Is The Ford OBD2 P0705 Code Troublesome For Your Vehicle?

Ford Obd2 P0705 code indicating a Transmission Range Sensor (TRS) circuit malfunction can indeed be troublesome, but understanding its causes and solutions can help resolve it efficiently; MERCEDES-DIAGNOSTIC-TOOL.EDU.VN provides expert insights into diagnosing and fixing this issue. Discover the potential causes, diagnostic steps, and solutions for the P0705 code, ensuring your Ford runs smoothly. This includes transmission repair, voltage checks, and sensor replacement.

1. What Does the Ford OBD2 P0705 Code Mean?

The Ford OBD2 P0705 code indicates a malfunction in the Transmission Range Sensor (TRS) circuit, also known as the Neutral Safety Switch or Manual Lever Position Sensor (MLPS). This sensor tells the car’s computer (PCM or TCM) what gear the transmission is in (Park, Reverse, Neutral, Drive, etc.).

1.1 Understanding the Function of the Transmission Range Sensor (TRS)

The Transmission Range Sensor (TRS) plays a vital role in your Ford’s transmission system. Here’s a detailed look at its functions:

• Gear Position Indication: The primary job of the TRS is to inform the Powertrain Control Module (PCM) or Transmission Control Module (TCM) about the gear shift position. This includes Park (P), Reverse (R), Neutral (N), and Drive (D) positions.
• Starting Safety: The TRS ensures that the engine can only be started when the transmission is in Park or Neutral, preventing accidental starts in gear.
• Backup Lights Activation: In many vehicles, the TRS also controls the activation of the backup lights when the transmission is shifted into Reverse.
• Data Transmission: The sensor sends signals to the computer, which uses this information to manage various functions, such as shift timing and torque converter lockup.
• Interaction with Other Sensors: The computer receives signals from both the vehicle speed sensor and the TRS. This helps in cross-checking the vehicle’s state; for example, the TRS should indicate Park while the speed sensor shows zero if the vehicle is stationary.

Why is the TRS Important?

The TRS is crucial for the safe and efficient operation of your vehicle. A malfunctioning TRS can lead to several issues, including:

• Starting Problems: Difficulty in starting the car or being able to start it in any gear, which can be dangerous.
• Backup Light Issues: Failure of the backup lights to activate when in Reverse, posing a safety hazard.
• Erratic Shifting: Irregular shift RPMs, delayed engagement, and overall poor transmission performance.
• Fuel Economy Reduction: Inefficient transmission operation can lead to a drop in fuel economy.
• Safety Concerns: The vehicle may start in gear, posing a significant safety risk.

Troubleshooting the TRS

When the P0705 code appears, it’s essential to diagnose the TRS promptly. Common issues include loose connections, corrosion, physical damage, or internal sensor failure. Depending on the vehicle model, the TRS may be located externally on the transmission or internally within the valve body.

External TRS: Easier to access and replace, often found on older models.
Internal TRS: Requires more extensive work, including draining the transmission fluid and removing the pan, typically found on newer models.
Regular inspection and maintenance of the TRS can prevent many of these issues, ensuring your Ford operates smoothly and safely.

1.2 What triggers the P0705 Code?

Several factors can trigger the P0705 code in your Ford:

• Defective Transmission Range Sensor (TRS): The sensor itself might be faulty due to wear and tear or internal damage.
• Misalignment of the TRS: If the sensor is not properly aligned, it can send incorrect signals to the PCM.
• Wiring Issues: Damaged, corroded, or loose wiring and connectors in the TRS circuit can cause signal disruptions.
• PCM/TCM Issues: Although less common, a malfunctioning Powertrain Control Module (PCM) or Transmission Control Module (TCM) can also trigger this code.
• Mechanical Problems: Issues within the transmission, such as a faulty shift linkage, can affect the TRS’s operation.

