On Scan Tools
May be better suited to a different forum but recently saw comments here.
First, I have had a number of scan tools in the past ranging from a thermal paper device suitable only for C3 engines to commercial laptop programs (Diacom). Each has its uses.
For general purpose through 1993, what I keep in my Fiero and take with me on trips is an OTC 2000. This is a now-obsolete (read: low current value) professional handheld device that plugs into the ALDL port and provides a readout of various parameters from the ECM serial data stream. This includes the PROM ID, trouble codes, and a broad range of data points from the TPS reading to the current BLM value.
This is essential to determining some problems like an O2 sensor that ceased to function over 70 mph or a TPS that failed only under braking.
Nothing is quite as good for tuning as a recording laptop that allows you to capture a number of frames during operation but this works fine for most diagnostics and good working units are in the $50-$100 range (can find better deals but this is the norm).
There are some caveats though the OTC 2000 is a very rugged unit but basically if the display lights up properly and asks for data it will probably work.
First a usable OTC 2000 consists of four parts.
- the handheld display with power (lighter) cable and adapter cable: the latter are permanently attached to the unit but need to be intact
- the cartrige. Contains the program parameter and works with the year indicated back. Occasionally it will work with a later year if the engine did not change e.g. I can read my 90 Bonne SE with an 89 GM Cartrige. Cartiges may be for a number of car lines (Ford, GM, Chrysler, Import) or there are "3 in 1" cartidges for Ford, GM, and Chrysler. The last cartrige issued for the OTC 2000 was for the 1993 model year. After that it was replaced by the OTC 4000
- the cables: you must have the right adapter cable for the cars you are going to use it with: Ford is different from GM is different from Chrysler. Since all of my cars are GM I tape the GM adapter to the connector.
- the documentation: to know what you are looking at you need the books. To know which mode has coolant temp and rpm you need the cards that slip in the back of the OTC 2000 (you enter the mode by a number code. Since the display does not tell you what you are looking at, just two sets of values and a mode number, you need to know.
Many have a nice grey plastic case to hold multiple cartidges and cable adapters. I have one but never use it since all I need is the unit/cartridge/cable/cards and do not need to switch.
The ultimate of course is a laptop with frame storage capability (is a way to connect a OTC to a laptop but is involved) and ALDL software. There are a number of flavors both free and commercial but all require a special cable you won't find at Comp-USA. We can discuss these if you like but I have had DIACOM for over a decade
Anyone else out there use an OTC 2000 ?