P0116 Code: Toyota Camry (2018-2024) - Causes, Symptoms & Fixes

No recalls found in NHTSA database

Note on the data: The provided NHTSA data for Toyota Camry (2018-2024) does not include any entries for P0116. The single owner complaint listed in the data is for P0442 (not P0116). This guide uses the actual code definition (P0116) and general Camry practice, but the Camry-specific complaint statistics for P0116 are not available from the supplied data.

1. CODE MEANING AND SEVERITY

• What P0116 means:
  • P0116 is the Engine Coolant Temperature Sensor Range/Performance code. It indicates the engine control module (ECM/PCM) detected that the Engine Coolant Temperature (ECT) sensor reading is out of the expected range or the sensor is not performing correctly.
  • The ECT sensor provides the PCM with coolant temperature data. If the signal or resistance is outside the specified range, the PCM may set P0116 and may adjust fuel delivery and ignition timing accordingly.
• How serious it is:
  • Moderate to potentially serious. If left unresolved, the engine may run too rich or too lean, create drivability issues, reduce fuel economy, and in some cases contribute to overheating risk or poor cold-start behavior. On Camry 2018-2024, driving with a faulty ECT reading can also cause the climate control to behave oddly (e.g., heater output not matching actual coolant temperature) and may trigger other related codes.
• What to do first:
  • Treat as a legitimate DTC that warrants inspection of the cooling system, ECT sensor circuit, and related wiring. Don’t assume it’s just a sensor fault; always verify cooling system health and electrical integrity.

2. COMMON CAUSES ON TOYOTA CAMRY

• Faulty Engine Coolant Temperature (ECT) sensor itself.
• Damaged, corroded, or loose wiring/connector to the ECT sensor (including the sensor’s ground or signal circuit).
• PCM (ECM/PCM) reference or ground issues affecting the 5V reference or signal return.
• Coolant level too low, contaminated coolant, or air in the cooling system causing improper sensor readings.
• Thermostat stuck open, partially stuck, or not reaching proper operating temperature (affects actual coolant temperature and sensor readings relationship).
• Cooling system problems (radiator cap, water pump, fan operation, clogged radiator) that keep the engine from reaching/holding expected temperatures.
• Recent coolant work or sensor replacement done incorrectly (miswiring, bad seal, or air pockets).
• PCM software/calibration issues in rare cases (software updates may be needed; check TSBs/recall status if applicable).

Note: The Camry (2018-2024) often positions the ECT sensor near the thermostat housing. Wiring harnesses in that area are common points for inspection.

3. SYMPTOMS THAT OFTEN ACCOMPANY P0116

• Check Engine Light (CEL) illuminated with P0116 in the trouble codes.
• Inconsistent or abnormal engine temperature readings on the gauge (gauge may read colder or hotter than normal, or swing).
• Rough idle or irregular engine running, especially during cold starts or warm-up.
• Poor or delayed warm-up and heater performance (heater may not get as warm as expected).
• Potential fuel economy changes (may run richer or poorer depending on PCM compensation).
• In some cases, if the sensor reading is severely out of range, the vehicle may run in a degraded mode and feel less responsive until the issue is addressed.
• If the engine overheats due to cooling system issues, obvious overheating symptoms can appear (steam, higher under-hood temperatures, coolant loss).

4. DIAGNOSTIC STEPS (CAMRY-SPECIFIC APPROACH)
   Important: Start with a scan tool to pull DTCs, view live data, and capture freeze-frame data. Then inspect both the electrical side and the cooling system.

• Step 1: Retrieve and review data

  • Use a capable OBD-II scanner to confirm P0116 and note any related codes (P0115, P0117, P0118, P0125, etc.).
  • Check freeze-frame data for the ECT sensor reading at the time the code was stored, the actual coolant temperature, engine RPM, and load.
  • Record live data: ECT sensor voltage or resistance (depending on how your scanner presents it), ECT sensor temperature, and actual engine coolant temperature.

• Step 2: Inspect cooling system health

  • Check coolant level in the reservoir and radiator (when safe to do so) and inspect for leaks.
  • Look for coolant discoloration, contamination, or oil in the coolant (which can indicate other issues).
  • Pressure test the cooling system to identify leaks in hoses, radiator, cap, water pump, or heater core.
  • Verify coolant is the correct specification for Toyota Camry (use the recommended long-life coolant; if contaminated, flush as needed).

• Step 3: Inspect the ECT sensor and circuit

  • Visually inspect the ECT sensor and its wiring harness for damage, corrosion, or loose connections near the thermostat housing.
  • Disconnect the sensor connector and inspect pins for bent or corroded terminals; reconnect securely.
  • Check for damaged insulation or chafed wires along the harness (particularly where the harness runs near hot engine areas).
  • With a multimeter, test the ECT sensor circuit:
    • Confirm the PCM provides the expected 5V reference from the sensor circuit (check reference voltage at the connector).
    • Measure the ECT sensor resistance (or voltage) at the sensor terminals while the engine is at a known temperature (use a known-accurate temperature source or ambient conditions and a temperature-to-resistance chart for the Camry’s ECT sensor). Compare to the service manual specification for resistance vs temperature.
  • If readings are outside spec or do not change with temperature, replace the ECT sensor.

• Step 4: Check for proper coolant temperature vs observed data

  • Compare the ECT sensor reading to the actual engine coolant temperature (as reported by the PCM via live data). If the sensor reading is far from actual coolant temperature and wiring looks good, sensor replacement is warranted.
  • If the coolant temperature reading tracks actual temperature but the PCM is still throwing P0116, consider PCM or software-related issues (less common; verify with updates or dealership if needed).

