Chevrolet Trax: DTC P0033-P0035

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 Solenoid Valve Control Circuit

DTC P0034

Turbocharger Bypass Solenoid Valve Control Circuit Low Voltage

DTC P0035

Turbocharger Bypass Solenoid Valve Control Circuit High Voltage

Diagnostic Fault Information

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 PWM solenoid valve, in order to regulate the pressure ratio of the turbocharger. A turbocharger bypass valve also controlled by the ECM by utilizing a remotely mounted solenoid valve is integrated into the bypass valve to prevent turbocharger 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 turbocharger 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 bypass solenoid valve has the following circuits:

• Ignition voltage
• Turbocharger bypass solenoid valve control

As engine load and engine speed increases, the turbocharger bypass solenoid valve remains commanded ON by the ECM. As soon as the throttle closes the turbocharger bypass solenoid valve is commanded OFF by the ECM, in order to allow the turbocharger bypass valve to open and allow the turbocharger air to recirculate, there by preventing turbocharger surging.

Conditions for Running the DTC

• The engine is not cranking.
• The powertrain relay voltage is greater than 11 V.
• The run/crank voltage is greater than 6 V.
• The DTC run continuously when the above conditions are met.

Conditions for Setting the DTC

The ECM detects an open, a short to ground, or a short to voltage on the turbocharger bypass solenoid valve control circuit for greater than 1 s.

Action Taken When the DTC Sets

DTC P0033, P0034, P0035 are Type B DTCs.

Conditions for Clearing the DTC

DTC P0033, P0034, P0035 are Type B DTCs

Reference Information

Schematic Reference

Engine Controls Schematics (Encore) , Engine Controls Schematics (Trax)

Connector End View Reference

WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT CONNECTOR END VIEWS - INDEX - ENCORE WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT CONNECTOR END VIEWS - INDEX - TRAX

Description and Operation

Turbocharger 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 (LUV) , Powertrain Diagnostic Trouble Code (DTC) Type Definitions (2H0)

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification

1. Ignition ON, Verify the parameters listed below do not display Malfunction when commanding the Turbocharger Bypass Solenoid Valve ON and OFF with a scan tool:

• Turbocharger Bypass Solenoid Valve Control Circuit Low Voltage Test Status
• Turbocharger Bypass Solenoid Valve Control Circuit Open Test Status
• Turbocharger Bypass Solenoid Valve Control Circuit High Voltage Test Status

• If Malfunction is displayed

Refer to Circuit/System Testing.

• If Malfunction is not displayed

2. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
3. Verify a DTC does not set.

• If a DTC sets

Refer to Circuit/System Testing

• If a DTC does not set

4. All OK

Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the Q40 Turbocharger Bypass Solenoid Valve. Ignition ON.
2. Verify a test lamp illuminates between the ignition circuit terminal 2 and ground.

• If the test lamp does not illuminate and the circuit fuse is good

1. Ignition OFF, remove the test lamp.
2. Test for less than 2 ohms in the ignition circuit end to end.

• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, verify the fuse is not open and there is voltage at the fuse.
• If the test lamp does not illuminate and the circuit fuse is open

1. Ignition OFF, remove the test lamp.

NOTE: An internal short in any component supplied by the fuse may cause the fuse to open and set a DTC when the component is activated.

2. Test for infinite resistance between the ignition circuit and ground.

• If less than infinite resistance, repair the short to ground on the circuit.
• If infinite resistance, test all components connected to the ignition voltage circuit for a short and replace as necessary.

If the test lamp illuminates

3. Verify that a test lamp does not illuminate between the control circuit terminal 1 and the ignition circuit terminal 2.

• If the test lamp illuminates

1. Ignition OFF, disconnect the harness connector at the K20 Engine Control Module. Remove the test lamp.
2. Test for infinite resistance between the control circuit and ground.

• If less than infinite resistance, repair the short to ground on the circuit.
• If infinite resistance, replace the K20 Engine Control Module.