1.3 Common Symptoms Associated with the P0705 Code

Recognizing the symptoms associated with the P0705 code can help you diagnose and address the issue promptly:

• Difficulty Starting the Vehicle: The engine may fail to start, or it may only start in Neutral.
• Starting in Any Gear: The vehicle may start in any gear, which is a significant safety hazard.
• Backup Lights Not Working: The backup lights may fail to illuminate when the vehicle is in Reverse.
• Erratic Shifting: The transmission may shift erratically or not shift at all.
• Transmission Stuck in Gear: The transmission may get stuck in a particular gear.
• Check Engine Light: The check engine light will be illuminated on the dashboard.

Understanding these symptoms and potential causes will help you effectively troubleshoot and resolve the P0705 code in your Ford.

2. Identifying the Root Causes of the Ford OBD2 P0705 Code

Identifying the root cause of the Ford OBD2 P0705 code is crucial for effective repair. The most common causes include a faulty Transmission Range Sensor (TRS), wiring and connection problems, and issues with the Powertrain Control Module (PCM).

2.1 Faulty Transmission Range Sensor (TRS)

A faulty TRS is the most frequent culprit behind the P0705 code. The TRS, also known as the Manual Lever Position Sensor (MLPS) or Neutral Safety Switch, communicates the gear position to the vehicle’s computer.

• Wear and Tear: Over time, the sensor can wear out due to constant use and exposure to environmental factors.
• Internal Damage: The internal components of the sensor may become damaged, leading to inaccurate readings or complete failure.
• Contamination: Exposure to dirt, debris, and transmission fluid can contaminate the sensor, affecting its performance.

How to Diagnose a Faulty TRS:

• Visual Inspection: Check the sensor for any signs of physical damage, such as cracks or broken connectors.
• Multimeter Testing: Use a multimeter to check the sensor’s resistance and voltage outputs. Compare these readings with the manufacturer’s specifications to identify any discrepancies.
• OBD-II Scanner: Use an OBD-II scanner to read the sensor data and look for erratic or missing signals.

2.2 Wiring and Connection Problems

Wiring and connection issues are another significant cause of the P0705 code. Damaged or corroded wiring can disrupt the signal between the TRS and the vehicle’s computer.

• Corrosion: Exposure to moisture and road salt can cause corrosion on the wiring and connectors.
• Damage: Wires can become damaged due to rubbing against other components or being pinched during maintenance.
• Loose Connections: Loose or disconnected connectors can interrupt the signal flow.

How to Diagnose Wiring and Connection Problems:

• Visual Inspection: Inspect the wiring harness and connectors for any signs of damage, corrosion, or loose connections.
• Wiring Diagram: Refer to the vehicle’s wiring diagram to trace the TRS circuit and identify any potential problem areas.
• Multimeter Testing: Use a multimeter to check the continuity of the wires and the voltage at the connectors.

2.3 Powertrain Control Module (PCM) Issues

Although less common, issues with the PCM can also trigger the P0705 code. The PCM is responsible for processing the signals from the TRS and controlling the transmission.

• Software Glitches: Software glitches or corrupted data can cause the PCM to misinterpret the TRS signals.
• Internal Failure: In rare cases, the PCM itself may fail, leading to incorrect readings and error codes.

How to Diagnose PCM Issues:

• Software Update: Check for any available software updates for the PCM. Updating the software can resolve known glitches.
• PCM Testing: A professional technician can use specialized diagnostic tools to test the PCM and determine if it is functioning correctly.
• PCM Replacement: If the PCM is found to be faulty, it may need to be replaced and reprogrammed.

By systematically diagnosing these potential causes, you can accurately identify the root of the P0705 code and implement the necessary repairs.

3. Step-by-Step Diagnostic Procedures for the P0705 Code

Diagnosing the P0705 code requires a systematic approach. Follow these step-by-step procedures to identify the root cause of the problem accurately.

3.1 Initial Inspection and Preparation

Before diving into complex diagnostics, start with a thorough visual inspection and gather the necessary tools.

