P0545 code meaning
Exhaust Gas Temperature Sensor Circuit Low Bank 1 Sensor 1
Powertrain system Generic code P05xx codes Check engine light
What P0545 means
The exhaust gas temperature sensor is a thermistor in a voltage divider with the module's pull-up resistor; the first one (sensor 1) sits before the turbocharger, the oxidation catalyst or after it depending on the maker. Diesels use it for particulate filter regeneration and component protection; CARB names it explicitly as a monitored input. P0545 means the signal is below range: GM L5P below 142 Ω in 10 of 20 samples, GM LML below 0.65 V, Ford 6.7 L below 0.10 V for about 2 s, Saab 9-5 2.0 TiD below 0.1 V for 1 s. Usually a signal shorted to ground. GM USA uses two trips, GM Europe in the Saab one. The module uses a substitute value and blocks filter regeneration.
P0545 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyMedium, DIY possible
- Typical labor0.5 to 1.5 hours
- Clears after repairAfter a drive cycle
Symptoms of P0545
- Check engine light on
- Particulate filter regeneration missing, filter warning
- Possible power reduction
Common causes of P0545
- Most likelySignal line shorted to ground (chafed on the exhaust or bracket)
- PossibleSensor shorted internally
- PossibleConnector damp or corroded
- Less likelyEngine module
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Exhaust gas temperature sensorSensor wiringEngine control module
What each part of P0545 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 5 | Area: vehicle speed, idle control and auxiliary inputs. |
| 45 | The exact fault in that area. |
What to do next
- Note P0545 and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P0545
What does P0545 mean?
P0545 means "Exhaust Gas Temperature Sensor Circuit Low Bank 1 Sensor 1". The exhaust gas temperature sensor is a thermistor in a voltage divider with the module's pull-up resistor; the first one (sensor 1) sits before the turbocharger, the oxidation catalyst or after it depending on the maker. It is a generic code, so it means the same on every make.
Is it safe to drive with P0545?
Drive gently and only to a workshop. With P0545 the car can go into limp mode (reduced power) to protect itself.
Will P0545 fail an emissions test?
Yes, it can. P0545 is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P0545 to fix?
Difficulty: medium. A typical repair takes 0.5 to 1.5 hours of work. A careful DIY repair is possible with basic tools and a scanner.
Will P0545 clear itself after the repair?
After the repair the car has to complete a drive cycle (a mix of city and highway driving) before the test runs again. Until then the readiness monitor shows "not ready", which can fail an inspection.