P219A

DTC P219A

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

* Review Strategy Based Diagnosis Strategy Based Diagnosis for an overview of the diagnostic approach.

* Diagnostic Procedure Instructions Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptor

DTC P219A
- Air Fuel Imbalance

Circuit/System Description

The Air Fuel Imbalance 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, P0068, P0101, P0102, P0103, P0106, P0107, P0108, P0116, P0117, P0118, P0122, P0123, P0128, P0201-P0204, P0261, P0262, P0264, P0265, P0267, P0268, P0270, P0271, P0300, P0301-P0304, P0340, P0341, P0365, P0366, P0411, P0442, P0455, P0496, P1248, P1249, P124A, P124B, P16F3, P2101, P2135, P2147, P2148, P2150. P2151, P2153, P2154, P2156, P2157, P2440, P2444 are not set.

* The EVAP intrusive diagnostics and device control 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 -20°C (-4°F).

* The engine speed is between 1,250-4,200 RPM.

* The mass air flow is between 0-100 g/s.

* The AIR pump is not ON.

* 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 air fuel imbalance 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 Schematics [1][2]Electrical Diagrams

Connector End View Reference

Component Connector End Views Outside Rearview Mirror - Driver

Electrical Information Reference

* Circuit Testing Circuit Testing

* Troubleshooting with a Test Lamp Troubleshooting with a Test Lamp

* Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections

* Wiring Repairs Wiring Repairs

* Connector Repairs Connector Repairs

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References Control Module References for scan tool information

Circuit/System Testing

1. Diagnose any other DTCs that are set. Refer to Diagnostic Trouble Code (DTC) List - Vehicle Diagnostic Trouble Code (DTC) List - Vehicle.

2. With the engine idling and the transmission in the Park or Neutral position, observe the manifold absolute pressure (MAP) sensor parameter. The MAP sensor parameter should be between 20-48 kPa.

• If the MAP sensor parameter is not between 20-48 kPa, refer to DTC P0106 P0106.

3. Inspect the air induction system for modified, damaged, leaking, or restricted components.

4. Inspect the crankcase ventilation system for improper operation. Refer to Crankcase Ventilation System Inspection/Diagnosis (With Turbocharger) Testing and Inspection.

5. Inspect the vacuum hoses for splits, kinks, and improper connections.

6. Test for a restricted, damaged, leaking, or modified exhaust system from the catalytic converter forward.

7. Test the fuel injectors for improper operation. Refer to Fuel Injector Solenoid Coil Test Fuel Injector Solenoid Coil Test.

8. Test for fuel contamination. Refer to Alcohol/Contaminants-in-Fuel Diagnosis Testing and Inspection.

9. Test for excessive fuel in the crankcase due to leaking injectors. Change engine oil as necessary.

10. Test the ignition system for improper operation. Refer to Electronic Ignition System Diagnosis Electronic Ignition (EI) System Diagnosis.

11. 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 Symptoms - Engine Mechanical.

Repair Instructions

Perform the Diagnostic Repair Verification Verification Tests after completing the diagnostic procedure.