Selected Link ECUs have the ability to control Continuously Variable Valve Timing (VVT). VVT is used by engine manufacturers to dynamically adjust valve timing which can increase power, improve economy and reduce emissions. Link ECUs use a high speed precision Proportional-Integral-Derivative (PID) control algorithm to accurately position the cam shafts. Closed loop control allows cam positioning to remain unaffected by variations in oil temperature and pressure.

 

Warning: VVT control is an advanced feature. Although Link VVT control provides a large amount of status information, it should only be set-up and operated by experienced tuners. Failure to correctly set up VVT Control can result in unpredictable cam timing which can result in engine damage. DO NOT adjust anything you are not completely sure of!

 

Warning: It is strongly recommended to use the preset VVT configuration if one is offered in the software instead of a custom configuration.

 

 

VVT Configuration

To set up VVT Control, the following steps must be taken:

 

1.Select the Cam Control Mode, it is strongly recommended to use the preset VVT configuration if one is offered in the software instead of a custom configuration.

2.Set the Cam Sensor Inputs - A camshaft position sensor must be wired to either a digital input or Trigger 2. For simplicity, wiring a cam's position sensor and solenoid to the same numbered auxiliary output and digital input is recommended but this isn't a requirement.

3.Set the PWM Outputs - The cam shafts position control solenoid must be wired to an auxiliary output. For simplicity, wiring a cam's position sensor and solenoid to the same numbered auxiliary output and digital input is recommended but this isn't a requirement.

4.Run the Cam Angle Test Calibrate function to automatically setup the Tooth Count and Tooth Offsets settings.

5.Tune The Control Algorithm - Only necessary if not using a preset VVT configuration.

6.Observe VVT Control runtime status information in the VVT tab of the Runtime Values window (F12 key) to ensure correct operation.

 

General VVT setup advice

·If the sensors are wired backwards or trigger arming voltages set incorrectly VVT control will not work.

·Some engines can-not run VVT control below about 1500 RPM.

·VVT control is closed loop, it will keep trying to correct cam position until it matches the target.

·If the closed loop control is tuned wrong (PID numbers) then it may not be able to control the cams.

·If the solenoids are not wired or working correctly it will not be able to control the cams.

·If the runtime status for the cams shows happy with no errors then it is most likely reading position correctly (after offsets are set correctly).

·If position is being read correctly but target is not being reached then it is most likely that the solenoids or control numbers are incorrect.