P0073 - Understanding DTC P0073: Common Issues in 2013-2018 Ford Focus and Other Models

Quick Answer

P0073 means: P0073 indicates an issue with the ambient air temperature sensor circuit.

Fix: Check and replace faulty components Cost: $75 - $150 Time: 90-180 minutes

Can I drive with P0073? Immediate diagnosis and repair are recommended to avoid performance issues.

Common Questions

What does P0073 mean and how does it affect my car?

The P0073 code indicates an issue with the ambient air temperature sensor circuit, which can lead to reduced engine efficiency and performance. If not addressed, it could cause your vehicle to run poorly in varying weather conditions.

What are the most common causes of P0073 and how much does it cost to fix?

Common causes of P0073 include a faulty ambient air temperature sensor, wiring issues, and, in rare cases, ECM failures. Repair costs typically range from $75 for sensor replacement to potentially $1,000 for ECM issues, depending on the specific problem.

Can I drive my car with P0073 or should I stop immediately?

While it's possible to drive with P0073, it's not advisable, especially if you're experiencing symptoms like stalling or decreased fuel efficiency. It's best to have it diagnosed and repaired as soon as possible.

How can I diagnose P0073 myself using GeekOBD APP?

Using the GeekOBD APP, you can scan for DTCs, view live data from the ambient air temperature sensor, and perform a freeze frame analysis to understand the conditions under which the code was triggered.

What vehicles are most commonly affected by P0073?

P0073 is commonly reported in 2013-2018 Ford Focus models, 2010-2015 Toyota Prius, and 2012-2016 Honda Civic. Check for any recalls or technical service bulletins related to your vehicle.

How can I prevent P0073 from happening again?

Regular vehicle maintenance, including checking the ambient air temperature sensor and its wiring during service intervals, can help prevent issues. Keeping the sensor clean and free from debris is also important.

What is P0073?

The diagnostic trouble code (DTC) P0073 refers to a problem with the ambient air temperature sensor circuit. This code indicates that the Engine Control Module (ECM) has detected an abnormal voltage signal from the ambient air temperature sensor, typically located near the front grille or under the hood. The ambient air temperature sensor is crucial as it informs the ECM about the outside temperature, which plays a significant role in optimizing engine performance and fuel efficiency. When the P0073 code is triggered, it may lead to poor fuel economy, increased emissions, and a decrease in engine performance. Drivers may experience issues such as rough idling, stalling, or a reduced ability to accelerate. Ignoring this code can lead to more severe problems down the line, particularly affecting the vehicle's performance in various weather conditions. For instance, the code is often seen in vehicles like the 2013-2018 Ford Focus, 2010-2015 Toyota Prius, and 2012-2016 Honda Civic. Immediate attention is recommended to prevent further complications.

System: P - Powertrain (Engine, Transmission, Emissions)

Symptoms

Common symptoms when P0073 is present:

  • Check engine light stays on constantly, indicating the ECM has detected a persistent fault in the ambient air temperature sensor.
  • Engine hesitates during acceleration, which can be particularly noticeable when the temperature outside is significantly different from the vehicle's operating temperature.
  • Fuel economy decreases by 10-15%, as the engine control module struggles to adjust fuel delivery based on incorrect temperature readings.
  • Inconsistent engine performance, where the engine may stall unexpectedly or run roughly when the ambient temperature varies.
  • Increased emissions, as a faulty ambient air temperature sensor can lead to incorrect air-fuel mixture adjustments.

Possible Causes

Most common causes of P0073 (ordered by frequency):

  1. Faulty ambient air temperature sensor (70% likelihood) - Over time, these sensors can fail due to exposure to extreme temperatures and weather conditions, leading to inaccurate readings.
  2. Wiring issues (15% likelihood) - Damaged or corroded wiring can disrupt the signal sent from the sensor to the ECM, causing the P0073 code to trigger.
  3. ECM failure (10% likelihood) - Although rare, a malfunctioning ECM may misinterpret signals from the temperature sensor, leading to erroneous fault codes.
  4. Poor connections (3% likelihood) - Loose or corroded connectors can create intermittent faults that may lead to the P0073 code.
  5. Environmental factors (2% likelihood) - Extreme weather conditions or debris affecting sensor placement can cause temporary issues with sensor accuracy.

P0073 Repair Costs

Cost Breakdown by Repair Type

Sensor Replacement

Replacing the faulty ambient air temperature sensor is the most common repair method.

