2005 Cadillac cts , replaced throttle body and position sensor and replaced accelerator sensor, throttle doesn't respond properly and nothing in reverse, how do I reset without a scanner.?

engine losing power sign ??? .You mean ENGINE POWER REDUCED ? This has to do with electronic throttle control -Throttle Actuator Control (TAC) System Description

The throttle actuator control (TAC) system is used to improve emissions, fuel economy, and driveability. The TAC system eliminates the mechanical link between the accelerator pedal and the throttle plate. The TAC system eliminates the need for a cruise control module and idle air control motor. The following is a list of TAC system components:
• The accelerator pedal assembly includes the following components:
- The accelerator pedal
- The accelerator pedal position (APP) sensor 1
- The APP sensor 2
• The throttle body assembly includes the following components:
- The throttle position (TP) sensor 1
- The TP sensor 2
- The throttle actuator motor
- The throttle plate
• The engine control module (ECM)

TAC System Default Actions/Reduce Power Modes
There are 2 reduce power modes that the engine control module (ECM) can default to if an error is detected in the throttle actuator control (TAC) system. If an accelerator pedal position (APP) sensor 1 or APP sensor 2 circuit fault, throttle position (TP) sensor 2 circuit fault, or if a TP sensor 1 circuit fault is detected with some APP angle, the ECM goes into one of the 2 reduce power modes. In this mode, the engine torque is limited so that the vehicle cannot reach speeds of more than 100 km/h (60 mph). The ECM remains in this reduce power mode during the entire ignition cycle even if the fault is corrected.
If there is a condition with the throttle actuator control circuits, throttle actuator command vs actual position fault, return spring check fault, or a TP sensor 1 circuit fault, the ECM goes into the other reduce engine power mode. In this mode, the engine speed is limited to 2,500 RPM and the 3-6 fuel injectors are randomly turned OFF. At this time the Reduced Power indicator is commanded ON. The ECM remains in the reduce power mode during the entire ignition cycle even if the fault is corrected. Observe, if a TP sensor 1 or throttle actuator control circuit fault is present at the time the vehicle is at idle, with no accelerator pedal angle, the engine may stall.
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You need to have a qualified repair shop check it out.

Classic symptoms. Clean throttle body and MAF. Check for diagnostic codes.

https://www.google.com/search?q=2005+Cadillac+CTS%2C+clean+throttle+body+and+MAF

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Your vehicle does not have a idle air control valve , don't know how you came up with that .(code reader ? ) Your vehicle has what is called drive by wire - electronic throttle control . Or as GM calls their system TAC - throttle actuator control .

Throttle Actuator Control (TAC) Overview
The throttle actuator control (TAC) system uses vehicle electronics and components to calculate and control the position of the throttle blade. This eliminates the need for a mechanical cable attachment from the accelerator pedal to the throttle body. This system also performs the cruise control functions as well.
The TAC system components include, but are not limited to, the following:
• The accelerator pedal position (APP) sensors
• The throttle body assembly
• the engine control module (ECM)
The APP sensors and the throttle body assembly provide inputs to the ECM to ensure accurate calculations and control of the TAC system.
Accelerator Pedal Position (APP) Sensor
The APP sensor is mounted on the accelerator pedal assembly. The APP is actually 2 individual APP sensors within 1 housing. These are 2 separate signal, low reference, and 5-volt reference circuits. The APP sensor 1 voltage increases as the accelerator pedal is depressed. The APP sensor 2 voltage also increases as the accelerator pedal is depressed, but the voltage range for sensor 2 is approximately half of sensor 1.


Your best bet mite be to take it to a qualified repair shop that has the right diagnostic tools to find the problem .

https://www.youtube.com/watch?v=x4xcQSRAgFI

https://www.youtube.com/watch?v=oPPLAHSSluw

Your dts uses drive by wire. The gas pedal is actually an electrical switch connected to the engine computer which then actuate a throttle body motor which causes the car to speed up or slow down. If you mean the car won't acceleration then the throttle actuator is probably going out, this is common and you replace the throttle body assembly as the actuator is sealed onto it. Had the same problem with my 04 srx (which is mechanically the same as a cts). If you have a check engine light on (and you should) get the codes read first as there are a few other problems that can cause throttle problems, however they are less likely the cause.

Could possibly be ! check the part numbers , should be stamped on the part somewhere . Do they both have electronic throttle control ?

P2138 Throttle/Pedal Pos Sensor Voltage Correlation

Potential Causes of P2138 DTC It's been my experience that the wiring connector or "pig tail" on the throttle body gives problems in the form of a poor connection.The female terminals on the pigtail corrode or pull out of the connector. Possible bare wire on pigtail shorting to ground. The top cover on the throttle body distorted preventing the gears from turning properly. The electronic throttle body is faulty. The accelerator pedal sensor or its wiring failed. The engine management computer has failed. The TPS sensors were not correlating for a few seconds and the computer needs to be cycled through its relearn phase to restore active response to the throttle body, or the computer needs reprogramming at the dealer.

it is part of the gas pedal

Yes but i dont think thats your problum. i bet you its just the contacts that plug in the throttle body. they dont fit well it happends alot with the 2003 cts you can fix it by un pluging it putting a dent in the back of all 6 contacts. i used a dart tip to do it. then usr some cleener on them you should be good.

The TPS "Throttle Position Sensor" is located in the same place on ALL vehicles that are equipped with one of these....On the Throttle Body.

Throttle Position Sensor Removal & Installation The throttle position sensor is an integral part of the Throttle Body and is only serviced as a complete unit.