P1491 — Secondary Switch Solenoid Circuit Malfunction

What Does P1491 Mean?

P1491 is a diagnostic trouble code indicating: Secondary Switch Solenoid Circuit Malfunction. This code relates to the manufacturer-specific powertrain system. The vehicle's computer detected a condition outside normal operating parameters and stored this code.

Symptoms of P1491

⚠️ Check Engine Light (MIL) illuminated
⚠️ Erratic Secondary Switch Solenoid readings
⚠️ Related system operating intermittently
⚠️ Reduced engine performance

Common Causes

🔍 Wiring issue in Secondary Switch Solenoid circuit (damaged, chafed, or corroded)
🔍 Faulty Secondary Switch Solenoid connector or terminal
🔍 Failed Secondary Switch Solenoid
🔍 ECM/PCM connection issue

Frequently Asked Questions

What does P1491 mean?

P1491 indicates: Secondary Switch Solenoid Circuit Malfunction. The vehicle's computer has detected that the Secondary Switch Solenoid is not operating within its expected parameters and stored this diagnostic trouble code.

Can I drive with code P1491?

You can drive short distances for essential trips, but schedule a diagnosis soon. Driving with P1491 for extended periods may cause additional problems.

How much does it cost to fix P1491?

Repair costs for P1491 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 Secondary Switch Solenoid wiring and connectors
🔧 Replace faulty Secondary Switch Solenoid

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.

P1491: Secondary Switch Solenoid Circuit Malfunction