• Visual Inspection:

  • Check the TRS and its wiring for any obvious damage, such as cracks, corrosion, or loose connections.
  • Inspect the shift linkage for any signs of damage or misalignment.

• Gather Tools:

  • OBD-II scanner
  • Multimeter
  • Wiring diagram for your specific Ford model
  • Basic hand tools (sockets, wrenches, screwdrivers)

3.2 Using an OBD-II Scanner

An OBD-II scanner is essential for reading the diagnostic trouble codes and accessing live data from the vehicle’s computer.

• Connect the Scanner:

  • Plug the OBD-II scanner into the diagnostic port, usually located under the dashboard on the driver’s side.

• Read the Codes:

  • Turn the ignition to the “ON” position (engine off).
  • Use the scanner to read and record any stored trouble codes. Note any other codes that may be present.

• Clear the Codes:

  • After recording the codes, clear them from the PCM.

• Test Drive:

  • Take the vehicle for a test drive to see if the P0705 code returns. Monitor the TRS data using the scanner to check for any abnormalities.

3.3 Testing the Transmission Range Sensor (TRS)

Testing the TRS involves checking its resistance, voltage, and signal output to ensure it is functioning correctly.

• Locate the TRS:

  • Refer to the vehicle’s service manual to locate the TRS. It is typically found on the transmission case, near the shift linkage.

• Check the Wiring:

  • Disconnect the TRS connector and inspect the terminals for corrosion or damage.
  • Use a wiring diagram to identify the correct terminals for testing.

• Resistance Test:

  • Set the multimeter to the resistance (Ohms) setting.
  • Measure the resistance between the specified terminals of the TRS in different gear positions.
  • Compare the readings to the manufacturer’s specifications. Any significant deviation indicates a faulty sensor.

• Voltage Test:

  • Set the multimeter to the DC voltage setting.
  • With the ignition on, measure the voltage at the specified terminals of the TRS connector.
  • Compare the readings to the manufacturer’s specifications. Incorrect voltage levels can indicate a wiring problem or a faulty PCM.

• Signal Output Test:

  • Use the OBD-II scanner to monitor the TRS signal output while shifting through the gears.
  • Check for any erratic or missing signals. The TRS signal should change smoothly and consistently with each gear position.

3.4 Inspecting and Testing the Wiring

Thoroughly inspect the wiring and connectors associated with the TRS circuit.

• Visual Inspection:

  • Check the wiring harness for any signs of damage, such as cuts, abrasions, or melted insulation.
  • Inspect the connectors for corrosion, loose terminals, or broken locking tabs.

• Continuity Test:

  • Disconnect the battery to prevent electrical damage.
  • Use the multimeter to perform a continuity test on each wire in the TRS circuit.
  • Check for any open circuits or shorts to ground.

• Voltage Drop Test:

  • With the circuit loaded (ignition on), measure the voltage drop across each wire and connector in the TRS circuit.
  • Excessive voltage drop indicates a high-resistance connection.

By following these detailed diagnostic steps, you can systematically identify the cause of the P0705 code and implement the appropriate repairs.

4. Common Solutions for Resolving the Ford OBD2 P0705 Code

Once you have identified the root cause of the P0705 code, you can proceed with the necessary repairs. Common solutions include replacing the Transmission Range Sensor (TRS), repairing or replacing damaged wiring, and addressing Powertrain Control Module (PCM) issues.

4.1 Replacing the Transmission Range Sensor (TRS)

If the TRS is found to be faulty, replacement is usually the most effective solution.

• Preparation:

  • Gather the necessary tools, including sockets, wrenches, screwdrivers, and a new TRS.
  • Refer to the vehicle’s service manual for specific instructions and torque specifications.

• Removal:

  • Disconnect the negative battery cable to prevent electrical damage.
  • Locate the TRS on the transmission case.
  • Disconnect the electrical connector from the TRS.
  • Remove the mounting bolts or screws securing the TRS to the transmission.
  • Carefully remove the old TRS.

