The P0968 trouble code is a diagnostic trouble code (DTC) that indicates an issue with the Pressure Control Solenoid ‘C’ control circuit in an automatic transmission. This code is generic and applies to a wide range of vehicles equipped with OBD-II systems, including models from manufacturers like Ford, Honda, Nissan, and Chevrolet. When the Powertrain Control Module (PCM) detects an open circuit or malfunction in the solenoid’s control circuit, it triggers the P0968 code. Understanding this code is crucial for vehicle owners and DIY mechanics, as it can lead to significant transmission issues if not addressed promptly.
| P0968 Code Meaning | P0968 Code Common Causes |
|---|---|
| Pressure Control Solenoid ‘C’ Control Circuit/Open | Defective pressure control solenoid |
| Transmission fluid pressure regulation failure | Contaminated transmission fluid |
| Transmission performance issues | Restricted transmission filter |
| Increased fuel consumption | Faulty wiring or connectors |
| Transmission overheating | Faulty PCM or TCM |
Symptoms of P0968 Code
Understanding the symptoms associated with the P0968 trouble code is essential for diagnosing and addressing the underlying issues. Common symptoms include:
- Increased fuel consumption: A malfunctioning solenoid can lead to inefficient transmission operation, causing higher fuel usage.
- Check Engine Light activated: The PCM will illuminate the check engine light when it detects this trouble code.
- Transmission overheating: An inability to regulate fluid pressure can cause excessive heat in the transmission system.
- Harsh or slipping shifts: The vehicle may experience rough gear changes or slipping during acceleration.
- Limp mode activation: To protect the transmission, the PCM may limit vehicle speed and performance when this code is detected.
Technical Explanation of P0968 Code
The P0968 code indicates a failure in the control circuit for the Pressure Control Solenoid ‘C’. This solenoid plays a critical role in regulating hydraulic pressure within the transmission, which is necessary for smooth shifting and overall performance. When the PCM detects an open circuit in this solenoid’s control line, it triggers the P0968 code.
How Pressure Control Solenoids Work
Pressure control solenoids are electro-mechanical devices that adjust hydraulic pressure based on signals received from the PCM. They operate by opening and closing valves to allow or restrict fluid flow within the transmission. If there is an issue with the wiring or if the solenoid itself fails, it can lead to improper fluid pressure regulation, resulting in various performance issues.
Step-by-Step Diagnosis of P0968 Code
Diagnosing a P0968 trouble code involves several systematic steps:
- Use an OBD-II Scanner: Start by connecting an OBD-II scanner to retrieve any stored codes. Confirm that P0968 is present.
- Visual Inspection: Check all wiring and connectors associated with the Pressure Control Solenoid ‘C’. Look for signs of damage, corrosion, or loose connections.
- Fluid Inspection: Examine the transmission fluid for contamination or degradation. Dirty fluid can affect solenoid performance.
- Solenoid Testing: Use a multimeter to test the resistance of the Pressure Control Solenoid ‘C’. Compare your readings to manufacturer specifications.
- Check Transmission Pressure: Using diagnostic equipment, verify that the hydraulic pressure within the transmission meets specified levels.
- Inspect Related Components: Evaluate other components such as the valve body, transmission pump, and PCM for faults that could contribute to the issue.
Solution Methods for P0968 Code
Once diagnosed, addressing a P0968 trouble code typically involves one or more of the following solutions:
- Change Transmission Fluid and Filter: If contamination is found, replacing old fluid and a clogged filter can resolve many issues related to solenoids.
- Replace Defective Pressure Control Solenoid: If testing indicates a faulty solenoid, replacement is necessary.
- Repair Wiring and Connectors: Damaged wiring should be repaired or replaced to restore proper electrical flow.
- Inspect and Repair Transmission Pump: If the pump is malfunctioning, it may need repair or replacement to ensure adequate hydraulic pressure.
- Reprogram or Replace PCM/TCM: In cases where electronic control modules are defective, reprogramming or replacement may be required.
Cost Estimates
The cost of repairs related to a P0968 trouble code can vary significantly based on several factors:
- Fluid Change: $100 – $300 depending on fluid type and labor costs.
- Pressure Control Solenoid Replacement: $150 – $500 including parts and labor.
- Wiring Repairs: $50 – $200 based on extent of damage.
- Transmission Pump Replacement: $500 – $1,500 depending on vehicle make/model.
- PCM/TCM Reprogramming/Replacement: $200 – $1,000 depending on complexity.
Warnings and Recommendations
When dealing with a P0968 trouble code:
- Always consult your vehicle’s service manual for specific diagnostic procedures tailored to your make and model.
- If you are not confident in performing these diagnostics or repairs yourself, seek professional assistance from an ASE-certified technician.
- Ignoring this code can lead to severe transmission damage over time; prompt attention is crucial.
Frequently Asked Questions About P0968
- What does error code P0968 mean?
The error code P0968 indicates that there is an open circuit in the Pressure Control Solenoid ‘C’ control circuit. - How serious is a P0968 code?
This code can lead to significant transmission problems if not addressed promptly; it may cause slipping gears or overheating. - Can I drive my car with a P0968 code?
While it may be possible to drive short distances, it’s advisable to address this issue immediately to avoid further damage. - What are common causes of a P0968 code?
Common causes include defective solenoids, contaminated fluid, damaged wiring, and faulty electronic control modules. - How do I reset a P0968 code?
You can reset this code using an OBD-II scanner after addressing any underlying issues; however, ensure all repairs are completed first. - Will changing my transmission fluid fix a P0968 error?
If contamination is present, changing your transmission fluid may resolve the issue; however, further diagnostics may be necessary. - What tools do I need to diagnose a P0968 code?
A basic OBD-II scanner and multimeter are essential tools for diagnosing this trouble code. - Can I fix a P0968 error myself?
If you have mechanical knowledge and tools, many aspects of diagnosing and repairing this issue can be done at home; otherwise, consult a professional.
In conclusion, understanding and addressing the P0968 trouble code is essential for maintaining your vehicle’s transmission health. By following proper diagnostic procedures and implementing necessary repairs promptly, you can prevent further complications and ensure smooth driving experiences.