turbotech

If you are wanting to adjust your wastegate then you will need to make the rod longer. Meaning that you will need to loosen the outer nut and move the inner nut outward. Then tighten. I have mine ran in all the way, which makes the rod shorter, and have been running it that way for about 3 years.

camaro98z28

Ok finally got a code p2261.

ATLsilverSS

that is the bypass valve stuck closed i'm not sure if that would cause boost spike or not

turbotech

Subject: LNF Malfunction Indicator Lamp (MIL), Check Engine Light Illuminated with One or More of the Following Diagnostic Trouble Codes (DTCs) P0096, P0335, P0806, P2199, P2261 (Reprogram ECM)


Models: 2008 Chevrolet HHR SS

with ECOTEC® 2.0L I-4 Cylinder Turbocharged Engine (VIN X -- RPO LNF)




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Condition
Some customers may comment on Malfunction Indicator Lamp (MIL), Check Engine Light Illumination. Typically, there will be no driveability symptoms or engine performance concerns.

Upon further investigation, one or more of the following DTCs may be stored in the ECM:

• DTC P0096: Intake Air Temperature (IAT) Sensor 2 Performance

• DTC P0335: Crankshaft Position (CKP) Sensor Circuit

• DTC P0806: Clutch Pedal Position (CPP) Sensor Circuit Performance

• DTC P2199: Intake Air Temperature (IAT) Sensor 1-2 Correlation

• DTC P2261: Turbocharger Bypass Valve Stuck Closed

Correction
If routine diagnosis using SI does not reveal any obvious cause, Do Not replace the following components :

• Intake Air Temperature (IAT) Sensor for DTC P0096 or P2199

• Crankshaft Sensor for DTC P0335

• Clutch Pedal Position (CPP) Sensor for P0806

• Turbocharger Bypass Valve for DTC P2261

Important: Verify that the 12-volt battery has a battery charge of 12 to 16 volts. The battery must be able to maintain a charge during programming. Only use approved Midtronics 165-PCS charger or equivalent to maintain proper battery voltage during programming.

Important: Select J2534 MDI and Reprogram ECU from the Select Diagnostic Tool and Programming Process screen. The J2534 MDI will reprogram the modules in less time than the Tech 2® scan tool.

Reprogram the ECM using the latest calibration if the above concern is encountered. A revised engine calibration has been developed to address these issues. Reprogram the ECM with the latest software calibration. The service calibration is available on TIS2WEB using the Service Programming System (SPS). As always, make sure your Tech 2® is updated with the latest software version.

Warranty Information
For vehicles repaired under warranty, use:

Labor Operation
Description
Labor Time

J6354
Powertrain Control Module -- Engine Reprogramming with SPS
Use Published Labor Operation Time

turbotech

PIP4669A: Intermittent DTC P2261 Setting - (Aug 10, 2009)


Subject: Intermittent DTC P2261 Setting


Models: 2008-2010 Chevrolet Cobalt SS

2008-2010 Chevrolet HHR SS




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This PI was superseded to update model years. Please discard PIP4669.


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The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.

Condition/Concern:
A technician may find DTC P2261: Turbocharger Bypass Valve Stuck Closed set with no problem found. It may be intermittent in nature or they may find the dtc will set after a hard acceleration, usually in third gear. DTC P2261 is a type B dtc and will not set on the first drive cycle the dtc sets, therefore multiple test drives should be performed to confirm repair.

Recommendation/Instructions:
SI diagnostics for this DTC states that the ECM compares the measured MAF reading to the modeled MAF and has detected a series of pulsations in the induction system that exceed a calibrated threshold. A snapshot of "Induction Data" will show the fault, however the tech may need to compare the snapshot data to another vehicle if they are unfamiliar with the readings. They should note a fluctuation and or a difference in the desired versus requested boost level. When diagnosing this dtc pay close attention to Circuit/System testing step #1. This step has you inspecting for any vacuum leaks, damage, restrictions, improper routing or connecting of the vacuum hoses on the charge air bypass valve solenoid, the charge air bypass valve, and the charge air bypass valve vacuum tank.

We have found leaking vacuum tanks causing this dtc. When testing the vacuum tank, care must be used or the results may not be valid. The vacuum tank has an integral check valve not noted in SI. To check the Vacuum Tank operation, disconnect the hose that runs from the tank to the Bypass Valve Solenoid at the solenoid and apply vacuum to the tank. The tank should be able to maintain vacuum with no decay. Note: If you remove the vacuum hose from the intake manifold and plug it and the decay stops the check valve is leaking, if the decay continues the tank itself is leaking.

Note: Front wheel drive platforms using the 2.0 Liter RPO (LNF) incorporate a charge air bypass valve supplemental vacuum tank. The purpose of the tank is to provide an instant source of vacuum to the bypass valve via the bypass solenoid (when it is commanded open by the ECM). This results in less pressure buildup under closed throttle conditions, thereby reducing compressor noise, surge and spool time.

Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed

turbotech

DTC P2261
Diagnostic Instructions
• Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

• Review Strategy Based Diagnosis for an overview of the diagnostic approach.

• Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptor
DTC P2261: Turbocharger Bypass Valve Stuck Closed

System Description
The BorgWarner™ dual-scroll turbocharger (TC) incorporates a wastegate that is controlled by a pressure differential, that is determined by the engine control module (ECM) by means of a PWM solenoid, in order to regulate the pressure ratio of the compressor. A charge air bypass valve is integrated within the unit, and is also controlled by the ECM by utilizing a remotely mounted solenoid to prevent compressor surging and damage from vibrations by opening during abrupt closed throttle conditions. When the valve is commanded open during closed throttle deceleration conditions, the bypass valve allows the air to recirculate in the TC and maintain compressor speed. Within a calibrated range during the closed throttle event, or upon a wide open throttle command, the valve will then close to optimize TC response.