• Installation:

  • Clean the mounting surface on the transmission case.
  • Install the new TRS, ensuring it is properly aligned.
  • Tighten the mounting bolts or screws to the specified torque.
  • Reconnect the electrical connector to the TRS.

• Testing:

  • Reconnect the negative battery cable.
  • Use an OBD-II scanner to clear the P0705 code.
  • Start the vehicle and shift through the gears to ensure the transmission is functioning correctly.
  • Monitor the TRS data using the scanner to verify that the new sensor is providing accurate readings.

4.2 Repairing or Replacing Damaged Wiring

If the P0705 code is caused by damaged wiring or connectors, repairing or replacing the affected components is essential.

• Repairing Wiring:

  • Inspect the wiring harness for any signs of damage, such as cuts, abrasions, or corrosion.
  • If the damage is minor, you can repair the wiring by splicing in new sections of wire and using heat-shrink tubing to protect the connections.
  • Ensure that all connections are secure and properly insulated.

• Replacing Wiring:

  • If the wiring is severely damaged or corroded, it may be necessary to replace the entire wiring harness or individual wires.
  • Use a wiring diagram to identify the correct wire gauge and color for each circuit.
  • Route the new wiring carefully, avoiding any sharp edges or hot components.
  • Secure the wiring harness with zip ties or clips to prevent it from rubbing against other parts of the vehicle.

• Connector Replacement:

  • Inspect the connectors for corrosion, loose terminals, or broken locking tabs.
  • If the connectors are damaged, replace them with new ones.
  • Use a specialized crimping tool to ensure that the terminals are securely attached to the wires.
  • Apply dielectric grease to the terminals to prevent corrosion.

4.3 Addressing Powertrain Control Module (PCM) Issues

If the P0705 code is caused by a software glitch or internal failure of the PCM, the following solutions may be necessary:

• Software Update:

  • Check for any available software updates for the PCM.
  • Updating the software can resolve known glitches and improve the performance of the PCM.
  • Follow the manufacturer’s instructions for performing the software update.

• PCM Replacement:

  • If the PCM is found to be faulty, it may need to be replaced and reprogrammed.
  • PCM replacement should be performed by a qualified technician with specialized diagnostic tools.
  • The new PCM will need to be programmed with the vehicle’s VIN and other specific information.

By implementing these solutions, you can effectively resolve the P0705 code and restore your Ford’s transmission to proper working order.

5. Advanced Techniques for Diagnosing and Fixing the P0705 Code

For complex cases of the P0705 code, advanced diagnostic techniques may be necessary. These techniques involve using specialized tools and in-depth knowledge of the vehicle’s systems.

5.1 Using a Digital Storage Oscilloscope (DSO)

A Digital Storage Oscilloscope (DSO) can be used to analyze the signal patterns from the TRS and identify intermittent issues that may not be apparent with a multimeter or OBD-II scanner.

• Connecting the DSO:

  • Connect the DSO probes to the TRS signal wires.
  • Set the DSO to the appropriate voltage and time scales.

• Analyzing the Signal:

  • Monitor the TRS signal while shifting through the gears.
  • Look for any abnormal patterns, such as signal dropouts, excessive noise, or incorrect voltage levels.
  • Compare the signal patterns to known good waveforms to identify any discrepancies.

5.2 Performing a Pinpoint Test

A pinpoint test involves systematically testing each component and circuit in the TRS system to isolate the cause of the P0705 code.

• Gathering Information:

  • Refer to the vehicle’s service manual for the pinpoint test procedure.
  • Obtain a wiring diagram of the TRS circuit.

• Testing Components:

  • Use a multimeter to test the resistance, voltage, and continuity of each component in the TRS circuit.
  • Check for any open circuits, shorts to ground, or high-resistance connections.
  • Compare the test results to the manufacturer’s specifications.

• Isolating the Fault:

  • By systematically testing each component, you can isolate the fault to a specific area of the TRS system.
  • Once the fault has been identified, you can proceed with the necessary repairs.

