P0113 Code: Honda Accord (2018-2023) - Causes, Symptoms & Fixes

P0113 Diagnostic Guide for 2018–2023 Honda Accord

Data note (from the supplied dataset): No recalls found in NHTSA database. No owner complaints recorded for this make/model/year/issue combination. This guide uses general automotive diagnostic knowledge for P0113, with the data limitations clearly stated.

CODE MEANING AND SEVERITY

• Code meaning: P0113 = Intake Air Temperature (IAT) Sensor 1 Circuit High Input. The engine control unit (ECU) is reading a higher-than-expected voltage from the IAT sensor circuit.
• What this means in practice: The ECU uses the IAT reading to help determine air density and adjust fuel delivery and ignition timing. A high input can cause the ECU to miscalculate air mass, potentially leaning or enriching the air-fuel mixture depending on the vehicle’s calibration.
• Severity: Moderate. It can run poorly, reduce fuel economy, and illuminate the check engine light. It is typically not an immediate safety risk, but persistent issues may affect drivability and emissions. If combined with other faults, performance can deteriorate more noticeably.

COMMON CAUSES ON HONDA ACCORD

• Faulty IAT sensor itself (most common): Sensor may be out of spec, stuck high, or providing erratic readings.
• Wiring or connector problems: Damaged, frayed, or corroded wires, loose or unplugged connectors, or poor grounding in the IAT circuit.
• Intake air duct or vacuum/air leaks near the sensor: Cracked hoses, loose clamps, or improper sealing around the IAT sensor housing or intake tube can create incorrect readings.
• IAT sensor integrated with MAF sensor (some designs): If the MAF assembly is faulty or the IAT portion is compromised, the circuit may present high input symptoms.
• PCM/control wiring issue (less common): A fault in the ECU’s sensor circuit reference or a shared ground can produce high readings.
• Contaminants or oil/soot on the sensor or housing: Dirt buildup can affect sensor readings over time.
• Environmental conditions or aftermarket components: Non OEM hoses or ductwork, aftermarket intake systems, or weather-related moisture intrusion can influence readings.

SYMPTOMS to watch for

• Check Engine Light (MIL) illuminated with P0113 stored.
• Noticeable drop in fuel economy or altered fuel trims.
• Idle instability or rough idle, especially around cold startup.
• Hesitation, stumbling, or reduced throttle response under acceleration.
• Mild loss of power or turbo lag (in turbocharged Accords) under certain conditions.
• Occasional misfire-like feeling or engine running richer/leaner than expected.
• In some cases, no obvious symptoms beyond the MIL until the code is read.

DIAGNOSTIC STEPS (practical workflow)

Note: This is a generalized Honda Accord approach for P0113. Always refer to service manual for exact spec values and wiring diagrams.

A. Confirm the DTC and context

• Use an OBD-II scan tool to confirm P0113.
• Review freeze frame data: engine coolant temp, intake air temp reading, RPM, load, vehicle speed at the time of fault.
• Clear the code after repairs to verify a real fix (and recheck after a test drive).

B. Visual inspection

• Inspect the IAT sensor and its connector for corrosion, bent pins, damage, or moisture.
• Check wiring harness harnesses near the intake tubing for wear, rubbing, or pinched wires.
• Inspect the air intake ducts, hoses, and clamps for cracks, breaks, or loose connections.
• Inspect for oil or debris buildup on the sensor or in the intake tract.

C. Diagnostic testing of the IAT sensor circuit

• With engine off, back-probe the IAT signal wire and the 5V reference and ground as available in your Honda wiring diagram.
• Verify supply voltages:
  • 5V reference should be present on the reference line.
  • Signal line should vary with temperature (as the intake air temp changes, the signal voltage should move within the expected range).
  • Ground should be solid with minimal resistance.
• Start the engine and monitor real-time IAT readings (via a scan tool). Compare the IAT voltage/reading with ambient air temperature and with live data from the IAT sensor:
  • At ambient conditions, the IAT reading should correlate reasonably to the actual air temperature. If the sensor shows a consistently high reading regardless of ambient temperature, suspect the sensor or its wiring.
• If possible, test the IAT sensor resistance using a multimeter at room temperature and at a warmer temperature (as defined by the service manual). Compare to spec.

D. Check for air leaks and related components

• Perform a smoke test or spray-equalization checks around intake hoses, throttle body gasket, and vacuum lines to identify leaks that could affect readings.
• Make sure clamps are tight and hoses are properly sealed.

