P0073 — Outside Air Temperature Sensor – High Input #

Note: The title and wording of this code may vary depending on the vehicle manufacturer.

• Ford: Ambient Air Temperature Sensor Circuit High Input
• GM (Chevrolet/Buick/GMC): Ambient Air Temperature Sensor Circuit High Voltage
• Toyota: Outside Air Temperature Sensor Circuit High Input
• Hyundai/Kia: Ambient Temperature Sensor Circuit High
• BMW: Outside Temperature Sensor, Input Too High

Summary of DTC P0073 #

The P0073 diagnostic trouble code (DTC) relates to the outside air temperature sensor—a component that measures the temperature outside your vehicle and informs systems like climate control and engine management. Specifically, this code signals a “high input” condition, meaning the sensor or its circuit is reading a voltage higher than what the ECM (Engine Control Module) expects. This typically points to an open circuit or a wiring problem, rather than a mechanical fault. Depending on your vehicle, the check engine light may illuminate, and you might notice inaccuracies in outside temperature readings. While this code is not typically linked to hazardous driving conditions, it can affect comfort and, in rare cases, engine performance.

Common Symptoms for DTC P0073 #

While the P0073 code is not usually associated with severe drivability issues, it can cause some inconvenience or minor operational quirks. Most notably, drivers might notice the following:

• Check Engine Light (CEL) illuminated
• Outside temperature display stuck at an abnormally high value (often 140°F/60°C or higher)
• Automatic climate control not functioning correctly (e.g., blowing full cold air regardless of setting)
• Delayed or incorrect operation of heated/cooled seats in some vehicles
• Remote start or auto-defrost features may not operate as intended

Most Likely Causes for DTC P0073 #

The most common root causes for a P0073 code involve electrical faults, often with the sensor’s wiring or the sensor itself. Here are the most frequent culprits, in order of likelihood:

1. Open circuit or broken wire in the outside air temperature sensor circuit
2. Faulty or disconnected outside air temperature sensor
3. Corroded or loose connector at the sensor or harness
4. Short to power (12V supply) in the sensor wiring
5. ECM (Engine Control Module) internal fault (rare)

Step-by-Step Diagnostic for DTC P0073 #

Correctly diagnosing a P0073 code requires methodical testing to distinguish between a component failure and a wiring or connector issue. Here’s a recommended diagnostic approach:

• Step 1: Verify the presence of P0073 with a scan tool and check for other related codes.
• Step 2: Locate the outside air temperature sensor (often in the front grille, behind the bumper, or near the radiator support).
• Step 3: Inspect the sensor and its wiring for physical damage, corrosion, or disconnection.
• Step 4: Use a digital multimeter to check for proper voltage supply and ground at the sensor connector.
• Step 5: Measure sensor resistance (should vary with temperature, typically around 10kΩ at room temp); an infinite reading may indicate an open circuit.
• Step 6: If wiring and sensor check out, clear the code and test drive. If the code returns, consider ECM diagnostics or dealer-level scan tools for deeper analysis.

Possible Repairs for DTC P0073 #

Once the root cause has been identified, here are the most common repairs to resolve a P0073 code:

• Repair or replace damaged or open wiring in the temperature sensor circuit
• Replace the outside air temperature sensor if faulty or out-of-spec
• Clean or replace corroded connectors at the sensor or harness
• Repair shorts to power or ground in the circuit
• (Rare) Replace or reprogram the ECM/PCM if a confirmed internal fault is found

Is It Safe to Drive With Code P0073? #

Yes, you can usually drive with a P0073 code, as it does not directly affect engine safety or essential vehicle functions. However, be aware that your climate control system may not work properly, and other features relying on accurate outside temperature readings (like auto-defrost or remote start) may not function as intended. If you rely heavily on these features for comfort or safety, address the code promptly.

Vehicles Most Commonly Affected by DTC P0073 #

This code is generic and can appear on any OBD-II equipped vehicle, but it’s most commonly reported on certain models. Based on field experience and repair database trends, you’re most likely to find P0073 on:

• Ford F-150, Ford Escape, Ford Focus
• Chevrolet Silverado, Chevrolet Malibu
• Toyota Camry, Toyota RAV4
• Hyundai Sonata, Hyundai Elantra
• Kia Sorento, Kia Optima
• BMW 3 Series, BMW X5
• Volkswagen Jetta, Volkswagen Passat

Common Mistakes & Best Practices with P0073 #

Misdiagnosis is common with DTC P0073, especially when skipping basic visual inspections or misinterpreting scan tool data. Here’s how to avoid common pitfalls:

• Don’t replace the sensor before checking for damaged or disconnected wiring.
• Always verify proper voltage and ground at the sensor connector with a multimeter.
• Don’t overlook corrosion or water intrusion at connectors, especially after winter or car washes.
• After repairs, always clear codes and confirm the fix with a road test.
• Refer to the OEM wiring diagram for your specific vehicle before probing circuits.

Quick FAQ About P0073 #

Q: Can I just reset the code and be done?
A: Clearing the code without addressing the underlying issue will likely result in the code returning. Always investigate the cause before resetting.

Q: Will this code affect my emissions test?
A: While P0073 is not a direct emissions code, a persistent check engine light can cause your vehicle to fail readiness checks in many states or provinces. Fix the issue before your next test.