C0138 Code - Base Brake System Pressure Circuit/Sensor Low
Quick Answer
The C0138 code indicates a problem with the base brake system pressure circuit or sensor being too low. Common causes include Brake fluid leaks, Faulty base brake pressure sensor, Malfunctioning ABS module. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
- What it means
- C0138 indicates Base Brake System Pressure Circuit/Sensor Low.
- Common causes
- Common causes include Brake fluid leaks, Faulty base brake pressure sensor, Malfunctioning ABS module.
- Severity
- High - diagnose this code as soon as possible.
- Can I drive?
- Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
Fix Your Car Smarter
Try the New AutoCodes App!
Get complete OBDII diagnostics, repair solutions, and cost estimates, plus AI chat support on demand.
Code C0138 Description
The C0138 code indicates a problem with the base brake system pressure circuit or sensor being too low. The base brake system is a crucial component of the vehicle's braking system, responsible for generating and maintaining the hydraulic pressure necessary for effective braking. When the pressure in the base brake system is too low, it can lead to decreased braking performance, longer stopping distances, and potential safety hazards.
Common Causes of C0138
- Brake fluid leaks
- Faulty base brake pressure sensor
- Malfunctioning ABS module
- Damaged brake lines
- Contaminated brake fluid
Symptoms of C0138
- Illuminated brake warning light on the dashboard
- Soft or spongy brake pedal
- Increased stopping distance
- Brake fluid leaks under the vehicle
- Difficulty stopping the vehicle
How to Fix C0138
- Perform a visual inspection of the brake system to check for any leaks or damage.
- Test the base brake pressure sensor to determine if it is functioning correctly.
- Inspect the ABS module for any issues and replace if necessary.
- Check and replace any damaged brake lines.
- Flush and replace the brake fluid to ensure it is clean and free of contaminants.
Cost to Fix C0138
The cost of repairing a base brake system pressure circuit/sensor low issue can vary depending on the specific cause of the problem and the extent of the repairs needed. Generally, the cost of parts for this repair can range from $100 to $500, while labor costs can range from $150 to $300. This estimate does not include diagnostic fees, which can vary depending on the shop's rates and the time required to pinpoint the issue. It is recommended to get a detailed quote from a trusted auto repair shop to determine the exact cost for your specific situation.
Need more information about the C0138 code?
Need more information on how to fix the C0138 code? Get Access to Factory Service Manuals
Need Help with the Code?
Get the C0138 code diagnosed by a professional: Find a repair shop in your area
Code C0138 Information for Specific Makes
- C0138 Buick — Base Brake System Pressure Circuit/Sensor Low
- C0138 Cadillac — Base Brake System Pressure Circuit/Sensor Low
- C0138 Chevrolet — Base Brake System Pressure Circuit/Sensor Low
- C0138 GMC — Base Brake System Pressure Circuit/Sensor Low
- C0138 Pontiac — Base Brake System Pressure Circuit/Sensor Low
- C0138 Saturn — Base Brake System Pressure Circuit/Sensor Low
Frequently Asked Questions about C0138 Code
What does the OBDII code C0138 mean?
C0138 indicates a problem with the base brake system pressure circuit or sensor, specifically signaling that the pressure is too low.
What are common symptoms associated with the C0138 code?
Symptoms may include a warning light on the dashboard, reduced braking efficiency, a spongy brake pedal, or a complete loss of brake pressure in severe cases.
What could cause the C0138 code to trigger?
Possible causes include a faulty brake pressure sensor, wiring issues, leaks in the brake system, or problems with the brake control module.
How can I diagnose the C0138 code?
Start by scanning the vehicle for trouble codes, inspecting the brake system for leaks, checking the brake pressure sensor and its wiring, and testing the brake control module.
Is it safe to drive with the C0138 code?
It is not safe to drive with this code as it indicates a potential issue with the brake system, which could lead to brake failure.
What repairs are typically needed for the C0138 code?
Repairs may involve replacing a faulty brake pressure sensor, fixing wiring or connector issues, or addressing any leaks in the brake system.
Can the C0138 code be cleared without fixing the issue?
While you can clear the code, if the underlying issue is not resolved, it will likely return, and the brake system may remain compromised.
How can I prevent the C0138 code from appearing in the future?
Regular maintenance of the braking system, including inspections for leaks and ensuring proper sensor function, can help prevent the C0138 code from occurring.
Will the C0138 code affect my vehicle's performance?
Yes, low brake pressure can significantly impact your vehicle's braking performance, making it potentially dangerous to drive.
Discuss the causes and fixes for C0138 OBDII Code
Code C0138 comments
No comments found for this page.
Fix Your Car Smarter
Try the New AutoCodes App!
Get complete OBDII diagnostics, repair solutions, and cost estimates, plus AI chat support on demand.