E. Isolate sensor vs. MAF vs. other sensors

• If your vehicle uses an IAT integrated with the MAF, consider testing or temporarily substituting a known-good MAF to see if readings normalize. If the IAT/Sensor portion is suspect, replace the IAT sensor (or the entire MAF assembly if required by design).
• After ensuring IAT wiring and sensor are good, clear codes and drive normally to see if P0113 returns.

F. Post-repair verification

• Clear the check engine light and run a road test to ensure the fault does not reappear.
• Confirm fuel trim behavior returns to normal ranges.
• Re-scan to confirm P0113 is not present; if it returns, re-evaluate for wiring faults or MAF/IAT integration issues.

RELATED CODES

• P0111 IAT Circuit Range/Performance
• P0112 IAT Circuit Low Input
• P0114 IAT Circuit Intermittent (if applicable in your model/year; some vehicles have variations)
• P0113 is the High Input counterpart to these IAT codes. If other IAT-related codes appear, they often point to the same root causes (sensor, wiring, or intake issues).

REPAIR OPTIONS AND COSTS (2025 price ranges)

Prices vary by region, shop, and whether you replace the sensor alone or the entire assembly. The following are typical ranges for the US market in 2025.

• IAT sensor replacement (standalone sensor, common on many Honda engines)

  • Parts: roughly $15–$60
  • Labor: ~0.3–1.0 hours
  • Estimated total: $60–$180

• IAT sensor integrated with MAF sensor (if replacement requires MAF)

  • Parts: roughly $150–$350
  • Labor: ~0.6–1.5 hours
  • Estimated total: $250–$500

• Intake duct/hose repair or replacement (cracked duct, loose clamp)

  • Parts: $20–$80
  • Labor: ~0.5–1.0 hours
  • Estimated total: $100–$200

• Wiring harness/connector repair (if wiring damage is identified)

  • Parts: $5–$50 (connectors, wires)
  • Labor: 1.0–2.0 hours
  • Estimated total: $150–$400

• Miscellaneous (cleaning, quick connector reseating, or sensor re-seat)

  • Parts: minimal
  • Labor: variable
  • Estimated total: $50–$150

Notes:

• These ranges are general estimates for 2018–2023 Honda Accord; exact pricing depends on engine type (1.5L turbo vs 2.0L turbo), location, and whether the part is OEM or aftermarket.
• If the IAT issue is due to a broader intake system problem or a faulty MAF sensor that includes IAT functionality, costs can increase accordingly.
• Always verify whether a repair is covered under warranty if the vehicle is still under manufacturer or powertrain warranty.

DIY vs PROFESSIONAL

• DIY viability:
  • Replacing the IAT sensor (if it's a simple plug-in sensor in the intake tract) is generally straightforward and can be a good DIY project for a confident home mechanic.
  • Tools you’ll typically need: basic hand tools, a multimeter (for voltage/ground checks), and sometimes a trim tool to access connectors. Wear safety gear and disconnect the battery when working near electrical connectors.
  • Pros: lower cost, quick turnaround, learning opportunity.
  • Cons: risk of misdiagnosis if you don’t verify wiring and sensor behavior; improper reseating or damaged connectors can cause more faults.
• Professional route:
  • Recommended if the IAT sensor is integrated with the MAF, if wiring harness damage is suspected, or if the fault persists after a sensor replacement.
  • Pros: diagnostic accuracy, proper testing equipment, factory service data, and proper reassembly.
  • Cons: higher labor cost.

PREVENTION

• Regular air intake maintenance:
  • Replace air filters as per Honda maintenance schedule; a clogged filter can contribute to readings anomalies.
  • Inspect intake hoses and clamps during routine service for cracks and leaks.
• Use OEM or high-quality sensors and matched MAF/air intake components when replacements are needed to avoid integration compatibility issues.
• Keep the intake area clean and free of oil or dirt that could contaminate sensors.
• Prevent moisture intrusion in the intake path by ensuring seals and ducts are intact, especially in wet climates or off-road conditions.
• Periodically scan for codes and monitor live sensor data to catch drift in readings before they trigger a MIL.

Data transparency and limitations

• The provided dataset shows no recalls and no owner complaints for this specific issue on the 2018–2023 Honda Accord. No model-specific recall or complaint data is available here, so this guide relies on general diagnostic practice and Honda-engineering norms for IAT sensor behavior.
• If you have dealer service data, TSBs, or warranty bulletins specific to your VIN or region, those should be reviewed and prioritized.

If you want, I can tailor the diagnostic steps to your exact engine variant (1.5L vs 2.0L turbo) and your preferred diagnostic approach (scan tool model, multimeter testing method, etc.).