Buick Regal: DTC P219A

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 P219A

Fuel Trim Cylinder Balance

Circuit/System Description

The Fuel Trim Cylinder Balance diagnostic detects a rich or lean cylinder to cylinder air/fuel ratio imbalance. The diagnostic monitors the pre-catalyst heated oxygen sensor (HO2S) signal's frequency and amplitude characteristics by calculating an accumulated voltage over a predetermined sample period. An imbalance is indicated when multiple samples of the accumulated voltage are consistently higher than the desired value.

Conditions for Running the DTC

• DTCs P0016, P0017, P0030, P0036, P0053, P0054, P0068, P0101, P0102, P0103, P0106, P0107, P0108, P0116, P0117, P0118, P0019, P0122, P0123, P0128, P0131 - P0135, P0137, P0138, P013A, P013B, P013E, P013F, P0140, P0141, P0171, P0172, P0201 - P0204, P0222, P0223, P0261, P0262, P0264, P0265, P0267, P0268, P0270, P0271, P0300, P0301 - P0304, P0340, P0341, P0365, P0366, P0411, P0442, P0455, P0458, P0496, P111E, P1133, P1248, P1249, P124A, P124B, P16A0, P16A1, P16A2, P16F3, P2101, P2135, P2147, P2148, P2150. P2151, P2153, P2154, P2156, P2157, P2270, P2271, P2440, P2444 or P2A00 are not set.
• The evaporative emission system device control and intrusive diagnostics are not active.
• The engine overspeed protection is not active.
• The engine is in closed loop status.
• The system voltage is greater than 11 V.
• The engine coolant temperature (ECT) is warmer than -20ºC (-4ºF).
• The engine speed is between 1, 200 - 4, 000 RPM.
• The mass air flow is between 0 - 100 g/s.
• The secondary air injection pump (if equipped) is not ON.
• The Exhaust Camshaft Position and Intake Camshaft Position are between 0 - 35 degrees.

  Engine run time is greater than 30 s.

• Fuel level is greater than 10% and no fuel level sensor fault is present.
• The DTC runs continuously when the above conditions have been met.

Conditions for Setting the DTC

Multiple samples of the pre-catalyst HO2S accumulated voltage are consistently greater than the desired value.

Action Taken When the DTC Sets

DTC P219A is a Type A DTC.

Conditions for Clearing the MIL/DTC

DTC P219A is a Type A DTC.

Diagnostic Aids

• The fuel trim cylinder balance diagnostic is very sensitive to heated oxygen sensor (HO2S) design. A non-OE sensor or an incorrect part number may cause a DTC to set.
• Monitoring the misfire current counters, or misfire graph, may help to isolate the cylinder that is causing the condition.
• Certain aftermarket air filters may cause a DTC to set.
• Certain aftermarket air induction systems or modifications to the air induction system may cause a DTC to set.
• Certain aftermarket exhaust system components may cause a DTC to set.

Reference Information

Schematic Reference

Engine Controls Wiring Schematics (LTG)

Connector End View Reference

Component Connector End View Index

Component View Reference

Powertrain Component Views

Electrical Information Reference

• Circuit Testing
• Troubleshooting with a Test Lamp
• Testing for Intermittent Conditions and Poor Connections
• Wiring Repairs
• Connector 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 no other DTCs are set.

• If any other DTCs are set

Refer to Diagnostic Trouble Code (DTC) List - Vehicle for further diagnosis.

• Go to next step: If no other DTCs are set

3. Verify DTC P219A is not set.

• If a DTC is set

Refer to Circuit/System Testing.

• Go to next step: If no DTC is set

4. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed in the Freeze Frame/Failure Records data.

5. Verify DTC P219A is not set.

• If a DTC is set

Refer to Circuit/System Testing.

• Go to next step: If no DTC is set

6. All OK.

Circuit/System Testing

1. Engine idling, transmission in Park or Neutral, verify the manifold absolute pressure (MAP) sensor parameter is between 20 - 48 kPa.

• If not within the specified range.

Refer to DTC P0106.

• Go to next step: If within the specified range, inspect for the conditions listed below:
• Modified, damaged, leaking, or restricted air induction system components.
• Improperly operating crankcase ventilation system. Refer to Crankcase Ventilation System Inspection/Diagnosis.
• Split, kinked, or improperly connected vacuum hoses.
• Restricted, damaged, leaking, or modified exhaust system from the catalytic converter forward. Refer to Symptoms - Engine Exhaust.
• Improperly operating fuel injectors. Refer to Fuel Injector Diagnosis.
• Fuel contamination. Refer to Alcohol/Contaminants-in-Fuel Diagnosis.
• Excessive fuel in the crankcase due to leaking injectors. Change engine oil as necessary.
• Improperly operating ignition system. Refer to Electronic Ignition System Diagnosis.
• If a condition is found

Repair as necessary.

• Go to next step: If no condition is found

2. Test the engine for any mechanical conditions such as sticking valves, lifters, etc., which could alter the flow into the combustion chamber. Refer to Symptoms - Engine Mechanical.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the repair.

Perform the scan tool Fuel Trim Reset after completing the repair.

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