Buick Regal: DTC P0650, P263A, or P263B
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 P0650
Malfunction Indicator Lamp (MIL) Control Circuit Open
DTC P263A
Malfunction Indicator Lamp (MIL) Control Circuit Low Voltage
DTC P263B
Malfunction Indicator Lamp (MIL) Control Circuit High Voltage
Diagnostic Fault Information
Circuit/System Description
The malfunction indicator lamp (MIL) illuminates to inform the driver that an
emission system fault has
occurred and the powertrain control system requires service. Ignition voltage is
supplied directly to the
MIL. The engine control module (ECM) turns the MIL ON by grounding the MIL
control circuit when
the emission system fault occurs. Under normal operating conditions, the MIL
should be ON only when
the ignition is ON and the engine is OFF.
Conditions for Running the DTC
- The engine speed is greater than 80 RPM.
- The ignition voltage is between 11 - 32 V.
- The DTCs run continuously when the above conditions are met.
Conditions for Setting the DTC
DTC P0650 or DTC P263A
The ECM detects low voltage during the MIL control circuit driver OFF state.
This indicates either a
shorted to ground or an open MIL control circuit.
DTC P263B
The ECM detects high voltage on the MIL control circuit during the driver ON
state. This indicates a
shorted to voltage MIL control circuit.
Action Taken When the DTC Sets
DTC P0650, P263A, and P263B are Type B DTCs
Conditions for Clearing the DTC
DTC P0650, P263A, and P263B are Type B DTCs
Diagnostic Aids
- If the condition is intermittent, move the related harnesses and
connectors while monitoring the
scan tool MIL control circuit status parameters. Perform this test with the
ignition ON and the
engine OFF, and with the engine running. The MIL control circuit status
parameters change from
OK or Not Run to Malfunction if there is a condition with a circuit or a
connection.
- If the ECM detects low voltage on the MIL control circuit during the
control circuit driver OFF
state, DTCs P0650 and DTC P263A may set simultaneously.
Reference Information
Schematic Reference
- Engine Controls Wiring Schematics (LTG)
- Instrument Cluster Wiring Schematics
Connector End View Reference
- Component Connector End View Index
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 the parameters listed below do not display Malfunction when commanding
the Malfunction
Indicator Lamp On and Off with a scan tool.
- The MIL Control Circuit Low Voltage Test Status
- The MIL Control Circuit Open Test Status
- The MIL Control Circuit High Voltage Test Status
If Malfunction is displayed
- Refer to Circuit/System Testing.
3. Engine running.
4. Verify the parameters listed below do not display Malfunction when commanding
the Malfunction
Indicator Lamp On and Off with a scan tool.
- The MIL Control Circuit Low Voltage Test Status
- The MIL Control Circuit Open Test Status
- The MIL Control Circuit High Voltage Test Status
- If Malfunction is displayed
Refer to Circuit/System Testing.
- Go to next step: If Malfunction is not displayed
5. Verify the malfunction indicator lamp turns ON and OFF when commanding the
Malfunction
Indicator Lamp On and Off with a scan tool.
- If the malfunction indicator lamp does not turn ON and OFF
Refer to Circuit/System Testing.
- Go to next step: If the malfunction indicator lamp turns ON and OFF
6. 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.
Refer to Diagnostic Trouble Code (DTC) List - Vehicle for further
diagnosis.
- Go to next step: If the DTC does not set
7. All OK.
Circuit/System Testing
1. Ignition OFF.
2. Disconnect the X1 harness connector at the K20 Engine Control Module.
3. Ignition ON, verify the malfunction indicator lamp does not illuminate.
- If the malfunction indicator lamp illuminates
- Test for infinite resistance between the control circuit terminal X1 71
and ground.
- If less than infinite resistance, repair the short to ground in the
circuit.
- If infinite resistance, replace the P16 Instrument Cluster.
- Go to next step: If the malfunction indicator lamp does not
illuminate
4. Connect a 3 A fused jumper wire between the control circuit terminal X1 71
and ground.
5. Verify the malfunction indicator lamp illuminates.
- If the malfunction indicator lamp illuminates
Replace the K20 Engine Control Module.
- If the malfunction indicator lamp does not illuminate
- Test for less than 1 V between the control circuit terminal X1 71 and
ground.
- If 1 V or greater, repair the short to voltage in the circuit.
- Go to next step: If less than 1 V
- Ignition OFF.
- 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.
- Go to next step: If less than 2 Ω.
6. Ignition OFF, disconnect the harness connector at the instrument cluster.
7. Ignition ON, verify a test lamp illuminates between the between the ignition
voltage circuit
terminal X1 8 and ground.
- If the test lamp does not illuminate and the circuit fuse is open
- Ignition OFF.
- Test for infinite resistance between the ignition voltage circuit and
ground.
- If less than infinite resistance, repair the short to ground in the
circuit.
- If the test lamp does not illuminate and the circuit fuse is good
- Ignition OFF.
- Test for less than 2 Ω in the ignition voltage circuit end to end.
- If 2 Ω or greater, repair the open/high resistance in the circuit.
- Go to next step: If the test lamp illuminates
8. Replace the P16 Instrument Cluster.
Repair Instructions
Perform the Diagnostic Repair Verification after completing the repair.
- Instrument Cluster Replacement
- Control Module References for control module 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 prior to using this diagnostic
procedure: Diagnostic
System Check - Vehicle
Review the description of Strategy Based Diagnosis:Strateg
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For equivalent regional tools, refer to Special Tools.
WARNING: Refer to Brake Dust Warning.
NOTE:
Brake rotor assembled lateral runout (LRO) exceeding the maximum
allowable specification can cause thickness variation to develop in the
brake roto
If equipped, the FCA system may
help to avoid or reduce the harm
caused by front-end crashes. When
approaching a vehicle ahead too
quickly, FCA provides a red flashing
alert on the windshield and rapidly
beeps. FCA also lights an amber
visual alert if following another
vehicle much too closely.
FCA