2006 3.8L the engine misfire.

First do a throttle body cleaning. There are many ways to do it. Here is one of them.

https://www.youtube.com/watch?v=Gisr5dK0WDg

Best Manuals I don't know abut your model but i'm sure this lady here can help you

If you would like help we would need the DTC - diagnostic trouble code .Is their a Reduced Engine Power Mode message showing on the instrument cluster ?
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.
IF you do not know this your best bet would be to take to a qualified repair shop .
DTC P0506
DTC P0507
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.

Multiple misfires can be caused by a few different things , intake manifold vacuum leaks , low fuel pressure , basic things like plug wires an spark plugs needing to be changed if hasn't been done already . How many miles on the vehicle ? If over 100,000 K timing chain an gear wear can also cause this . The powertrain control module (PCM) uses information from the ignition control (IC) module and the camshaft position (CMP) sensor in order to determine when an engine misfire is occurring. By monitoring the variations in the crankshaft rotation speed for each cylinder the PCM is able to detect individual misfire events. A misfire rate that is high enough can cause the three-way catalytic converter to overheat under certain conditions. The malfunction indicator lamp (MIL) will flash ON and OFF when the conditions for 3-way catalytic converter overheating are present.
If the misfire is random, check for the following conditions:
?€¢
System grounds

Ensure all connections are clean and properly tightened.

?€¢
Mass air flow sensor

A mass air flow (MAF) sensor output that causes the PCM to sense a lower than normal air flow will cause a lean condition. Try operating the vehicle within the Failure Records conditions with the MAF sensor disconnected. If the lean or misfiring condition is not present with the MAF sensor disconnected, replace the Mass Airflow Sensor Replacement .

?€¢
Damaged accessory drive belt or driven accessory

A damaged serpentine belt or belt driven accessory can cause engine load variations sufficient to set a misfire DTC.

?€¢
Air induction system

Vacuum leaks that cause intake air to bypass the MAF sensor will cause a lean condition. Check for disconnected or damaged vacuum hoses, incorrectly installed or malfunctioning crankcase ventilation valve, or for vacuum leaks at the throttle body, exhaust gas recirculation (EGR) valve, and intake manifold mounting surfaces.

?€¢
Fuel pressure

Perform a fuel system pressure test. A malfunctioning fuel pump, a plugged filter, or a malfunctioning fuel system pressure regulator will contribute to a lean condition. Refer to Fuel System Diagnosis .

?€¢
Fuel injectors

Refer to Fuel Injector Solenoid Coil Test .

?€¢
Water contamination in the fuel system can cause a single cylinder to misfire as well as cause a random misfire, refer to Alcohol/Contaminants-in-Fuel Diagnosis .

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EGR system

Check for leaking valve, adapter, or feed pipes which will contribute to a lean condition or excessive EGR flow.

?€¢
Extended idle

Excessive Open Loop operation caused by extended idling or short trip driving may leave deposits on the heated oxygen sensors. The deposits cause oxygen sensors to respond slowly to exhaust oxygen content, affecting fuel control and causing a misfire to be indicated at idle. This condition is not permanent. To determine if this condition is causing the DTC P0300 to set, review the Freeze Frame/Failure Records for DTC P0300. If the DTC P0300 occurs at high engine speeds, the condition described above did not cause the DTC to set. If the DTC P0300 occurs at idle or very low engine speeds and at engine coolant temperatures below 80?°C (176?°F), the condition described above is very likely the cause of the DTC to set. The deposits on the heated oxygen sensors can be eliminated by operating the vehicle fully warm at mass air flows above 15 g/s.

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)

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The manifold absolute pressure (MAP)

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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.
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Idle the engine.



