How to test for code P219B

Scott Owner/Technician Missouri Posted   Latest  
2016 Chevrolet Tahoe LTZ 5.3L (C L83 Flex) 6-spd (6L80) — 1GNSKCKC7GR339878
P219B — Bank 2 Air-Fuel Ratio Imbalance
P0300 — Random/Multiple Cylinder Misfire Detected
P050D — Cold Start Rough Idle
Check Engine Light

We have this customer with the 16 Tahoe that keeps setting this P219B code intermittently. We ran 2 cans of BG 44K through it prior, then removed injectors for cleaning and balancing.

We were told they were good, but got no PRE cleaning data as I had suspected. Problem is still there.

What I am looking for is a good way to test for this code, so we can be sure how to fix it.

Anybody spent the time necessary to be able to isolate this?

Tyler Technician

I've had success using secondary ignition waveforms to isolate a problem injector on these engines. Use the misfire counts to narrow down which cylinder on bank two is suspect. Compare the suspect pattern to a cylinder on bank one for reference. If you find a lean pattern on the suspect cylinder, you can be reasonably confident in an injector issue.

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Gary Diagnostician
New Jersey

Check alcohol content level % if it reads over 10% do a flex fuel alcohol content reset/relearn with the scanner.

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Shawn Technician

I agree with the first suggestion, If alcohol % is too high and running 10% or less ethanol It should effect both banks not just one. Also make sure you are not just looking at the fuel system. Check the exhaust manifold on B2 for leaks, I believe any leak before the B2S1 may also set this code by pulling in outside oxygen. If no intake leaks, injector wave forms & balance look good and no…

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John Instructor

Hi Scott One routine is to capture the upstream O2's synced with an ignition command. The out of balance cylinder will show as hash on top of the O2 signal. You'll need to use an overlay to identify the exhaust pulses to a specific cylinder. Something to think about is if a cylinder is losing compression, it will still get all of the fuel assigned to it and will end up showing rich. Hope This…

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Rusty Owner/Technician

I’d start with a look at misfire data, both active and history and take a gander at FF trim data to see what the ECM is thinking. I assume your live trim data isn’t helping?

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Kyle Mechanic

Check mode 6 for your history misfires. They are most likely the culprit injectors. You can also run an injector balance with your scanner but it can be hit or miss and there is a little bit of a science to interpreting the results.

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Tanner Instructor
South Carolina

You can look at mode 6 data to determine if a cylinder is misfiring. My experience with these is that replacing one injector typically leads to an imbalance again a couple months down the road do to different flow rates. My advice is if you narrow it down to an injector problem, then they should all be replaced.

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Joseph Technician

Replace all injectors , assure no exh leaks nd perform gm top eng clean

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