Welcome to the DoItYourself Forums!

To post questions, help other DIYers and reduce advertising (like the one on your left), join our DIY community. It's free!

gm codes


mcpeople's Avatar
Visiting Guest

Posts: n/a

05-06-02, 01:56 PM   #1  
mcpeople
gm codes

hi all my service engine soon light comes on for a brief period while driving then goes out when I checked the code it comes up with 12. the vechicle is a 1988 chevy pickup with a 305 5.0 tbi. when I check the gm codes they start at 13

 
Sponsored Links
Joe_F's Avatar
Visiting Guest

Posts: n/a

05-06-02, 03:27 PM   #2  
Joe_F
Start by checking the links in my signature file below to be sure you are doing it right...tell us what you find.

 
mcpeople's Avatar
Visiting Guest

Posts: n/a

05-06-02, 03:35 PM   #3  
mcpeople
gm codes

I have jumpered a and b on the connector when I turn on the ign. the service engine light flashes once pauses then flashes twice ......I belive this represents 12 the light had not come on before testing ....do I have to wait till the light comes on again then test for codes again thanks again

 
davo's Avatar
Member

Join Date: Apr 2002
Posts: 2,417

05-06-02, 04:11 PM   #4  
The light will flash code 12 a total of 3 times,which means no rpm reference pulse.This is normal because the engine is not running,it will go to the next code after that.Again it will repeat 3 times and go to the next code and so on.I believe your counting the code properly just wait for more.By the way some codes will not set instantly,there are parameters that need to be met.Good Luck

 
mcpeople's Avatar
Visiting Guest

Posts: n/a

05-06-02, 04:34 PM   #5  
mcpeople
gm

thanks after doing this I got codes of 13, 32 and 45 and after looking them up I'm guessing it's the O2 sensor and the egr valve

 
Search this Thread