• Step 5: Inspect thermostat operation

  • A thermostat stuck closed or slow to open can cause higher actual engine temperatures and affect sensor readings relationship. If the engine heats up unusually quickly or remains hot, test or replace the thermostat.
  • If the thermostat is fine and readings still out of range, focus on sensor/wiring or PCM.

• Step 6: Address related cooling components

  • Inspect radiator fans (electric fans, fuses, relays) and ensure they engage at the correct engine temperatures.
  • Inspect radiator, hoses, clamps, and the radiator cap for leakage or pressure issues.
  • If leakage or overheating is found, repair/replace as appropriate and re-test.

• Step 7: Re-test and confirm

  • After any replacement (ECT sensor, thermostat, wiring repair, coolant flush), clear codes and run the vehicle through warm-up and a road test.
  • Re-scan to confirm P0116 is cleared and that no new related codes appear.
  • Monitor live data to ensure ECT sensor and actual coolant temperature align over a range of conditions (cold start, warm-up, steady hot engine).

• Step 8: Escalation if still unresolved

  • If the issue persists after sensor, wiring, thermostat, and cooling system are verified, consider PCM software/ECU update or reprogramming (via a Toyota dealership or a shop that provides factory-level software updates).
  • In rare cases, PCM replacement may be necessary, but this is uncommon for P0116.

5. RELATED CODES

• P0115: Engine Coolant Temperature Sensor Circuit Malfunction
• P0117: Engine Coolant Temperature Sensor Circuit Low Input
• P0118: Engine Coolant Temperature Sensor Circuit High Input
• P0125: Insufficient coolant temperature for closed loop (engine not reaching proper operating temperature)
• P0128: Coolant Temperature Below Thermostat Regulating Temperature (specific to closed-loop control)
  Note: These related codes indicate similar or related sensor circuit or temperature control issues and are often checked when diagnosing P0116.

6. REPAIR OPTIONS AND COSTS (2025 PRICE RANGE)
   Prices vary by region, vehicle exact engine, and shop. The following are typical ranges (parts and labor estimates) for a Camry 2018-2024:

• ECT sensor replacement

  • Parts: $20–$70
  • Labor: $50–$150
  • Total: $70–$220

• Thermostat replacement (with coolant flush and bleed)

  • Parts: $15–$60
  • Labor: $100–$200
  • Coolant: $15–$30
  • Total: $130–$290

• Coolant flush and system bleed

  • Parts: typically included with flush
  • Labor: $80–$150
  • Total: $80–$150 (plus any coolant costs)

• Cooling system leaks (hose, radiator hose, clamps, water pump seals)

  • Parts: $10–$200 (depending on part)
  • Labor: $80–$300
  • Total: $90–$500

• Radiator replacement (if needed)

  • Parts: $150–$400
  • Labor: $300–$700
  • Total: $450–$1100

• Wiring harness/connector repair

  • Parts: $10–$100 (connector or harness sections)
  • Labor: $60–$200 (depends on accessibility)
  • Total: $70–$300

• PCM software update or reflash (dealer/independent shop)

  • Parts: $0–$50
  • Labor: $50–$150
  • Total: $50–$200

• Notes:

  • If more than one item is found (eg, ECT sensor plus thermostat or coolant leaks), total cost increases accordingly.
  • Always replace coolant with the correct specification for Toyota Camry when performing service.

7. DIY vs PROFESSIONAL

• DIY-friendly tasks (if you have the tools and comfort):
  • Visual inspection of the ECT sensor and connector.
  • Basic scan tool data check to view live ECT readings and coolant temperature.
  • Inspect coolant level and look for obvious leaks.
  • Replacing the ECT sensor or thermostat is often doable with basic hand tools, but requires proper coolant drain/refill and bleeding.
  • Performing a coolant flush and bleeding can be messy and requires proper disposal and technique; ensure you have the correct coolant and follow the manufacturer’s bleed procedures.
• Tasks best left to a professional:
  • Accurate resistance measurements of the ECT sensor at known temperatures without the correct charts or specification values.
  • Verifying 5V reference and ground integrity to the ECT sensor with the PCM wiring diagrams.
  • Diagnosing PCM/software issues or performing dealership-level software updates.
  • Cooling system pressure testing and leak diagnosis beyond obvious leaks.
• If you’re not comfortable with electrical testing, wiring checks, or cooling system bleeding, seek a qualified technician (Toyota specialist or a shop with Camry experience).

8. PREVENTION

• Regular cooling system maintenance:
  • Use the correct Toyota-approved coolant and change at the interval recommended in the owner’s manual.
  • Periodically inspect hoses, clamps, radiator, and the radiator cap for wear or leaks.
  • Check coolant level and condition regularly; top off as needed and perform a coolant flush at recommended intervals.
• Electrical cleanliness and integrity:
  • Inspect the ECT sensor connector during routine maintenance for corrosion or loose pins.
  • If you notice wiring harness wear or chafing, address it promptly to prevent future sensor failures.
• Heed warning signs early:
  • If the engine temperature gauge reads unusual values or you notice rough running, address cooling or sensor issues promptly to avoid potential engine damage.
• Proper maintenance intervals:
  • Follow Camry service intervals for thermostat, sensor checks, and cooling system inspections, especially if the vehicle is used in extreme temperatures or heavy-duty driving conditions.

Important caveat about the data used here:

• The provided data set does not include any P0116 complaints for the 2018-2024 Toyota Camry and lists no recalls for this model in the NHTSA database. The diagnostic guide above is based on the standard definition of P0116 and Toyota Camry maintenance practices, not on Camry-specific complaint data for P0116. If you want Camry-specific fault trends or TSB/recall references for P0116, you would need to consult Toyota service bulletins or a comprehensive NHTSA/ Toyota database source beyond the supplied data.