- Shorted wire check (ST CUT RLY1 CL- line to power)
-1. Jump the SCS line with the HDS.
-2. Disconnect the following connector.
PCM connector A (51P) -3. Turn the vehicle to the ON mode.
-4. Measure the voltage between test points 1 and 2.
Test condition Vehicle ON mode Starter cut relay 1: disconnected PCM connector A: disconnected Test point 1 PCM connector A (51P) No. 51 Test point 2 Body ground Is there 0.1 V or less?
YES
The ST CUT RLY1 CL- wire is OK. Update the PCM if it does not have the latest software, or substitute a known-good PCM , then recheck. If DTC P016F5 goes away and the PCM was updated, troubleshooting is complete. If DTC P16F5 goes away and the PCM was substituted, replace the original PCM .
NO
Repair a short to power in the ST CUT RLY1 CL- wire between the PCM (A51) and starter cut relay 1.
NO RELATED
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.