P0073: Outside (ambient) air temperature sensor circuit signal too high

Ambient air temperature sensor circuit high input

Severity: Monitor

Kelley Blue Book calls it one of the least serious codes and says most vehicles stay drivable with it, though automatic climate control and the temperature display can misbehave.

It gets more serious if:

Inspect soon: Get it checked soon if the A/C stops working or the check engine light stays on with other codes stored. Ford bulletin 16-0054 describes an A/C that can shut off when the computer thinks it is freezing outside.

Source: how we rate severity

P0073 in short

P0073 means the computer sees the outside air temperature sensor sending a signal that is higher than it should be, so the circuit is shorted to power or open. A loose or corroded connector, damaged wiring or a failed sensor is typical. It mostly affects the temperature display and climate control, and the car is usually safe to drive.

The ambient air temperature sensor sits near the front of the vehicle and sends a voltage the computer converts to outside temperature. P0073 sets when that signal is above the normal range, which usually means the circuit is open or shorted to power.

Ford and Chrysler bulletins show how that happens on real vehicles: a front connector left disconnected after bumper work on Police Explorers, a corroded connector at the front fascia on a Pacifica, and a loose connector. Ford also says the A/C can shut off if the computer reads below 30 F while it is actually warmer.

TroubleCodes.net and Kelley Blue Book add a failed sensor and damaged wiring, and rarely a control module. Chrysler also lists P0073 among many codes in a 2014 Grand Cherokee reflash bulletin, so a dealer should check for software.

Most likely causes

Cause 1: Disconnected, loose or corroded connector at the front end
Supported by vehicle data
Why it ranks here
Ford SSM 46338 and 47529 say to check connector C134 first on Police Utility Explorers, and Chrysler 9004290 repairs a corroded XY101 front fascia connector for P0073. Unverified bulletin summaries.
What would change this
Rises if the front bumper or grille was worked on recently or the connector is loose or green. Falls if the connector is clean, tight and dry.
Cause 2: Damaged wiring, or a short to power
Common general cause
Why it ranks here
TroubleCodes.net lists a wiring short to positive voltage and a damaged harness; Kelley Blue Book lists faulty wiring connections.
What would change this
Rises if the harness is chafed or pinched near the bumper. Falls if the circuit tests good.
Cause 3: Failed or damaged ambient temperature sensor
Common general cause
Why it ranks here
Both references list the sensor. Its exposed front position makes damage and corrosion likely, and TroubleCodes.net notes collision and road debris damage.
What would change this
Rises if a scan tool shows an extreme or frozen reading. Falls if a good sensor on the same wiring shows the same code.
Cause 4: Powertrain computer software (2014 Grand Cherokee)
Supported by vehicle data
Why it ranks here
Chrysler 18-018-14 reprograms the powertrain computer and lists P0073 among its codes. The summary does not say why the computer sets it.
What would change this
Rises on a 2014 Grand Cherokee with several of the listed codes. Falls on other vehicles.
How to test the engine control module (ecm / pcm)
Cause 5: Engine computer
Possible — needs testing
Why it ranks here
TroubleCodes.net and Kelley Blue Book list a module fault, but rarely, and only after wiring and sensor are cleared. A Fusion Hybrid owner reports the sensor was replaced without resolving the larger problem.
What would change this
Rises only if new sensor and good wiring still give the code. Falls if any other cause is found.
How to test the engine control module (ecm / pcm)

What to test first

Start at step 1. Each result tells you what it means and where to go next.

Step 1: Read all stored codes. Note whether P0070 or P0074 (same sensor circuit) or a lost-communication code is stored with P0073.
Low riskTool: OBD-II scan tool
- IfP0070 or P0074 is stored too
  It meansThe fault is in the sensor circuit; check the front connector first.
  Go to step 2
- IfP0073 is stored with many unrelated codes on a 2014 Grand Cherokee
  It meansAsk about the powertrain computer reflash.
  Points to: Powertrain computer software (2014 Grand Cherokee)
- IfP0073 is alone
  It meansInspect the connector and sensor.
  Go to step 2
Step 2: With the engine off, look at the ambient temperature sensor behind the bumper or grille and its connector for a disconnected plug, corrosion, water or damage, especially if the bumper was recently removed.
Low risk
- IfThe connector is disconnected, loose or corroded
  It meansReconnect or repair it and clear the code.
  Points to: Disconnected, loose or corroded connector at the front end
- IfThe sensor or wiring is damaged
  It meansRepair or replace it.
  Points to: Failed or damaged ambient temperature sensor
- IfEverything looks fine
  It meansHave the circuit tested.
  Go to step 3
Step 3: Have the sensor and its circuit tested for resistance, shorts to power and good ground with a multimeter.
Use cautionTool: multimeter, scan tool
Warning:The sensor is at the front of the engine bay, near fans that can start without warning. Probing the wrong pin can damage the control module.
- IfThe sensor resistance is out of range or the reading is stuck
  It meansReplace the sensor.
  Points to: Failed or damaged ambient temperature sensor
- IfThe circuit has a short to power or an open
  It meansRepair the wiring.
  Points to: Damaged wiring, or a short to power
- IfSensor and wiring both test good
  It meansThe module is suspect.
  Points to: Engine computer

Symptoms

Wrong or missing outside temperature on the dash
Automatic climate control or A/C not working as expected
Check engine light, sometimes with no other change

How to fix

Step 1: With the engine off, check that the ambient temperature sensor connector behind the front bumper is fully seated, clean and dry.

