Hello and welcome to Just answer.com, Super mechanic here. About your vehicle.
ECT, (electronic throttle control)
OPERATION The Electronic Throttle Control (ETC) indicator gives an indication to the vehicle operator when the ETC system, or a circuit or component of the system is ineffective. The ETC indicator is controlled by a transistor on the instrument cluster circuit board based upon cluster programming and electronic messages received by the cluster from the Powertrain Control Module (PCM) over the Controller Area Network (CAN) data bus. The ETC indicator Light Emitting Diode (LED) is completely controlled by the instrument cluster logic circuit, and that logic will only allow this indicator to operate when the instrument cluster receives a battery current input on the fused ignition switch output (run-start) circuit. Therefore, the LED will always be OFF when the ignition switch is in any position except ON or START. The LED only illuminates when it is provided a path to ground by the instrument cluster transistor. The instrument cluster will turn ON the ETC indicator for the following reasons:
You will want to have the code(s) read to know for sure, but it sounds like the APPS may be bad.
Normally Autozone will read the codes as a service at no charge to you, and also tell you the most likely part or system the problem is in. Then we will have a better understanding of what area the problem may be in, thanks