program code reader

[phonedrn8]

how far can a code scanner go into history? i have a brake light and ABS light problem happens when it wants to . dealewrship says bring in Monday night get to it Tues.. Want to go get a OBD2 scanner are they worth it? and how much should i spend around 150.00

[GM-Tech]

how far can a code scanner go into history?

 

Depends. There are a variety of factors, but most DTC's will remain in history for 40-50 drive cycles where the DTC test has run AND passed. In other words, just turning the key on and off 50 (or even 100) times won't clear it. The conditions have to be met for the particular module to say, "Okay, I've run the test and it passed" and do that 40-50 times. The light itself may turn off immediately when the problem doesn't exist, or it may require 2-3 drive cycles where the DTC passes before the light goes off... but the DTC will still be in history. This all depends on the module in which the DTC is set, but primarily the PCM is the one that will keep the light on even after the problem is fixed. You have to either clear it with a scanner or it has to go through those required drive cycles before the light will go off.

 

There's often some freeze frame data or failure records that will tell you under what conditions the DTC set, how many miles ago, etc., etc.

 

I can't comment on the aftermarket code scanners. Don't know anything about them. The one we use in the dealership is the best of course, but at $2300.00, just a bit beyond the average do-it-yourselfer's budget. Heck, I have a hard time getting our dealership to buy an extra one at that price. We have two and could use one or two more.