P1091 Possible Causes
- Faulty VVEL actuator motor relay
- VVEL actuator motor relay harness is open or shorted
- Poor electrical connection in VVEL actuator motor relay circuit
- Faulty VVEL control module
- Faulty engine control module (ECM)
How is P1091 Code Repaired?
Start by checking the “Possible Causes” listed above. Visually inspect the corresponding wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector pins.
Possible Symptoms
Check engine light illuminated (or service engine soon warning light)
P1091 Meaning
VVEL (Variable Valve Event & Lift) is a system that continuously controls valve event and valve lift. The rotational movement of the drive shaft equipped with an eccentric cam is transmitted to the output cam via the rocker arm and two types of links to push the intake valve. The engine control module (ECM) determines the target valve lift based on driving conditions and sends the control signal to the VVEL control module. The VVEL control module controls the rotation of the control shaft using the VVEL actuator motor and changes the output cam movement by shifting the linkage pivot point. As a result, valve lift continuously changes to improve engine power and response.
Power to the VVEL actuator motor is supplied to the VVEL control module through the VVEL actuator motor relay. The VVEL actuator motor relay is controlled ON/OFF by the VVEL control module. Additionally, when the VVEL actuator motor relay cannot be controlled by the VVEL control module for any reason, it is controlled ON/OFF by the ECM.