Generic fault code
P0073 — Ambient air temperature sensor, circuit A: signal high
The control unit stores code P0073 when it detects this fault: “Ambient air temperature sensor, circuit A: signal high”.
Indicative severity: LowFuel and air metering
Reviewed by Daniel Morales, founder of Reprorace SL, on
What does code P0073 mean?
The engine measures the incoming air and meters the fuel so the mixture is right; the throttle, the accelerator pedal and the turbo are here too. A fault usually shows as higher fuel use, jerking, lack of power or hard starting.
- System
- P · Powertrain
- Area
- Fuel and air metering · Car system: Fuel and air
- Type
- Generic (SAE J2012 / ISO 15031-6): the same meaning on every make
- Indicative severity
- Low. Check at the next service; usually does not affect safety or driveability.
What usually causes code P0073?
- Open circuit (broken wire or terminal)
The most likely causes come first. Only a check on the car confirms which one is yours.
What are the symptoms of code P0073?
- Often nothing you notice while driving
- The control unit uses a substitute value: slightly higher fuel use or worse starting
- On diesels, particulate filter regenerations that do not finish
These are the usual symptoms of this kind of fault: not all of them always appear, and sometimes you notice nothing.
Can I keep driving with code P0073?
Usually yes, with care. This kind of fault does not usually affect safety or how the car drives, but have it checked at the next service. If you notice anything different (jerking, noises, smells, smoke or a red warning light), stop somewhere safe and get advice.
This is guidance only: only someone who checks the car can say whether it is safe to drive.
An indicative description of the code's generic meaning. Each manufacturer may give it a different meaning, conditions or tests: always follow its service information and your workshop's advice.
What you can do yourself
For this kind of fault
It is usually a fault of the sensor or its wiring, not a real temperature. Check that its connector is pushed home; if the code comes back after clearing it, the workshop will measure the circuit.
Read the code and keep the report: with an ECO-LITE in the OBD socket you see it on your phone or computer, with the data captured when the fault happened.
Look for anything obvious: a loose connector, a disconnected hose, a fuel cap not closed properly or a low fluid level. Do not take apart anything you do not know.
Clear the code only after writing it down or after the repair. Clearing turns the light off, but it also deletes the freeze-frame data and the readiness monitors used at the inspection.
Drive normally for a few days and read the codes again. If the code comes back, the fault is still there: book the workshop and bring the report.
Read your car's fault codes on your phone
With an ECO-LITE in the OBD socket you see the codes in your account, with the data captured when the fault happened, and your workshop can check them remotely, always with your permission.
Related codes
- P0070Ambient air temperature sensor, circuit A: malfunction
- P0071Ambient air temperature sensor, circuit A: range/performance
- P0072Ambient air temperature sensor, circuit A: signal low
- P0074Ambient air temperature sensor, circuit A: intermittent/erratic
- P050ECold start engine exhaust temperature: too low
- P0514Battery temperature sensor, circuit: range/performance
P00xx codes: fuel and air metering and auxiliary emission controls
In the glossary
Read more: Remote OBD diagnostics: what it is, how it works and what it can't do