The P0987 trouble code is a diagnostic trouble code (DTC) that indicates an issue with the Transmission Fluid Pressure Sensor/Switch “E” Circuit. This code is part of the On-Board Diagnostics II (OBD-II) system and is typically triggered when the Engine Control Module (ECM) detects an abnormal voltage reading from the transmission fluid pressure sensor or switch. Understanding this code is crucial for vehicle owners and DIY mechanics, as it can affect transmission performance and overall vehicle operation.
| P0987 Code Meaning | P0987 Code Common Causes |
|---|---|
| Transmission Fluid Pressure Sensor/Switch “E” Circuit malfunction | Faulty transmission fluid pressure sensor |
| Abnormal voltage reading detected by the ECM | Wiring issues (shorts, opens, or corrosion) |
| Potential internal mechanical issues within the transmission | Poor electrical connections |
| Transmission Control Module (TCM) malfunction | Low transmission fluid level |
| Contaminated transmission fluid | |
| Faulty transmission solenoid | |
| Mechanical failures within the transmission system |
Symptoms of P0987 Code
When the P0987 code is triggered, drivers may experience various symptoms, including:
- Malfunction Indicator Light (MIL): The check engine light may illuminate on the dashboard.
- Transmission Performance Issues: Shifting may become erratic or harsh, leading to poor acceleration or delayed gear changes.
- Limp Mode Activation: The vehicle may enter limp mode, which limits performance to protect the engine and transmission.
- Fluid Leaks: Visible leaks around the transmission area may occur if there are underlying issues.
Understanding these symptoms can help in diagnosing and addressing the underlying problems associated with the P0987 code.
Technical Explanation
The P0987 code is associated with the Transmission Fluid Pressure Sensor/Switch “E,” which monitors the hydraulic pressure within the transmission. This sensor provides critical data to the ECM or TCM to ensure optimal shifting and performance. When the ECM detects that the voltage signal from this sensor falls outside predetermined parameters, it triggers the P0987 code.
The possible reasons for this malfunction include:
- Faulty Sensor: The sensor itself may be defective, providing incorrect readings.
- Wiring Issues: Damaged wiring or poor connections can disrupt the signal sent to the ECM.
- Fluid Quality: Contaminated or low transmission fluid can affect sensor performance.
- Internal Transmission Problems: Mechanical failures within the transmission can also trigger this code.
Step-by-Step Diagnosis
Diagnosing a P0987 trouble code involves a systematic approach. Here’s a step-by-step guide:
- Check for Additional Codes: Use an OBD-II scanner to check for any other stored trouble codes that may provide additional context.
- Inspect Transmission Fluid: Check both the level and condition of the transmission fluid. Dark, dirty, or low fluid can indicate problems.
- Visual Inspection: Examine wiring and connectors associated with the Transmission Fluid Pressure Sensor for any signs of damage, corrosion, or loose connections.
- Test Voltage at Sensor: With a multimeter, measure the voltage at the sensor connector with the ignition on (engine off). Compare readings against manufacturer specifications.
- Check Continuity: Use a multimeter to test for continuity in the wiring harness to ensure there are no shorts or open circuits.
- Sensor Testing: If everything checks out electrically, test the Transmission Fluid Pressure Sensor itself for functionality according to manufacturer specifications.
- Inspect TCM/PCM: If all else fails, consider checking for faults in the Transmission Control Module (TCM) or Powertrain Control Module (PCM).
Solution Methods
To resolve a P0987 trouble code, several solutions may be implemented based on diagnosis:
- Replace Faulty Sensor: If testing reveals that the Transmission Fluid Pressure Sensor is defective, replace it with a new one.
- Repair Wiring Issues: Address any damaged wiring or poor connections found during inspection.
- Fluid Change: If fluid quality is poor, drain and replace it with fresh transmission fluid according to manufacturer specifications.
- Address Internal Problems: If internal mechanical issues are suspected, further inspection of the transmission may be necessary, potentially requiring professional assistance.
- Clear Codes and Test Drive: After repairs are made, clear any stored codes using an OBD-II scanner and take the vehicle for a test drive to ensure proper operation and verify that no codes return.
Cost Estimates
The cost of diagnosing and repairing a P0987 trouble code can vary significantly based on several factors:
- Diagnostic Fees: Expect to pay between $100 and $150 for a professional diagnostic service if you choose not to perform it yourself.
- Sensor Replacement Costs: A new Transmission Fluid Pressure Sensor typically costs between $50 and $150 depending on your vehicle make and model.
- Wiring Repairs: Repairing damaged wiring can range from $50 to $200 based on labor rates and parts needed.
- Fluid Change Costs: A complete transmission fluid change may cost between $100 and $300 depending on fluid type and labor involved.
Overall repair costs can range from $200 to over $1,000 depending on severity and required repairs.
Warnings and Recommendations
While dealing with a P0987 trouble code:
- Always prioritize safety; if unsure about any diagnosis or repair steps, seek professional assistance.
- Regularly check your vehicle’s transmission fluid level and quality as part of routine maintenance to prevent issues from arising in the first place.
- Be cautious of DIY repairs; improper handling of electrical components can lead to further damage or safety hazards.
Closing Paragraph
The P0987 trouble code indicates an issue with your vehicle’s Transmission Fluid Pressure Sensor/Switch “E” Circuit. Understanding its causes, symptoms, and solutions is vital for maintaining your vehicle’s performance. By following systematic diagnostic steps and addressing issues promptly, you can ensure your vehicle operates smoothly while avoiding costly repairs down the line. Always consult your vehicle’s service manual for specific details related to your make and model, and don’t hesitate to seek professional help when needed.
Frequently Asked Questions About P0987
- What does error code P0987 mean?
P0987 indicates a malfunction in the Transmission Fluid Pressure Sensor/Switch “E” Circuit. - How serious is a P0987 code?
This issue can lead to poor transmission performance but is generally not immediately serious. - Can I drive my car with a P0987 code?
While you may be able to drive short distances, it’s advisable to address this issue promptly. - What are common symptoms of a P0987 code?
Symptoms include shifting problems, check engine light activation, and potential limp mode. - How do I fix a P0987 code?
Fixes include replacing faulty sensors, repairing wiring issues, or changing contaminated fluid. - Can low transmission fluid cause a P0987 code?
Yes, low fluid levels can lead to incorrect readings from the pressure sensor. - Is it safe to ignore a P0987 trouble code?
No; ignoring it could lead to further damage or more costly repairs down the line. - When should I seek professional help for P0987?
If you’re unsure about diagnosing or repairing this issue yourself, consult a certified mechanic.