P03AC — Cylinder 3 Pressure Sensor Circuit High

What Does P03AC Mean?

P03AC is a diagnostic trouble code indicating: Cylinder 3 Pressure Sensor Circuit High. This code relates to the ignition system system. The vehicle's computer detected a condition outside normal operating parameters and stored this code.

Symptoms of P03AC

⚠️ Check Engine Light (MIL) illuminated
⚠️ Cylinder 3 Pressure Sensor reading stuck at maximum value
⚠️ Related system operating erratically or in default mode
⚠️ Engine misfires or rough running

Common Causes

🔍 Short to voltage in Cylinder 3 Pressure Sensor wiring harness
🔍 Corroded or water-damaged Cylinder 3 Pressure Sensor connector
🔍 Faulty Cylinder 3 Pressure Sensor outputting maximum voltage
🔍 Damaged wiring rubbing against metal components
🔍 ECM/PCM internal fault (rare)

Frequently Asked Questions

What does P03AC mean?

P03AC indicates: Cylinder 3 Pressure Sensor Circuit High. The vehicle's computer has detected that the Cylinder 3 Pressure Sensor is not operating within its expected parameters and stored this diagnostic trouble code.

Can I drive with code P03AC?

Only short distances if absolutely necessary. P03AC affects a critical system and should be diagnosed within a few days to avoid further damage.

How much does it cost to fix P03AC?

Repair costs for P03AC typically range from $20 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 repair Cylinder 3 Pressure Sensor wiring for short to voltage
🔧 Clean or replace corroded Cylinder 3 Pressure Sensor connector
🔧 Replace faulty Cylinder 3 Pressure Sensor

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.

P03AC: Cylinder 3 Pressure Sensor Circuit High