Front wheel drive platforms also incorporate a charge air bypass valve vacuum tank. The purpose of the tank is to provide an instant source of vacuum to the bypass valve, when it is commanded open by the ECM. This results in less pressure buildup under closed throttle conditions, thereby reducing compressor noise and surge.

The purpose of this diagnostic is to determine if the charge air bypass valve is stuck closed. The ECM will first verify the integrity of the following sensors. The ECM then compares the actual measured mass air flow (MAF) to a modeled airflow that is derived from these inputs:

• Throttle position (TP)

• Engine speed

• Intake air pressure sensor

• Manifold absolute pressure (MAP) sensor

Conditions for Running the DTC
• DTCs P0033, P0034, P0035, P0096, P0097, P0098, P0099, P0100, P0101, P0102, P0103, P0106, P0107, P0108, P0121, P0122, P0123, P0221, P0222, P0223, P0234, P0236, P0237, P0238, P0299, P2227, P2228, or P2229, is not set.

• The boost pressure versus the BARO pressure ratio is between 1.1-3.3.

• The charge air bypass valve has been commanded ON for greater than 1 second immediately after an abrupt closed throttle has occurred and the resulting pressure ratio across the compressor exceeds the calibrated pressure ratio limit.

• The battery voltage is between 10-18 volts.

• This DTC runs continuously within the enabling conditions.

Conditions for Setting the DTC
The ECM by comparing the measured MAF to the modeled MAF has detected a series of pulsations in the induction system that exceed a calibrated threshold.

Action Taken When the DTC Sets
DTC P2261 is a Type B DTC.

Conditions for Clearing the MIL/DTC
DTC P2261 is a Type B DTC.

Diagnostic Aids
The bypass valve vacuum tank contains an internal check valve to prevent the tank from being pressurized during boost conditions. A leaking check valve will result in insufficient vacuum to open the turbocharger bypass valve after a quick throttle closing, causing abnormal pulsations and unusual noise.

Reference Information
Schematic Reference
Engine Controls Schematics

Connector End View Reference
Component Connector End Views

Description and Operation

• Turbocharger System Description

• Boost Control System Description


Electrical Information Reference

• Circuit Testing

• Connector Repairs

• Testing for Intermittent Conditions and Poor Connections

• Wiring Repairs


DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference
Control Module References for scan tool information.

Circuit/System Verification
•Verify that DTC P0033, P0034, or P0035 is not set.
⇒ If any of the DTCs are set, refer to DTC P0033-P0035.

•Use the scan tool output controls to command the TC Bypass Solenoid ON and OFF. An audible click should be heard and felt.
⇒ If the click is not heard or felt, refer to DTC P0033-P0035.

•Set up the scan tool for a snapshot of the induction data list. With the emergency brake on, the vehicle transmission in neutral, and the engine idling, perform a wide open throttle and then quickly release the accelerator. Review the Boost Pressure Sensor parameter. There should not be any abnormal pulsations of the parameter. The pressure should peak and then decay with a smooth or stair step pattern without saw tooth pulsations. Refer to graphs below for examples of a normal Boost Pressure Sensor parameter and a Boost Pressure Sensor parameter with abnormal pulsations.
• Normal Boost Pressure





• Boost Pressure with Abnormal, Sawtooth, Pulsations





•With the parking brake ON and the engine idling in neutral, perform an audible test of the valve by depressing the throttle wide open, then quickly releasing it to a closed throttle position. A valve that is stuck shut will generate an unusual pulsating noise. Compare to a similar vehicle. There should not be any unusual noise.
⇒ If there is unusual noise, refer to Turbocharger Cleaning and Inspection.

•Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
Circuit/System Testing
•Inspect for any vacuum leaks, damage, restrictions, improper routing or connecting of the vacuum hoses on the charge air bypass valve solenoid and the charge air bypass valve.
⇒ If a condition is found, repair as necessary.

•Inspect the bypass valve vacuum tank for any vacuum leaks, damage, restrictions, improper routing or connecting of the vacuum hoses. Remove the vacuum hose that runs from the tank to the bypass valve solenoid at the solenoid and apply vacuum to the tank. The tank should be able to maintain vacuum without decay. If the tank is unable to maintain vacuum, remove the vacuum hose from the intake manifold and plug the hose. If the decay stops, the internal check valve is leaking. If the decay continues, the tank itself is leaking.
⇒ If a condition is found, repair as necessary.

•Clear the DTC and operate the vehicle within the Conditions for Running the DTC.
⇒ If the DTC cannot be cleared or continues to reset, then replace the charge air bypass valve.

Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• Charge Air Bypass Valve Vacuum Tank Replacement

• Charge Air Bypass Valve Replacement

• Control Module References for ECM replacement, setup, and programming

RobSSTurbo

Fix it yet?

camaro98z28

Is P2261 a drivetrain code? My scanner says P2261 and a EVA is flashing

Greybeard999

P2261 Turbocharger Bypass Valve Stuck Closed

camaro98z28

Im guessing its a powertrain code. I only have 38k + miles on the car.i have an overboost issue but no code popped up until this one. Can the be related?