P2044 — Reductant Temperature Sensor Circuit Low

powertrain (engine/transmission)

Is it safe to drive?

Short-term driving is OK In most cases the car remains drivable, possibly with reduced performance or a disabled auxiliary system. If symptoms include stalling, no-start or brake/steering warnings, treat it as urgent.

How to diagnose with an OBD scanner

Read the code and freeze frame Connect an OBD2 scanner, confirm P2044 is stored, and save the freeze frame data — it shows engine conditions when the fault was detected.
Check for companion codes and TSBs Related codes often reveal the real root cause. Also check manufacturer technical service bulletins (TSB) for your make and model — many P0xxx issues have factory fixes or software updates. Search by VIN on the manufacturer site or nhtsa.gov.
Inspect wiring and connectors Visually inspect the wiring harness and connectors related to the reductant temperature sensor for damage, corrosion, chafing or poor contact.
Subsystem check Check for supply voltage at the reductant temperature sensor connector first; then measure resistance from the signal wire to ground — near-zero ohms confirms a short to ground in the harness.
Subsystem check Measure reference voltage, ground and signal continuity at the component connector.
Subsystem check Wiggle-test the harness while watching the signal in live data — dropouts reveal broken wires.
Verify the repair Clear the code, complete a full drive cycle including the conditions from the freeze frame, and confirm P2044 does not return.

Approximate repair cost

Repair cost depends on which component actually failed. Typical scenarios for P2044 (parts and labor, USD, independent shop rates): Repair wiring or connectors: $80–$250; Replace the faulty sensor or actuator: $150–$500; Control module repair: $300–$1,000. Overall, fixing P2044 usually costs between $80 and $1,000. An accurate diagnosis before buying parts saves money — the most expensive scenario is rarely the first one to check.

Common questions

What does OBD2 code P2044 mean?

Reductant Temperature Sensor Circuit Low (P2044): a powertrain (engine/transmission) fault affecting the sensor and actuator circuits. The car is usually drivable while you plan the repair. Most often caused by faulty sensor or actuator of the affected circuit, open or shorted wiring in the circuit, poor ground connection.

How do I diagnose P2044 myself?

Start with a scan: confirm P2044, save the freeze frame and note any companion codes. Then inspect the wiring and connectors related to the reductant temperature sensor, and verify the suspect component against live data before buying parts.

What is the most common cause of P2044?

The most common causes are: faulty sensor or actuator of the affected circuit, open or shorted wiring in the circuit, poor ground connection.

What are the symptoms of P2044?

Drivers most often notice: Check Engine Light on, possible limp mode depending on the affected component, increased fuel consumption in some cases, the affected system operates intermittently or not at all.

Will P2044 clear itself?

Sometimes P2044 clears after a few drive cycles if the fault was intermittent — for example a loose connector or a tank of bad fuel. The underlying cause usually remains, so the code tends to return. Clear it once; if it comes back, diagnose rather than erase it repeatedly.

What does P2044 mean?

P2044 is logged by the onboard diagnostics when the sensor and actuator circuits does not behave as expected. The official definition is “Reductant Temperature Sensor Circuit Low”. This is a powertrain (engine/transmission) category code.

“Circuit low” means the voltage on the reductant temperature sensor circuit stays below the expected minimum — close to ground. The usual physical reasons are a short to ground, a chafed wire touching metal, a missing supply voltage, or a failed component dragging the signal down.

To set P2044, the control module compares live readings of the sensor and actuator circuits against calibrated limits, usually over several drive cycles. Alongside the code it stores a freeze frame — a snapshot of rpm, load, coolant temperature and vehicle speed at the moment of failure. Reading that snapshot first saves diagnostic time.

Common symptoms of P2044

Check Engine Light on
possible limp mode depending on the affected component
increased fuel consumption in some cases
the affected system operates intermittently or not at all

What causes P2044?

signal wire shorted to ground (chafed insulation)
missing supply voltage to the reductant temperature sensor
failed reductant temperature sensor pulling the signal low
corroded, loose or damaged connector
faulty sensor or actuator of the affected circuit
control module driver fault
poor ground connection

How to diagnose P2044

Connect an OBD2 scanner, confirm P2044 is stored, and save the freeze frame data — it shows engine conditions when the fault was detected.
Related codes often reveal the real root cause. Also check manufacturer technical service bulletins (TSB) for your make and model — many P0xxx issues have factory fixes or software updates. Search by VIN on the manufacturer site or nhtsa.gov.
Visually inspect the wiring harness and connectors related to the reductant temperature sensor for damage, corrosion, chafing or poor contact.
Check for supply voltage at the reductant temperature sensor connector first; then measure resistance from the signal wire to ground — near-zero ohms confirms a short to ground in the harness.
Measure reference voltage, ground and signal continuity at the component connector.
Wiggle-test the harness while watching the signal in live data — dropouts reveal broken wires.
Clear the code, complete a full drive cycle including the conditions from the freeze frame, and confirm P2044 does not return.

How to fix P2044

Start with the cheapest and most common causes before replacing expensive parts:

Repair wiring or connectors — $80–$250
Replace the faulty sensor or actuator — $150–$500
Control module repair — $300–$1,000

How much does it cost to fix P2044?

Repair cost depends on which component actually failed. Typical scenarios for P2044 (parts and labor, USD, independent shop rates):

Repair wiring or connectors: $80–$250
Replace the faulty sensor or actuator: $150–$500
Control module repair: $300–$1,000

Overall, fixing P2044 usually costs between $80 and $1,000. An accurate diagnosis before buying parts saves money — the most expensive scenario is rarely the first one to check.

Can you drive with P2044?

In most cases the car remains drivable, possibly with reduced performance or a disabled auxiliary system. If symptoms include stalling, no-start or brake/steering warnings, treat it as urgent.