P078B - Transmission Range Sensor Performance Problem in Common Vehicles Like Ford and Chrysler

Quick Answer

P078B means: The P078B code signals an issue with the transmission range sensor's performance in your vehicle.

Fix: Check and replace faulty components Cost: $200 - $400 Time: 90-180 minutes

Can I drive with P078B? It's advisable to address this issue promptly to avoid further transmission damage.

Common Questions

What does P078B mean and how does it affect my car?

The P078B code indicates a problem with the transmission range sensor, which can lead to shifting issues and negatively impact your vehicle's performance. If not addressed, it could cause further transmission damage.

What are the most common causes of P078B and how much does it cost to fix?

The most common causes include a faulty transmission range sensor, wiring issues, and low transmission fluid. Repair costs for sensor replacement typically range from $200 to $400.

Can I drive my car with P078B or should I stop immediately?

It's advisable to stop driving your vehicle if you see the P078B code, as it can lead to significant transmission issues and safety hazards.

How can I diagnose P078B myself using GeekOBD APP?

You can use the GeekOBD APP to scan your vehicle for the P078B code, read freeze frame data, and monitor sensor performance to help pinpoint the issue.

What vehicles are most commonly affected by P078B?

Common vehicles affected include the 2015-2019 Ford Fusion and various models from Chrysler. Be sure to check for any recalls or Technical Service Bulletins (TSBs) related to your vehicle.

How can I prevent P078B from happening again?

Regular maintenance, including checking transmission fluid levels and ensuring wiring is intact, can help prevent future occurrences of the P078B code.

What is P078B?

The P078B diagnostic trouble code indicates a problem with the transmission range sensor, which plays a crucial role in the proper function of your vehicle's automatic transmission. This sensor helps the vehicle's computer determine the correct gear selection based on the position of the gear shift lever. When the sensor malfunctions or provides incorrect readings, it can lead to shifting issues, including erratic gear changes, difficulty in shifting, or even preventing the vehicle from starting. Commonly seen in vehicles like the 2015-2019 Ford Fusion and various Chrysler models, a P078B code can indicate a range of issues from a simple sensor malfunction to more complex wiring problems. If you ignore this code, it may lead to further transmission damage, resulting in more expensive repairs down the line. Therefore, understanding and addressing the P078B code quickly is essential for maintaining your vehicle's performance and reliability.

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

Symptoms

Common symptoms when P078B is present:

  • The check engine light illuminates and remains on, indicating a need for immediate diagnostics.
  • You may experience harsh or delayed shifting when accelerating, which can be frustrating and dangerous.
  • Fuel economy may drop noticeably, often by 10-15%, due to improper gear selection.
  • The vehicle may fail to start if the transmission range sensor is entirely faulty, leaving you stranded.
  • You might notice unusual engine revving or slipping while driving, which can be alarming.

Possible Causes

Most common causes of P078B (ordered by frequency):

  1. {'cause': 'Faulty Transmission Range Sensor', 'likelihood': '60%', 'details': 'The most common reason for a P078B code is a malfunctioning transmission range sensor itself, which can fail due to wear or damage.'}
  2. {'cause': 'Wiring Issues', 'details': 'Damaged or frayed wiring connected to the transmission range sensor can lead to incorrect readings and trigger the P078B code.'}
  3. {'cause': 'Transmission Fluid Problems', 'details': 'Low or contaminated transmission fluid can also lead to shifting issues and contribute to the P078B code. Regular maintenance and fluid checks can prevent this.'}
  4. {'cause': 'ECM Malfunction', 'details': 'In rare cases, a faulty Engine Control Module (ECM) can misinterpret sensor signals, triggering the P078B code.'}
  5. {'cause': 'Mechanical Issues', 'details': 'Less common issues like internal transmission problems can also cause this code, necessitating a more thorough inspection.'}

P078B Repair Costs

Cost Breakdown by Repair Type

Transmission Range Sensor Replacement

Replacing the faulty transmission range sensor to restore proper functionality.

  • Total: $200 - $400
  • Success rate: 85%
Money-Saving Tips for P078B
  • 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 P078B Diagnosis Process

Follow these systematic steps to accurately diagnose P078B. Each step builds on the previous one to ensure accurate diagnosis.

Step 1: Step 1

Step 1: Initial visual inspection - Check for damaged wiring, loose connections, or corrosion on the transmission range sensor (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

Step 2: OBD2 scan with GeekOBD APP - Use the app to retrieve all codes and freeze frame data for context on the fault (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

Step 3: Component testing - Employ a multimeter or diagnostic tool to test the transmission range sensor and its wiring for proper function (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

Step 4: System function test - After repairs, verify the proper operation of the transmission system and clear any codes (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

Step 5: Road test verification - Drive under various conditions to ensure that the issue is resolved and the code 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: Ford Fusion 2016 Transmission Range Sensor Replacement

Vehicle: 2016 Ford Fusion, 65,000 miles

Problem: Customer reported harsh shifting and check engine light.

Diagnosis: OBD2 scan revealed P078B, leading to inspection of the sensor and wiring.

Solution: Replaced the faulty transmission range sensor and cleared the code.

Cost: $350 (parts: $150, labor: $200)

Result: Customer reported smooth shifting and no reoccurrence of the check engine light.

Case Study 2: Chrysler 300 2018 Sensor Issue

Vehicle: 2018 Chrysler 300, 40,000 miles

Problem: Vehicle hesitated to start and displayed P078B.

Diagnosis: Inspection showed damaged wiring to the transmission range sensor.

Solution: Repaired the wiring and replaced the sensor.

Cost: $300 (parts: $150, labor: $150)

Result: Vehicle started normally and operated without issues post-repair.

Diagnose P078B

Use GeekOBD APP for professional diagnosis!

  • Real-time data monitoring
  • Advanced diagnostic features
  • Step-by-step repair guidance
  • Professional-grade analysis
Download GeekOBD APP Get MOBD Adapter

Code Information

Code: P078B
System: Powertrain (Engine, Transmission, Emissions)
Severity: HIGH
Category: Engine Codes