5.3 Checking for Transmission Mechanical Issues

In some cases, the P0705 code may be caused by mechanical issues within the transmission itself.

• Shift Linkage:

  • Inspect the shift linkage for any signs of damage, misalignment, or excessive play.
  • Adjust the shift linkage as necessary to ensure proper alignment and smooth operation.

• Valve Body:

  • If the transmission is exhibiting shifting problems, the valve body may be the cause.
  • The valve body contains a series of valves and solenoids that control the flow of transmission fluid.
  • A faulty valve or solenoid can cause erratic shifting or prevent the transmission from shifting at all.
  • The valve body may need to be removed, cleaned, and inspected for damage.

• Internal Transmission Components:

  • In rare cases, the P0705 code may be caused by damage to internal transmission components, such as the gears, clutches, or bands.
  • A thorough inspection of the transmission may be necessary to identify any internal damage.

By using these advanced techniques, you can diagnose and repair even the most complex cases of the P0705 code.

6. Preventing the Ford OBD2 P0705 Code

Preventing the Ford OBD2 P0705 code involves regular maintenance and proactive measures to ensure the Transmission Range Sensor (TRS) and related components remain in good working order.

6.1 Regular Maintenance Practices

Regular maintenance is crucial for preventing the P0705 code and ensuring the longevity of your Ford’s transmission system.

• Check Transmission Fluid:

  • Regularly check the transmission fluid level and condition.
  • Low or contaminated transmission fluid can cause shifting problems and damage the TRS.
  • Follow the manufacturer’s recommendations for changing the transmission fluid.

• Inspect Wiring and Connectors:

  • Periodically inspect the wiring and connectors associated with the TRS for any signs of damage, corrosion, or loose connections.
  • Repair or replace any damaged wiring or connectors as needed.
  • Apply dielectric grease to the connectors to prevent corrosion.

• Shift Linkage Inspection:

  • Inspect the shift linkage for any signs of damage, misalignment, or excessive play.
  • Adjust the shift linkage as necessary to ensure proper alignment and smooth operation.

6.2 Proactive Measures

In addition to regular maintenance, taking proactive measures can help prevent the P0705 code.

• Use Quality Parts:

  • When replacing the TRS or other transmission components, use high-quality parts from reputable manufacturers.
  • Cheap or inferior parts may not meet the vehicle’s specifications and can fail prematurely.

• Protect Wiring:

  • Protect the wiring harness from damage by routing it carefully and securing it with zip ties or clips.
  • Avoid exposing the wiring to sharp edges, hot components, or abrasive surfaces.

• Regular Inspections:

  • Have the transmission system inspected by a qualified technician during regular maintenance visits.
  • Early detection of potential problems can prevent more serious issues from developing.

6.3 Monitoring Vehicle Performance

Keep an eye on your vehicle’s performance and be aware of any unusual symptoms that may indicate a problem with the transmission system.

• Listen for Unusual Noises:

  • Pay attention to any unusual noises coming from the transmission, such as clunking, grinding, or whining.

• Watch for Shifting Problems:

  • Be aware of any shifting problems, such as erratic shifting, delayed engagement, or failure to shift.

• Check for Warning Lights:

  • Monitor the dashboard for any warning lights, such as the check engine light or the transmission warning light.
  • If any warning lights illuminate, have the vehicle inspected by a qualified technician as soon as possible.

By following these preventive measures, you can reduce the risk of experiencing the P0705 code and keep your Ford’s transmission system running smoothly.

7. Understanding the Role of a Mechanic

While some diagnostic and repair tasks can be performed by vehicle owners, certain situations require the expertise of a professional mechanic.

7.1 When to Consult a Professional Mechanic

Knowing when to consult a professional mechanic can save time, money, and potential damage to your vehicle.

• Complex Diagnostics:

  • If you are unable to diagnose the cause of the P0705 code using basic diagnostic tools and techniques, it is best to consult a professional mechanic.
  • Complex diagnostics may require specialized tools and knowledge of the vehicle’s systems.

