C05CD: Brake Master Cylinder Piston Position Sensor B Circuit Voltage High

Severity

High

System

Chassis

Last reviewed: Jan 1, 0001 Last updated: Jan 1, 0001

Methodology: We combine code standards with complaint and reliability patterns, then review for clear, vehicle-first diagnosis steps.

Sources: SAE/OBD-II definitions, manufacturer service information, and public reliability reports (including NHTSA where applicable).

Limits: Guidance is informational and may not match every model-year or revision. Confirm with the official manual and diagnostics before replacing parts. For safety-critical or electrical work, use a qualified technician.

What Does C05CD Mean?

C05CD is a diagnostic trouble code indicating: Brake Master Cylinder Piston Position Sensor B Circuit Voltage High. This code relates to the chassis system. The vehicle's computer detected a condition outside normal operating parameters and stored this code.

Symptoms of C05CD

⚠️ Check Engine Light (MIL) illuminated
⚠️ Erratic Brake Master Cylinder Piston Position Sensor B readings
⚠️ Related system operating intermittently
⚠️ ABS or stability control warning light

Common Causes

🔍 Wiring issue in Brake Master Cylinder Piston Position Sensor B circuit (damaged, chafed, or corroded)
🔍 Faulty Brake Master Cylinder Piston Position Sensor B connector or terminal
🔍 Failed Brake Master Cylinder Piston Position Sensor B
🔍 ECM/PCM connection issue

Frequently Asked Questions

What does C05CD mean?

C05CD indicates: Brake Master Cylinder Piston Position Sensor B Circuit Voltage High. The vehicle's computer has detected that the Brake Master Cylinder Piston Position Sensor B is not operating within its expected parameters and stored this diagnostic trouble code.

Can I drive with code C05CD?

Only short distances if absolutely necessary. C05CD affects a critical system and should be diagnosed within a few days to avoid further damage.

How much does it cost to fix C05CD?

Repair costs for C05CD typically range from $100 to $400, depending on the root cause. Simple wiring or connector repairs are on the lower end, while component replacement costs more. A proper diagnosis ($80–$150 at most shops) will identify the exact cause before committing to expensive parts.

What To Do Next

Possible Fixes

🔧 Inspect and repair Brake Master Cylinder Piston Position Sensor B wiring and connectors
🔧 Replace faulty Brake Master Cylinder Piston Position Sensor B

1
Find your vehicle above
Click your make and model for real owner reports and common causes specific to your vehicle.
2
Check for recalls
Go to nhtsa.gov/recalls and enter your VIN. Free repairs if covered.
3
Get a professional diagnosis
A code alone doesn't identify the exact failed part. A diagnostic ($50–$150) pinpoints the root cause.

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