Engine Aftertreatment Temperature Sensor 2 - High
Aftertreatment temperature sensor 2 is reading too high.
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What it means (plain English)
The engine's computer monitors temperatures in the exhaust system to avoid damage. If sensor 2 reports a temperature higher than expected, it could mean there's a problem with the sensor, the wiring, or an actual overheating issue in the system.
What the computer is actually seeing
The ECM sees a voltage from the sensor that corresponds to a temperature above its normal operating range, typically over 200°C (392°F), which is outside the expected limits for normal operation.
What a healthy reading looks like
Temperature readings should normally be between 100°C (212°F) and 200°C (392°F) during standard operation; anything above is flagged as high.
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 wiring and connectors for sensor 2 for damage or corrosion; repair if needed. Decision: If wiring is good, proceed to step 2; if bad, fix wiring and retest.
- 22. Measure voltage at the sensor connector with the engine running; compare to specifications (0.5V to 4.5V). Decision: If voltage is out of spec, replace the sensor; if within spec, proceed to step 3.
- 33. Inspect the exhaust system for leaks or restrictions that might cause excessive heat; address any issues found. Decision: If no leaks/restrictions, retest after repairs; if found, fix and retest.
Common causes
- Faulty temperature sensor 2
- Short or open circuit in the wiring harness
- Exhaust leaks affecting sensor readings
- Exhaust system overheating due to poor airflow or restricted DPF
Typical repair cost
$$$
Related codes
Frequently asked questions
Can I drive with this code active?
It's not recommended. It can lead to overheating and damage to the aftertreatment system.
Will this code come back after clearing?
If the underlying issue isn't fixed, yes, it will return.
Does this code indicate a bad sensor every time?
Not necessarily; it can also be caused by wiring issues or system overheating.
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