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



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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

no symotoms.? how many miles on car 50k or 250k miles>?
no other DTC, did you use scan tool? and one that read ALL VW DTC. if not FAIL. you will.

how can I fix.?
you want to fix the car or the TB?
most cars, its a new TB.
im not VW savvy, (can fix any car) but not their policies.
anyone can go to vw.com and to the parts page and see what is sold
anyone. just do it.
my guess, is you didnt read the FSM yet, on this failure
why not? it explains how to isolate the true cause.
4th generation and 5 sub types. from FUN to blue motion.....
2002 to 2009
P1568
got others?>

* VW DTC 17579 (P1171) - Throttle Actuation Potentiometer Signal 2 Range/Performance
* VW DTC 17950 (P1542) - Throttle Actuation Potentiometer Range/Performance
* VW DTC 17953 (P1545) - Throttle Position. Contr Malfunction
* VW DTC 17976 (P1568) - Idle Speed Control; Throttle Position - Mechanical Malfunction

so what does it mean.
it means idle can not be controls for any of many reasons.
the tech makes sure the engine runs ok, is in closed loop hot.
if not we fix that first , because misfiring or bogging engines the idle can be impossible to control.
then check that the throttle butterfly plat is not sticking (clean it)
if the throttle motor sticks the motor is bad. end of live for TB.
my guess is you dont have a scan tool, am I right>?

fixing cars with out one, is a bad idea.
engines can go lean and stall or surge.
engines can go rich misfire and stall.
we make sure that is not happening first and
the law is, IDLE is the last thing to work right on all EFI engines.
hell carbs. (ever get a vacuum leak with a carb ,it stalls)

Hi there:
DTC P1200 - lnjector control circuit


The PCM has the ability to detect a misfire by monitoring the 3X reference and camshaft position input signals from the Ignition Control Module. The PCM monitors crankshaft speed variations (reference period differences) to determine if a misfire is occurring. If 2 percent or more of all cylinder firing events are misfires, emission levels may exceed mandated standards. The PCM determines misfire level based on the number of misfire events monitored during a 200 engine revolution test sample. The PCM continuously tracks 16 consecutive 200 revolution test samples. If 11 or more misfires are detected during any 5 of the 16 samples, DTC P0300 will set. If the misfire is large enough to cause possible three-way catalytic converter damage, DTC P0300 may set during the first 200 revolution sample in which the misfire was detected. In the case of a catalyst damaging misfire, the Malfunction Indicator Lamp (MIL) will flash to alert the vehicle operator of the potential of catalyst damage.


CONDITIONS FOR SETTING THE DTC

* No Vehicle Speed Sensor (VSS), Transaxle, Throttle Position (TP) sensor, Fuel trim, Fuel injector circuit, Engine Coolant Temperature (ECT) sensor, Crankshaft Position (CKP) sensor, Camshaft Position (CMP) sensor, or Mass Air Flow (MAF) sensor DTC(s) set.

* Engine speed between 450 and 5800 RPM.

* System voltage between 9 and 16 volts.

* The ECT indicates an engine temperature between -7 degrees C (19 degrees F) and 120 degrees C (248 degrees F).

* Throttle angle steady.

* The PCM is detecting a crankshaft RPM variation indicating a misfire sufficient to cause three-way catalytic converter damage or emissions levels to exceed mandated standard.


ACTION TAKEN WHEN THE DTC SETS

* If the misfire level is non-catalyst damaging, the PCM will illuminate the MIL during the second key cycle in which the DTC sets.

* If the misfire is severe enough to cause possible catalyst damage, the PCM will immediately flash the MIL while the misfire remains at catalyst damaging levels.

* The PCM will disable Torque Converter Clutch (TCC) operation.

* The PCM will store conditions which were present when the DTC set as Freeze Frame and Fail Records data.


CONDITIONS FOR CLEARING THE MIL/DTC

* The PCM will turn the MIL OFF during the third consecutive trip in which the diagnostic has been run and passed.

* The history DTC will clear after 40 consecutive warm-up cycles have occurred without a fault.

* The DTC can be cleared by using the scan tool Clear Info function or by disconnecting the PCM battery feed.

DIAGNOSTIC AIDS

The scan tool provides information that can be useful in identifying the misfiring cylinder. If the DTC P0300 is currently stored as DTC status Failed Since Code Clear, the misfire history counters (Misfire Hist #1 - #6) will still contain a value that represents the level of misfire detected on each cylinder. The scan tool displayed misfire counter values (Misfire Hist. #1 through #6) can be useful in determining whether the misfire affects a single cylinder, a cylinder pair (cylinders that share an ignition coil-1/4, 2/5, 3/6), or is random. If the largest amount of activity is isolated to a cylinder pair, check for the following conditions:

* Secondary Ignition Wires.

