S420 throttle body problem

Have you had the vehicle plugged into an OBD2 scanner to look for trouble codes? This will give more clues as to what this issue could be. If you have to pay for this ask at 4 or 5 places as prices can be VERY different.
Simply "throwing" parts at the problem is a Very expensive way to work. Comment below with the codes and I'll see if I can help you more.

Idle air control motor probly bad..its rite in back of throttlbody..wack it fewtimes w wrench it often gits betta. Its caysin a vacuumleak. jyst replace w new one..it about time..

DTC P2101 Control Module Throttle Actuator Position Performance

The engine control module (ECM) controls the throttle valve by applying a varying voltage to the throttle actuator control (TAC) motor. The ECM monitors the actual throttle valve position using throttle position (TP) sensors 1 and 2. The ECM compares this actual position to the commanded throttle position. If the difference between the actual position and the commanded position is more than a predetermined value, this DTC sets.

2
Turn ON the ignition, with the engine OFF.
Clear the DTCs with a scan tool.
Start the engine.
Perform the following tests:
• Rapidly depress the accelerator pedal from the rest position to the wide open throttle (WOT) position and release the pedal. Repeat the procedure several times.
• Slowly depress the accelerator pedal to WOT and then slowly return the pedal to closed throttle. Repeat the procedure several times.
Observe the DTC information with a scan tool.
Does DTC P0121, P0122, P0123, P0221, P0222, or P0223 fail this ignition?


