Quick Answer
C0738 means: C0738 refers to a malfunction in the clutch pressure sensor, often impacting transmission performance.
Can I drive with C0738? Immediate diagnosis is recommended to avoid serious transmission damage.
Common Questions
What does C0738 mean and how does it affect my car?
C0738 signifies an issue with the clutch pressure sensor in your vehicle's transmission. This can lead to poor shifting performance, decreased fuel efficiency, and may eventually cause severe transmission failure if not addressed. The vehicle might enter a fail-safe mode, impacting drivability.
What are the most common causes of C0738 and how much does it cost to fix?
The most common cause of C0738 is a faulty clutch pressure sensor, which can cost between $150 to $300 to replace. Other causes include wiring issues and low transmission fluid levels. Repair costs can vary based on the specific problem but generally range from $100 to $300.
Can I drive my car with C0738 or should I stop immediately?
While you might be able to drive your car with the C0738 code, it's not advisable. Continuing to drive could worsen the problem and lead to more extensive damage. It's best to get the issue diagnosed and repaired as soon as possible.
How can I diagnose C0738 myself using GeekOBD APP?
To diagnose C0738 with the GeekOBD APP, start by scanning for DTCs and noting any other related codes. Check the freeze frame data for performance metrics at the time of the fault. Perform a visual inspection of the sensor and wiring, and use the APP for further diagnostics if necessary.
What vehicles are most commonly affected by C0738?
C0738 is frequently seen in 2011-2019 Ford F-150s and 2010-2015 Chevrolet Silverados. These vehicles have known issues related to clutch pressure sensor failures, and owners should be vigilant about symptoms.
How can I prevent C0738 from happening again?
To prevent C0738 from reoccurring, ensure regular transmission fluid changes and check the clutch pressure sensor during routine maintenance. Keeping an eye on wiring and connectors for wear and tear can also help mitigate future issues.
What is C0738?
The Diagnostic Trouble Code (DTC) C0738 indicates a malfunction related to the clutch pressure sensor input within the transmission system. This code is most commonly found in certain Ford and General Motors vehicles, particularly models like the 2011-2019 Ford F-150 and 2010-2015 Chevrolet Silverado. When the vehicle's onboard diagnostics detect that the clutch pressure sensor is not providing a valid signal, it triggers the C0738 code. This can lead to issues such as erratic shifting, decreased performance, or even transmission failure if not addressed promptly. The clutch pressure sensor is crucial for ensuring the proper operation of the transmission by providing information regarding the hydraulic pressure necessary for smooth gear changes. If this sensor fails, it can result in the check engine light illuminating, and the vehicle may enter a fail-safe mode to prevent further damage. Ignoring the C0738 code can lead to more severe transmission issues and expensive repairs down the line, making it essential to diagnose and resolve the problem as soon as possible.
System: C - Chassis (ABS, Steering, Suspension)
Symptoms
Common symptoms when C0738 is present:
- The check engine light is illuminated, indicating a problem that needs attention.
- Shifting between gears becomes erratic, causing the vehicle to hesitate or jerk during acceleration.
- Fuel economy may decrease significantly, potentially by as much as 10-15%, due to inefficient transmission operation.
- You may notice unusual sounds from the transmission, such as grinding or whining, especially during gear changes.
- In extreme cases, the vehicle may go into limp mode, severely limiting speed and performance.
Possible Causes
Most common causes of C0738 (ordered by frequency):
- The most common cause is a faulty clutch pressure sensor, which has a 70% likelihood of being the issue. Over time, wear and tear can lead to sensor failure.
- Wiring issues, such as damaged or corroded connectors, can also lead to a poor signal from the sensor, accounting for about 15% of cases. Regular inspections can help prevent this.
- Low transmission fluid levels or dirty fluid can cause the sensor to malfunction, which can be avoided by following routine maintenance schedules.
- Less common but serious causes include internal transmission problems that may require complete transmission replacement.
- A rare cause could be a malfunction in the Engine Control Module (ECM), which may misinterpret sensor signals, leading to incorrect diagnostics.
C0738 Repair Costs
Cost Breakdown by Repair Type
Clutch Pressure Sensor Replacement
Replacing the faulty clutch pressure sensor with an OEM part.
- Total: $150 - $300
- Success rate: 90%
Wiring Repair
Repairing or replacing damaged wiring and connectors leading to the sensor.
- Total: $100 - $200
- Success rate: 80%
Money-Saving Tips for C0738
- 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 C0738 Diagnosis Process
Follow these systematic steps to accurately diagnose C0738. Each step builds on the previous one to ensure accurate diagnosis.
Step 1: Step 1
Step 1: Initial visual inspection - Check for obvious signs like damaged wiring, loose connections, or corrosion (5-10 minutes)
Step 2: Step 2
Step 2: OBD2 scan with GeekOBD APP - Retrieve all codes and freeze frame data to understand the fault context (10-15 minutes)
Step 3: Step 3
Step 3: Component testing - Use a multimeter or specific diagnostic tools to test the clutch pressure sensor and wiring (20-30 minutes)
Step 4: Step 4
Step 4: System function test - Verify proper operation after repairs and clear codes using the GeekOBD APP (10-15 minutes)
Step 5: Step 5
Step 5: Road test verification - Drive the vehicle under various conditions to confirm repair success and ensure the check engine light stays off (15-20 minutes)
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: Clutch Pressure Sensor Replacement on a 2015 Ford F-150
Vehicle: 2015 Ford F-150, 85,000 miles
Problem: Customer reported erratic shifting and check engine light.
Diagnosis: Diagnostic scan revealed C0738. Visual inspection showed a faulty clutch pressure sensor.
Solution: Replaced the clutch pressure sensor with an OEM part.
Cost: $250 (parts and labor)
Result: After replacement, the vehicle shifted smoothly and the check engine light remained off.
Case Study 2: Wiring Repair for C0738 on a 2013 Chevrolet Silverado
Vehicle: 2013 Chevrolet Silverado, 90,000 miles
Problem: Customer experienced poor acceleration and check engine light.
Diagnosis: Found C0738 and damaged wiring leading to the clutch pressure sensor.
Solution: Repaired the wiring harness and replaced the connectors.
Cost: $150 (including parts and labor)
Result: Vehicle performance improved significantly, and the check engine light turned off.