P1591 — Neutral Position Switch Circuit Low Input

What Does P1591 Mean?

P1591 is a manufacturer-specific diagnostic trouble code: Neutral Position Switch Circuit Low Input. This code applies to SUBARU vehicles. Unlike generic OBD-II codes, manufacturer-specific codes are defined by the vehicle maker and may only apply to certain makes and models.

Symptoms of P1591

⚠️ Check Engine Light (MIL) illuminated
⚠️ Neutral Position Switch reading at zero or minimum value
⚠️ Related system not functioning or in fail-safe mode
⚠️ Reduced engine performance

Common Causes

🔍 Open or broken wire in Neutral Position Switch circuit
🔍 Poor ground connection at Neutral Position Switch
🔍 Faulty Neutral Position Switch with no output signal
🔍 Disconnected or loose Neutral Position Switch connector
🔍 Blown fuse in related circuit

Frequently Asked Questions

What does P1591 mean?

P1591 indicates: Neutral Position Switch Circuit Low Input. The vehicle's computer has detected that the Neutral Position Switch is not operating within its expected parameters and stored this diagnostic trouble code.

Can I drive with code P1591?

You can drive short distances for essential trips, but schedule a diagnosis soon. Driving with P1591 for extended periods may cause additional problems.

How much does it cost to fix P1591?

Repair costs for P1591 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 Neutral Position Switch circuit
🔧 Clean and secure Neutral Position Switch connector and ground points
🔧 Replace failed Neutral Position Switch

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.

P1591: Neutral Position Switch Circuit Low Input