mrkauffman

Having trouble reading the codes for the check engine light so i just took a video of it, maybe someone here can decipher it. i read the thread that explained it but im still confused.

http://youtu.be/bA2YsLrbCfA

thanks in advance!

-Robert

mrkauffman

im having trouble embedding the video, any suggestions?

CCKen

I just left clicked the link and it opened to the video.

Can't help you on the code(s) though. Can't read morse code.

97AT4x4XJ

I can read morse code, but I am too lazy to do it. So, why don't you do it yourself.
Here is top secret info, don't tell anybody:
any time you check codes, you will see first code 12 and last code 55.
What you need is codes after 12 and before 55.
One more time:
if everything is OK, you will see codes 12 and 55. If something is wrong you'll see codes between 12 and 55.
code 12 is one blink, then 2 blinks.
GM cars always have first code 12.
First short blinks in your video mean nothing, but they are confusing.

You have problem codes (decoding for 84-86)
21 TPS
51 PROM
41 no distributor signals


for 91-97:
21 O2 sensor
51 O2 sensor lean
41 Alternator field not switching properly

jakbob

Codes- 12, 21, 51, 41, 55

12 battery/comp disconnected recently
21 oxygen sensor signal doesnt changr
51 oxygen sensor stuck in lean position (bad MAP can cause this)
41 alternator field control circuit open/shorted
55 end of codes

For future reference, short pause is in between digits, long pause is between codes.

Flash-pause-flash-flash is code 12.

jakbob

Damn you beat me to it... damn phone

97xjCrow

Can a stopped up cat cause a 21?

mrkauffman

im guessing 21 and 51 can be fixed by a new o2 sensor? or is it something else...

and regarding the alternator code, whats that mean exactly?

actually, there is this thing called search on the forums, ill try using them, lol

thank you! i was not aware of the first code being 12, it threw me off big time

mrkauffman

well i searched and didnt find as much as expected, but some symptoms ive been having is the car does take a bit to start.

tjwalker

First of all, always post the year/engine when you start a thread. There are significant differences through the years.

A code 41 is almost always a failed alternator.

Looks like you need a new oxygen sensor as well.

mrkauffman

my apologies, 1995 4.0L 4x4 Auto

mrkauffman

would a failed alternator have any other symptoms?