P0548 code meaning
Exhaust Gas Temperature Sensor Circuit Low Bank 2 Sensor 1
Powertrain system Generic code P05xx codes Check engine light
What P0548 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. Bank 2 sensor 1 exists only on V engines with a separate exhaust path per cylinder bank. No manufacturer document available to us uses this code; the thresholds known for bank 1 apply by analogy. P0548 means the signal is below range, usually a short to ground – for bank 1 GM uses below 142 Ω, Ford below 0.10 V.
P0548 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyMedium, DIY possible
- Typical labor0.5 to 2 hours
- Clears after repairAfter a drive cycle
Symptoms of P0548
- Check engine light on
- Particulate filter regeneration missing, filter warning
- Possible power reduction
Common causes of P0548
- Most likelySignal line shorted to ground
- 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 P0548 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. |
| 48 | The exact fault in that area. |
What to do next
- Note P0548 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 P0548
What does P0548 mean?
P0548 means "Exhaust Gas Temperature Sensor Circuit Low Bank 2 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 P0548?
Drive gently and only to a workshop. With P0548 the car can go into limp mode (reduced power) to protect itself.
Will P0548 fail an emissions test?
Yes, it can. P0548 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 P0548 to fix?
Difficulty: medium. A typical repair takes 0.5 to 2 hours of work. A careful DIY repair is possible with basic tools and a scanner.
Will P0548 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.