Faulty engine coolant temperature sensor 2 (the sensor itself has drifted or failed).; Damaged or corroded wiring or connector at sensor 2, including chafed insulation or pushed-back pins.; High resistance in the sensor ground circuit or a poor ground connection.; A stuck-open or stuck-closed thermostat causing the coolant temperature to change slower or faster than the PCM expects.; Low coolant level or air pockets in the cooling system affecting sensor 2's reading.; An intermittent open or short in the signal circuit due to heat or vibration.; In rare cases, a PCM software issue or internal fault in the sensor 2 input circuit.

DTC codes / P21xx · Fuel and air metering / P2183

P2183Engine Coolant Temperature Sensor 2 Circuit Range/Performance

P2183 means the powertrain control module (PCM) has detected that the second engine coolant temperature (ECT) sensor circuit is performing outside its expected range or response time. This sensor is typically used to monitor coolant temperature at a different point in the cooling system, such as the radiator outlet, to verify thermostat operation and protect the engine. The PCM compares its signal against model expectations and sets the code when the voltage or calculated temperature does not behave as designed.

SystemPowertrain

Code typeGeneric (all makes)

SeverityMedium

Fix difficultyIntermediate

AreaFuel and air metering

Symptoms you may notice

Illumination of the check engine light, often with no other noticeable symptoms.
Inaccurate or erratic temperature gauge readings on the dashboard.
Poor fuel economy or slightly rough running during warm-up.
Cooling fan may run constantly or not at all, depending on the failure mode.
In rare cases, the engine may enter a reduced power or fail-safe mode.
A noticeable difference between the temperature readings from the two coolant sensors if data is monitored.

Common causes, most likely first

Faulty engine coolant temperature sensor 2 (the sensor itself has drifted or failed).
Damaged or corroded wiring or connector at sensor 2, including chafed insulation or pushed-back pins.
High resistance in the sensor ground circuit or a poor ground connection.
A stuck-open or stuck-closed thermostat causing the coolant temperature to change slower or faster than the PCM expects.
Low coolant level or air pockets in the cooling system affecting sensor 2's reading.
An intermittent open or short in the signal circuit due to heat or vibration.
In rare cases, a PCM software issue or internal fault in the sensor 2 input circuit.

How to diagnose and fix it

Verify coolant level and condition; top up and bleed the system if low or air-locked.
Use a scan tool to read live data from both coolant temperature sensors and compare their readings during warm-up.
Visually inspect sensor 2, its connector, and the wiring harness for damage, corrosion, or loose pins.
Perform a resistance test on sensor 2 and compare it to the manufacturer's temperature-resistance chart.
Check the sensor ground circuit for excessive resistance using a multimeter and a known good ground.
If wiring and sensor test good, check thermostat operation by monitoring coolant temperature rise and comparing it to the expected warm-up curve.
Replace sensor 2 only after confirming the circuit and thermostat are functioning correctly, then clear the code and verify the repair.

Why Sensor 2 Often Gets Misdiagnosed

A stuck-open thermostat can set P2183 because the coolant never reaches the temperature the PCM expects, making the sensor appear faulty when it is actually accurate.
Air pockets trapped near sensor 2 after a coolant service are a common cause of this code, and the sensor may test perfectly on the bench.
The second coolant sensor is frequently used for radiator outlet temperature monitoring, so a restricted radiator or failing water pump can skew its readings.
Many technicians replace sensor 2 without checking the ground circuit, which often has higher resistance than the signal wire and causes a false range error.
P2183 can be set by a sensor that is slow to respond rather than completely failed, so a simple resistance check at one temperature may not reveal the problem.

Can I keep driving with P2183?

You can usually drive the vehicle with P2183 set, but avoid heavy loads or long trips until the fault is diagnosed because inaccurate coolant temperature data can affect cooling fan operation and fuel mixture. If the temperature gauge climbs into the red or the engine runs poorly, stop and have it checked immediately.

Tools that help

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Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.