What is the throttle body's function - 2006 Cadillac CTS

That vehicle doesn't have a IAC valve. That vehicle has TAC - electronic throttle control.

Throttle Actuator Control (TAC) System Description
Purpose
The throttle actuator control (TAC) system delivers improved throttle response and greater reliability and eliminates the need for mechanical cable. The TAC system performs the following functions:
• Accelerator pedal position (APP) sensing
• Throttle positioning to meet driver and engine demands
• Throttle position sensing
• Internal diagnostics
• Cruise control functions
• Manage TAC electrical power consumption
The TAC system includes the following components:
• The APP sensors
• The throttle body assembly
• The powertrain control module (PCM)
Accelerator Pedal Position (APP) Sensor
The accelerator pedal contains 2 individual accelerator pedal position (APP) sensors within the assembly. The APP sensors 1 and 2 are potentiometer type sensors each with 3 circuits:
• A 5-volt reference circuit
• A low reference circuit
• A signal circuit
The APP sensors are used to determine the pedal angle. The powertrain control module (PCM) provides each APP sensor with a 5-volt reference circuit and a low reference circuit. The APP sensors provide the PCM with signal voltage proportional to the pedal movement. Both APP sensor signal voltages are low at rest position and increase as the pedal is applied.
Throttle Body Assembly
The throttle assembly contains the following components:
• The throttle blade
• The throttle actuator motor
• The throttle position (TP) sensor 1 and 2
• The throttle actuator control (TAC) module
The throttle body functions similar to a conventional throttle body with the following exceptions:
• There is no longer an idle air control (IAC) motor and associated air passages.
• An electric motor opens and closes the throttle valve.
• The TAC module is located within the throttle body assembly.
• The throttle blade is spring loaded in both directions and the default position is slightly open.
• There are 2 individual TP sensors within the throttle body assembly.
The TP sensors are used to determine the throttle plate angle. The TP sensors provide the powertrain control module (PCM) with a signal voltage proportional to throttle plate movement. Both TP sensor signal voltages are low at closed throttle and increase as the throttle opens.

What is the DTC - diagnostic trouble code ? No code tells you a part is bad . Diagnostic testing procedures are given for each code the vehicle can set . Your vehicle can set numerous code's for the electronic throttle control an not one of them tell's you out right to replace the throttle body or the APP sensors . Looking at factory service repair info for the code an doing diagnostic testing befor replacing any parts should be done.

The throttle actuator control (TAC) system delivers improved throttle response and greater reliability and eliminates the need for mechanical cable. The TAC system performs the following functions:
• Accelerator pedal position sensing
• Throttle positioning to meet driver and engine demands
• Throttle position sensing
• Internal diagnostics
• Cruise control functions
• Manage TAC electrical power consumption
The TAC system components include the following:
• The accelerator pedal position (APP) sensors
• The throttle body assembly
• The throttle actuator control module
• The powertrain control module (PCM)

Accelerator Pedal Position (APP) Sensor
The accelerator pedal assembly contains 2 individual APP sensors within the assembly. The accelerator pedal position (APP) sensors 1 and 2 potentiometer type sensors each with 3 circuits:
• A 5-volt reference circuit
• A low reference circuit
• A signal circuit
The APP sensors are used to determine the pedal angle. The control module provides each APP sensor a 5-volt reference circuit and a low reference circuit. The APP sensors then provide the control module with signal voltage proportional to pedal movement. APP sensor 1 signal voltage is low at the rest position and increases as the accelerator pedal is applied. APP sensor 2 signal voltage is high at the rest position and decreases as the accelerator is applied.

Throttle Body Assembly
The throttle body assembly consists of the throttle body, the throttle position (TP) sensors, and the throttle actuator motor. The throttle body functions similar to a similar to a conventional throttle body with the following exceptions:
• An electric motor opens and closes the throttle valve.
• The throttle blade is spring loaded in both directions and the default position is slightly open.
• There are 2 individual TP sensors within the throttle body assembly.
The TP sensors 1 and 2 are potentiometer type sensors each with 3 circuits:
• A 5-volt reference circuit
• A low reference circuit
• A signal circuit
The TP sensors are used to determine the throttle plate angle. The control module provides each TP sensor a 5-volt reference circuit and a low reference circuit. The TP sensors then provide the control module with signal voltage proportional to throttle plate movement. Both TP sensor signal voltages are low at closed throttle and increase as the throttle opens.

