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.
2021 Honda Clarity Plug-In HybridFACTORY OEM SERVICE PROCEDURE
Engine Control System / Engine Mechanical - Testing & Troubleshooting - (Plug- In)
- Test
- System Description
- Rewrite
- Adjustment
- Removal, Installation & Inspection
- How to Information
- Inspection
- Learning Reset Clear
- Check
- Component Location Index
- Applying Procedure
- Troubleshooting
- Connector View
- General Information
- Engine Configuration
- How to Enter PGM-FI System Maintenance Mode
- How to Set Readiness Codes
- Malfunction Indicator Lamp (MIL) Indication (In relation to Readiness Codes)
- Catalytic Converter Monitor and Readiness Code
- Evaporative Emission (EVAP) Control System Monitor and Readiness Code
- Air Fuel Ratio (A/F) Sensor Monitor and Readiness Code
- Air Fuel Ratio (A/F) Sensor Heater Monitor Readiness Code
- Misfire Monitor and Readiness Code
- Fuel System Monitor and Readiness Code
- Comprehensive Component Monitor and Readiness Code
- EGR Monitor and Readiness Code
- Symptom Troubleshooting Index for Viewer
- After warming up, idle speed is above specifications without load (MIL works OK, no DTCs set)
- After warming up, idle speed is below specifications without load (MIL works OK, no DTCs set)
- Cold fast idle too high (MIL works OK, no DTCs set)
- Cold fast idle too low (MIL works OK, no DTCs set)
- Difficult to refuel (MIL works OK, no DTCs set)
- Engine is hard to start (MIL works OK, no DTCs set)
- Engine stalls (MIL works OK, no DTCs set)
- Engine starts but stalls immediately (MIL works OK, no DTCs set, immobilizer indicator stays on or flashes)
- Engine will not start(MIL works OK, no DTCs set, generator motor works OK)
- Engine will not start, and HDS does not communicate with the PCM(MIL comes on and stays on, no DTCs set)
- HDS does not communicate with the PCM or the vehicle
- Idle speed fluctuates (MIL works OK, no DTCs set)
- Low power (MIL works OK, no DTCs set)
- MIL comes on and stays on, or never comes on at all, no DTCs set
Factory Service Tools
Use the Manual With the Right Hardware
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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.