Diagnostic Aids
• Use the J 35616-A/BT-8637 Connector Test Adapter Kit for any test that requires probing the ECM harness connector or a component harness connector.
• The lower connector of the ECM is connector C1 and the upper connector of the ECM is connector C2. Refer to Engine Controls Component Views .
• Inspect for a condition in which the throttle valve may have been held open. For example, ice may have formed in the throttle bore causing the throttle valve not to close. Observe the Freeze Frame/Failure Records.
• The throttle valve is spring loaded to a slightly open position. The throttle valve should be open approximately 3-5 percent. This is referred to as the rest position.
• The throttle valve should not be completely closed or open any more than a specified amount.
• The throttle valve should move open and to the closed position without binding under the normal spring pressure.
• The throttle should NOT be free to move open or closed WITHOUT spring pressure.
• The scan tool has the ability to operate the throttle control system using the TP function located in the TAC System menu. This function operates the throttle valve through the entire range in order to determine if the TAC system operates correctly.
• For an intermittent condition, refer to Intermittent Conditions .
Test Description
The numbers below refer to the step numbers on the diagnostic table.
This step determines if the condition exists. A TP sensor DTC may cause this DTC to set.
Depending on the condition, DTC P0638, P2100, P2101, and/or P2119 may set individually or together.
An incorrect idle learned position may cause this DTC to set. If the throttle value was restricted the ECM could learn the incorrect position. For example, ice may form in the throttle body causing the throttle valve restriction. Observe the Freeze Frame/Failure Records to determine when the condition occurred.
When the ignition is turn ON, the ECM operates the TAC motor to verify the integrity of the system prior to start-up. This can be seen by the momentary flash of the test lamp as the ignition is turned ON.
P2101 Control Module Throttle Actuator Position Performance Step
Action
Values
Yes
No
Schematic Reference: Engine Controls Schematics
Connector End View Reference: Engine Control Module Connector End Views or Engine Controls Connector End Views
1
Did you perform the Diagnostic System Check - Vehicle?
--
Go to Step 2
Go to Diagnostic System Check - Vehicle
2
Turn ON the ignition, with the engine OFF.
Clear the DTCs with a scan tool.
Start the engine.
Perform the following tests:
• Rapidly depress the accelerator pedal from the rest position to the wide open throttle (WOT) position and release the pedal. Repeat the procedure several times.
• Slowly depress the accelerator pedal to WOT and then slowly return the pedal to closed throttle. Repeat the procedure several times.
Observe the DTC information with a scan tool.
Does DTC P0121, P0122, P0123, P0221, P0222, or P0223 fail this ignition?
--
Go to Diagnostic Trouble Code (DTC) List - Vehicle
Go to Step 3
3
Did DTC P0638, P2100, P2101, and/or P2119 fail this ignition?
--
Go to Step 5
Go to Step 4
4
Observe the Freeze Frame/Failure Records for this DTC.
Turn OFF the ignition for 30 seconds.
Start the engine.
Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records.
Did the DTC fail this ignition?
--
Go to Step 5
Go to Diagnostic Aids
5
Turn OFF the engine.
Turn ON the ignition, with the engine OFF.
Observe the TP sensor 1 voltage parameter with a scan tool.
Is the voltage within the specified range?
0.40-0.80 V
Go to Step 6
Go to DTC P0121
6
Observe the TP sensor 2 voltage parameter with a scan tool.
Is the voltage within the specified range?
4.7-4.1 V
Go to Step 7
Go to DTC P0221
7
Perform the idle learn procedure. Refer to Idle Learn .
Clear the DTCs with a scan tool.
Turn OFF the ignition for 30 seconds.
Start the engine.
Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.
Does DTC P0638, P2100, P2101, and/or P2119 fail this ignition?
--
Go to Step 8
Go to Step 19
8
Notice: Refer to Disengaging Connectors Notice in the Preface section.
Important: Disconnecting the throttle body harness connector causes additional DTCs to set.
Disconnect the throttle body harness connector. Refer to Throttle Body Assembly Replacement .
Turn ON the ignition, with the engine OFF.
Measure the voltage of the throttle actuator control (TAC) motor control 1 and TAC motor control 2 circuits of the TAC motor with a DMM connected to the engine control module (ECM) housing.
Is the voltage within the specified range for both circuits?
2-4 V
Go to Step 9
Go to Step 10
9
Turn OFF the ignition.
Connect the J 34730-405 Injector Test Lamp between the TAC motor control 1 and TAC motor control 2 circuit of the throttle body harness connector.
Important: The test lamp intensity should be bright. Compare to another vehicle.
Turn ON the ignition for about 5 seconds and then turn OFF the ignition while you observe the test lamp. Repeat this procedure as necessary.
Does the test lamp turn ON and then OFF each time the ignition is cycled?
--
YES - Go to Step 13
NO - Go to Step 12
10
Is the voltage less than the specified value?
2 V
YES - Go to Step 11
NO - Go to Step 15
11
Test the TAC motor control circuit that measured below the specified value for an open or a short to ground. Refer to Circuit Testing and Wiring Repairs .
Did you find and correct the condition?
--
Go to Step 19
Go to Step 14
12
Turn OFF the ignition.
Disconnect the ECM.
Test for continuity between the TAC motor control 1 and TAC motor control 2 circuit of the throttle body harness connector.
Is there continuity?
--
Go to Step 16
Go to Step 14
13
Test for shorted terminals and for poor connections at the throttle body connector. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .
Did you find and correct the condition?
--
Go to Step 19
Go to Step 17
14
Test for shorted terminals and for poor connections at the ECM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .
Did you find and correct the condition?
--
Go to Step 19
Go to Step 18
15
Repair the appropriate TAC motor control circuit for a short to voltage. Refer to Wiring Repairs .
Did you complete the repair?
--
Go to Step 19
--
16
Repair the short between the TAC motor control circuits 1 and 2. Refer to Wiring Repairs .
Did you complete the repair?
--
Go to Step 19
--
17
Replace the throttle body assembly. Refer to Throttle Body Assembly Replacement .
Did you complete the replacement?
--
Go to Step 19
--
18
Replace the ECM. Refer to Control Module References for replacement, setup, and programming.
Did you complete the replacement?
--
Go to Step 19
--
19
Clear the DTCs with a scan tool.
Turn OFF the ignition for 30 seconds.
Start the engine.
Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records.
Did the DTC fail this ignition?
--
Go to Step 2
Go to Step 20
20
Observe the Capture Info with a scan tool.
Are there any DTCs that have not been diagnosed?
--
Go to Diagnostic Trouble Code (DTC) List - Vehicle
System OK

DTC P0121: Throttle Position (TP) Sensor 1 Performance
Circuit/System Description
The engine control module (ECM) uses the following information to calculate an expected airflow rate:
?€¢
The throttle position (TP)

?€¢
The barometric pressure (BARO)

?€¢
The manifold absolute pressure (MAP)

?€¢
The intake air temperature (IAT)

?€¢
The engine RPM

P0121 The predicted air flow and the predicted MAP combined are outside a calibrated range for more than 3 seconds.
Circuit/System Testing

1. Inspect for the following conditions:
?€¢
Vacuum hoses for splits, kinks, and proper connections as shown on Vehicle Emission Control Information label



?€¢
Inspect thoroughly for any type of leak or restriction



?€¢
Air leaks at throttle body mounting area and intake manifold sealing surfaces



?€¢
Throttle body for dirt, debris, and coking--Refer to Throttle Body Cleaning.


