C0748 - Understanding Transfer Case Fluid Pressure Sensor Circuit Range/Performance Problem in Popular Vehicles

Quick Answer

C0748 means: C0748 indicates a problem with the transfer case fluid pressure sensor circuit, which can affect your vehicle's 4WD functionality.

Fix: Check and replace faulty components Cost: $150 - $300 Time: 90-180 minutes

Can I drive with C0748? Immediate attention is recommended to avoid further damage to the transfer case.

Common Questions

What does C0748 mean and how does it affect my car?

C0748 indicates a malfunction in the transfer case fluid pressure sensor circuit. This can lead to issues like difficulty in switching between drive modes, which is especially concerning if you're in a situation requiring four-wheel drive. Ignoring this code could result in further mechanical damage, compromising your vehicle's performance and safety.

What are the most common causes of C0748 and how much does it cost to fix?

The most common cause of C0748 is a faulty transfer case fluid pressure sensor, which typically costs between $150-$300 to replace. Other causes include wiring issues and control module failures, with repair costs ranging from $100 to $800 depending on the complexity of the issue.

Can I drive my car with C0748 or should I stop immediately?

While you may still be able to drive your vehicle, it is not advisable to ignore the C0748 code. Continuing to drive with this issue could lead to further damage to the transfer case and affect your vehicle's safety. It's best to have it diagnosed and repaired as soon as possible.

How can I diagnose C0748 myself using GeekOBD APP?

To diagnose C0748 using the GeekOBD APP, first connect the app to your vehicle's OBD2 port. Use the app to scan for trouble codes and review the freeze frame data for insights into the vehicle's performance at the time of the error. This information will help you pinpoint the issue more accurately before seeking repairs.

What vehicles are most commonly affected by C0748?

C0748 is frequently reported in models like the 2011-2016 Ford Explorer and the 2010-2015 Chevrolet Equinox. Owners of these vehicles should be particularly vigilant about symptoms related to their transfer case functionality.

How can I prevent C0748 from happening again?

Regular maintenance of your vehicle's transfer case is crucial. This includes checking and changing the transfer case fluid per manufacturer recommendations, inspecting wiring for wear and tear, and addressing any unusual noises or performance issues promptly to prevent the recurrence of C0748.

What is C0748?

The diagnostic trouble code (DTC) C0748 indicates a problem with the transfer case fluid pressure sensor circuit, often seen in vehicles with four-wheel drive (4WD) and all-wheel drive (AWD) systems. This code specifically means that the fluid pressure sensor, which monitors the hydraulic pressure within the transfer case, is either out of range or not performing as expected. If this sensor fails, it can lead to issues with the vehicle's ability to switch between 2WD and 4WD, causing potential drivability problems. Commonly affected vehicles include the 2011-2016 Ford Explorer and the 2010-2015 Chevrolet Equinox. Symptoms may include abnormal shifting, unexpected loss of power to the wheels, or difficulties engaging 4WD. Ignoring this code can lead to further mechanical issues and safety hazards, making it crucial for vehicle owners to address it promptly. Additionally, the problem may stem from wiring issues, a faulty sensor, or even a malfunctioning transfer case control module. Regular maintenance, such as checking the transfer case fluid levels, can help in the early detection of such issues, ultimately saving time and repair costs.

System: C - Chassis (ABS, Steering, Suspension)

Symptoms

Common symptoms when C0748 is present:

  • The check engine light is illuminated, indicating a malfunction that needs attention.
  • Difficulty engaging or switching between 2WD and 4WD, which may leave you stranded in adverse conditions.
  • Strange noises or grinding sounds from the transfer case when attempting to shift modes.
  • Reduced vehicle performance, especially in off-road conditions, as the vehicle may not engage the necessary drive mode.
  • Unstable handling and traction issues during acceleration, particularly in slippery conditions.

Possible Causes

Most common causes of C0748 (ordered by frequency):

  1. Faulty transfer case fluid pressure sensor (70% likelihood) - This is the most common issue leading to code C0748, where the sensor may fail due to wear and tear or manufacturing defects.
  2. Wiring problems (20% likelihood) - Damaged, corroded, or shorted wiring can disrupt the signal to the vehicle's computer, leading to incorrect readings.
  3. Transfer case control module malfunction (5% likelihood) - A failure in the control module may prevent it from accurately interpreting the sensor's readings.
  4. Fluid contamination (3% likelihood) - Contaminants in the transfer case fluid can cause sensor errors and affect performance.
  5. Rarely, a mechanical failure in the transfer case itself (2% likelihood) can lead to incorrect pressure readings.

