Performance enthusiasts also liked replaceable PROMs because the chip could be replaced with one that provided more spark advance, fuel enrichment, a higher rev limit, etc., to squeeze more power out of the engine.īut replaceable PROMS had a serious drawback: there were too many of them! Every model year and every running change meant another PROM had to be created. It also meant that if a bug was later discovered in the original factory programming, it could be corrected in the field by simply replacing the original PROM with an updated corrected PROM (a tactic GM has successfully used over the years to fix many factory flaws). A replaceable PROM chip also meant the PCM could be “retuned” if necessary to correct certain kinds of emissions or driveability problems. GM pioneered the replaceable PROM chip as a way of programming PCMs to fit a wide range of GM makes and models. Previously, Program Read Only Memory (PROM) chips held all of the PCMs vital calibration information and operating instructions.

The first such application was the 1990 Geo Storm. After diagnosis, technicians can complete the job with special tests and functions such as caliper rewind, brake bleed, automated EVAP test, throttle initialization, tire calibration, VIN read write, steering angle reset and many more.How to: American vehicles (GM Ford Chrysler) PCM flash reprogramming tutorial in detail for newbies.įlash reprogrammable PCMs have been ussed in vehicles since the 1990s.

Plus millions of exclusive vehicle-specific Troubleshooter tips that are based on real world experience. MODIS Ultra includes unique automated tests such as cylinder contribution tests, drive cycle procedures and after-repair validation tests. Exclusive Fast-Track Guided Component Tests include automatic meter setup, connector diagrams and a waveform library, providing access find, verify and replace the part at the root cause of the problem. MODIS Ultra combines the quick operation and broad scanner coverage of the famous SOLUS Ultra, along with a built-in graphing meter and two-channel high-speed scope.

The Snap-on MODIS Ultra multi-function tool provides complete start to finish diagnostics that includes a fully integrated scan tool, lab scope, vehicle-specific communication software and expert information resources – all-in-one diagnostic tool.

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