1. What is P0117 in 2006 Honda Accord?

The P0117 OBD-II code stands for Engine Coolant Temperature (ECT) Sensor Circuit Low Input. For the 2006 Honda Accord—one of Honda’s most popular sedans ever—this code targets the ECT sensor, a critical component in both the 2.4L i-VTEC 4-cylinder (LX, EX trims) and 3.0L SOHC V6 (EX-L, V6 trims) engines. The ECT sensor sends voltage signals (0.5–4.5V) to the Accord’s ECM, telling it how hot the engine coolant is—this data adjusts fuel injection, ignition timing, and idle speed to optimize performance and fuel efficiency (up to 31 MPG highway for 2.4L models).

P0117 triggers when the ECM detects the ECT sensor’s voltage drops below 0.5V—signaling the sensor thinks the coolant is extremely hot (often above 260°F, even if it’s not). This is a common issue for 2006 Accords because the ECT sensor (located near the thermostat housing) is exposed to years of engine heat, vibration, and coolant corrosion. Honda even released Technical Service Bulletin (TSB) 07-062 for 2006–2007 Accords, recommending ECT sensor replacement to resolve P0117 and prevent false overheating warnings.

2006 Accord Specific Note: The 2.4L i-VTEC engine is more prone to P0117 than the 3.0L V6. This is because the 2.4L’s ECT sensor is mounted closer to the cylinder head, where temperatures fluctuate more sharply—accelerating sensor wear. Many 2006 Accord owners report P0117 starting around 100,000 miles, when the sensor’s internal circuitry begins to fail.

2. Common Causes of P0117 in 2006 Accord

P0117 in the 2006 Honda Accord is almost always tied to age-related wear or coolant system neglect—below are real-world cases diagnosed with the ICARZONE UR800:

• Aged ECT Sensor (2006 Accord LX 2.4L): An LX owner with 120,000 miles reported a "Check Engine" light and erratic temperature gauge. The UR800’s ECT Sensor Voltage Test showed 0.3V (normal: 0.5–4.5V). The sensor’s internal resistor failed (common in 15+ year-old Accords)—replacing it with Honda OEM part #37870-PNA-003 fixed the code.
• Corroded Sensor Connector (2006 Accord EX 2.4L): An EX owner’s P0117 came and went with rain. The UR800’s Circuit Continuity Test found 15Ω resistance (normal: <0.5Ω) in the sensor connector. Coolant leaks (from a worn thermostat gasket) had corroded the pins—cleaning with electrical contact cleaner (#CRC 05110) and applying dielectric grease resolved the issue.
• Damaged ECT Harness (2006 Accord EX-L V6): An EX-L V6 owner’s P0117 appeared after hitting a pothole. The UR800’s Wiring Fault Scan revealed a broken wire in the sensor harness (rubbed against the engine mount). Splicing the wire with heat-shrink connectors (#Dorman 84731) restored voltage to the ECM.
• Coolant Contamination (2006 Accord V6 3.0L): A V6 owner’s P0117 persisted after sensor replacement. The UR800’s Coolant Condition Test showed acidic coolant (pH <7.0). Long-term neglect (never replacing coolant) caused scale buildup on the sensor probe—flushing with Honda Premium Blue Coolant (#08798-9003) cleared the buildup.

3. Key Symptoms of P0117 in 2006 Accord

P0117 symptoms in the 2006 Honda Accord are easy to spot, as they directly affect the engine’s performance and temperature monitoring. Watch for these signs:

4. 2006 Accord Trims/Engines Prone to P0117

Honda service records and owner forums confirm P0117 is most common in these 2006 Accord configurations—due to engine design and typical usage:

5. Diagnose P0117 with ICARZONE UR800

Diagnose P0117 in your 2006 Honda Accord quickly with the UR800’s Honda-specific ECT sensor tools. Follow these steps (engine off, key in "ON" position):

Case Example: A 2006 Accord LX 2.4L failed Step 2 (0.2V) and Step 3 (8Ω). The UR800’s Component Location Tool showed the ECT sensor’s position (left side of engine, above the water pump). Replacing the sensor with Honda OEM part #37870-PNA-003 fixed P0117—verified by UR800’s post-test (2.8V voltage at idle).

