P0073: Ambient Air Temperature Sensor Circuit High
Key takeaways
- P0073 means the outside air temperature sensor's signal is above its normal range, which usually means an open circuit, and the reading drops to something like -40°F or disappears.
- The sensor sits low at the front of the car, behind the grille or bumper, where water, salt and minor impacts get to its connector.
- It's safe to drive; you may lose the outside temperature display and automatic climate control can behave oddly.
- Check the connector before buying a sensor: several Stellantis bulletins start with reseating or resealing the front-end connector.
- 54 manufacturer bulletins name P0073, 48 of them from Chrysler, Ram, Jeep, Alfa Romeo and Dodge.
What P0073 means
The sensor that measures outside air temperature is sending a signal the computer reads as open, so it has stopped trusting it. Scanners call it Ambient Air Temperature Sensor Circuit High. The ambient sensor is a thermistor, usually clipped behind the front grille or lower bumper. Its resistance rises as the air gets colder, pushing the signal voltage up. When the voltage sits at the top of its range, as it does when a wire or connector is open, the computer sets P0073. The dash usually shows -40°F or dashes instead of the outside temperature.
Besides the dash display, the reading feeds automatic climate control and, on many cars, the engine computer, which uses outside temperature to decide when to run some emissions self-tests. That’s why a sensor this simple can turn on the check engine light.
Is it safe to drive?
Yes. The engine doesn’t need this sensor to run safely. You may lose the outside temperature display, and automatic climate control may pick the wrong fan speed or blend; on some cars the A/C won’t run because the computer thinks it’s freezing outside. The one thing that changes the answer: if P0073 came right after a front-end hit, get the car checked for damage to the radiator, fans and other parts behind the bumper, not just the sensor.
Causes, ranked
| Cause | How you confirm it | Typical cost (US independent shop, 2026) |
|---|---|---|
| Connector loose, wet or corroded | Water or green corrosion in the plug; code clears after cleaning and reseating | $0 to reseat; $100–$250 for a connector repair |
| Sensor failed open | Resistance infinite or far out of spec; jumping the connector makes the reading jump to very hot | $50–$200 |
| Wire broken or pinched near the bumper | Recent bumper, grille or accessory work; no continuity back toward the module | $100–$250 |
| Module software | Bulletin for your model calls for a reflash | $100–$200, often $0 under a bulletin |
What to check first
- Read the outside temperature on the dash or in live data. A steady -40°F or no reading points to an open circuit, not a slightly-off sensor.
- Find the sensor and check the connector. Look for water, corrosion, a broken lock tab or a connector knocked loose. Clean, reseat and clear the code.
- Think about recent work. Bumper or grille repairs, light bars, plows and other front-end accessories often pinch or cut this wire.
- Test before you buy. Jumping the connector should make the reading swing to very hot; if it does, the wiring is fine and the sensor is open. If not, trace the wire.
- Clear it and drive. After any connector or sensor fix, clear the code and drive a few days to confirm it stays off.
The bulletins point at the front end more than the sensor. Stellantis notices for Chrysler, Dodge, Jeep and Ram models tell technicians to disconnect and reconnect the sensor and road-test before ordering a new one, and several trace P0073 to water and corrosion in a front-fascia connector, sometimes with an active grille shutter code alongside. Ford bulletins cover F-Super Duty diagnosis steps, 2014–2016 Transit Connect 2.5L A/C problems, and Police Interceptor wiring disturbed during accessory installs.
What it costs
The cheap outcome is free: a connector you clean and reseat yourself. The common outcome is a new sensor at $50–$200 installed, or a connector or wire repair at $100–$250. That’s about as expensive as P0073 gets unless there’s other front-end damage. A quick connector check during a $100–$180 diagnosis saves ordering a sensor you didn’t need.
Related codes
P0073 has close cousins on the same sensor: P0070 (range or performance) and P0072 (circuit low, reads too hot). An intake air temperature code like P0113 is the same kind of open-circuit fault on a different sensor, under the hood. For what else the light might be telling you, see check engine light on.
What owners report to NHTSA
3 complaints filed with NHTSA mention P0073, 3 of them since 2015, across 3 different models. The component owners most often filed it under: air bags.
Manufacturer service bulletins that name P0073
54 technical service bulletins and manufacturer communications filed with NHTSA mention P0073, from 6 makes. A bulletin means the manufacturer has documented a known cause or a fix procedure for that model. Examples:
- CHRYSLER PACIFICA (2023, 2024), bulletin 10247408: Ambient Air Temperature Sensor 2023-24MY RU Ambient Air Temperature Sensor not reading temp correctly or setting DTC P0073, P0070-15. Before ordering a new sensor, make sure to disconnect and connect sensor and drive veh…
- FORD F-250 SD (2023), bulletin 10233841: Some 2021-2022 F-Super Duty vehicles may exhibit an illuminated malfunction indicator lamp (MIL) with diagnostic trouble code (DTC) P0073 for the ambient air temperature sensor stored in the powertrain control (PCM). Whe…
- CHRYSLER 300 (2022, 2023, 2020, 2021), bulletin 10236878: Malfunction Indicator Lamp Illuminated. U11E9 Lost Communication With AGS. Ambient Air Temp Incorrectly Displayed. P0070 And P0073 Set For Ambient Air Temp Sensor
- DODGE CHALLENGER (2023, 2022), bulletin 10236878: Malfunction Indicator Lamp Illuminated. U11E9 Lost Communication With AGS. Ambient Air Temp Incorrectly Displayed. P0070 And P0073 Set For Ambient Air Temp Sensor
- JEEP GRAND CHEROKEE (2023, 2022), bulletin 10236873: Ambient Air Temperature Missing, Malfunction Indicator Lamp (MIL) Lamp On, Diagnostic Trouble Code (DTC) P0070-15 Ambient Air Temperature Sensor Circuit-Circuit Short to Battery or Open, P0073 Ambient Air Temperature Sen…
- RAM 1500 (2016, 2017, 2018, 2019), bulletin 10236873: Ambient Air Temperature Missing, Malfunction Indicator Lamp (MIL) Lamp On, Diagnostic Trouble Code (DTC) P0070-15 Ambient Air Temperature Sensor Circuit-Circuit Short to Battery or Open, P0073 Ambient Air Temperature Sen…
Sources: NHTSA Office of Defects Investigation complaint database and manufacturer communications file, snapshots September 2026. A complaint or bulletin that mentions a code is a report about that vehicle, not a statement that the code has one cause.
Frequently asked questions
Can I drive with a P0073 code?
Yes. The engine doesn't need the outside air sensor to run safely. You may lose the outside temperature display, and the automatic climate control may run the wrong fan speed or temperature. Get it fixed so the check engine light can warn you about something else.
Why does my outside temperature read -40°F?
That's what most cars show when the ambient sensor circuit is open, which is exactly what P0073 describes. The computer sees the highest possible signal voltage and translates it to the coldest temperature on its scale.
Where is the ambient air temperature sensor?
On most cars it's a small sensor clipped behind the front grille or lower bumper, often near the hood latch or a tow hook. That spot keeps it out of engine heat but exposes the connector to water, road salt and parking bumps.
Can I fix P0073 myself?
Often. Unplug the sensor, look for corrosion or water, clean and reseat the connector, and clear the code. If it comes back, a replacement sensor usually unclips by hand on many cars, though some need the grille or bumper cover loosened.