Check the secondary wires associated with the affected cylinder pair for disconnected ignition wires or for excessive resistance. The wires should measure under 30,000 ohms (30 K ohms). Replace any wires with excessive resistance.

* Damaged Or Faulty Ignition Coil.

Check for cracks, carbon tracking or other damage. Also check coil secondary resistance. Secondary resistance should be between 5000 ohms and 8000 ohms (5 K ohms and 8 K ohms). Replace any faulty coil(s). Refer to Ignition Control Module.

* Substitute a Known Good Coil.

Switch ignition coils and retest. If the misfire follows the coil, replace the ignition coil.

If the misfire is random, check for the following conditions

* System Grounds.

Ensure all connections are clean and properly tightened. Refer to Ground Distribution in Electrical Diagrams.

* Mass Air Flow sensor.

A Mass Air Flow (MAF) sensor output that causes the PCM to sense a lower than normal air flow will cause a lean condition. Try operating the vehicle within the fail records conditions with the MAF sensor disconnected. If the lean or misfiring condition is not present with the MAF sensor disconnected, replace the MAF sensor. Refer to MAF Sensor.

* Damaged accessory drive belt or driven accessory.

A damaged serpentine belt or belt driven accessory can cause engine load variations sufficient to set a misfire DTC.

* Vacuum Leaks.

Vacuum leaks that cause intake air to bypass the MAF sensor will cause a lean condition. Check for the following conditions:

- Disconnected or damaged vacuum hoses. Refer to Emission Hose Routing Diagram.

- Incorrectly installed or faulty crankcase ventilation valve. Refer to Positive Crankcase Ventilation Valve

- Vacuum leaks at the throttle body, EGR valve, and intake manifold mounting surfaces.

* Fuel Pressure.

Perform a fuel system pressure test. A faulty fuel pump, plugged filter, or faulty fuel system pressure regulator will contribute to a lean condition. Refer to Fuel System Pressure Test. See: Computers and Control Systems > Component Tests and General Diagnostics > Fuel System Pressure Test

* Fuel injector(s). Go to Fuel Injector Coil Test. See: Computers and Control Systems > Component Tests and General Diagnostics > Fuel Injector Coil Test

* Contaminated Fuel. Go to Alcohol/Contaminants-in-Fuel Testing Procedure. See: Fuel Delivery and Air Induction > Testing and Inspection

* EGR System.

Check for leaking valve, adapter, or feed pipes which will contribute to a lean condition or excessive EGR flow.

* Extended Idle.

Excessive open loop operation caused by extended idling or short trip driving may leave deposits on the heated oxygen sensors. The deposits cause oxygen sensors to respond slowly to exhaust oxygen content, affecting fuel control and causing a misfire to be indicated at idle. This condition is not permanent. To determine if this condition is causing the DTC P0300 to be set, review the freeze frame and fail records data for DTC P0300. If the DTC P0300 occurs at high engine speeds, the condition described above did not cause the DTC P0300 to set. If the DTC P0300 occurs at idle or very low engine speeds and at engine coolant temperatures below 80 degrees C (176 degrees F), the condition described above is very likely the cause of the DTC P0300 being set. The deposits on the heated oxygen sensors can be eliminated by operating the vehicle fully warm at mass air flows above 15 gm/s.

Important: If the level of misfire was sufficient to cause possible catalyst damage (if the MIL was flashing), ensure that the DTC P0420 test is completed and passed after verifying the misfire repair.

Reviewing the Fail Records vehicle mileage since the diagnostic test last failed may help determine how often the condition that caused the DTC to be set occurs. This may assist in diagnosing the condition.