On your vehicle

Ford

2014–2016 · Transit Connect
Supported by vehicle data
Ford bulletin 16-0054 covers an inaccurate ambient temperature display and an inoperative A/C with P0073 on 2014-2016 Transit Connect 2.5L. Whether it is still current is not verified.
2016–2017 · Explorer
Supported by vehicle data
Ford SSM 46338 says to check connector C134 first when P0073 sets on 2016-2017 Explorer Police Utility vehicles after bumper work. Whether it is still current is not verified.

16-0054Status unverified
2.5L A/C inoperative or ambient display inaccurate, P0073
2014–2016transit-connect · issued June 22, 2016 · NHTSA 10075284
Intermittent inaccurate ambient temperature display and/or inoperative A/C on the Transit Connect 2.5L, with P0073, P0074 and/or U0422.
We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.
SSM 46338Status unverified
Explorer Police Utility MIL with P0073 (connector C134)
2016–2017explorer · issued March 15, 2017 · NHTSA 10095208
Check wiring connector C134 first; it may have been left disconnected after front bumper cover work.
We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.
SSM 47529Status unverified
Police Interceptor Utility P0073 (connector C134)
2016–2019explorer · issued December 3, 2018 · NHTSA 10149766
Same C134 connector check for 2016-2019 Police Interceptor Utility vehicles.
We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.

Chrysler

2020 · Pacifica
Supported by vehicle data
Chrysler 9004290 repairs the corroded XY101 front fascia connector for P0073 on the 2020 Pacifica. Whether it is still current is not verified.

9004290Status unverified
Front fascia wiring for U11E9 and/or P0073 (XY101 connector)
2020pacifica · issued September 28, 2020 · NHTSA 10180176
Repair a corroded or wet XY101 connector with a repair kit, or replace the harness if more corrosion is found.
We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.

All Body electrical codes

P0073 questions

Can I drive with P0073?

Usually. Kelley Blue Book calls it one of the least serious codes, but the A/C or climate control may misbehave.

Why did my A/C stop working with P0073?

Ford bulletin 16-0054 says some Transit Connects shut the A/C off when the ambient reading wrongly falls below 30 F.

Sources and review

P0073 OBD-II code page — Kelley Blue Book (Cox Automotive)
P0073 trouble code page — TroubleCodes.net
Ford 16-0054: 2.5L A/C inoperative and/or ambient temperature display inaccurate, P0073, P0074, U0422 — Ford (filed with NHTSA)
Ford SSM 46338: Explorer Police Utility MIL with ambient air temperature sensor DTC P0073 — Ford (filed with NHTSA)
Ford SSM 47529: Police Interceptor Utility ambient air temperature sensor DTC P0073 — Ford (filed with NHTSA)
Chrysler (FCA US) 9004290: Front fascia wiring for U11E9 and/or P0073 — Chrysler (FCA US) (filed with NHTSA)
Chrysler (FCA US) 18-018-14: MIL illumination, diagnostic and system improvements (PCM flash) — Chrysler (FCA US) (filed with NHTSA)
NHTSA complaint 11752200: 2019 Ford Fusion Hybrid — NHTSA Office of Defects Investigation
Chrysler (FCA US) S2208000080: Ambient air temperature missing, MIL on, P0070-15 and P0073 — Chrysler (FCA US) (filed with NHTSA)

Last reviewed: October 16, 2026
Written by: Saurabh K.
Editorial review: Pending
Technician review: Technician review pending

This page explains what a code usually means; it is not a substitute for a professional inspection. How we source and review · Report an error

Severity: Monitor

Most likely causes

Cause 1: Disconnected, loose or corroded connector at the front end

Cause 2: Damaged wiring, or a short to power

Cause 3: Failed or damaged ambient temperature sensor

Cause 4: Powertrain computer software (2014 Grand Cherokee)

Cause 5: Engine computer

What to test first

Step 1: Read all stored codes. Note whether P0070 or P0074 (same sensor circuit) or a lost-communication code is stored with P0073.

Step 2: With the engine off, look at the ambient temperature sensor behind the bumper or grille and its connector for a disconnected plug, corrosion, water or damage, especially if the bumper was recently removed.

Step 3: Have the sensor and its circuit tested for resistance, shorts to power and good ground with a multimeter.