  • Total: $75 - $150
  • Success rate: 90%
Wiring Repair

Repairing or replacing damaged wiring and connectors.

  • Total: $50 - $100
  • Success rate: 85%
ECM Reprogramming

In rare cases, the ECM may require reprogramming or replacement.

  • Total: $200 - $1,000
  • Success rate: 75%
Money-Saving Tips for P0073
  • Start with the most common and least expensive repairs first
  • Use GeekOBD APP to confirm diagnosis before replacing expensive parts
  • Consider preventive maintenance to avoid future occurrences
  • Compare prices for OEM vs aftermarket parts based on your needs
  • Address the issue promptly to prevent more expensive secondary damage

Diagnostic Steps

Professional P0073 Diagnosis Process

Follow these systematic steps to accurately diagnose P0073. Each step builds on the previous one to ensure accurate diagnosis.

Step 1: Step 1: Initial visual inspection - Check for obvious signs like damaged wiring, loose connections, or corrosion (5-10 minutes)

Step 1: Initial visual inspection - Check for obvious signs like damaged wiring, loose connections, or corrosion (5-10 minutes).

GeekOBD APP Tip: Use GeekOBD APP to monitor real-time data during this diagnostic step for accurate results and professional-grade analysis.
Step 2: Step 2: OBD2 scan with GeekOBD APP - Retrieve all codes and freeze frame data to understand the fault context (10-15 minutes)

Step 2: OBD2 scan with GeekOBD APP - Retrieve all codes and freeze frame data to understand the fault context (10-15 minutes).

GeekOBD APP Tip: Use GeekOBD APP to monitor real-time data during this diagnostic step for accurate results and professional-grade analysis.
Step 3: Step 3: Component testing - Use a multimeter or specific diagnostic tools to test the ambient air temperature sensor and its wiring (20-30 minutes)

Step 3: Component testing - Use a multimeter or specific diagnostic tools to test the ambient air temperature sensor and its wiring (20-30 minutes).

GeekOBD APP Tip: Use GeekOBD APP to monitor real-time data during this diagnostic step for accurate results and professional-grade analysis.
Step 4: Step 4: System function test - Verify proper operation after repairs and clear codes using the GeekOBD APP (10-15 minutes)

Step 4: System function test - Verify proper operation after repairs and clear codes using the GeekOBD APP (10-15 minutes).

GeekOBD APP Tip: Use GeekOBD APP to monitor real-time data during this diagnostic step for accurate results and professional-grade analysis.
Step 5: Step 5: Road test verification - Drive the vehicle under various conditions to confirm repair success and ensure the check engine light does not reappear (15-20 minutes)

Step 5: Road test verification - Drive the vehicle under various conditions to confirm repair success and ensure the check engine light does not reappear (15-20 minutes).

GeekOBD APP Tip: Use GeekOBD APP to monitor real-time data during this diagnostic step for accurate results and professional-grade analysis.

Important Notes

  • Always verify the repair with GeekOBD APP after completing diagnostic steps
  • Clear codes and test drive to ensure the problem is resolved
  • Address underlying causes to prevent code recurrence

Real Repair Case Studies

Case Study 1: Ambient Air Temperature Sensor Replacement on 2015 Ford Focus

Vehicle: 2015 Ford Focus, 45,000 miles

Problem: Customer reported the check engine light was on and experienced poor fuel economy.

Diagnosis: Using the GeekOBD APP, we retrieved the P0073 code and confirmed the ambient air temperature sensor was malfunctioning.

Solution: Replaced the ambient air temperature sensor and cleared the code.

Cost: $100 (sensor cost: $75, labor: $25)

Result: The check engine light was cleared, and the customer reported improved fuel efficiency.

Case Study 2: Wiring Repair on 2014 Honda Civic

Vehicle: 2014 Honda Civic, 60,000 miles

Problem: Check engine light was illuminated, and the engine was stalling at idle.

Diagnosis: After running diagnostics with the GeekOBD APP, found P0073 due to damaged wiring.

Solution: Repaired the wiring harness leading to the ambient air temperature sensor.

Cost: $80 (labor: $80)

Result: The vehicle ran smoothly post-repair, and the check engine light did not return.

Diagnose P0073

Use GeekOBD APP for professional diagnosis!

  • Real-time data monitoring
  • Advanced diagnostic features
  • Step-by-step repair guidance
  • Professional-grade analysis
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Code Information

Code: P0073
System: Powertrain (Engine, Transmission, Emissions)
Severity: HIGH
Category: Engine Codes