On most systems, idle speed is completely controlled by the throttle plate angle.
Throttle-by-wire allows engines to better utilize variable valve timing and direct injection for torque and power.
Installation is not a plug and play procedure for some vehicles. This video is sponsored by Auto Value and Bumper to Bumper.
Swapping one throttle-by-wire unit for a new unit in hopes of resolving a code or limp-mode problem is not an option due to the high price and strict manufacturer return policies.
The main reason for the switch to Throttle-By-Wire (TBW) or Drive-by-Wire is that it allows the ECM to work in harmony with other engine control systems such as cruise control, traction control, torque management and stability control.
Jason Stahl discusses the best and safest way to reset a throttle-by-wire system. Sponsored by Standard.
With carburetors, idle was a set RPM number that depended on the angle of the primary’s throttle. During a tune up, idle was set with a screwdriver. Also set was the fast idle cam that changed the throttle angle when the choke was set on some carburetors. Idle was a fixed angle and the idle would change as the A/C compressor clutch engaged or electrical loads increased.
A simple cable linking the gas pedal to the throttle plate just wasn’t good enough for engineers, who have now complicated the design with throttle-by-wire.
The PCM continuously monitors the commanded and actual throttle positions. The commanded throttle position is compared to the actual throttle position based on accelerator pedal position and possibly other limiting factors, and both values should be within a calibrated range of the other.
If you have just cleaned the throttle body and now you’ve a fluctuating idle and code P2279 (intake air system leak), the problem could be that the system needs to relearn the new throttle plate position because the system could be operating using the old data.
A simple cable linking the gas pedal to the throttle plate just wasn’t good enough for engineers, who have now complicated the design with throttle-by-wire. Why do engineers do these things to us? That expensive throttle body can’t be cheaper than a little throttle cable — or can it? Does this design provide any advantages