DTC P004B-P004D

 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 P004B 00

Turbocharger 2 Wastegate Solenoid Valve Control Circuit Malfunction

 DTC P004C 54

Turbocharger 2 Wastegate Solenoid Valve Control Circuit Low Voltage

 DTC P004D 00

Turbocharger 2 Wastegate Solenoid Valve Control Circuit High Voltage

 Diagnostic Fault Information

Circuit Short to Ground Open/High Resistance Short to Voltage Signal Performance
Ignition

P004C 54

 P004C 54

 -

 -
Output Control

P004C 54

 P004C 54

 P004D 00

 P004B 00


 Typical Scan Tool Data

Turbocharger B Wastegate Duty Cycle

Circuit Short to Ground Open Short to Voltage
Operating Conditions: engine running

Parameter Normal Range: 0-100%
Ignition

0-100%

 0-100%

 0-100%
Output Control

0-100%

 0%

 0-100%


 Circuit/System Description

The position of the boost pressure actuator HPT is controlled by the engine control module (ECM). The ECM utilizes a boost pressure actuator HPT and a turbocharger pressure sensor to control the boost pressure. The ECM will vary the boost dependant upon the load requirements of the engine. The ECM uses a pulse width modulation on the control circuit to control the solenoid valve.

 Conditions for Running the DTC


• The ignition is ON or the engine is running.
• The ignition voltage is greater than 16.5 V.

• The ECM has commanded the boost pressure actuator HPT ON and OFF at least once during the ignition cycle.

• The DTCs run continuously when the above conditions are met.
 Conditions for Setting the DTC

P004B 00, P004C 54, and P004D 00

The control module detects that the commanded state of the driver and the actual state of the control circuit do not match.

  Action Taken When the DTC Sets

DTCs P004B, P004C, and P004D are Type B DTCs.

 Conditions for Clearing the DTC

DTCs P004B, P004C, and P004D are Type B DTCs.

 Diagnostic Aids

Engine running, increase the engine speed to 1 500 RPM and maintain. With a scan tool, command the Boost Pressure Actuator HPT OFF. The Boost Pressure Sensor parameter should increase to 100-140 kPa (14.5-20.3 PSI) when the Boost Pressure Actuator HPT is commanded ON and decrease to near 96 kPa (14.21 PSI) when commanded OFF.

 Reference Information

 Schematic Reference

Engine Controls Schematics

Connector End View Reference

Component Connector End Views

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

Scan Tool Reference

Control Module References for scan tool information

 Circuit/System Verification


1. Engine running, command the Boost Pressure Actuator HPT between 0-5% with a scan tool. You should hear an audible click.

2. 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. Ignition OFF, disconnect the harness connector at the M91B Boost Pressure Actuator HPT.
2. Ignition ON, verify that a test lamp illuminates between the ignition circuit terminal 2 and ground.
3. If the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance. If the circuit tests normal and the ignition circuit fuse is open, test all components connected to the ignition voltage circuit and replace as necessary.
4. Verify that a test lamp does not illuminate between the ignition circuit terminal 2 and the control circuit terminal 1.
5. If the test lamp illuminates, test the control circuit for a short to ground. If the circuit tests normal, replace the K20 Engine Control Module.
6. Command the M91B Boost Pressure Actuator HPT ON with a scan tool. Verify that a test lamp does illuminate between the ignition circuit terminal 2 and the control circuit terminal 1.
7. If the test lamp does not illuminates, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the K20 Engine Control Module.
8. If all circuits test normal, test or replace the M91B Boost Pressure Actuator HPT.
 Component Testing


Static Test

1. Ignition OFF, disconnect the harness connector at the M91B Boost Pressure Actuator HPT.
2. Test for 5-20 Ω between the control terminal 1 and the ignition terminal 2 of the M91B Boost Pressure Actuator HPT.
3. If not within the specified range, replace the M91B Boost Pressure Actuator HPT.
4. Test for infinite resistance between each terminal and the M91B Boost Pressure Actuator HPT housing/case.
5. If not the specified value, replace the M91B Boost Pressure Actuator HPT.
 Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.


• Turbocharger Control Solenoid Valve Replacement (LBY/A20DTR) Turbocharger Control Solenoid Valve Replacement (LBS/A20DTH)

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