If the test lamp does not illuminate

4. Remove the test lamp.
5. Verify the scan tool Turbocharger Bypass Solenoid Valve Control Circuit High Voltage Test Status parameter is OK when commanding the Turbocharger Bypass Solenoid Valve Active with a scan tool.

• If OK is not displayed

1. Ignition OFF, disconnect the harness connector at the K20 Engine Control Module, ignition ON.
2. Test for less than 1 V between the control circuit and ground.

• If 1 V or greater, repair the short to voltage on the circuit.
• If less than 1 V, replace the K20 Engine Control Module.

If OK is displayed

6. Install a 3 A fused jumper wire between the control circuit terminal 1 and the ignition circuit terminal 2.
7. Verify the scan tool Turbocharger Bypass Solenoid Valve Control Circuit High Voltage Test Status parameter is Malfunction when commanding the Turbocharger Bypass Solenoid Valve Active with a scan tool.

If Malfunction is not displayed

1. Ignition OFF, disconnect the harness connector at the K20 Engine Control Module.
2. Test for less than 2 ohms in the control circuit end to end.

• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, replace the K20 Engine Control Module.

If Malfunction is displayed

3. Test or replace the Q40 Turbocharger Bypass Solenoid Valve.

Component Testing

Static Test

1. Ignition OFF, disconnect the harness connector at the Q40 Turbocharger Bypass Solenoid Valve.
2. Test for 20-27 ohms between terminal 1 and terminal 2 of the solenoid valve

If not between 20-27 ohms

Replace the Q40 Turbocharger Bypass Solenoid Valve.

If between 20-27 ohms

3. All OK

Dynamic Test

1. Install a 10 A fused jumper wire between the Ignition terminal 2 and 12 V. Install a jumper wire between the control terminal 1 and ground.
2. Verify the solenoid clicks.

If the solenoid does not click

Replace the Q40 Turbocharger Bypass Solenoid Valve.

If the solenoid clicks

3. All OK

Repair Instructions

Perform the Diagnostic Repair Verification after completing the repair.

• Charge Air Bypass Regulator Solenoid Valve Replacement
• Control Module References for ECM replacement, programming and setup

DTC P0068 OR P1101

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 P0068

Throttle Body Air Flow Performance

DTC P1101

Intake Air Flow System Performance

Circuit/System Description

The engine control module (ECM) compares actual airflow based on throttle position (TP) to a calculated airflow based on manifold absolute pressure (MAP) sensor, and mass air flow (MAF).

Conditions for Running the DTC

DTC P0068

• The engine speed is at least 800 RPM.
• The ignition voltage is at least 6.4 V.
• The DTC runs continuously when the above conditions are met.

DTC P1101

• DTC P0102, P0103, P0107, P0111, P0112, P0113, P0116, P0117, P0118, P0335,or P0336 is not set
• The engine speed is between 400-7,000 RPM
• The engine coolant temperature (ECT) is between -7 to +125ºC (+19 to +257ºF).
• The intake air temperature (IAT) is between -20 to +125ºC (-4 to +257ºF).
• The DTC runs continuously when the above conditions are met.

Conditions for Setting the DTCs

The ECM detects that the actual airflow rate is greater than the calculated airflow.

Action Taken When the DTCs Set

• DTC P0068 is a type A DTC.
• DTC P0068 is a type B DTC; with RPO LDD.
• DTC P1101 is a type B DTC.

Conditions for Clearing the DTCs

• DTC P0068 is a type A DTC.
• DTC P0068 is a type B DTC; with RPO LDD.
• DTC P1101 is a type B DTC.

Reference Information

Schematic Reference

Engine Controls Schematics (Encore) , Engine Controls Schematics (Trax)

Connector End View Reference

WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT CONNECTOR END VIEWS - INDEX - ENCORE WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT CONNECTOR END VIEWS - INDEX - TRAX

Electrical Information Reference

• Circuit Testing
• Connector Repairs
• Testing for Intermittent Conditions and Poor Connections
• Wiring Repairs

Powertrain Component Views

Powertrain Component Views

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions (LUV) , Powertrain Diagnostic Trouble Code (DTC) Type Definitions (2H0)

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification

1. Ignition ON.
2. Verify that DTC DTC P0641, P0651, P0697, or P06A3 is not set.

• If any of the DTCs are set

Refer to DTC P0641, P0651, P0697, or P06A3 (ECM) for further diagnosis.