• Extensive Repairs:

  • If the P0705 code is caused by extensive damage to the wiring harness, transmission, or PCM, it is best to have the repairs performed by a professional mechanic.
  • Extensive repairs may require specialized tools and expertise.

• Uncertainty:

  • If you are unsure about any aspect of the diagnostic or repair process, it is always best to consult a professional mechanic.
  • Attempting to perform repairs without the necessary knowledge and skills can result in further damage to the vehicle.

7.2 What to Expect from a Mechanic

When you take your vehicle to a mechanic, you can expect them to perform a thorough inspection and provide you with an accurate diagnosis and repair plan.

• Thorough Inspection:

  • The mechanic will perform a thorough inspection of the transmission system, including the TRS, wiring, connectors, and PCM.
  • They will use specialized diagnostic tools to identify the cause of the P0705 code.

• Accurate Diagnosis:

  • The mechanic will provide you with an accurate diagnosis of the cause of the P0705 code.
  • They will explain the problem in detail and answer any questions you may have.

• Repair Plan:

  • The mechanic will provide you with a detailed repair plan, including a list of the necessary repairs and the estimated cost.
  • They will obtain your approval before beginning any repairs.

• Quality Repairs:

  • The mechanic will perform quality repairs using high-quality parts.
  • They will test the repaired system to ensure that it is functioning correctly.

• Warranty:

  • The mechanic may offer a warranty on the repairs they perform.
  • Be sure to ask about the warranty before approving the repairs.

7.3 Finding a Reputable Mechanic

Finding a reputable mechanic is essential for ensuring that your vehicle is properly diagnosed and repaired.

• Ask for Recommendations:

  • Ask friends, family, and colleagues for recommendations.

• Check Online Reviews:

  • Check online reviews to see what other customers have to say about the mechanic’s services.

• Verify Credentials:

  • Verify that the mechanic is licensed and certified.
  • Check for certifications from organizations such as the National Institute for Automotive Service Excellence (ASE).

• Get an Estimate:

  • Get an estimate from several mechanics before choosing one.
  • Be sure to compare the estimates carefully and ask about any hidden fees.

• Trust Your Gut:

  • Trust your gut. If you don’t feel comfortable with a particular mechanic, it is best to choose someone else.

By following these guidelines, you can find a reputable mechanic who will properly diagnose and repair your vehicle.

8. Estimated Repair Costs for the Ford OBD2 P0705 Code

Understanding the estimated repair costs for the Ford OBD2 P0705 code can help you budget for the necessary repairs. The actual cost can vary depending on the cause of the problem, the make and model of your vehicle, and the labor rates in your area.

8.1 Cost of Replacing the Transmission Range Sensor (TRS)

The cost of replacing the Transmission Range Sensor (TRS) typically ranges from $150 to $500.

• Parts Cost: The TRS itself can cost anywhere from $50 to $200, depending on the brand and quality.
• Labor Cost: The labor cost can range from $100 to $300, depending on the complexity of the repair and the labor rates in your area.

8.2 Cost of Wiring Repairs

The cost of wiring repairs can vary widely depending on the extent of the damage.

• Minor Repairs: Minor wiring repairs, such as splicing in a new section of wire or replacing a connector, can cost $50 to $200.
• Extensive Repairs: Extensive wiring repairs, such as replacing an entire wiring harness, can cost $200 to $1000 or more.

8.3 Cost of PCM Replacement

The cost of replacing the Powertrain Control Module (PCM) can be significant.

• Parts Cost: The PCM itself can cost anywhere from $500 to $1500, depending on the make and model of your vehicle.
• Labor Cost: The labor cost can range from $100 to $500, depending on the complexity of the repair and the labor rates in your area.
  *Note: The PCM may need to be reprogrammed, which can add to the overall cost.

8.4 Additional Costs

In addition to the costs listed above, there may be additional costs associated with the P0705 code.

