SES code P0700

[wizkid]

I know someone posted a link to a site with the codes, but I can't find the link. I got a p0700 today.

I hadn't driven my little indeglow for about 3 weeks, and went to take off today for an errand. I let it run for a bout 30 seconds (probably less) and dropped it into neutral and coasted into the road. I put it in reverse to keep it going, and AHHHHH no reverse. :eek: I idled it in neutral for another minute, and tried drive. It would barely creep into the driveway. And, of course the ses light came on. After I got it back in the driveway, I let it idle for another minute, and tried reverse -- NADA! Since I was back in the driveway, I shut it off, let it sit for a few seconds, and started it up. YEA, the tranny is working fine again.

I figure the tranny lost it's prime in the converter, and it isn't really a problem. If I let it sit this long, I'm going to let it idle longer. I want to check on the code though, and I'll probably drop it by the dealer to read and reset the computer. If anyone knows what the code is, or a link to a web site that I can cross-reference the code at, I'd really apprieciate it.
W.Kid

[ 04-19-2002: Message edited by: wizkid ]</p>

[mdrag]

wizkid,

Check out:

http://www.obdii.com/codes.asp

General Motors P0700 Transmission Control System

Not too long ago, BigAl posted a great explanation of why this happens:

http://forum.62-65-dieselpage.com/cgi-bin/ultimatebb.cgi?ubb=get_topic&f=7&t=003020&p=

Moving topic to 2500HD/3500 HD TRUCKS & DRIVETRAIN forum.

[hoot]

Mine has done that twice. Both times under load.

[wizkid]

:eek: Dropping out under load?? :eek:

That would be a bad thing. I know what caused my glitch. It sat in the driveway for a month, and the tranny lost it's prime.

I just looked at some of mdrags pics! Can I work on my truck in YOUR shop Mdrag? I'm stuck having to work on my truck in my cold snowy driveway :(

Well, I guess we didn't get alot of snow this year, but it was cold!

[ 04-20-2002: Message edited by: wizkid ]</p>

[hoot]

WIZ,

Your discription of the events that followed are exactly like mine. The key is to turn it off and wait a minute. Sounds like limp mode to me. I believe this trans can go into limp mode even when not under stressful conditions. It may get a poor out-of-tolerance shift that may cause it to believe it's slipping. I'm only speculating but I think it can happen. This trans shifting is 100% computer/hydraulic clutch shifting that requires quite a bit of synchronization. Sometimes everything may not work exactly right and it thinks something is wrong. I may pick up too great a diffrence in shaft rpm during one of these off-shifts which could throw it into limp. Maybe BigAl or someone who knows the latest and greatest on the Allisons out there that have displayed this limp more often than not.

It is also possible that if your tranny "drained" as you suspect, that the lack of fluid in the right places caused it to go into limp (safety) mode. All the 700 code means is that a code was set in the ECM, by the TCM. That needs a seperate diagnostic if I remember correctly.

[ 04-20-2002: Message edited by: hoot ]</p>

[Maximus]

Wizkid
I received the SES light and P0700 code twice under load. The tranny would not up shift and at times felt like it was slipping. The dealer spent the day diagnosing this with the techs at GM. It turn out they needed to remove the pan on the tranny to diagnose the wiring harness. As the tech start to run Ohm