Exhaust Gas Temperature Sensor Circuit Low Bank 1 Sensor 1
What it means
P0545 means the ECM sees an abnormally low voltage from the bank 1, sensor 1 exhaust gas temperature (EGT) sensor circuit — typically a short to ground, an open circuit, or a failing sensor. The EGT sensor protects the catalytic converter and, on diesels, manages particulate-filter regeneration, so some vehicles reduce power when it fails. The usual causes are the sensor itself or its wiring.
Can I keep driving? Usually drivable, but some vehicles reduce power to protect the exhaust when this sensor fails. On diesels it can affect particulate-filter regeneration — have it checked.
Common symptoms
What you'll notice
- Check-engine light on
- Reduced power on vehicles that derate to protect the exhaust
- Slightly reduced fuel economy
- On diesels, disrupted DPF regeneration
Common causes
Most likely first
- Failed exhaust gas temperature (EGT) sensorLikely
- Short to ground in the sensor circuit (low voltage)Common
- Open circuit or high resistance in the wiringCommon
- Corroded or loose connector at the sensorLess often
- ECM/PCM fault (rare)Less often
How to diagnose & fix
Work through it in order
- Read freeze-frame data and confirm the code with a scan tool.
- Inspect the EGT sensor connector and wiring for a short to ground or open.
- Compare the sensor's resistance/voltage against spec at a known temperature.
- Check the sensor is properly seated in the exhaust.
- Replace the EGT sensor if it reads out of range. Clear and re-test.
FAQ
Quick answers
Is it safe to drive with P0545?+
Can I just clear P0545?+
Related codes
Often seen with P0545
Read & clear P0545 yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.