Your best bet , take it to a qualified repair shop.

At the throttle pedal.

It is located in the throttle body assembly . Your vehicle has electronic throttle control .
Throttle Body Assembly
The throttle body assembly contains the following components:
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The throttle blade

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The throttle actuator motor

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The throttle position (TP) sensor 1 and 2

The throttle body functions are similar to a conventional throttle body with the following exceptions:
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An electric motor opens and closes the throttle valve.

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The throttle blade is spring loaded in both directions and the default position is slightly open.

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There are 2 individual TP sensors within the throttle body assembly.

Oh yea it has two TPS - throttle position sensors ! An you have to replace the whole assembly !

There is no "fuse" for the throttle body. The throttle body gets all of its power and ground from the Powertrain Control Module. If your throttle body (or accelerator) is not functioning properly, you need to scan your PCM to find out why.

Cleaning your throttle body should take care of both problems. Clean your throttle body with throttle body cleaner. First disconnect the battery, clean the TB with TB cleaner, must be nice and shiny. When finished, hook the battery back up and drive around for 20 minutes or so with all accessories off, so the computer will relearn a properly functioning throttle body.

Your computer learned some bad habits, so when you changed the battery, the computer thought the throttle body was clean and functioning properly. So when you changed it, this caused all your problems. Very common, keep your throttle body clean, should be done at least once a year. Total cost if you do it yourself is around $5, for the can of TB cleaner.

Very common problem after a battery change. Clean your throttle body with throttle body cleaner. First disconnect the battery, clean the TB with TB cleaner, must be nice and shiny. When finished, hook the battery back up and drive around for 20 minutes or so with all accessories off, so the computer will relearn a properly functioning throttle body.

Your computer learned some bad habits, so when you changed the battery, the computer thought the throttle body was clean and functioning properly. So when you changed it, this caused all your problems. Very common, keep your throttle body clean, should be done at least once a year. Total cost if you do it yourself is around $5, for the can of TB cleaner.

I'm taking a wild guess that you recently unhooked or replaced your battery?

Your problem is a dirty throttle body, and if you do it yourself, can cost you about $5 for the can of throttle body cleaner. Unhook your battery again, and clean the throttle body and butterfly very well, must be shiny. Careful as the butterfly is very sharp. While removing the entire throttle body and cleaning it is best, leaving it bolted on will solve your problem too. When finished, hook your battery back up and drive around for 20 minutes or so with all accessories OFF. During this period, your computer will relearn a properly functioning throttle body.

Your computer learned some bad habits before the battery was unhooked the first time. When it was hooked back up, it thought the throttle body was clean and functioning properly. Cleaning it takes care of this problem. I do mine about once a year.

For a new Body style 2004 ( not a Heritage or Lightning ) there is not an IAC.

The IAC functions are now part of the throttle by wire operation in the 2004-08 MY F-150s.
The Throttle Plate Position Controller is part opened by the PCM ( actually a chip embedded in the PCM specific to this function ) when the engine is at idle and the throttle is off ( i.e. not be pressed down ).

If you are talking about a 2004 Heritage or Lightning ( the same body style as the 99-03 MY ), the IAC is on the back of the throttle body, under the plastic throttle body cover.



Not too sure which 2004 version you are talking about, just wanted to cover both 2004 options for the location on the IAC.

Clean your throttle body. Disconnect the battery, and take the plastic resonator and large hoses off that attach to the throttle body. Clean with throttle body cleaner, must be nice and shiny. When finished, drive around for 20 min or so, so the computer can re-learn the properly functioning throttle body. Your computer learned some bad habits with the dirty throttle body, so when you disconnect the battery and reconnect it, it thinks the throttle body is clean and functioning properly which is not the case. If you do it yourself, can cost you a can of throttle body cleaner $7.