For 1990-2009 cars

### 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 Descriptors

DTC P0033: Turbocharger Bypass Valve Solenoid Control Circuit
DTC P0034: Turbocharger Bypass Valve Solenoid Control Circuit Low Voltage
DTC P0035: Turbocharger Bypass Valve Solenoid Control Circuit High Voltage

### Diagnostic Fault Information

Circuit | Short to Ground | High Resistance | Open | Short to Voltage | Signal Performance
--- | --- | --- | --- | --- | ---
Ignition 1 Voltage Circuit | P0010, P0013, P0033, P0034, P0245, P2088, P2090 | P0033 | P0033, P0034 | -- | --
Turbocharger Bypass Valve Control Circuit | P0034 | P0033 | P0033 | P0035 | P0033

### Circuit/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 compressor bypass valve also controlled by the ECM by utilizing a remotely mounted solenoid is integrated into the unit to prevent compressor surging and damage from vibrations by opening during abrupt closed throttle conditions. When the valve is 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 turbo response. The TC bypass valve solenoid has the following circuits:

• | An ignition 1 voltage circuit

• | The turbocharger bypass valve control circuit

As engine load and RPM increases the TC Bypass Solenoid parameter should remain commanded ON by the ECM. As soon as the throttle closes the TC Bypass Solenoid parameter should be commanded OFF by the ECM, in order to allow the turbocharger bypass valve to open and allow the TC air to recirculate, thereby preventing compressor surging.

### Conditions for Running the DTCs

• | The engine speed is greater than 80 RPM.

• | The battery voltage is between 10-18 volts.

• | The bypass valve must be activated in order to set the open and short to ground faults.

• | This DTC runs continuously within the enabling conditions.

### Conditions for Setting the DTCs

The ECM detects an open, a short to ground, or a short to voltage on the TC bypass valve solenoid control circuit for greater than 4 seconds continuously, or 50 seconds cumulative.

### Action Taken When the DTCs Set

DTC P0033, P0034, P0035, are Type B DTCs.

### Conditions for Clearing the MIL/DTCs

DTC P0033, P0034, P0035, are Type B DTCs.

### Diagnostic Aids

• | A restriction that exists in the exhaust system will hinder the performance of the engine and the turbocharger. Refer to Restricted Exhaust.

• | For additional turbocharger and boost system information, refer to Turbocharger System Description and Boost Control System Description.

### Reference Information

#### Schematic Reference

Engine Controls Schematics

#### Connector End View Reference

• | Engine Control Module Connector End Views

• | Engine Controls Connector End Views

#### 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

• | Scan Tool Data List

• | Scan Tool Data Definitions

• | Scan Tool Output Controls

• | Scan Tool Snapshot Procedure

### Circuit/System Verification

Use the scan tool output controls to command the TC Bypass Solenoid Command parameter ON and OFF. An audible click should be heard and felt.

### Circuit/System Testing

1. Clear the DTCs with a scan tool.
2. Ignition OFF, disconnect the harness connector at the TC bypass valve solenoid.
3. Ignition ON, verify that a test lamp illuminates between the voltage supply circuit terminal 2 and ground.

Important: If the ignition fuse is open, it will be necessary to test the spliced voltage supply circuits and the components for a short to ground.

⇒ | If a test lamp does not illuminate test the voltage supply circuit for a short to ground or an open/high resistance.

4. Verify that a test lamp does not illuminate between the control circuit terminal #1 and ground.

⇒ | If the test lamp illuminates, test the control circuit for a short to voltage. If the circuit tests normal, replace the ECM.

5. Connect a test lamp between the control circuit terminal 1 and the voltage supply circuit terminal 2.
6. Command the TC bypass solenoid ON and OFF with a scan tool. The test lamp should turn ON and OFF when changing between the commanded states.

⇒ | If the test lamp is always ON, test the control circuit for a short to ground. If the circuit tests normal, replace the ECM.

⇒ | If the test lamp is always OFF, test the control circuit for an open/high resistance. If the circuit tests normal, replace the ECM.

7. If the circuits test normal, replace the TC bypass valve solenoid.

### 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