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DTC P0506

CIRCUIT DESCRIPTION
The throttle actuator control (TAC) motor is controlled by the engine control module (ECM). The DC motor located in the throttle body drives the throttle plate. In order to decrease idle speed, the ECM commands the throttle closed reducing air flow into the engine and the idle speed decreases. In order to increase idle speed, the ECM 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

CONDITIONS FOR RUNNING THE DTC
- DTCs P0068, P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0117, P0118, P0120, P0122, P0123, P0171, P0172, P0201, P0202, P0203, P0204, P0205, P0206, P0207, P0208, P0220, P0121, P0222, P0223, P0230, P0300, P0336, P0442, P0446, P0449, P0452, P0453, P0455, P0462, P0463, P0496, P1516, P2101, P2135, P2176 are not set.
- The engine is operating for at least 60 seconds.
- The engine coolant temperature (ECT) is more than -60°C (-140°F).
- The intake air temperature (IAT) is more than -10°C (-14°F).
- The barometric pressure (BARO) is more than 65 kPa.
- The system voltage is between 9-18 volts.
- The vehicle speed is less than 1.6 km/h (1 mph).
- DTC P0506 runs continuously when the above conditions are met.

CONDITIONS FOR SETTING THE DTC
- The actual idle speed is approximately 100 RPM lower than the desired idle speed.
- The above condition is present for 5 seconds.

ACTION TAKEN WHEN THE DTC SETS
- The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
- The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

CONDITIONS FOR CLEARING THE MIL/DTC
- The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
- A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
- A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
- Clear the MIL and the DTC with a scan tool.

TEST DESCRIPTION

View & Print Options Step 1 - Step 5
The number below refers to the step number on the diagnostic table.
2. This test determines whether the engine can achieve the commanded RPM. If the engine does not reach the commanded RPMs, the test determines whether the RPM is too high or too low.
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unfortunately no ! Your best bet take it to the dealer . The P0420 always ends up being the catalytic converter ! P2104 isn't throttle air control . P2112 - Throttle Actuator Control (TAC) System - Stuck Closed. Description: This powertrain control module (PCM) fault status indicates the throttle plate is at a lower angle than commanded. Possible Causes:

• Binding throttle body, stuck closed.
• Damaged PCM.

Diagnostic Aids: Application Key On Engine Off Key On Engine Running Continuous Memory All GO to DV1
P2104 - Throttle Actuator Control (TAC) System - Forced Idle Description: The TAC system is in the failure mode effects management (FMEM) mode of forced idle. Possible Causes:

• Open or short in multiple accelerator pedal position (APP) sensor circuits.
• Damaged APP sensor.
• Damaged powertrain control module (PCM).

Diagnostic Aids: This DTC is an informational DTC and can be set in combination with a number of other DTCs which are causing the FMEM. Diagnose other DTCs first. Application Key On Engine Off Key On Engine Running Continuous Memory All GO to QE1
P0506 - Idle Air Control (IAC) System RPM Lower Than Expected For Vehicles With Electronic Throttle Control (ETC) Description: This DTC is set when the powertrain control module (PCM) detects an engine idle speed that is less than the desired RPM. Possible Causes:

• Air intake restriction.
• Exhaust restriction.
• Engine mechanical fault.
• Damaged electronic throttle body (ETB).
• Damaged PCM.

Diagnostic Aids: This DTC is informational only and it may be accompanied by other DTCs. Diagnose other DTCs first. If other DTCs are not present inspect the intake air system for air restrictions and damage. If no concerns are present, clear the DTC and retest. For All Others Description: This DTC is set when the powertrain control module (PCM) detects an engine idle speed that is less than the desired RPM. Possible Causes:

• IAC circuit open.
• Air inlet is plugged.
• B+ or VPWR to IAC solenoid open.
• Damaged or incorrect IAC valve.
• IAC valve stuck closed.
• VPWR to IAC solenoid open.
• IAC circuit shorted to PWR.

Diagnostic Aids: Disconnect the IAC valve and look for little or no change in engine RPM as an indication of a stuck or damaged valve. Application Key On Engine Off Key On Engine Running Continuous Memory Vehicles With Electronic Throttle Control (ETC) Refer to the Description, Possible Causes and Diagnostic Aids for the DTC. All others GO to KE1