Ecm Self Diagnoses

[unccpathfinder]

Finally got around to diagnosing the 87 to see what the SES light is all about...I got code 13 which is engine coolant temp circuit (which I removed not thinking it would negatively impact anything and installed an aftermarket gage...dumb me)

 

my question is for the self diagnoses does it start with the lowest code and go up from that...i know I have more than just the coolant circuit thats bad but it only flashes the 13 so I didnt know if it flashed all codes or shows the 1 it experiences 1st or what...

 

the truck runs like ass and im almost 100% sure its not the engine coolant temp causing that (unless its making the ECM go crazy)...I'm going to start with this and see if that corrects it if not I guess i'll scan for more codes...the fsm doesnt really go into detail on multiple codes in the self diag setting

 

Thanks

 

 

 

edit:

 

just tried it out and the error is gone and the idle straightened up a lot and it doesnt seem to studder anymore...I also found that the intake had come loose on my journey across the country so with those 2 it seems as if it fixed it right up...i didnt get it up to operating temp right now b/c I cant keep coolant in it so i know when I get that leak fixed I will get at least an O2 error since I dont have a heated sensor yet...but was still curious as to whether it will show more than 1 code at a time...

Edited August 27, 2007 by unccpathfinder

[RedPath88]

Yes it can and will show more than one code if more than one has been triggered. It will flash one after another until it displays them all.

[unccpathfinder]

sweet thanks...

[Alkorahil]

Finally got around to diagnosing the 87 to see what the SES light is all about...I got code 13 which is engine coolant temp circuit (which I removed not thinking it would negatively impact anything and installed an aftermarket gage...dumb me)

 

my question is for the self diagnoses does it start with the lowest code and go up from that...i know I have more than just the coolant circuit thats bad but it only flashes the 13 so I didnt know if it flashed all codes or shows the 1 it experiences 1st or what...

 

the truck runs like ass and im almost 100% sure its not the engine coolant temp causing that (unless its making the ECM go crazy)...I'm going to start with this and see if that corrects it if not I guess i'll scan for more codes...the fsm doesnt really go into detail on multiple codes in the self diag setting

 

 

 

First off, were you in Diagnostic Mode III?

 

the ECU will flash the error codes stored in memory with a short 3 second (or so) pause between each code. Each code starts with a green light so you know when you are seeing green it is the start of a code. It will continue to flash the error codes stored until you turn the vehicle back off at which time it clears all the error codes and goes back into Mode I.

 

If you have any other problems they probably will not show up till you get the vehicle running again fully because you have cleared the memory.

 

I also believe the ECU needs the temp sensor.....for proper running.

And if you do not have an O2 sensor your Pathy's engine could simply stall out when it gets warmed up and the ECU goes to check the O2 sensor for a reading of 1 volt, doesnt find it and freaks out.

Edited August 27, 2007 by Alkorahil

[unccpathfinder]

First off, were you in Diagnostic Mode III?

 

yep

and goes back into Mode I.

 

I do not believe that is a completely true statement...or maybe just a warning should be added ot make sure the idle is set back to the original position

 

it'll run without the O2 and run pretty good when I 1st was testing the swap i ran it without an O2...

 

still couldnt pinpoint my coolant leak so i didnt get a chance to warm it all the way up and let it throw more codes if its going to...I was just curious as to how it handled multiple codes

 

Thanks for the replies