2. Allow the engine to reach operating temperature. Observe the MAP Sensor Voltage parameter with a scan tool. Voltage should be more than 0.8 volt and less than 4 volts.
?‡'
If more than 4 volts or less than 0.8 volt, refer to DTC P0106.

3. Idle the engine. Observe the MAP Sensor kPa parameter with a scan tool. Increase the engine speed slowly and then back to idle. The MAP sensor kPa should change smoothly and gradually as engine speed is increased and returned to idle.
?‡'
If the MAP sensor kPa does not change, refer to DTC P0106.

4. Take a snapshot of the engine data list while performing the actions listed below. The mass air flow (MAF) sensor g/s should change smoothly and gradually as the engine speed is increased and is returned to idle.
?€¢
Idle the engine.



?€¢
Increase the engine speed slowly to 3,000 RPM, then back to idle.



?€¢
Exit from the snapshot and review the data.



?€¢
Observe the Mass Air Flow (MAF) Sensor parameter frame by frame with a scan tool. The MAF sensor g/s should change smoothly and gradually as the engine speed is increased and is returned to idle.



?‡'
If the MAF sensor g/s does not change smoothly and gradually as the engine speed is increased and is returned to idle, refer to DTC P0101 or P1101.


5. Inspect the throttle body for the following conditions:

?€¢
Loose or damaged throttle blade

?€¢
Broken throttle shaft

?€¢
Any throttle body damage

?‡'
If any of these conditions exist, replace the throttle body assembly.

What Colorado do you have ? 2 wheel or 4 wheel drive ? Sport ,sport LS 3.5L , Z71, Z71 LS. etc. what size engine ? an does it have electronic throttle control ? I have factory service info an it is not showing that code .
DTC P0506

Circuit Description

The throttle actuator control (TAC) motor is controlled by the powertrain control module (PCM). The DC motor located in the throttle body drives the throttle plate. In order to decrease idle speed, the PCM commands the throttle closed reducing air flow into the engine and the idle speed decreases. In order to increase idle speed, the PCM commands the throttle plate open allowing more air to pass the throttle plate. If the actual idle RPM does not match the desired idle RPM within a calibrated time, this DTC sets.

DTC Descriptor

This diagnostic procedure supports the following DTC:
DTC P0506 Idle Speed Low
DTC P0507

Circuit Description

The throttle actuator control (TAC) motor is controlled by the powertrain control module (PCM). The DC motor located in the throttle body drives the throttle plate. In order to decrease idle speed, the PCM commands the throttle closed reducing air flow into the engine and the idle speed decreases. In order to increase idle speed, the PCM commands the throttle plate open allowing more air to pass the throttle plate. If the actual idle RPM does not match the desired idle RPM within a calibrated time, this DTC sets.

DTC Descriptor

This diagnostic procedure supports the following DTC:
DTC P0507 Idle Speed High
Cleaning the throttle body mite take care of it !
Cleaning Cleaning An Electronic Throttle Body Safely

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.

REDUCED POWER
Refer to:
• Powertrain Control Module Description for the 2.8L engine
• Powertrain Control Module Description for the 3.5L engine

Throttle Actuator Control (TAC) System
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
• The powertrain control module (PCM)
Each of these components interface together to ensure accurate calculations and control of the throttle position.

Accelerator Pedal Position (APP) Sensor
The accelerator pedal position (APP) sensor is mounted on the accelerator pedal assembly. The APP is 2 individual APP sensors within one housing. There are 2 separate signal, low reference, and 5-volt reference circuits. APP sensor 1 voltage increases as the accelerator pedal is depressed. APP sensor 2 voltage decreases as the accelerator pedal is depressed.
Throttle Body Assembly
The throttle body for the throttle actuator control (TAC) system is similar to a conventional throttle body with several exceptions. One exception being the use of a motor to control the throttle position instead of a mechanical cable. Another exception is the throttle position (TP) sensor. The TP sensor is mounted in the throttle body assembly. The TP sensor is 2 individual TP sensors within the throttle body assembly. Two separate signals, low reference, and 5-volt reference circuits are used to connect the TP sensors and the powertrain control module (PCM). TP sensor 2 signal voltage increases as the throttle opens. TP sensor 1 signal voltage decreases as the throttle opens.