• Diagnostic Fees: Some mechanics may charge a diagnostic fee to determine the cause of the P0705 code. This fee can range from $50 to $150.
• Towing Fees: If your vehicle is not drivable, you may need to pay for towing. Towing fees can range from $50 to $200.
• Rental Car Fees: If your vehicle will be in the shop for an extended period, you may need to rent a car. Rental car fees can vary widely depending on the type of vehicle and the rental period.

By understanding the estimated repair costs for the P0705 code, you can be prepared for the financial implications of the necessary repairs.

9. How To Use Multimeter to Test the TRS (Transmission Range Sensor)

Using a multimeter to test the Transmission Range Sensor (TRS) is a crucial step in diagnosing the P0705 code. This process helps you verify whether the sensor is functioning correctly by measuring its resistance and voltage outputs. Here’s a detailed guide on how to perform these tests.

9.1 Preparation and Safety Measures

Before you begin, it’s important to gather the necessary tools and take appropriate safety measures to protect yourself and your vehicle.

• Tools and Materials:

  • Digital Multimeter: A reliable multimeter is essential for measuring resistance and voltage.
  • Vehicle Service Manual: Refer to your vehicle’s service manual for specific instructions and wiring diagrams.
  • Wiring Diagram: A detailed wiring diagram helps you identify the correct terminals on the TRS.
  • Basic Hand Tools: You’ll need tools such as sockets, wrenches, and screwdrivers to access the TRS.
  • Safety Glasses: Protect your eyes from debris and potential hazards.
  • Gloves: Wear gloves to protect your hands from dirt and chemicals.

• Safety Measures:

  • Disconnect the Battery: Before starting any electrical testing, disconnect the negative battery cable to prevent electrical shocks and damage to the vehicle’s electrical system.
  • Work in a Well-Ventilated Area: Ensure you are working in an area with good ventilation to avoid inhaling harmful fumes.
  • Follow Instructions: Always follow the instructions in your vehicle’s service manual and the multimeter’s user guide.

9.2 Locating the Transmission Range Sensor

The location of the TRS can vary depending on the make and model of your Ford. Consult your vehicle’s service manual for the exact location. Generally, it’s found on the transmission case, near the shift linkage.

• Identifying the TRS:

  • Refer to the service manual to identify the TRS. It’s typically a small sensor with an electrical connector attached.
  • The TRS is usually mounted on the side of the transmission, where the shift linkage connects.

• Accessing the TRS:

  • You may need to remove some components to access the TRS, such as the air filter box or other parts obstructing the view.
  • Use the appropriate tools to remove these components carefully, and keep track of their locations for reassembly.

9.3 Testing Resistance

Testing the resistance of the TRS involves measuring the resistance between specified terminals in different gear positions. This test helps determine if the sensor is properly detecting each gear.

• Steps for Resistance Testing:

  1. Disconnect the Electrical Connector: Disconnect the electrical connector from the TRS.
  2. Set the Multimeter: Set your multimeter to the resistance (Ohms) setting. Typically, you’ll use the lowest Ohm setting for accurate readings.
  3. Identify the Terminals: Refer to the wiring diagram to identify the correct terminals for each gear position.
  4. Measure Resistance: Measure the resistance between the specified terminals for each gear position (Park, Reverse, Neutral, Drive, etc.).
  5. Record Readings: Record the resistance readings for each gear position.
  6. Compare to Specifications: Compare your readings to the manufacturer’s specifications in the service manual. Significant deviations indicate a faulty sensor.

• Interpreting Resistance Readings:

  • A very high or infinite resistance indicates an open circuit.
  • A very low resistance indicates a short circuit.
  • Readings that deviate significantly from the manufacturer’s specifications indicate a faulty sensor.

9.4 Testing Voltage

Testing the voltage at the TRS helps verify that the sensor is receiving the correct power supply from the vehicle’s electrical system.

