P1801 — Transmission Clutch Interlock Safety Switch Open Circuit

What Does P1801 Mean?

P1801 is a manufacturer-specific diagnostic trouble code: Transmission Clutch Interlock Safety Switch Open Circuit. This code applies to OTHER, BUICK, CADILLAC, CHEVY, GM 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 P1801

⚠️ Check Engine Light (MIL) illuminated
⚠️ Erratic Transmission Clutch Interlock Safety Switch Open readings
⚠️ Related system operating intermittently
⚠️ Reduced engine performance

Common Causes

🔍 Wiring issue in Transmission Clutch Interlock Safety Switch Open circuit (damaged, chafed, or corroded)
🔍 Faulty Transmission Clutch Interlock Safety Switch Open connector or terminal
🔍 Failed Transmission Clutch Interlock Safety Switch Open
🔍 ECM/PCM connection issue

Frequently Asked Questions

What does P1801 mean?

P1801 indicates: Transmission Clutch Interlock Safety Switch Open Circuit. The vehicle's computer has detected that the Transmission Clutch Interlock Safety Switch Open is not operating within its expected parameters and stored this diagnostic trouble code.

Can I drive with code P1801?

You can drive short distances for essential trips, but schedule a diagnosis soon. Driving with P1801 for extended periods may cause additional problems.

How much does it cost to fix P1801?

Repair costs for P1801 typically range from $80 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 Transmission Clutch Interlock Safety Switch Open wiring and connectors
🔧 Replace faulty Transmission Clutch Interlock Safety Switch Open

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.

P1801: Transmission Clutch Interlock Safety Switch Open Circuit