scan tool

[James Bru]

Are scan tools useful?

Topic

[Its me]

Yes, they are very useful. Unlike regular code readers, a scan tool can let you know other things such as coolant temperature, Long and short term fuel trims and O2 sensor readings.

Some scanners are also bi-directional that allow you to make the car do certain things (I.E. Activate solenoids in a ABS system when you bleed it)….

Code readers only tell you part of the story, the scan tool fills in a lot of other blanks… I love my MODIS, plus it also has a lab scope….

Lastly, the greatest diagnostic tool….. the brain (with experience preferably)… An example I’ll use is the typical ACURA 3.5 which throws an EGR code… If you don’t know, you may just throw another EGR valve on it and think the problem is solved, but the code never goes away… Experience teaches you that there are passageways that get clogged and need to be cleaned out and there is nothing wrong with the EGR valve…

Karl

[James Bru]

I got a 1995 firebird and i see a jack for a scan tool i thought they didn’t have scan tool in 95?

[Its me]

They had different scan tools then… ODB I was what was used. There are some that tell you good information (not as much as ODB II) Also, you can use a paperclip to jump the reader and it will flash the trouble codes (if you didn’t already know that)

Back in the day I used an ALLTEST 3256… You can get them dirt cheap nowadays… Tells you much more than you might think… I used mine predominately for GM’s made in the late 80’s… I still have it somewhere! You can find these pretty cheap on EBAY

Here is what it can tell you:

A/C Switch
Air Control
Air Flow
Air switch
Battery Voltage
Baro
Block learn
Booste wast
CCP Solenoid
Clear flood
coolant temp
Coolant fan

Crank
Cross count
Dwelll + RPM
EFE Solenoid
EGR %
EGR Pressure (V)
EGR Solenoid
EPR
EST
Exhaust Gas
Freon/Head
Gear 3/4

IAC
Igniyion
INJ Base PW
integrator
knock rtd
loop status
LV8
Man air temp
MAP/VAC (V)
MPH + TPS (V))
Nose switch
Oxygen (V)

Park/Neutral
Power Steer
Prom ID
Rear VAC BRK
Selection
SPK ADV RTD
Spark Count
TCC SOL + MPH
TPS (V) + RPM
Trouble Cd
Water INJ
WOT

When I used this, I used the Baro quite a bit as well as LOOP STATUS to check if the car was in OPEN or CLOSED Loop. Also you could check the O2 readings and see them switch back from lean and rich. Also used the TPS function A lot. Those computer controlled carbs had to be set just right…(anyone else remember this fun of drilling in the protective cover on the carb)

https://www.ericthecarguy.com/forum/8-Service-and-Repair-Questions-Answered-Here/44161-pre-obd-diagnostics#54179

Karl

[Author]

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