Autonatomy · Electronic Throttle Control Lab

Learning objective

Distinguish accelerator pedal position (APP) from throttle position (TPS), observe electronic throttle motor control, and use commanded-versus-actual data to reason about an ETC fault.

Simplified warm, naturally aspirated gasoline engine teaching model. Pedal-to-throttle mapping, sensor voltage ranges, motor control, default angles, fault responses, and airflow values are illustrative—not OEM specifications. Do not infer a vehicle-specific diagnosis from these values.

1 · Operate the system

Accelerator pedal: 15%Engine speed: 900 RPMIntroduce a fault

The two sensor channels are illustrative redundant signals; real ETC designs can use different slopes, offsets, and plausibility checks.

2 · The Challenger

The scan tool shows a high throttle command, but actual throttle position remains near idle. Which area should you investigate first?

Choose an answer Throttle actuator, its power/ground, wiring, and mechanical movement Replace the accelerator pedal without further testing Assume the MAF sensor must be defective

Choose an answer and explain your reasoning.

3 · Watch the throttle respond

APP sensor 1—

APP sensor 2—

Commanded throttle—

Actual throttle / TPS 1—

TPS sensor 2—

Estimated airflow—

ETC control status—

Command / actual difference—

4 · Technician's reasoning

Compare APP channels for plausibility, then compare throttle command with actual position. If the command and feedback disagree, inspect the actuator circuit and throttle mechanism using vehicle-specific service information. An APP or TPS plausibility fault may trigger a protective throttle strategy; this model demonstrates one possible response, not a universal limp-home angle.