Severity High
P2043

Reductant Temperature Sensor Circuit Range/Performance

📅 Last reviewed: July 2026
What does the P2043 code mean?

The P2043 code indicates that the reductant temperature sensor circuit in the selective catalytic reduction (SCR) system is reporting a signal that is out of the expected range or not performing correctly. This sensor monitors the temperature of the diesel exhaust fluid (DEF) to ensure proper injection and system operation. A fault can lead to incorrect DEF dosing, potentially causing increased emissions or triggering the check engine light.

High
Severity
$50-$150
Typical Cost
High
Frequency

1. Most Common Causes

2. Symptoms You Will Notice

3. Step-by-Step Diagnosis

1

Step 1: Use an OBD2 scanner to confirm the code and check for related codes.

2

Step 2: Visually inspect the reductant temperature sensor and its wiring for damage, corrosion, or loose connections.

3

Step 3: Test the sensor resistance and compare with manufacturer specifications.

4

Step 4: Check the sensor circuit for shorts or opens using a multimeter.

5

Step 5: If necessary, replace the sensor and clear the code, then test drive to verify repair.

4. Frequently Asked Questions

Is it safe to drive with this code?

It is generally not recommended to drive long distances with this code, as it can lead to increased emissions and potential damage to the SCR system. However, short trips may be possible if the vehicle is not in limp mode.

How much does it cost to fix?

The cost to fix P2043 typically ranges from $50 to $150 for parts and labor, depending on the sensor price and labor rates.

5. Commonly Affected Makes

This is a generic OBD2 code, potentially applicable to any manufacturer using this diagnostic standard.

6. Related Codes

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