• If none of the DTCs are set

3. Ignition ON.
4. Verify the scan tool Throttle Body Idle Airflow Compensation parameter is less than 90 %.

• If 90 % or greater

Refer to Throttle Body Inspection and Cleaning .

• If less than 90 %

5. Verify the scan tool Throttle Position Sensors 1 and 2 Agree/Disagree parameter displays Agree while performing the Throttle Sweep Test with a scan tool.

• If Disagree

Refer to DTC P0121-P0123, P0222, P0223, or P2135 for further diagnosis.

• If Agree

6. Determine the current vehicle testing altitude.
7. Verify the scan tool MAP Sensor pressure parameter is within the range specified in the Altitude Versus Barometric Pressure table.

• If the MAP Sensor parameter is not in range

Refer to DTC P0106 for further diagnosis.

• If the MAP Sensor parameter is within range

8. Verify the engine is equipped with a turbocharger.

• If not equipped with a turbocharger

Refer to Step 11.

• If equipped with a turbocharger

9. Verify the scan tool Boost Pressure Sensor parameter is within the range specified in the Altitude Versus Barometric Pressure table.

• If the Boost Pressure Sensor parameter is not in range

Refer to DTC P0236 for further diagnosis.

• If the Boost Pressure Sensor parameter is within range

10. Verify the scan tool Boost Pressure Sensor parameter decreases after starting the engine.

• If the Boost Pressure Sensor parameter does not decrease

Refer to DTC P0236 for further diagnosis.

• If the Boost Pressure Sensor parameter is within range

11. Engine idling, verify the scan tool MAP Sensor pressure parameter is between 26-52 kPa (3.8-7.5 PSI) and changes with accelerator pedal input.

• If not between 26-52 kPa (3.8-7.5 PSI) or does not change

Refer to DTC P0106 for further diagnosis.

• If between 26-52 kPa (3.8-7.5 PSI) and changes

12. Verify the scan tool MAF Sensor g/s parameter changes smoothly and gradually as the engine speed is increased and decreased while performing the actions listed below.

1. Engine idling
2. Perform the scan tool snapshot function.
3. Increase the engine speed slowly to 3,000 RPM and then back to idle.
4.  Exit from the scan tool snapshot and review the data.
5.  Observe the MAF Sensor parameter frame by frame with a scan tool.

• If the MAF Sensor parameter does not change smoothly and gradually

Refer to DTC P0101 for further diagnosis.

• If the MAF Sensor parameter changes smoothly and gradually

13. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
14.  Verify the DTC does not set.

• If the DTC does set

Refer to Circuit/System Testing for further diagnosis.

• If the DTC does not set

15. All OK

Circuit/System Testing

NOTE: You must perform the Circuit/System Verification before proceeding with Circuit/System Testing.

1. Verify the integrity of the entire air induction system by verifying that none of the following conditions exist:

• Any damaged components
• Improper operation of turbocharger wastegate actuator or bypass valve; where equipped
• Improperly installed components
• Collapsed, restricted, or damaged components
• Loose clamps, cracks, or other damage
• An air flow restriction
• Restricted air filter
• Splits, kinks, leaks, or improper connections at the vacuum hoses
• Vacuum leaks at the intake manifold, MAP sensor, and throttle body
• Water intrusion
• Any snow or ice buildup, in cold climates
• Contamination of the MAF sensor element
• Missing, restricted, or leaking exhaust components-Refer to Symptoms - Engine Exhaust for further diagnosis.

• If a condition is found

Repair or replace component as appropriate.

• If no condition is found

2. Test the engine for a mechanical condition. Refer to Symptoms - Engine Mechanical for diagnosis.

• If a condition is found

Repair or replace component as appropriate.

• If no condition is found

3. All OK

Repair Instructions

Perform the Diagnostic Repair Verification after completing the repair.

Control Module References for engine control module replacement, programming, and setup

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