Remember drive-by-cable systems? Back in the day a car's accelerator pedal used to physically be connected to the throttle via a cable. So when you "step on the gas" the cable and mechanical linkages would open the throttle and off you went.
Nowadays most throttles are controlled electronically in what's called a drive-by-wire system. Instead of an actual cable, a series of sensors relay information to an electronic control unit (ECU) which then does some on-the-fly calculations before opening or closing some electromechanical actuators on the throttle.
It has some big advantages, which we'll touch on later, but it comes at the cost of complications and frustrating problems like delayed acceleration response.
One of the more common complaints about Chevrolet's implementation of the electronic throttle control is a delayed acceleration or throttle lag.
In other words when you step on the gas, it takes the car a second or two before it starts to move. Those seconds can feel like an enternity when you're driving. At best it's a frustrating experience. At worst it can be downright dangerous, like when trying to cross traffic.
Each system is unique to the automaker but they all have a variety of computers, sensors, and potentiometers that need to talk to each other in perfect sync. Even if every component is operational, sensors can still send delayed information or the computer can experience some hiccup in its calculations. All it takes is a little electrical delay.
And it doesn't matter how hard you stomp on the accelerator pedal, that delay translates to throttle lag or "dead zone."
Tracking down specific electrical delays can be a nightmare. Sometimes things can be improved by replacing sensors, updating software, or replacing / cleaning the throttle body. But without specific error codes it can be a bit of a wild goose chase.
Generally, yes. Drive-by-wire systems offer a number of advantages:
It's able to work in conjunction with safety systems such as the electronic stability control (ESC) and lane assist.
It makes convenience features like adaptive cruise control possible.
Some are even programmed to help with fuel efficiency.
Improving performance with a throttle controller ∞
Automakers are trying to improve the drive-by-wire experience by installing a range of "throttle controllers" to counteract lag.
Throttle controllers can catch the signal between the accelerator sensor and the ECU, and modify it if needed. There are aftermarkt sensors that can be installed and automakers are continuing to try to improve performance with each subsequent generation.
This problem has popped up in the following Chevrolet generations.
Most years within a generation share the same parts and manufacturing process. You can also expect them to share the same problems. So while it may not be a problem in every year yet, it's worth looking out for.