P219A

DTC P219A or P219B

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 Descriptors

DTC P219A
- Fuel Trim Cylinder Balance Bank 1

DTC P219B
- Fuel Trim Cylinder Balance Bank 2

Circuit/System Description

The Fuel Trim Cylinder Balance diagnostic detects a rich or lean cylinder to cylinder air/fuel ratio imbalance in each bank. 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 P0030, P0050, P0053, P0059, P0068, P0101, P0102, P0103, P0106, P0107, P0108, P0116, P0117, P0118, P0120, P0122, P0123, P0125, P0128, P0131, P0132, P0133, P0134, P0135, P0151, P0152, P0153, P0154, P0155, P015A, P015B, P015C, P015D, P0178, P0179, P0201-P0208, P0220, P0222, P0223, P0300, P0301-P0308, P0442, P0443, P0446, P0449, P0452, P0453, P0455, P0496, P0606, P0641, P0651, P1133, P1153, P1516, P2101, P2120, P2122, P2123, P2125, P2127, P2128, P2135, P2138, P2176, or P2269 are not set.

* The intrusive diagnostics, device controls, engine overspeed protection, traction control, or reduced engine power is not active.

* The engine is in closed loop status.

* The system voltage is between 10-32 V for greater than 4 s.

* The engine run time is greater than 125 s.

* The engine coolant temperature (ECT) is warmer than -20°C (-4°F).

* The engine speed is between 425-6,000 RPM.

* The mass air flow is between 20-510 g/s.

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

DTCs P219A and P219B are Type B DTCs.

Conditions for Clearing the MIL/DTC

DTCs P219A and P219B are Type B DTCs.

Diagnostic Aids

* The fuel trim cylinder balance diagnostic is very sensitive to 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 (LS3) [1][2]Electrical DiagramsEngine Controls Schematics (LS7) [1][2]Electrical DiagramsEngine Controls Schematics (LS9) [1][2]Electrical Diagrams

Connector End View Reference

Component Connector End Views 5 Bow Lowered Switch (CM7)

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

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. Ignition ON, observe the scan tool DTC information. Verify there are no other DTCs set.

• If a DTC is set, refer to Diagnostic Trouble Code (DTC) List - Vehicle Diagnostic Trouble Code (DTC) List - Vehicle for further diagnosis.

2. Engine idling, observe the MAP sensor parameter. The reading should be between 19-42 kPa (2.7-6 PSI).

• If not within the specified range, refer to DTC P0106 (Without Supercharger) P0106DTC P0106 (Supercharger) or DTC P0107 or P0108 (Without Supercharger) P0107DTC P0107 or P0108 (Supercharger) .

3. Ignition OFF, verify that none of the conditions listed below exists:

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

* Inspect the crankcase ventilation system for improper operation. Refer to Crankcase Ventilation System Inspection/Diagnosis Testing and Inspection.

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

* Inspect for vacuum leaks at the intake manifold, the throttle body, and the injector O-rings.

* Test for a restricted, damaged, leaking, or modified exhaust system from the catalytic converter forward. Refer to Symptoms - Engine Exhaust Symptoms - Engine Exhaust.

* Test the fuel injectors for improper operation. Refer to Fuel Injector Diagnosis (CH47976) Fuel Injector Diagnosis (CH47976)Fuel Injector Diagnosis (J39021 or Scan Tool) Fuel Injector Diagnosis (J39021 or Scan Tool).

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

* Test for excessive fuel in the crankcase due to leaking injectors.

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

4. If all the above conditions test normal, test the engine for any mechanical conditions that 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.