Engine Exhaust Temperature Sensor 1, Circuit Range/Performance Problem
There's a problem with the voltage signal from the engine exhaust temperature sensor 1.
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What it means (plain English)
The exhaust temperature sensor measures how hot the exhaust gases are. If it's sending a weird voltage signal—like too low or too high—then the engine control module thinks something's off.
What the computer is actually seeing
The engine control module (ECM) expects a voltage signal that typically ranges from 0.5V to 4.5V, depending on the temperature. If the signal falls outside of this range or behaves erratically, it triggers the fault code.
What a healthy reading looks like
Normal operation should show exhaust gas temperatures ranging from 300°F to 1300°F, with corresponding voltages between 0.5V (low temp) and 4.5V (high temp).
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 connector at the exhaust temperature sensor 1 for any damage or corrosion. Repair as necessary.
- 22. Using a multimeter, measure the voltage at the sensor connector with the engine running. It should read between 0.5V and 4.5V. If it's outside this range, the sensor could be faulty.
- 33. If the voltage is within range, check for exhaust leaks near the sensor that could affect readings. Repair any leaks found.
- 44. If previous steps are good, replace the exhaust temperature sensor 1 and clear the codes. Test drive to see if the code reappears.
Common causes
- Faulty engine exhaust temperature sensor 1
- Wiring issues including shorts, breaks, or corrosion
- Connector issues such as poor contact or corrosion
- Exhaust leaks affecting sensor readings
Typical repair cost
$$$
Related codes
Frequently asked questions
Is it safe to drive with this fault code?
It's drivable, but performance may be affected. Fix it soon to avoid potential engine issues.
Will the code come back after repair?
If the fault is properly identified and repaired, the code should not return.
Why does this code pair with SPN 2188?
SPN 2188 indicates a similar issue with the second exhaust temperature sensor, often caused by the same underlying issues.
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