The P0707 diagnostic trouble code (DTC) indicates a problem with the Transmission Range Sensor (TRS) circuit, specifically that the Powertrain Control Module (PCM) has detected a low voltage input. The TRS, also known as the Neutral Safety Switch, is crucial for determining the gear selector position and relaying this information to the PCM. This code signifies a potential malfunction in the sensor, its wiring, or the PCM itself, impacting vehicle operation and safety.
The P0707 code can lead to various drivability issues, including starting problems, incorrect gear selection, and a lack of engine power. Addressing this code promptly is essential to ensure safe and reliable vehicle operation.
| Category | Description | Potential Causes |
|---|---|---|
| Definition | Transmission Range Sensor Circuit Low Input | The PCM has detected a voltage signal from the TRS that is lower than the expected range. |
| Symptoms | Vehicle won't start Vehicle starts in gear other than Park or Neutral Incorrect gear selection Transmission shifting problems Check Engine Light illuminated Vehicle stuck in one gear (limp mode) Reverse lights not working Cruise control inoperative |
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| Potential Causes | Faulty Transmission Range Sensor (TRS) Damaged or corroded wiring harness or connectors Short to ground in the TRS circuit Open circuit in the TRS circuit Loose or corroded ground connection Faulty PCM (rare) Misadjusted Transmission Range Sensor Contamination within the sensor (fluid, debris) * Mechanical issues within the transmission linkage |
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| Diagnostic Steps | Visually inspect the TRS, wiring, and connectors for damage or corrosion Check the TRS adjustment Test the TRS using a multimeter according to the manufacturer's specifications Check for shorts to ground or open circuits in the TRS wiring Verify the ground connection to the TRS Inspect the transmission fluid level and condition * Test the PCM (as a last resort) |
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| Common Mistakes | Replacing the TRS without properly diagnosing the problem Ignoring wiring issues Failing to check the TRS adjustment Assuming the PCM is faulty without proper testing |
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| Related Codes | P0705 - Transmission Range Sensor Circuit Malfunction P0706 - Transmission Range Sensor Circuit Range/Performance P0708 - Transmission Range Sensor Circuit High Input P0709 - Transmission Range Sensor Circuit Intermittent |
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| Tools Needed | OBD-II Scanner Multimeter Wiring Diagram for your vehicle Socket set and wrenches Test light Jack and jack stands (if necessary for access) |
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| Severity | Moderate to High. Can prevent the vehicle from starting or cause unsafe driving conditions. | |
| Repair Cost | $100 - $500 (depending on the cause and the cost of parts and labor) |
Detailed Explanations
Definition: The P0707 code signifies that the PCM has registered a voltage signal from the Transmission Range Sensor (TRS) that falls below the expected threshold. This low voltage suggests a problem within the TRS circuit, preventing the PCM from accurately determining the gear selector position.
Symptoms: The symptoms of a P0707 code can vary, but common indicators include the vehicle failing to start, starting in an incorrect gear (other than Park or Neutral), incorrect gear selection, and transmission shifting problems. The Check Engine Light will also illuminate. In some cases, the vehicle may be stuck in one gear (limp mode) or the reverse lights might not function. Cruise control may also become inoperative.
Potential Causes: Several factors can trigger a P0707 code. A faulty Transmission Range Sensor (TRS) is a primary suspect. Damaged or corroded wiring harness or connectors can disrupt the signal. A short to ground or an open circuit within the TRS circuit can also cause the low voltage reading. Loose or corroded ground connections are another possibility. Although less common, a faulty PCM can also be the culprit. A misadjusted TRS or contamination within the sensor (due to fluid or debris) can also lead to this issue. Finally, mechanical issues within the transmission linkage can affect the TRS operation.
Diagnostic Steps: A systematic approach is crucial for diagnosing a P0707 code. Start by visually inspecting the TRS, wiring, and connectors for any signs of damage or corrosion. Check the TRS adjustment to ensure it's properly aligned. Use a multimeter to test the TRS according to the manufacturer's specifications. Look for shorts to ground or open circuits in the TRS wiring. Verify the ground connection to the TRS is secure and clean. Inspect the transmission fluid level and condition. As a last resort, test the PCM, keeping in mind that PCM failure is relatively rare.
Common Mistakes: Avoid common pitfalls during diagnosis. Don't replace the TRS without properly diagnosing the problem first. Ignoring wiring issues is another frequent mistake. Always check the TRS adjustment before replacing any parts. And, don't automatically assume the PCM is faulty; thoroughly investigate other potential causes first.
Related Codes: Several other DTCs are related to the TRS. P0705 indicates a general Transmission Range Sensor Circuit Malfunction. P0706 signifies a Transmission Range Sensor Circuit Range/Performance issue. P0708 indicates a Transmission Range Sensor Circuit High Input, and P0709 indicates a Transmission Range Sensor Circuit Intermittent problem. Understanding these related codes can provide valuable context during diagnosis.
Tools Needed: You'll need several tools to diagnose and repair a P0707 code. An OBD-II Scanner is essential for reading the DTCs. A multimeter is necessary for testing the TRS and wiring. A wiring diagram specific to your vehicle is crucial for tracing the TRS circuit. You'll also need a socket set and wrenches for removing and installing the TRS. A test light can be helpful for checking for power and ground. Finally, you might need a jack and jack stands to access the TRS, depending on its location.
Severity: The severity of a P0707 code is considered moderate to high. It can prevent the vehicle from starting, which is a significant inconvenience. More importantly, it can also cause unsafe driving conditions due to incorrect gear selection or transmission malfunctions.
Repair Cost: The repair cost for a P0707 code can range from $100 to $500, depending on the underlying cause and the cost of parts and labor. A simple wiring repair might be relatively inexpensive, while replacing the TRS or addressing PCM issues will be more costly.
Frequently Asked Questions
What does the P0707 code mean?
The P0707 code means the PCM has detected a low voltage signal from the Transmission Range Sensor circuit. This suggests a problem with the sensor, its wiring, or the PCM itself.
Can I drive my car with a P0707 code?
Driving with a P0707 code is not recommended, as it can lead to starting problems, incorrect gear selection, and potentially unsafe driving conditions. It's best to address the issue as soon as possible.
What is a Transmission Range Sensor?
The Transmission Range Sensor (TRS), also called a Neutral Safety Switch, detects the position of the gear selector and sends this information to the PCM. This information is critical for starting the vehicle and controlling the transmission.
How do I fix a P0707 code?
Fixing a P0707 code involves diagnosing the underlying cause, which could be a faulty TRS, wiring issues, or a PCM problem. Refer to the diagnostic steps outlined above for a systematic approach.
Is the PCM always the problem with a P0707 code?
No, the PCM is rarely the problem. Always check the TRS, wiring, and connections before considering PCM replacement.
Conclusion
The P0707 code signals a low input in the Transmission Range Sensor circuit, potentially causing significant drivability issues. Thoroughly diagnose the problem using the steps outlined in this article, and remember to address wiring and adjustment issues before replacing parts. Prompt attention to this code ensures safe and reliable vehicle operation.