• Steps for Voltage Testing:

  1. Reconnect the Electrical Connector: Reconnect the electrical connector to the TRS.
  2. Set the Multimeter: Set your multimeter to the DC voltage setting.
  3. Identify the Terminals: Refer to the wiring diagram to identify the correct terminals for voltage testing.
  4. Turn Ignition On: Turn the ignition to the “ON” position, but do not start the engine.
  5. Measure Voltage: Measure the voltage between the specified terminals.
  6. Record Readings: Record the voltage readings.
  7. Compare to Specifications: Compare your readings to the manufacturer’s specifications.

• Interpreting Voltage Readings:

  • No voltage indicates a break in the power supply circuit.
  • Voltage levels outside the specified range indicate a wiring problem or a faulty PCM.

9.5 Analyzing the Results

After completing the resistance and voltage tests, carefully analyze the results to determine the condition of the TRS.

• If the Readings Are Within Specifications:

  • If the resistance and voltage readings are within the manufacturer’s specifications, the TRS is likely functioning correctly.
  • In this case, the P0705 code may be caused by a wiring problem, a PCM issue, or a mechanical problem within the transmission.

• If the Readings Are Outside Specifications:

  • If the resistance or voltage readings are outside the manufacturer’s specifications, the TRS is likely faulty and needs to be replaced.
  • Before replacing the TRS, double-check the wiring and connections to ensure they are in good condition.

By following these steps, you can effectively use a multimeter to test the TRS and determine if it is functioning correctly. This is a critical step in diagnosing the P0705 code and ensuring your Ford’s transmission system operates smoothly.

10. FAQ About Ford OBD2 P0705 Code

Here are some frequently asked questions about the Ford OBD2 P0705 code, providing quick and informative answers to common concerns.

10.1 What does the P0705 code mean on a Ford?

The P0705 code on a Ford indicates a malfunction in the Transmission Range Sensor (TRS) circuit. This sensor tells the car’s computer what gear the transmission is in, and a fault can cause shifting problems and other issues.

10.2 Can I drive my Ford with the P0705 code?

It is not recommended to drive your Ford with the P0705 code. The transmission may not shift properly, and the vehicle may start in any gear, posing a safety hazard.

10.3 How do I fix the P0705 code on my Ford?

To fix the P0705 code, you should:

• Inspect the TRS and its wiring for damage.
• Test the TRS with a multimeter.
• Replace the TRS if it is faulty.
• Repair or replace any damaged wiring or connectors.
• Check the PCM for any software updates or issues.

10.4 Is the P0705 code serious?

Yes, the P0705 code is serious because it can affect the safety and performance of your vehicle. It can lead to unpredictable shifting and the ability to start the car in any gear, which can be dangerous.

10.5 How much does it cost to fix the P0705 code?

The cost to fix the P0705 code can range from $150 to $500, depending on whether you need to replace the TRS, repair wiring, or address PCM issues.

10.6 Can a bad TRS cause no start?

Yes, a bad TRS can cause a no-start condition because the car’s computer needs to know the transmission is in Park or Neutral before allowing the engine to start.

10.7 What is the difference between a TRS and a neutral safety switch?

The TRS (Transmission Range Sensor) and the neutral safety switch often refer to the same component. The TRS is a more comprehensive sensor that indicates gear positions, while the neutral safety switch is primarily responsible for preventing the engine from starting unless the transmission is in Park or Neutral.

10.8 How do I test a TRS with a multimeter?

To test a TRS with a multimeter:

1. Disconnect the TRS connector.
2. Set the multimeter to measure resistance (Ohms).
3. Measure the resistance between specific terminals for each gear position, comparing the readings to the manufacturer’s specifications.
4. Also, check the voltage supply to the TRS to ensure it’s within the specified range.

10.9 Can a P0705 code affect fuel economy?

Yes, a P0705 code can affect fuel economy because the transmission may not shift optimally, leading to inefficient engine operation.

10.10 Is it possible to replace the TRS myself?

It is possible to replace the TRS yourself if you have basic