SCR Redundancy Temperature Sensor Circuit Range/Performance Problem
An issue was detected with the temperature sensor monitoring the SCR system.
Heads up: this code wasn't in our hand-written library yet, so DiagCoach AI built this page on the fly. Double-check critical specs against service info before condemning parts.
What it means (plain English)
The computer is saying that the temperature readings from the SCR system's sensor don't make sense, which can affect how well the emissions system works.
What the computer is actually seeing
The Engine Control Module (ECM) sees the temperature input from the SCR temperature sensor as outside the expected range, which can indicate a malfunctioning sensor or wiring issue.
What a healthy reading looks like
The SCR temperature should typically be between 100°F (38°C) and 400°F (204°C) during operation.
Guided diagnostic — the DiagCoach way
Don't just throw parts at it. Walk through these in order — each step tells you whether to keep going or stop and fix what you found.
- 11. Check the SCR temperature sensor wiring and connector for any visible damage or corrosion. If damaged, repair or replace.
- 22. Inspect the sensor for physical damage or contamination. Replace the sensor if necessary.
- 33. Using a scan tool, check the actual temperature reading from the SCR temperature sensor. If the reading is outside the expected range, replace the sensor.
- 44. Clear the code and run the engine to see if the code returns. If it does, further inspection of the wiring and ECM may be needed.
- 55. If the code does not return, monitor the SCR system for consistent temperature readings during operation.
Common causes
- Faulty SCR temperature sensor
- Wiring issue or short circuit in the sensor circuit
- Poor connection in the sensor connector
- Faulty ECM software or sensor calibration
Typical repair cost
$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
Moderate severity means you should fix it soon; drivability may be impacted, especially emissions.
Will this code come back after clearing?
If the underlying issue isn't resolved, yes, it will likely return.
Why does this code sometimes pair with P203C?
P203C indicates a similar problem with a different temperature sensor related to the SCR system.
Working a real vehicle right now?
Let DiagCoach walk you through it live with your specific symptoms, vehicle, and what you've already checked.
Start guided diagnostic →