P0116 Code: Chevrolet Malibu (2017-2023) - Causes, Symptoms & Fixes

No recalls found in NHTSA database.

Note: The data provided for 2017-2023 Chevrolet Malibu includes complaints for other OBDII codes (P0302, P0420) but does not include any documented instances of P0116. This guide uses general OBDII knowledge for P0116 and adapts it to what is typical for Malibu engines in these model years. If you have a Malibu with P0116, treat it as a sensor range/performance issue related to the Engine Coolant Temperature (ECT) system and follow the diagnostic steps accordingly. Always corroborate with GM service data when available.

CODE MEANING AND SEVERITY

• Code definition: P0116 = Engine Coolant Temperature Sensor Range/Performance problem. The PCM has detected that the ECT sensor signal is out of the expected range or is not responding correctly to temperature changes. This can be caused by a faulty sensor, wiring issues, or cooling system problems that affect temperature readings.
• Why it matters: The PCM uses the ECT signal to adjust fueling, ignition timing, idle, and other engine control strategies. An out-of-range or erratic ECT reading can lead to:
  • Poor or fluctuating fuel economy
  • Rough idle or misfire-like symptoms
  • Hard starting or extended cranking
  • Erratic or incorrect temperature readings on the gauge
  • Potential engine performance issues and increased emissions
• Severity: Medium to potentially high if the reading causes the engine to run too rich/lean or if the engine actually overheats due to incorrect temperature information. Addressing the root cause promptly helps prevent unnecessary catalyst wear or overheating-related damage.

COMMON CAUSES ON CHEVROLET MALIBU

• Faulty ECT sensor itself (most common)
• Damaged, corroded, or loose wiring/connector to the ECT sensor
• Ground or 5V reference issues in the PCM wiring harness
• Thermostat problems (stuck open or intermittently sticking), causing real temperature changes that don’t match the sensor’s reading
• Coolant level too low or incorrect coolant type/mixture
• Coolant leaks or air in the cooling system causing temperature readings to be unstable
• Engine overheating or inconsistent cooling system operation
• PCM/software calibration issue (less common, but possible if a calibration fault exists)

Note: Malibu engines in this generation (1.5L turbo, 2.0L turbo, etc.) use an ECT sensor located near the thermostat housing or on the engine block. Access and exact wiring colors can vary by engine family, so consult GM service information for your exact powertrain when performing tests.

SYMPTOMS

• Check Engine Light with P0116 stored or pending
• Temperature gauge reading that doesn’t match engine temperature (either too hot, too cold, or erratic)
• Crank time or extended warm-up period to reach operating temperature
• Noticeable drop in fuel economy or unusual fuel trims
• Rough idle or hesitation, especially during cold starts or after a cold soak
• Occasional misfiring symptoms if fueling goes rich/lean due to incorrect temperature data
• In rare cases, symptoms may be accompanied by related codes such as P0115 (ECT Circuit Malfunction) or P0128 (thermostat) if a related fault exists

DIAGNOSTIC STEPS

Important: Use an OBD-II scanner with live data capability and, if possible, GM-specific diagnostic information. Follow safety procedures when working around the cooling system and engine.

• Step 1: Confirm and document the DTC

  • Read the freeze frame data and note engine temperature, ambient temp, RPM, and load at the time of the fault.
  • Check for any related codes (P0115, P0128, P0117, P0118) that could point to harness/ground or thermostat issues.

• Step 2: Inspect the ECT sensor and its harness

  • Visually inspect the sensor for damage, oil leaks, or contamination.
  • Check the electrical connector for corrosion, bent pins, bent terminals, or a loose connection.
  • Disconnect the sensor and inspect the mating connectors; reseat with dielectric grease if appropriate.

• Step 3: Check wiring integrity and references

  • With the ignition on, test the ECT signal wire and the 5V reference/ground wires for continuity to the PCM and the sensor.
  • Look for damaged insulation, chafed harness, or pin push-in issues in the connector.
  • Check for any short to ground or short to voltage conditions.

• Step 4: Test the ECT sensor resistance (cold and warm)

  • Remove the sensor and measure resistance across the sensor terminals at known temperatures (coolant ambient and engine-warm temperature if feasible).
  • Compare readings to GM service data/specs for your exact engine. A sensor that is out of spec or whose value does not change appropriately with temperature indicates a faulty sensor.

• Step 5: Evaluate cooling system behavior

  • Ensure coolant level is correct and the coolant is in good condition (not degraded, not overdue for replacement).
  • Check for air pockets in the cooling system; bleed if necessary per GM procedure.
  • Verify thermostat operation: does the engine reach normal operating temperature within a reasonable time? Do fans come on when expected?
  • Look for signs of overheating or restricted coolant flow (sludge, blocked radiator, faulty water pump).

• Step 6: Monitor live data under steady-state and changing conditions

  • Use the scan tool to watch the ECT sensor reading as the engine warms from cold to operating temperature.
  • Confirm the ECT reading tracks actual coolant temperature (fan behavior, gauge reading, and manual temperature checks if possible).
  • If readings are wildly inconsistent or do not move with temperature changes, the sensor or its wiring is likely at fault; if readings are plausible but the PCM is misinterpreting them, the issue may be PCM/firmware related.

