P1491moderate severityPowertrain
Vacuum Cut Valve Bypass Valve
on 2006 Infiniti M45 4.5L V8 · RWD
What this code means
The vacuum cut valve bypass valve in the EVAP system is not working correctly. This affects fuel vapor control and can trigger the check engine light.
Symptoms
- Check engine light on
- Fuel odor
- Failed emissions test
Common causes
- Faulty bypass valve
- Vacuum hose leak or blockage
- Wiring or connector fault
- Damaged EVAP canister
Diagnostic steps
- Scan for stored codes
- Inspect vacuum hoses and connections
- Test bypass valve operation
- Check wiring and connector continuity
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Other Powertrain codes on this vehicle
P0001
Fuel Volume Regulator Control Circuit/Open
P0002
Fuel Volume Regulator Control Circuit Range/Performance
P0003
Fuel Volume Regulator Control Circuit Low
P0004
Fuel Volume Regulator Control Circuit High
P0005
Fuel Shutoff Valve A Control Circuit/Open
P0006
Fuel Shutoff Valve A Control Circuit Low
P0007
Fuel Shutoff Valve A Control Circuit High
P0008
Engine Position System Performance - Bank 1
P0009
Engine Position System Performance - Bank 2
P0010
Intake Camshaft Position Actuator Circuit/Open Bank 1