P0700 is the TCM requesting a MIL (Malfunction Indicator Light aka: "check engine"). All the 700 code does is tell the ECM "something's wrong" and to illuminate the MIL. There is another code in the TCM that you need to pull that will actually tell you what the malfunction is so let me know what that code is and I will help you out.

 

Bryan@ATS Diesel.

In the mean time I had the tranny serviced. I just checked for codes again and there weren't any.
Thanks for your reply.

 

You need to use a different scanner then. I guarantee there is another code in the TCM. Use either a GM Tech II scanner or EFI LIVE to get that code.

 

not always, it is also possible to set p0700 due to a low voltage condition caused by bad batteries.....

 

I have had the 0700 code before also. It has been awhile since i had it, could i still scan it with a tech II and retrive what my problem was or how long will it stay in the memory. My service engine light is no longer on.

 

Depends on how long ago it was. The ECM will store the code after the MIL has gone off for 120ish key cycles before it will delete it so like i said, it depends on how long ago it was.

 

I need your help i have an allison trans not shifting after sliding off road due to ice. I looked up stuff and called nearest diesel shop google showed mostly faulty tcm, the diesel shop said it was very unlikely. I have the codes due to me having a programmer on the truck but I DO NOT turn it up past towing mode. I'll add the codes to this reply. The other codes i have is for some glow plugs and the infamous u1300. But the first thing google pulled up about it not shifting was faulty tcm which will put the truck in limp mode and lock it in 3rd gear. Please help. Thanks in advance.

 

I just returned from the GM dealer. They checked for trouble codes and didn't find any in the engine or transmission.

 

I recently had that code come up and should be the tranny slipping enough to put the truck in a limp mode. I went to Autozone cuz they will scan codes for free and then I had him erase it.

 

Hey Woodie, your in my neck of the woods (Boise). The 700 code is a tranny code as stated above. Most likely also a limp code because of tranny slip. I can check your codes for you to see what really is going on.

Rob (208)484-3670

 

I had this code as well, truck would not shift gears but still drove at high way speeds, was stuck in 4th, so i pulled over and cleared it, a few days later it happened again but it came with a P0807 Clutch Pos Sensor Circ Lo, I think that was the code but not sure it could have been something different, is this me slipping my tranny, I assumed it was and backed my tune down but I'm scared to through the tranny, I have only had the truck a week. I am going to get a diff tranny I think.

 

yes for sure the 700 code comes up when u start getting on the gas inbetween 4th & 5th gears its the weak spot in our 5 speed allys take it easy on it in those gears. lol

there only good for around 90hp to wheels then they start slipping ..

what tuner and hp tune u running ?

thanks

 

running edge on 100hp extra, will a transgo help this? how much more hp will a transgo let me run before slipage?

 

The trans go helps prevent your probs from happening, will not fix it. A good trans (6 speed) with trans go should be good for @ +100hp. All depends on how hard you are on your truck.

 

I like to be hard on things but i will take it easy until I put in a better trans or a build kit.

 

i just had this code come up on my truck last week. No engine light came on though but truck would start surging around 1800 and couldn't get revs up past 2000. I still had 5th gear though. I limped my tranny before but it never acted like that before. I cleared the codes and it drove fine after that.

 

transmission malfunction p0700

 

mine drove just fine after clearing codes.

 

2005 D-Max

My 2005 duramax is throwing p0700 and saise in the details that it is tcm illumination. Does anyone have any idea i started it up and it ran for bout 30 secs like normal and then just died and just crank and crank and no smoke or anything. it ran just like it always did and im stumped.

 

My 2005 duramax is throwing p0700 and saise in the details that it is tcm illumination. Does anyone have any idea i started it up and it ran for bout 30 secs like normal and then just died and just crank and crank and no smoke or anything. it ran just like it always did and im stumped.

Hey man, had two trucks brought in through here the last few months with the weather getting wet... Somehow TCM's are shorting out, then truck wont crank. Check out your TCM, make sure it's responding.

 

02 silverado HD with P0700 TCM code

My check engine light came on but truck was driving fine. I stopped at Auto Zone to get the light checked and I got a P0700 code just means something is wrong. The slip of paper they gave me said it's my TCM. After that the light went off. A week later light came back on and now truck wont shift out of first gear. I tried to shift it manually but that didn't work. Are there different things I can check first or does this mean I need a new TCM?

 

You need to post the code-- do not guess by replacing expensive parts. Could just be a wire problem.

Does the shift display work OK-??

 

No it hasnt worked in a while but I know what gear im in so I didnt worry aboit it

 

I threw that code yesterday and went full limp mode today...New efi on my 130 tune. Your transmission needs to learn your programmer for a while before you jump on it...it will warn you a couple times before it goes into full limp mode." Shift inhibited"
Give it time driving regular so it learns fuel demands and shift points.
I just cleared my codes with torque and my check engine went off after 30 minutes of driving. All is back to normal. It's protecting itself from your foot!
Trans safe is about 90. Imma keep mine on 60 till I build this tranny.. maybe

 

I dont have a tuner. I unplugged the TCM and plugged it back in and the check engine light is off and its shifting fine. I dont know how long this will fix the problem for.

 

my 2003 chevy 2500 hd is pulling a p0700 code and will not start it did run then shut right down after a min or so please help supposed to drive to Florida to surprise my Dad for his 70th birthday

 

Jc1843 asked if the shift indicator is working. Mine is not and just had po 700 come on and truck went into limp mode. Cleared code with obd2 and took truck for test drive and no more limp but po 700 came back on. When I backed up and put into drive big clunk in
Transmission. Any suggestions would be appreciated.

 

Hey last night I had the same problem as you same thing happend I got the code cleared it and relearned the trans then turned it off for about an hour fuild was all fine and when turned it back on and drove it home was fine then went to back up and same thing as you. Now today went to a shop where I live and talked with them but couldn't read the trans codes so I warmed the trans up to try and get the code again but never came back up but now my cluster will only read R 3 and 1. When in P N D and 2 the cluster won't light up and the cts2 I have will just read park. The truck is a 2002 2500 with 188025km on it and it drive fine shifts fine just not reading now. Please can someone help I have to be able to drive to work come Monday

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The NSBU switch is very important on a 5 speed and if worn/shorted/water, it can and will affect the trans operation. I suggest replacing the NSBU switch first. As noted-- the P0700 just turns on the fault light-- then there is always another code/s. Cheap code readers DO NOT READ trans codes.

 

Yes I know that's all p0700 is, I can't anyone with a scanner that will read deeper yet or the history. What is NSBU? This is my first diesel I know some small stuff but not alot.

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The NSBU switch is located on the side of the trans, and shift lever. It send a signal to the TCM so it knows gear to select. Buy from Allison dealer-- GM $$$$

To replace [5 speed] block the wheels, put shift selector in "N", remove the shift cable, remove the harness connector/s [if glued in, use a heat gun/ blow dryer to loosen. Remove the old NSBU switch, install the new switch-- then Pull the lock pin from the NSBU. install the cable. Then it should be indexed correctly.

 

Okay thank you I'll do that. You think that's the problem not that I need a new tcm?

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