How is fault code P1491 fixed?

- Verify the connector is fully seated and its lock tab is engaged - Check for ignition voltage on the feed side of the valve with the key on - Measure coil resistance; an infinite reading confirms an open solenoid - Perform a continuity test from the valve connector through to the module pin - Wiggle test the harness while measuring to reveal an intermittent open - Repair the wire or terminal, or replace the purge valve - Clear the code and drive an EVAP monitor cycle to verify

Secondary Switch Solenoid Circuit Malfunction

Jump to the fix

Severity

Medium

Can I keep driving?

Usually drivable, but get it diagnosed without delay.

First step

Verify the connector is fully seated and its lock tab is engaged

PPowertrain
1Manufacturer-specific
4Powertrain (Other)
91Sequence number

What does it mean?

P1491 is a Powertrain (engine, transmission, fuel system) fault code. It indicates: Evaporative Emission System Purge Control Valve Circuit Open .

Symptoms

MIL on
Purge valve never operates, so the canister stays loaded with fuel vapour
Fuel smell, especially in hot weather or after filling the tank
Extended cranking after refuelling
EVAP readiness monitor stays incomplete
Idle quality is usually normal

Likely causes

Broken wire or a loose terminal in the purge valve connector
Purge solenoid coil open internally
Blown fuse feeding the purge circuit
Corroded terminals creating resistance high enough to read as an open
Connector left unplugged after previous service work
Wire broken inside the insulation from vibration and flexing
Module driver circuit open

How to fix it

Verify the connector is fully seated and its lock tab is engaged
Check for ignition voltage on the feed side of the valve with the key on
Measure coil resistance; an infinite reading confirms an open solenoid
Perform a continuity test from the valve connector through to the module pin
Wiggle test the harness while measuring to reveal an intermittent open
Repair the wire or terminal, or replace the purge valve
Clear the code and drive an EVAP monitor cycle to verify

Codes From the Same System

All Fault Codes

Related Similar Codes

This information follows the generic OBD-II definition and does not replace a vehicle-specific diagnosis. The severity rating is rule-based; an authorised diagnostic reading is required for a definitive answer.