P2261

DTC P2261

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Initial Inspection and Diagnostic Overview
* 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

System Description

The BorgWarner(TM) dual-scroll turbocharger 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 compressor bypass valve also controlled by the ECM and a solenoid is integrated into the unit to prevent compressor surging and damage from vibrations, and to optimize turbo response and quick engine torque build-up time. The compressor bypass valve, also known as the turbocharger bypass valve is serviceable in the field.

This purpose of this diagnostic is to determine if the turbocharger 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:

* The throttle position (TP)
* The engine speed
* The boost pressure sensor
* The manifold absolute pressure (MAP) sensor

If the measured MAF is not within a calibrated range of the modeled MAF then DTC P2261 will set.

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, P2229, are not set.
* The boost pressure versus the BARO pressure ratio is between 1.1-3.3.
* The Turbocharger bypass valve has been commanded ON for greater than one second.
* 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 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

* A restriction that exists in the exhaust system will hinder the performance of the engine and the turbocharger. Refer to Restricted Exhaust. Restricted Exhaust
* For additional turbocharger and boost system information, refer to Turbocharger System Description and Boost Control System Description.

Circuit/System Verification

* Inspect for Improper routing or connecting of the vacuum hoses on the turbocharger bypass valve solenoid and the turbocharger wastegate solenoid.
* Use the scan tool output controls to command the TC Bypass Solenoid ON and OFF. An audible click should be heard and felt.
* 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 snapshot data. With the RPM increasing the TC Bypass Solenoid parameter should remain commanded ON by the ECM. As soon as the throttle closes the TC Bypass Solenoid should be commanded OFF by the ECM and the Boost Pressure Sensor parameter should decrease drastically at first, and then gradually approach BARO. If the TC bypass valve is stuck shut, there will only be a slow and gradual reduction in the Boost Pressure Sensor parameter.

Circuit/System Testing

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 turbocharger bypass valve.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

* Charge Air Bypass Valve Solenoid Replacement
* Control Module References for ECM replacement, setup, and programming Programming and Relearning Verification Tests