P0397 — Cylinder 1 Pressure Sensor Circuit Low

What Does P0397 Mean?

P0397 is a diagnostic trouble code indicating: Cylinder 1 Pressure Sensor Circuit Low. 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 P0397

⚠️ Check Engine Light (MIL) illuminated
⚠️ Cylinder 1 Pressure Sensor reading at zero or minimum value
⚠️ Related system not functioning or in fail-safe mode
⚠️ Engine misfires or rough running

Common Causes

🔍 Open or broken wire in Cylinder 1 Pressure Sensor circuit
🔍 Poor ground connection at Cylinder 1 Pressure Sensor
🔍 Faulty Cylinder 1 Pressure Sensor with no output signal
🔍 Disconnected or loose Cylinder 1 Pressure Sensor connector
🔍 Blown fuse in related circuit

Frequently Asked Questions

What does P0397 mean?

P0397 indicates: Cylinder 1 Pressure Sensor Circuit Low. The vehicle's computer has detected that the Cylinder 1 Pressure Sensor is not operating within its expected parameters and stored this diagnostic trouble code.

Can I drive with code P0397?

Only short distances if absolutely necessary. P0397 affects a critical system and should be diagnosed within a few days to avoid further damage.

How much does it cost to fix P0397?

Repair costs for P0397 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

🔧 Repair broken wire or restore ground in Cylinder 1 Pressure Sensor circuit
🔧 Clean and secure Cylinder 1 Pressure Sensor connector and ground points
🔧 Replace failed Cylinder 1 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.

P0397: Cylinder 1 Pressure Sensor Circuit Low