Engine Exhaust Temperature Sensor 1 Circuit High
This code indicates a high signal from the Engine Exhaust Temperature Sensor 1.
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 Engine Exhaust Temperature Sensor measures how hot the exhaust gases are. If it reads too high, the engine control unit suspects a fault either in the sensor itself or in the circuit, as it shouldn't be over about 1.5 volts typically at idle.
What the computer is actually seeing
The engine control module (ECM) sees a voltage from the exhaust temperature sensor that exceeds the normal operating range. For a properly functioning sensor, the voltage should be between 0.5 to 1.5 volts under normal conditions, but in this case, it might be reading above 1.5 volts or showing an open circuit.
What a healthy reading looks like
Voltage should be between 0.5V and 1.5V when the engine is at operating temperature. Excessive values will indicate a fault.
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 the Engine Exhaust Temperature Sensor. Look for any signs of damage, corrosion, or loose connections. If found, repair or replace as necessary.
- 22. Using a multimeter, measure the voltage at the sensor while the engine runs. If it’s over 1.5 volts or showing unlikely readings, proceed to the next step.
- 33. Disconnect the sensor and check the resistance across the sensor terminals. If the resistance is outside the manufacturer’s specifications, replace the sensor. If the sensor is good, the issue may lie with the ECM.
- 44. If the sensor tests good, check the ECM for faults or software updates. Use a scan tool to see if there are any other related fault codes present.
Common causes
- Faulty exhaust temperature sensor
- Wiring issues such as shorts or opens in the circuit
- Corroded connectors or loose connections
- ECM software issue or damage
Typical repair cost
$$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
Yes, but only for a short distance. Monitor the exhaust system closely, as overheating can lead to more severe damage.
Will this code come back after clearing it?
It may come back if the underlying issue is not resolved, such as a faulty sensor or wiring problem.
Why do I see this code paired with other fault codes?
Related codes often indicate simultaneous issues in the exhaust system or sensor circuits, commonly influenced by similar faults.
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