I just got a p219a code on my 2011 Sierra 1500 slt 4 wheel drive. I’m starting to do the research on it and have found several different causes for that code. Is there a common problem that would cause this code, or I should look at first or just go down the line of possibilities? Any advice will be appreciated.

What engine?

Lc9. 5.3l It has 121000 miles on it

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Home >> GMC Truck >> 2011 >> Sierra 1500 2WD V8-5.3L >> Repair and Diagnosis >> A L L Diagnostic Trouble Codes ( DTC ) >> Testing and Inspection >> P Code Charts >> P219A >> Heavy Duty L96

Heavy Duty L96

DTC P219A or P219B (Heavy Duty L96)

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'* 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, P0119, P0122, P0123, P0128, P0131, P0132, P0133, P0134, P0135, P0151, P0152, P0153, P0154, P0155, P0201-P0208, P0222, P0223, P0300, P0301-P0308, P0442, P0443, P0446, P0449, P0452, P0453, P0455, P0496, P16F3, P2101, P2135 are not set.
* The device control is not active.
* The intrusive diagnostics are not active.
* The engine overspeed protection is not active.
* The power take-off (PTO) is not active.
* The traction control is not active.
* The engine is in air-fuel Closed Loop status.
* The system voltage is between 10-32 V.
* The engine coolant temperature (ECT) is greater than -20°C (-4°F).
* The engine speed is between 1000-3500 RPM.
* The mass air flow is between 10-510 g/*.

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 heated oxygen sensor (HO2S) design. A non-OE sensor or an incorrect part number may set a false DTC.
* Monitoring the misfire current counters, or misfire graph, may help to isolate the cylinder that is causing the condition.

Reference Information
Schematic Reference

Engine Controls Schematics (except L96) ([1][2]Electrical Diagrams)Engine Controls Schematics (L96) ([1][2]Electrical Diagrams)
Connector End View Reference

Component Connector End Views (Connector End Views By Name)
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. Read and record the Freeze Frame/Failure Records data taking note of the speed and load at which the DTC set.
2. Diagnose any other DTCs that are set. Refer to Diagnostic Trouble Code (DTC) List - Vehicle (Diagnostic Trouble Code (DTC) List - Vehicle).
3. 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 19-42 kPa.

• If the MAP sensor parameter is not between 19-42 kPa, refer to DTC P0106 (P0106) or DTC P0107 or P0108 (P0107).

4. Inspect the air induction system for modified, damaged, leaking, or restricted components.
5. Inspect the crankcase ventilation system for improper operation. Refer to Crankcase Ventilation System Inspection/Diagnosis (Testing and Inspection).
6. Inspect the vacuum hoses for splits, kinks, and improper connections.
7. Inspect for vacuum leaks at the intake manifold, the throttle body, and the injector O-rings.
8. Test for a restricted, damaged, leaking, or modified exhaust system from the catalytic converter forward. Refer to Symptoms - Engine Exhaust (Symptoms - Engine Exhaust).
9. Test the fuel injectors for improper operation. Refer to Fuel Injector Diagnosis (CH47976) (Testing and Inspection)Fuel Injector Diagnosis (J39021 or Scan Tool) (Testing and Inspection).
10. Test for fuel contamination. Refer to Alcohol/Contaminants-in-Fuel Diagnosis (Without Special Tool) (Alcohol/Contaminants-in-Fuel Diagnosis (Without Special Tool))Alcohol/Contaminants-in-Fuel Diagnosis (Special Tool) (Alcohol/Contaminants-in-Fuel Diagnosis (Special Tool)).
11. Test for excessive fuel in the crankcase due to leaking injectors.
12. Test the ignition system for improper operation. Refer to Electronic Ignition System Diagnosis (Electronic Ignition System Diagnosis).
13. 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. Verify the repair under the same speed and load as noted in the Freeze Frame/Failure Records data recorded during testing.


pro multis · About Operation CHARM

Has anything been done to the Oxygen sensors recently?

Are there any other codes stored?

There are no other codes stored. I have cleaned the MAF sensor and am going to change the pcv valve. I was going to order 2 o2 sensors I know I probably just need to change the up steam one on bank one but I figured why not do both. After that I was going to see if I can get a shop to see if I have any misfires on one of the injectors. Should I check anything else?

I'd look for a vacuum leak.

I’ve learned that the purge valve can be a problem

Yep, but likely it would have had a failed start condition after a recent refuel.

Well, I looked for a vacuum leak and didn’t find one. I sprayed every thing in that engine bay with Cathy cleaner, and didn’t hear any change in the motor. Oddly enough, the check engine light went away. So now I am really confused. Just replace the purge valve today and planning on doing the pcv valve. I even loosened and tightened the gas tank cap. Any other areas to look or just be grateful that it went away?