The P2045: Reductant Temperature Sensor Circuit High code indicates that the voltage in the reductant (DEF/AdBlue) temperature sensor circuit is higher than expected. This issue can be caused by high voltage in the circuit, a faulty sensor, or problems with wiring or connectors.
P2045 – Quick Overview
| Code | Information |
|---|---|
| Meaning | P2045: Reductant Temperature Sensor Circuit High |
| Is it serious? | Yes, high voltage in the temperature sensor circuit can lead to improper DEF system operation, resulting in poor NOx reduction and increased emissions. |
| Possible causes | – High voltage in the sensor circuit – Faulty sensor – Wiring or connector issues |
| How to diagnose? | – Measure voltage in the sensor circuit – Test the sensor – Inspect wiring and connectors |
P2045 Meaning
The P2045: Reductant Temperature Sensor Circuit High code indicates that the voltage from the reductant temperature sensor circuit is above the manufacturer’s specified range. The reductant temperature sensor monitors the temperature of the DEF fluid, which is critical for the proper function of the DEF injection system. If the voltage is too high, the sensor may not provide accurate readings, leading to improper DEF system operation.
Step-by-step diagnostic guide
| Action | Description | Tools Needed |
|---|---|---|
| Check for Other Codes | Use an OBD-II scanner to check for additional related codes. Other codes might provide further insight into the issue within the DEF system. | OBD-II Scanner |
| Measure Voltage in the Sensor Circuit | Use a multimeter to measure the voltage in the reductant temperature sensor circuit. Compare the voltage readings to the manufacturer’s specifications to confirm whether the voltage is too high. | Multimeter |
| Test the Reductant Temperature Sensor | Use a diagnostic tool or multimeter to test the sensor’s operation. If the sensor is not functioning properly or provides incorrect readings, it may need to be replaced. | Multimeter, Diagnostic Tool |
| Inspect Wiring and Connectors | Visually inspect all wiring and connectors connected to the reductant temperature sensor for signs of damage, corrosion, or loose connections that could lead to high voltage in the circuit. | Flashlight, Multimeter |
| Check Circuit Continuity | Perform a continuity test on the sensor’s wiring to ensure there are no shorts, breaks, or high resistance causing high voltage in the circuit. | Multimeter |
| Inspect the DEF System | Inspect the DEF system, including the tank and fluid lines, to ensure there are no issues with contamination or damage that could affect the temperature sensor’s performance. | Flashlight, Diagnostic Tool |
| Replace the Reductant Temperature Sensor | If the sensor is determined to be faulty, replace it with a new one. Ensure that it is properly installed to prevent further issues. | Replacement Sensor, Wrench |
| Repair or Replace Damaged Wiring | Repair or replace any damaged wiring, connectors, or circuit components to restore proper voltage in the sensor circuit and ensure accurate readings. | Wiring Repair Kit |
| Clear the Code and Test Drive | After repairs, clear the P2045 code using an OBD-II scanner. Test drive the vehicle to ensure that the issue is resolved and the sensor is operating correctly. | OBD-II Scanner, Vehicle Owner’s Manual |
| Recheck for Codes | After the test drive, re-scan the vehicle to confirm that the P2045 code has been cleared and has not returned. | OBD-II Scanner |
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