Reduced Engine Power Mode
When the PCM detects a problem with the throttle actuator control (TAC) system the PCM enters one of the following Reduced Engine Power Modes:
• Acceleration Limiting--The control module will continue to use the accelerator pedal for throttle control, however the vehicle acceleration is limited.
• Limited Throttle Mode--The control module will continue to use the accelerator pedal for throttle control, however the maximum throttle opening is limited.
• Throttle Default Mode--The control module will turn OFF the throttle actuator.
• Forced Idle Mode--The control module will perform the following actions:
- Limit engine speed to idle by positioning throttle position, or by controlling fuel and spark if throttle is turned OFF.
- Ignore accelerator pedal input.
• Engine Shutdown Mode--The control module will disable fuel and de-energize the throttle actuator.

Have you had it checked for DTC'S - diagnostic trouble codes ?

DTC P2176
The commanded throttle position (TP) is compared to the actual TP. Both values should be within a calibrated range of each other. The powertrain control module (PCM) continuously monitors the commanded and actual TPs. If the values are greater than the calibrated range, DTC P2176 sets.
--------------------------------------------------------------------------------
DTC P2138
The accelerator pedal position (APP) sensors 1 and 2 are located within the accelerator pedal assembly. Each sensor has the following circuits:
• A 5-volt reference circuit
• A low reference circuit
• A signal circuit
This provides the powertrain control module (PCM) with a signal voltage proportional to accelerator pedal movement. The APP sensor 1 signal voltage at rest position is near the low reference and increases as the pedal is actuated. The APP sensor 2 signal voltage at rest position is near the 5-volt reference and decreases as the pedal is actuated.
DTC P2135
The throttle actuator control (TAC) assembly has 2 throttle position (TP) sensors mounted within the assembly. The powertrain control module (PCM) provides individual signal, ground, and 5-volt reference circuits to each sensor. Both sensors operate within a voltage range between 0.35-4.65 volts. When the throttle is opened from 0-100 percent, one sensor signal voltage increases while the other decreases. The signal circuit for TP sensor 1 is referenced to ground, and the signal circuit for TP sensor 2 is pulled up to 5 volts within the PCM.
DTC P2128
DTC P2127
DTC P2125
DTC P2123

Drive by Wire Function and diagnostics by Wells

What repairs can fix the P0191 code?

• Replacing fuel filter(s) or fuel pump
• Replacing the fuel pressure regulator
• Repairing any broken, frayed, or shorted wires that lead to the fuel pressure sensor
• Repairing corroded connector to the fuel pressure sensor
• Replacing fuel pressure sensor
• Repairing any vacuum leaks in the engine
  
  Many times this error will also occur if there already exists fuel/air problems, like your previous code 2106 means there are one or more components in your car's intake/exhaus/air/injection systems that is having serious problems

DTC P1516 Throttle Actuator Control (TAC) Module Throttle Actuator Position Performance

Your vehicle has an electronic throttle body unit so it uses voltage signals to control throttle blade in the throttle body. There are a few different issues that can cause this problem.

First off there is a update for the PCM to address those codes, but you will have to take it to the dealer for that.

Second there is issues with the actuator on the throttle body binding up and causing the codes.

Third there is a yellow wire coming off the throttle body connector that breaks inside internally and cannot be seen to the naked eye. The best way to test that is to grab the wire about 5 inches from the connector and tug if it feels spongy or breaks, that

According to the manual

P0700 = EATX Controller DTC Present

Discription= An automatic transmission input DTC has been set in the transmission controller.

.

P1733 no listing in manual

P0743 =Torque Converter Clutch Soleniod/Trans Relay Circuits

Discription= An open or shorted condition detected in the torque converter part throttle unlock solenoid control circuit (3 speed auto RH trans. only).

hope this helps