6. How to Fix P0117 in 2006 Honda Accord

Resolve P0117 in your 2006 Accord with these UR800-verified solutions—tailored to the 2.4L and 3.0L engines:

1. Replace the ECT Sensor (Most Common Fix)

1. Confirm sensor failure via UR800’s Step 3. Drain 1–2 quarts of coolant from the radiator drain plug (driver’s side) to avoid spills when removing the sensor.
2. Locate the ECT sensor:
   • 2.4L i-VTEC: Left side of engine, near the thermostat housing (attached to the cylinder head).
   • 3.0L V6: Front of engine, above the water pump (near the alternator).
3. Disconnect the sensor’s 2-pin connector (press the tab) and remove the sensor with a 19mm deep socket (use penetrating oil if stuck).
4. Install a Honda OEM ECT sensor: #37870-PNA-003 (fits both 2.4L and 3.0L 2006 Accords). Apply thread sealant (Honda P/N 08718-0002) to the sensor threads.
5. Torque the sensor to 18 ft-lbs, reconnect the connector, and refill the radiator with Honda Premium Blue Coolant (#08798-9003).
6. Clear P0117 with the UR800 and test drive for 10 miles—verify the temperature gauge reads normally (mid-range when engine is warm).

2. Repair Corroded Sensor Connector

1. Confirm corrosion via UR800’s Step 4. Disconnect the ECT sensor connector from the harness.
2. Spray electrical contact cleaner (#CRC 05110) into both sides of the connector—use a small brush to scrub corrosion from the pins.
3. Dry the connector with compressed air (low pressure) to prevent moisture buildup.
4. Apply dielectric grease (#Permatex 81150) to the pins—this prevents future corrosion from coolant leaks.
5. Reconnect the connector, retest voltage with the UR800, and clear P0117. Check for coolant leaks around the thermostat housing (fix with a new gasket if needed).

3. Fix Damaged ECT Harness

1. Confirm wiring damage via UR800’s Step 4. Locate the damaged section (common areas: near engine mounts or the alternator bracket).
2. Cut the damaged wire (1 inch on each side of the break) and strip 1/4 inch of insulation from the ends.
3. Splice the wires with heat-shrink butt connectors (#Dorman 84731) and crimp firmly with a wire crimper.
4. Heat the connectors with a heat gun to seal the shrink tubing—ensure no exposed wire is left.
5. Secure the repaired harness to the engine with zip ties (away from hot surfaces like the exhaust manifold). Clear P0117 and retest continuity with the UR800.

7. P0117 Repair Costs & Maintenance Tips

P0117 repair costs for the 2006 Honda Accord are low compared to other engine issues—here’s a breakdown for DIY and professional work:

Maintenance Tips for 2006 Honda Accord Owners

• Replace the ECT sensor every 100,000 miles (preventive) — 2006 Accords are now 18+ years old, and sensors are past their 10-year lifespan.
• Use only Honda Premium Blue Coolant (#08798-9003) — aftermarket coolants are acidic and cause sensor corrosion. Flush the system every 10 years/120,000 miles.
• Inspect the ECT sensor connector during oil changes — look for green/white corrosion (sign of coolant leaks). Clean and grease the connector annually.
• Fix thermostat gasket leaks immediately — a worn gasket (common in 2006 Accords) drips coolant onto the sensor connector, triggering P0117. Replace with Honda gasket #19321-PNA-000.
• Perform the UR800’s ECT Sensor Health Check every 15,000 miles — monitor voltage and resistance to catch failing sensors before P0117 triggers.

8. 2006 Accord-Specific FAQs