Exhaust Gas Temperature Sensor 1 Circuit Malfunction (Bank 1)
There’s a problem with the exhaust gas temperature sensor circuit on bank 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 exhaust gas temperature sensor measures how hot the gases are coming out of the engine. If it's not working right, the engine can't adjust properly, which can waste fuel or harm components connected to the exhaust system.
What the computer is actually seeing
The engine control module (ECM) monitors the voltage signal from the exhaust gas temperature sensor. A valid signal should range from 0.5V to 4.5V depending on temperature; if the signal is outside this range or the sensor is shorted or open, the code will trigger.
What a healthy reading looks like
Expect a voltage between 0.5V to 4.5V from the exhaust gas temperature sensor during normal 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.
- 1Check the wiring and connectors for any visible damage or corrosion. Repair as needed.
- 2Verify the exhaust gas temperature sensor's resistance with a multimeter. It should be within manufacturer specifications; if it's open or shorted, replace the sensor.
- 3Check the voltage at the connector of the sensor with the ignition on and engine off; it should show a voltage in range (0.5V to 4.5V). If not, check back to the ECM for issues.
- 4If the sensor is functioning correctly, check for exhaust leaks around the sensor; they can provide false readings.
Common causes
- Wiring harness damage or short to ground
- Faulty exhaust gas temperature sensor
- Poor connector connection
- Corroded terminals
- Exhaust leak near the sensor
Typical repair cost
$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
It’s moderate severity, so you can drive it, but fixing soon is advised to prevent further damage to the exhaust system.
Will this code come back after resetting?
If the issue isn't fixed, yes, it will likely return after a few driving cycles.
Why does this code sometimes pair with P0548?
P0548 is similar and indicates a similar issue but for a different circuit; it often happens when there's a common wiring issue.
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