C0748 Repair Costs

Cost Breakdown by Repair Type

Replace Transfer Case Fluid Pressure Sensor

Replacing the faulty pressure sensor to restore normal functionality.

  • Total: $150 - $300
  • Success rate: 90%
Repair Wiring Harness

Fixing damaged wiring that may be causing sensor communication issues.

  • Total: $100 - $200
  • Success rate: 85%
Transfer Case Control Module Replacement

In cases of severe malfunction, replacing the entire control module may be necessary.

  • Total: $400 - $800
  • Success rate: 75%
Money-Saving Tips for C0748
  • 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 C0748 Diagnosis Process

Follow these systematic steps to accurately diagnose C0748. Each step builds on the previous one to ensure accurate diagnosis.

Step 1: Step 1: Initial visual inspection - Check for obvious signs like damaged wiring, loose connections, or corrosion (5-10 minutes)

Step 1: Initial visual inspection - Check for obvious signs like damaged wiring, loose connections, or corrosion (5-10 minutes).

GeekOBD APP Tip: Use GeekOBD APP to monitor real-time data during this diagnostic step for accurate results and professional-grade analysis.
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 2: OBD2 scan with GeekOBD APP - Retrieve all codes and freeze frame data to understand the fault context (10-15 minutes).

GeekOBD APP Tip: Use GeekOBD APP to monitor real-time data during this diagnostic step for accurate results and professional-grade analysis.
Step 3: Step 3: Component testing - Use a multimeter to test the fluid pressure sensor and wiring integrity (20-30 minutes)

Step 3: Component testing - Use a multimeter to test the fluid pressure sensor and wiring integrity (20-30 minutes).

GeekOBD APP Tip: Use GeekOBD APP to monitor real-time data during this diagnostic step for accurate results and professional-grade analysis.
Step 4: Step 4: System function test - Verify proper operation after repairs and clear codes using the GeekOBD APP (10-15 minutes)

Step 4: System function test - Verify proper operation after repairs and clear codes using the GeekOBD APP (10-15 minutes).

GeekOBD APP Tip: Use GeekOBD APP to monitor real-time data during this diagnostic step for accurate results and professional-grade analysis.
Step 5: Step 5: Road test verification - Drive the vehicle under various conditions to confirm repair success and monitor for code reappearance (15-20 minutes)

Step 5: Road test verification - Drive the vehicle under various conditions to confirm repair success and monitor for code reappearance (15-20 minutes).

GeekOBD APP Tip: Use GeekOBD APP to monitor real-time data during this diagnostic step for accurate results and professional-grade analysis.

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: Transfer Case Pressure Sensor Replacement in 2014 Ford Explorer

Vehicle: 2014 Ford Explorer, 75,000 miles

Problem: Customer reported difficulty in engaging 4WD and illuminated check engine light.

Diagnosis: Using the GeekOBD APP, the trouble code C0748 was confirmed. A visual inspection revealed frayed wires leading to the pressure sensor.

Solution: Replaced the transfer case fluid pressure sensor and repaired the damaged wiring.

Cost: $220 (sensor: $150, wiring repair: $70)

Result: After repairs, the 4WD engaged normally, and the check engine light was cleared with no reoccurrence of the code.

Case Study 2: Wiring Repair on 2013 Chevrolet Equinox

Vehicle: 2013 Chevrolet Equinox, 80,000 miles

Problem: Customer experienced erratic 4WD functionality and frequent check engine light activation.

Diagnosis: OBD2 scan indicated C0748. Further inspection found corroded wiring connections to the transfer case pressure sensor.

Solution: Repaired the wiring harness and cleaned the connections, ensuring a secure electrical signal.

Cost: $150 (wiring repair and labor)

Result: Post-repair, the vehicle's 4WD system functioned correctly, with no further check engine light issues.

Diagnose C0748

Use GeekOBD APP for professional diagnosis!

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Code Information

Code: C0748
System: Chassis (ABS, Steering, Suspension)
Severity: HIGH
Category: Chassis Codes