P05C6: Engine Coolant Pressure Sensor Circuit Intermittent/Erratic

Severity

Low

System

Vehicle Speed and Idle Control

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 P05C6 Mean?

P05C6 is a diagnostic trouble code indicating: Engine Coolant Pressure Sensor Circuit Intermittent/Erratic. This code relates to the vehicle speed and idle control system. The vehicle's computer detected a condition outside normal operating parameters and stored this code.

Symptoms of P05C6

⚠️ Check Engine Light (MIL) illuminated
⚠️ Engine Coolant Pressure Sensor signal cutting in and out
⚠️ Related system working sometimes but not consistently
⚠️ Erratic idle speed

Common Causes

🔍 Loose or intermittent connection at Engine Coolant Pressure Sensor
🔍 Wire chafing causing intermittent contact
🔍 Engine Coolant Pressure Sensor failing under heat or vibration
🔍 Corroded connector pins with partial contact

Frequently Asked Questions

What does P05C6 mean?

P05C6 indicates: Engine Coolant Pressure Sensor Circuit Intermittent/Erratic. The vehicle's computer has detected that the Engine Coolant Pressure Sensor is not operating within its expected parameters and stored this diagnostic trouble code.

Can I drive with code P05C6?

Yes, P05C6 is generally safe to drive with in the short term. However, it should still be addressed to pass emissions testing and prevent potential secondary issues.

How much does it cost to fix P05C6?

Repair costs for P05C6 typically range from $30 to $300, 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 reseat all Engine Coolant Pressure Sensor connectors
🔧 Repair chafed or damaged wiring in Engine Coolant Pressure Sensor circuit
🔧 Replace Engine Coolant Pressure Sensor if failing intermittently

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.

Related Codes

P0500 Vehicle Speed Sensor A Circuit P0501 Vehicle Speed Sensor A Circuit Range/Performance P0502 Vehicle Speed Sensor A Circuit Low P0503 Vehicle Speed Sensor Circuit Intermittent/High P0504 Brake Switch A/B Correlation P0505 Idle Control System P0506 Idle Control System RPM - Lower Than Expected P0507 Idle Control System RPM - Higher Than Expected P0508 Idle Air Control Circuit Low P0509 Idle Air Control Circuit High