Quick Answer
P0938 means: P0938 indicates a power steering pressure sensor circuit issue, often causing steering difficulties.
Can I drive with P0938? Immediate diagnosis and repair are recommended to ensure safe vehicle operation.
Common Questions
What does P0938 mean and how does it affect my car?
The P0938 code signifies that your vehicle's power steering pressure sensor is malfunctioning, which can lead to hard steering and increased effort while turning. This can affect your driving safety and cause further damage if not addressed.
What are the most common causes of P0938 and how much does it cost to fix?
Common causes include a faulty power steering pressure sensor, damaged wiring, or issues with the power steering pump. Repair costs can range from $100 to $800, depending on the specific repair needed.
Can I drive my car with P0938 or should I stop immediately?
It's best to avoid driving your vehicle if you see the P0938 code. Hard steering can compromise your control, especially in emergencies. Immediate diagnosis and repair are highly recommended.
How can I diagnose P0938 myself using GeekOBD APP?
Using the GeekOBD APP, you can scan for diagnostic trouble codes, view freeze frame data, and monitor the power steering pressure sensor readings in real time. This will help you identify whether the sensor is faulty.
What vehicles are most commonly affected by P0938?
The P0938 code is frequently found in models such as the 2007-2013 Chevrolet Silverado and GMC Sierra. Other GM vehicles with electronic power steering systems may also experience this issue.
How can I prevent P0938 from happening again?
Regular maintenance, including fluid checks and inspections of the power steering system, can help catch issues early. Additionally, keeping electrical connections clean and free from corrosion is crucial.
What is P0938?
The diagnostic trouble code P0938 indicates a problem with the power steering pressure sensor circuit, which is crucial for monitoring the hydraulic pressure in the power steering system. When this code appears, it typically means that the sensor is reporting values that are outside the expected range, which can lead to issues like hard steering, increased effort when turning the wheel, and potential damage to the steering system over time. This code is often found in vehicles such as the Chevrolet Silverado (2007-2013), GMC Sierra (2007-2013), and many other GM models equipped with electronic power steering systems. The underlying causes can include faulty wiring, a malfunctioning sensor, or issues within the power steering pump itself. If left unaddressed, this problem can affect the vehicle's handling and safety, making it crucial for car owners to diagnose and repair the issue promptly. Ignoring this code can lead to more severe steering problems and increased repair costs down the line.
System: P - Powertrain (Engine, Transmission, Emissions)
Symptoms
Common symptoms when P0938 is present:
- Check engine light illuminated, indicating an alert in the vehicle's diagnostic system.
- Steering becomes unusually heavy, especially during low-speed maneuvers, making it hard to turn the steering wheel.
- Increased effort required to turn the steering wheel, particularly noticeable during parking or tight turns.
- Unusual noises, such as whining or groaning, coming from the power steering pump area during operation.
- Intermittent loss of power steering assist, which can occur sporadically while driving.
Possible Causes
Most common causes of P0938 (ordered by frequency):
- The most common cause is a faulty power steering pressure sensor, which accounts for approximately 60% of P0938 cases. This sensor may fail due to wear and tear or exposure to extreme temperatures.
- Another frequent cause is damaged wiring or connectors in the sensor circuit, which can lead to incorrect readings. This type of failure typically results from corrosion or physical damage.
- Issues with the power steering pump itself can also contribute to this code. If the pump is not functioning correctly, it can cause fluctuating pressure readings.
- Less common but serious causes include low power steering fluid levels, which can lead to overheating and damage to the system if not addressed.
- A rare cause may be electronic control module (ECM) malfunctions, which can misinterpret sensor readings, although this scenario is less likely.
P0938 Repair Costs
Cost Breakdown by Repair Type
Replace Power Steering Pressure Sensor
Replacing the faulty power steering pressure sensor often resolves the P0938 code and restores normal steering function.
- Total: $150 - $300
- Success rate: 85%
Repair Wiring or Connectors
Repairing damaged wiring or connectors may be necessary if they are the root cause of the issue.
- Total: $100 - $200
- Success rate: 70%
Replace Power Steering Pump
In cases where the pump is malfunctioning, replacing it may be required, especially if fluid levels are not the issue.
- Total: $400 - $800
- Success rate: 90%
Money-Saving Tips for P0938
- 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 P0938 Diagnosis Process
Follow these systematic steps to accurately diagnose P0938. 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 around the power steering pressure sensor (5-10 minutes)
Step 1: Initial visual inspection - Check for obvious signs like damaged wiring, loose connections, or corrosion around the power steering pressure sensor (5-10 minutes).
Step 2: Step 2: OBD2 scan with GeekOBD APP - Retrieve all codes and freeze frame data to understand the fault context and confirm the presence of P0938 (10-15 minutes)
Step 2: OBD2 scan with GeekOBD APP - Retrieve all codes and freeze frame data to understand the fault context and confirm the presence of P0938 (10-15 minutes).
Step 3: Step 3: Component testing - Use a multimeter to check the voltage and resistance of the power steering pressure sensor, ensuring it is within manufacturer specifications (20-30 minutes)
Step 3: Component testing - Use a multimeter to check the voltage and resistance of the power steering pressure sensor, ensuring it is within manufacturer specifications (20-30 minutes).
Step 4: Step 4: System function test - After any repairs, verify proper operation of the power steering system and clear codes using the GeekOBD APP (10-15 minutes)
Step 4: System function test - After any repairs, verify proper operation of the power steering system and clear codes using the GeekOBD APP (10-15 minutes).
Step 5: Step 5: Road test verification - Drive the vehicle under various conditions to confirm that the steering functions correctly and that the P0938 code does not reappear (15-20 minutes)
Step 5: Road test verification - Drive the vehicle under various conditions to confirm that the steering functions correctly and that the P0938 code does not reappear (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: Power Steering Pressure Sensor Replacement on 2010 Chevrolet Silverado
Vehicle: 2010 Chevrolet Silverado 1500, 85,000 miles
Problem: Customer reported heavy steering and a check engine light.
Diagnosis: After scanning with GeekOBD, confirmed a P0938 code. Inspected wiring and sensors.
Solution: Replaced the power steering pressure sensor and repaired some corroded connectors.
Cost: $250 (sensor $150, labor $100)
Result: Steering returned to normal, and the check engine light was cleared.
Case Study 2: Wiring Repair for P0938 Code on 2012 GMC Sierra
Vehicle: 2012 GMC Sierra 2500HD, 60,000 miles
Problem: Customer noticed intermittent loss of power steering assist.
Diagnosis: GeekOBD scan revealed P0938, with visual inspection showing damaged wiring.
Solution: Repaired the wiring harness and cleared the code.
Cost: $180 (wiring repair and labor)
Result: Issue resolved, and the P0938 code did not return after testing.