Jump to content

5.3l silverado misterious DTC

Larsson

By Larsson
in Troubleshooting & Recalls

 Share

Recommended Posts

Larsson Enthusiast

Larsson

Posted
Posted

20240602_143938.thumb.jpg.fbb00b8c526aef2062feb307724ded6e.jpgHi guys, my 5.3L silverado has a strange dtc code which keeps on popping up. I can read the dtc with the hp tuners OBD2 scanner/reader but I can't figure out what the code means.

 

I can delete the check engine light message but after a few hours it comes back on so there is something going on according the computer. The problem is I can't figure out what is going on.

 

Does anyone has an idea?

 

I took some pictures from my laptop of what's wrong according to hp tuners.

CamGTP Senior Enthusiast

CamGTP

Posted
Posted

What are the actual fuel trims like if you data log them?

 

Are they very negative all the time or floating within that 5% of zero?

 

If it was me and the trims looks fine, I'd just disable the codes forever lol.

  • Like 1
Larsson Enthusiast

Larsson

Posted
  • Author
Posted

I'm going to look at the fueltrims this weekend, if I have the time to do so😇. I'll give you an update as soon as possible.

 

Is it a good idea to pour some cat cleaner in the gastank? Just to see if it helps?

Larsson Enthusiast

Larsson

Posted
  • Author
Posted

Does this help to pinpoint the problem?

Screenshot_20240605_211016_Gallery.jpg

newdude Senior Enthusiast

newdude

Posted
Posted

Original oxygen sensors in there still?  If any have been replaced, were they replaced with aftermarket ones?  

Larsson Enthusiast

Larsson

Posted
  • Author
Posted

Never changed the oxygen sensors. Maybe start there? Do I have to change all 4 of them? The ones before and after the cat? And only use gm genuine 😁

rlcole321 Enthusiast

rlcole321

Posted
Posted

What I notice as strange, is both downstream O2's are the same down to the 8th decimal point!!, got to be something going on there.

Larsson Enthusiast

Larsson

Posted
  • Author
Posted
18 hours ago, rlcole321 said:

What I notice as strange, is both downstream O2's are the same down to the 8th decimal point!!, got to be something going on there.

 

I looked back to the photo I shared and noticed it too. Maybe there is a short in the wirering somewhere?

Larsson Enthusiast

Larsson

Posted
  • Author
Posted

I'm going to look at the problem this saturday. If the weather stays dry😁.

Let you guys know what I found. In the mean time tips are more than welcome😇.

Larsson Enthusiast

Larsson

Posted
  • Author
Posted

I finished work early today so I had some time to check the connectors and wires of the O2 sensors. Everything looks normal. No damaged connectors or wires so far I can see. So I don't know how both the downstream sensors put out the same voltages. Maybe it's an idea just to replace all 4 O2 sensors and see where this leads to? 

asilverblazer Senior Enthusiast

asilverblazer

Posted
Posted

I don't think new sensors are going to fix that problem, I'd try to follow the sensor wiring to where they converge in the main harness then carefully examine from there upstream to the computer. 

 

The only way those two sensors are going to report identical voltage like that is if they are literally connected (via some problem) together somewhere. 

 

Unless someone else has some creative reasons why the PCM would see and report identical sensor voltages.

Larsson Enthusiast

Larsson

Posted
  • Author
Posted

I did some highway driving last week. About 400miles and the check engine light didn't came on since the last time I cleared the dtc's. Maybe the O2 sensors where a bit dirty? 

 

My plan now is to change all 4 O2 sensors and check the wiring from the two sensors past the cat. I keep you guys posted about the outcome.

 

In the mean time every suggestion/help is welcome😁

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share
Go to topic listing

  • Latest Articles

  • Posts

    • Aimatdeer
      Ac not keeping up

      By Aimatdeer · Posted

      Monday looks like a good day for the dealer to test an ac issue. Hopefully it all turns out good.
    • CamGTP
      Gas Prices

      By CamGTP · Posted

      Paid $2.72 for E85 today.
    • Atlas
      Gas Prices

      By Atlas · Posted

      Welcome back! No, it definitely doesn't pass the sniff test. Even "ceasefire" needs an alternative definition these days.    $5.29 at Kroger today
    • bluev8
      Intermittent no-code issues on 2022.5+ V8 trucks — what did the shop fail to capture?

      By bluev8 · Posted

      That makes sense, and I think you are describing the real product problem. Capturing data is the easy part. If the owner or technician has to manually dig through five minutes of millisecond-level logs, the product has already failed. The device would be at the ECM harness, not at the OBD port, so I agree that data retrieval and event marking need to be thought through carefully. The way I am thinking about the architecture is: The recorder itself should not depend on a phone, app, Bluetooth, Wi-Fi, or cloud connection to capture the event. It should always keep a local rolling buffer and lock the event locally. A button, phone app, or small cabin device would only act as an event marker. If the driver feels a stumble and presses the button 10–30 seconds later, the pre-buffer has to already contain the useful data. For data retrieval, the practical options would be a sealed service USB lead, Wi-Fi download, or a phone/cabin companion device. I would not expect the owner to remove the ECM-side module or work with raw files directly. The cloud or AI side would be for interpretation, not for capturing the event. The truck may have no connection when the issue happens, so the evidence has to be saved locally first. After that, cloud processing could help decode the data, compare it against baselines, and generate a readable report. For the first version, I would keep the automatic triggers conservative and objective: driver event marker bus-off error passive voltage drop / brownout device reset FIFO or queue overflow a normally periodic message disappearing side-to-side communication mismatch, if the topology supports that For “learning normal,” I agree with your point, but I would not want to overclaim it as automatic root-cause diagnosis at first. A realistic first step would be learned baseline comparison for that specific vehicle and operating condition. For example, a value would only be compared against similar conditions: RPM range load / MAP throttle position gear / vehicle speed coolant and oil temperature battery voltage AFM/DFM state, if decoded and validated Then the report could flag things like: this periodic message disappeared compared with its normal timing this value deviated from this vehicle’s normal range under similar conditions the same abnormal pattern repeated after the same type of event the anomaly occurred together with voltage, oil-pressure, misfire, or communication changes But I would still call that “abnormal pattern detected,” not “replace this part,” unless there is enough validated repair data behind it. So the intended product would not be “here is a huge log.” It would need to be an event package: what triggered the capture how much pre/post data was preserved what changed before and after the event whether the device itself reset, overflowed, or saw a bus error selected graphs around the event raw data only as supporting evidence From your perspective, what would make this kind of report useful instead of just another datalog? For example: What are the top 5 parameters or events you would want highlighted first? Would you trust a learned baseline for that specific vehicle, or would you prefer fixed thresholds? How much false-positive flagging would be acceptable before you stopped looking at the reports? What would a one-page report need to show for an independent shop to take it seriously? For misfire, AFM/DFM, oil pressure, or U-code complaints, what would you want the tool to flag automatically?
    • scotthvac.net
      2022-24 halogen - led grille swap

      By scotthvac.net · Posted

      2024 Silverado 2500 HD LTZ grille no camera Parts list   84603331 84913656 84913657 84913654 84913655 84911567 84911568 85646092 85646093 85797921 85797922   11570637  x10-15   grille/bumper bolts 11546500  x10      grille clips 11571006  x10      push/retainer clips 11546454  x6       nut retainers 11611609  x6       M5 bolts 11610700  x6       molding/trim retainers

  • GM-Trucks.com Clubs

  • Popular Contributors

×
×
  • Create New...