Buick Regal: DTC P0243, P0245, or P0246
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 P0243
Turbocharger Wastegate Solenoid Valve Control Circuit
DTC P0245
Turbocharger Wastegate Solenoid Valve Control Circuit Low Voltage
DTC P0246
Turbocharger Wastegate Solenoid Valve Control Circuit High Voltage
Diagnostic Fault Information
Circuit/System Description
The dual-scroll turbocharger incorporates a wastegate that is controlled by
the engine control module
(ECM) by means of a pulse width modulation (PWM) solenoid, to regulate the
pressure ratio of the
compressor. An ECM controlled compressor bypass valve is integrated into the
unit to prevent
compressor surging and damage from vibrations by opening during abrupt closed
throttle conditions.
The bypass valve is open during closed throttle deceleration conditions to allow
air to recirculate in the
turbocharger and maintain compressor speed.
As engine load and RPM increase, the turbocharger bypass valve is commanded
closed by the ECM. As
soon as the throttle closes, the valve is commanded open to allow the
turbocharger air to recirculate to
prevent compressor surging.
Conditions for Running the DTCs
- Ignition is On or the engine is running.
- Battery voltage is between 11 - 32 V.
- The DTCs run continuously when the above conditions are met.
Conditions for Setting the DTCs
P0243
The ECM detects an open circuit on the turbocharger wastegate solenoid
control circuit for greater than
2 s.
P0245
The ECM detects a short to ground on the turbocharger wastegate solenoid
control circuit for greater
than 2 s.
P0246
The ECM detects a short to voltage on the turbocharger wastegate solenoid
control circuit for greater
than 2 s.
Action Taken When the DTCs Set
- DTCs P0243, P0245, and P0246 are Type B DTCs.
- The ECM will disable boost control and limit the system to mechanical
boost only, resulting in a
substantial decrease in engine power.
Conditions for Clearing the MIL/DTCs
DTCs P0243, P0245, and P0246 are Type B DTCs.
Reference Information
Schematic Reference
Engine Controls Wiring Schematics (LTG)
Connector End View Reference
Component Connector End View Index
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. Ignition On
2. Verify a series of clicks, which increase in frequency, are heard or felt
from the Q42 Turbocharger
Wastegate Solenoid Valve when commanding the Turbocharger Wastegate Solenoid
Valve
between 15 - 100 % with a scan tool.
- If a series of clicks in increasing frequency are not heard or felt
Refer to Circuit/System Testing.
- Go to next step: If a series of clicks in increasing frequency is
heard or felt
3. Verify the parameters listed below do not display Malfunction when
commanding the
Turbocharger Wastegate Solenoid Valve between 15 - 100 % with a scan tool.
- Turbocharger Wastegate Solenoid Valve Control Circuit High Voltage Test
Status
- Turbocharger Wastegate Solenoid Valve Control Circuit Open Test Status
- Turbocharger Wastegate Solenoid Valve Control Circuit Low Voltage Test
Status
- If Malfunction is displayed
Refer to Circuit/System Testing.
- Go to next step: If Malfunction is not displayed
4. 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.
5. Verify a DTC does not set.
Refer to Circuit/System Testing
- Go to next step: If a DTC does not set
6. All OK.
Circuit/System Testing
1. Ignition Off, disconnect the harness connector at the Q42 Turbocharger
Wastegate Solenoid Valve,
ignition On.
2. Verify a test lamp illuminates between the ignition circuit terminal 1 and
ground.
- If the test lamp does not illuminate and the circuit fuse is good
- Ignition Off.
- Test for less than 2 Ω in the ignition circuit end to end.
- If 2 Ω or greater, repair the open/high resistance in the circuit.
- If less than 2 Ω, 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
- Ignition Off, remove the test lamp.
NOTE: A short circuit in any component supplied by the fuse may
cause the fuse to open and set a DTC when the component is
activated.
- 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 supplied by the fuse and
replace as
necessary.
- Go to next step: If the test lamp illuminates
3. Verify that a test lamp does not illuminate between the control circuit
terminal 2 and the ignition
circuit terminal 1.
- If the test lamp illuminates
- Ignition Off, disconnect the harness connector at the K20 Engine Control
Module.
- 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.
- Go to next step: If the test lamp does not illuminate
4. Remove the test lamp.
5. Verify the scan tool Turbocharger Wastegate Solenoid Valve Control Circuit
High Voltage Test
Status parameter is OK when commanding the Turbocharger Wastegate Solenoid Valve
between
15 - 100 % with a scan tool.
- Ignition Off, disconnect the harness connector at the K20 Engine Control
Module, ignition
On.
- 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.
- Go to next step: If OK is displayed
6. Install a 3 A fused jumper wire between the control circuit terminal 2 and
the ignition circuit
terminal 1.
7. Verify the scan tool Turbocharger Wastegate Solenoid Valve Control Circuit
High Voltage Test
Status parameter is Malfunction.
- If Malfunction is not displayed
- Ignition Off, disconnect the harness connector at the K20 Engine Control
Module.
- Test for less than 2 Ω in the control circuit end to end.
- If 2 Ω or greater, repair the open/high resistance in the circuit.
- If less than 2 Ω, replace the K20 Engine Control Module.
- Go to next step: If Malfunction is displayed
8. Test or replace the Q42 Turbocharger Wastegate Solenoid Valve.
Repair Instructions
Perform the Diagnostic Repair Verification after completing the repair.
- Turbocharger Wastegate Regulator Solenoid Valve Replacement
- Control Module References for ECM replacement, programming and setup
READ NEXT:
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.
Diag
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.
Diag
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.
Diag
SEE MORE:
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
D
Diagnostic Instructions
Perform the Diagnostic System Check prior to using this diagnostic
procedure:Diagnostic System
Check - Vehicle
Review the description of Strategy Based Diagnosis:Strategy Based
Diagnosis
An overview of each diagnostic category can be found here:Diagnostic
Procedure