• Step 7: Consider related components and software

  • If all electrical tests pass but the problem persists, consider a PCM software update or calibration check with the dealership (without assuming a defect—some updates affect sensor interpretation).
  • If the thermostat or cooling fans are intermittent, address those issues, as they can cause real temperature swings that complicate the sensor reading.

• Step 8: Repair/verify after repair

  • Replace the ECT sensor if it fails the resistance test or shows out-of-range readings.
  • Repair/replace damaged wiring or connectors as needed.
    Mineral oil or coolant contamination should be addressed if found. After any repair, clear the DTCs and perform a test drive to verify that P0116 does not return and that readings are in-range.

RELATED CODES

• P0115: Engine Coolant Temperature Sensor Circuit Malfunction — indicates an electrical fault in the sensor circuit, which can cause P0116 or masquerade as P0116 symptoms.
• P0128: Coolant Thermostat Temperature Regulation — indicates thermostat-related temperature control problems, which can mimic or contribute to ECT sensor range/performance symptoms.
• P0117: Engine Coolant Temperature Sensor Circuit Low Input
• P0118: Engine Coolant Temperature Sensor Circuit High Input
  Note: These codes are commonly observed with ECT-related symptoms; diagnosing P0116 often involves checking for these related codes and the associated wiring/thermostat conditions.

REPAIR OPTIONS AND COSTS (2025 PRICES)

Prices vary by region and shop. The ranges below reflect typical U.S. market costs including parts and labor.

• ECT sensor replacement

  • Parts: roughly $15–$60
  • Labor: about 0.5–1.0 hours
  • Total: approximately $60–$180
    Notes: Quick, common repair; often resolves the issue if the sensor is the fault.

• Thermostat replacement (including coolant flush if needed)

  • Parts: roughly $15–$50
  • Labor: about 1.0–2.0 hours
  • Total: approximately $150–$350
    Notes: If the thermostat is stuck or intermittently failing, it can cause real temperature changes that create P0116-like symptoms.

• Wiring harness/connector repair

  • Parts: $5–$100 (depends on what needs replacement)
  • Labor: $75–$200
  • Total: approximately $80–$300
    Notes: Damaged wiring or connectors can mimic sensor failure; repair costs vary with accessibility.

• Coolant system service (flush, fill, and leak repair if present)

  • Parts: $10–$40 (coolant)
  • Labor: $60–$150
  • Total: approximately $100–$250
    Notes: Essential if coolant contamination, low levels, or air pockets are present.

• PCM reprogramming or calibration update

  • Parts: typically negligible (software update)
  • Labor/Programming: $75–$150
  • Total: approximately $100–$250
    Notes: Only if a factory calibration issue is identified or a software update is issued by GM.

• Diagnostic labor for persistent P0116

  • Labor: 0.5–2.0 hours typical, depending on complexity
  • Total: $50–$200+ (diagnostic fees may apply)

DIY VS PROFESSIONAL

• DIY-friendly tasks (with caution):
  • Visual inspection of ECT sensor and connectors
  • Basic wiring checks (continuity, obvious damage)
  • Sensor replacement if comfortable with basic hand tools
  • Checking coolant level and basic coolant service (needs proper disposal and mixing)
  • Resurfacing or re-seating the sensor connections and cleaning connectors
• Tasks better left to a professional:
  • Testing sensor resistance accurately across temperature ranges (requires controlled conditions or specialized equipment)
  • Verifying 5V reference and PCM signal integrity (may require GM-specific scan tools)
  • Diagnosing complex harness faults, corrosion, or hidden damage
  • Thermostat replacement and coolant system bleeding performed correctly
  • Possible PCM software updates or reprogramming

PREVENTION

• Regular cooling system maintenance
  • Follow GM maintenance intervals for coolant flushes and radiator/system inspection.
  • Use the correct coolant type and mixture as specified by GM for your engine.
  • Keep coolant level in the recommended range and watch for signs of leaks.
  • Inspect radiator fans and wiring; ensure proper fan operation at all operating temperatures.
• Sensor and electrical care
  • Keep engine bay clean and free of oil leaks that could contaminate sensors.
  • Inspect electrical connectors for corrosion or damage during routine service.
  • If you notice recurring temperature faults, address them promptly to avoid running out-of-range conditions that can harm fuel trims and emissions.
• Driving habits
  • Short trips or repeated cold starts can place extra stress on cooling system and sensors; longer drives help the system maintain stable temperatures.
  • Address overheating or coolant boil-through promptly.

Summary

• P0116 denotes Engine Coolant Temperature Sensor Range/Performance problems, which can affect fuel economy, drivability, and emissions. In the Malibu 2017-2023 run, the most likely causes are a faulty ECT sensor, wiring/connector problems, or thermostat issues. Start with a thorough inspection of the sensor and harness, verify readings with a proper test, and address any cooling system problems. If needed, replace the ECT sensor, repair harnesses, and/or service the cooling system. As with any diagnostic, if the fault persists or you’re unsure, consult a qualified technician or GM dealership for calibration-specific guidance.