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    Fuel pressure was tested, and although specification was reached,a fuel volume test was conducted as well. After 10 seconds of elapsed time, the expected 500ml of fuel was not achieved. The system was only capable of supplying 350 ml.
    Brandon Steckler
    April 15, 2025
    This Mazda 3 was running rough after cold starts, and the only DTC stored was P0300, "Random misfire detected."
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    Brandon Steckler
    April 14, 2025
    In the world of diagnostics and driveability, a sound understanding of the component's functionality is an absolute must to maintain accuracy and efficiency. Let's consider the...
    Photos by author
    This warning on the dash of a 2016 Ram is alerting the customer to an issue with the Active-Level Four Corner Air Suspension system on the truck.
    Jeff Taylor
    April 14, 2025
    As vehicles evolve, so will suspension and steering systems. Essential steering angles and settings are as important as ever, and future advancements will further integrate with...
    Top 10 Diagnostic Products, Q1 2025
    Elli Carder
    April 1, 2025
    Check out the most viewed diagnostic products added to Vehicle Service Pros in Q1 of 2025.
    Photo courtesy of Scott Brown
    Figure 1 - Scan tool data
    Scott Brown
    March 5, 2025
    Using OBD-II, PIDs, DTCs, and other resources to diagnose today's engines.
    Figure 2- Suspect of a lean condition, additional hydrocarbon in the form of propane was used as an experiment for enrichment. The performance of the engine (via exhaust gas analysis) will be evaluated with the enrichment occurring. This will help determine the next step to take.
    Brandon Steckler
    Feb. 13, 2025
    A 2008 Mazda 3, with a 2.3L engine entered the shop with a complaint of rough-running and an MIL illuminated. The only DTC stored: random misfire detected.
    The rounded exhaust valve pocket and elevated intake manifold pressure come together like puzzle pieces inferring excessive valve overlap. Due to this valvetrain’s configuration, valve clearances are adjusted by way of selectable shims. The appropriate shim was chosen, and the clearances were brought back to within specification. The driveability symptom vanished, expected manifold vacuum was restored, and the fuel trim values nearly zeroed.
    Brandon Steckler
    Feb. 12, 2025
    A shop was facing a 2018 Ford Escape with a turbo-charged, four-cylinder engine. The vehicle suffered from a poor idle concern, intermittent cylinder No. 3 misfire at idle, but...
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    Elli Carder
    Dec. 30, 2024
    Check out the most viewed diagnostic products of Q4 in 2024.
    2024 Diagnostic Process
    Dec. 13, 2024
    A guide providing information on an array of diagnostic topics in the automotive industry.
    Image: ALLDATA
    Figure 1: The EPS is housed entirely in the steering column assembly on this example displayed. Although this is a typical configuration, it doesn’t mean every vehicle is configured this way.
    Brandon Steckler
    Dec. 3, 2024
    Electronic power steering assist systems have been around for a while but without system knowledge, techs still get ‘turned around.’
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    Scan Tool
    Emily Markham
    Dec. 3, 2024
    Finding your final diagnosis is simple – trust your process, look at all the angles, change your approach if needed.
    The broken exhaust valve spring is the cause of the driveability fault. Keep in mind that a broken spring can present intermittent faults or faults that only occur under certain operating conditions. It’s important to realize that a broken spring can still allow a perfectly passing compression test (or relative compression test) but fail a running test miserably.
    Brandon Steckler
    Dec. 2, 2024
    A 2015 GMC Yukon was misfiring under all operating conditions, even though the engine seemed to crank over well.
    Figure 1: A correlation of the CKP sensor signal to that of the CMP sensor(s) signals can be a great way of inferring camshaft timing. Keeping in mind the limitations of the test, it only truly reflects the timing of the reluctors. If they have lost their reference from their respective shafts, the timing will not be on.
    Brandon Steckler
    Dec. 2, 2024
    Sometimes seeing misfires reflected on a scan tool is the result of an ignition system fault. Typical testing for these mechanical faults can usually be discovered by simple relative...
    Photo courtesy of Scott Brown
    Figure 1 — Fueling Strategy using ANNs
    Scott Brown
    Nov. 26, 2024
    AI in automotive systems, fuel, emissions monitoring, and diagnostics and service.