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DTC P2261 (LLU)

DTC P2261 (LLU)

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 00

Turbocharger Bypass Valve Stuck

Circuit/System Description

The turbocharger incorporates a wastegate that is controlled by a pressure differential, that is determined by the engine control module (ECM) by means of a pulse width modulation (PWM) solenoid, in order to regulate the pressure ratio of the compressor. A charge air bypass valve is integrated within the module, 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 turbocharger 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 turbocharger 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

• Engine speed

• Boost Pressure Sensor


Conditions for Running the DTC


• DTCs P0033 00, P0034 00, P0035 00, P0097 00, P0098 00, P0100 00, P0101 00, P0102 00, P0103 00, P0121 00, P0122 00, P0123 00, P0221 00, P0222 00, P0223 00, P0234 00, P0237 00, P0238 00, P0299 00, P2228 00, or P2229 00, are not set.

• The boost pressure versus the Barometric Pressure (BARO) ratio is between 1.1-3.3.

• The charge air bypass valve has been commanded ON for greater than 1 s 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 V.

• The engine coolant temperature is above 39°C (102°F).

• The intake air temperature is above 4.5°C (40°F).

• 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


• DTCs P2261 00 is a Type C DTC.

• The service vehicle soon indicator will illuminate.


Conditions for Clearing the DTC

DTCs P2261 00 is a Type C DTC.

Reference Information

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Component Connector End Views

Description and Operation


• Boost Control System Description (LLU)

• Turbocharger System Description (LLU)


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


1. Verify that DTC P0033 00, P0034 00, or P0035 00 are not set.

2. If any of the DTCs are set, refer to DTC P0033-P0035 (LLU) .

3. Use the scan tool output controls to command the Turbocharger Bypass Solenoid to 100% and down to 0%. An audible click should be heard and felt.

4. If the click is not heard or felt, refer to DTC P0033-P0035 (LLU) .

5. Set up the scan tool for a snapshot of the induction data list. With the parking 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.

6. 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 a fluttering sound. There should not be any unusual noise.

7. If there is unusual noise, inspect the turbocharger.

8. 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


1. Inspect for any vacuum leaks, damage, restrictions, improper routing or connecting of the vacuum hoses on the Q40 Turbocharger Bypass Solenoid Valve solenoid, and the charge air bypass valve vacuum tank.

2. Clear the DTC and operate the vehicle within the conditions for running the DTC.

3. 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 Regulator Solenoid Valve Replacement

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