ABS Base Brake System Pressure Circuit Low
What does C0136 mean?
The C0136 code means the vehicle's onboard diagnostic system has detected: ABS Base Brake System Pressure Circuit Low. This is a critical severity code.
Common Symptoms
- ABS warning light on
- Brake warning light on
- Low brake pedal
- Increased stopping distance
- Soft or spongy brake pedal feel
Probable Causes (Ranked by Likelihood)
- Low brake fluid level Very High
- Brake fluid leak in the system High
- Worn brake pads causing caliper overextension Moderate
- Master cylinder internal failure Moderate
- ABS pressure sensor malfunction Low
Step-by-Step Diagnostic Procedure
-
Check brake fluid level in the master cylinder reservoir immediately
-
Inspect all brake lines, hoses, and calipers for fluid leaks
-
Check brake pad thickness on all four wheels
-
Test master cylinder by holding firm pedal pressure -- pedal should not sink
-
Monitor ABS pressure sensor data with a scan tool during brake application
Frequently Asked Questions
Is C0136 dangerous?
Yes. This code indicates low brake pressure, which directly affects your ability to stop the vehicle. Do not drive until the cause is identified and repaired. Have the vehicle towed to a repair shop if necessary.
Can worn brake pads cause low brake pressure?
Indirectly, yes. Severely worn pads cause the caliper pistons to extend further, drawing more fluid from the reservoir. If the fluid drops low enough, air can enter the system, causing low pressure.
How do I check for a brake fluid leak?
Visually inspect each wheel for wet spots around the calipers and hoses. Look under the vehicle along the brake lines for drips. Check the master cylinder area for fluid seepage. A UV dye can be added to the fluid to make small leaks easier to find.