coding problems

[James Schaack]

I finished reading the "how to" on checking codes for the 6.5TD engine and decided to give it a shot. I followed the instructions exactly (jumped the A&B prong then turned on the ignition) and the SES light never flashed any codes. I thought maybe for some odd reason it was the paper clip I was using so I got a piece of copper wire; still didn't work. Then I realized I had never seen the SES light come on with the rest of the indicators at start up, so I checked the bulb and it was fine. Does anybody have any advice on why the SES light isn't working and how to fix it so I can code my truck? Any help would be appreciated.

Thanks!
James

[James Schaack]

well, i think i answered my own question. when i sat down at my computer this morning i glanced over the diagnostic instruction sheet and realized it was for a 1994-1995 and i drive a 1993. i checked the members area and didn't see a post on how to diagnose a 1993. Can anybody tell me how to do it, if it is possible?

Thanks,
james

[ucdavis]

I don't know for sure, but I believe GM had pre-OBD vehicles configured for reading of computer parameters by their proprietary scantool devices (@ that time it was a Tech1 scanner, tho later Tech2 &3 models also do the older vehicles thru an adapter plug). There is an OBD system check function on the Tech line of scanners that is replicated in Mastertech (Tech & Mastertech scanners are made by Vetronix & use same software for GM rigs), Snap-On and OTC brands which can do at least some reading of the computer and help find the fault. B4 going to a shop for that (practically all shops have these scanners today) I'd check all fuses & the dash ground.

[DamienJ]

James I have a 1992 turbo and I check my codes buy the way you were describing.(shorting A&B together) So you might have to check out a few things. Mine wotks fine, I get the norm(code 12)
Good luck.

[cruzer]

DamienJ, Do you/can you actually get codes that are engine related on a 92/93 6.5td? anybody?

[cruzer]

DamienJ, Do you/can you actually get codes that are engine related on a 92/93 6.5td? anybody?

[J Vernon Bailey]

cruzer: I have an MPSI 9000 scan tool with the cartridge for my 93 6.5 TD. Up until I blew a head gasket last week and that was obvious, the only problem that registered on the scan tool was a faulty throttle position sensor. Haven't had any other engine problems. I will hook up in the next day or so and let you know what engine specific codes there may be.

Vernon

[Turbine Doc]

Shorting A to B in the diagnostic port was the same way I used to read codes on my 90 gasser, I think is was GM standard for many years to read them that way if you did not have a scan tool handy. By counting SES blink sequence you could determine fault code, per my 90 manual key on engine off blinks should be 1 then 2 or code 12 to let you know diagnostics are working for a set of 3 times, then if any fault is stored then the fault codes display.