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Discussion Starter · #1 ·
Hi I have a 2002 jeep grand cherokee and it won't go into over drive. The garage has put in a new transmission, TCM, ECM, and all the seniors on the transmission is new. Can someone please tell me where to look the only code that comes up is 700.
 

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Does it shift into overdrive?
That CEL code can involve a multitude of issues.
From low transmission fluid, blown transmission module, mal-adusted transmission linkage, wiring/connector issues to a faulty shift solenoid in the belly of the transmission.

Other than verifying the transmission fluid level your self and with a replacement tranny i'd look at the wiring/connectors, the linkage then the transmission control module.

Maybe others here have some other ideas.
BUMP.
 

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Discussion Starter · #3 ·
Fluid is fine and you can rest the computer and it will go into over drive once then it down shifts and want go into over drive anymore
 

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Fluid is fine and you can rest the computer and it will go into over drive once then it down shifts and want go into over drive anymore
Had this issue 'no over drive' issue before on a couple of my other vehicles, one when i lifted my XJ the other with my long gone Neon after a motor mount replacement.
Turned out in both cases the transmission linkage was out of adjustment but those were my issues and not necessarily yours.

When the tranny was replaced was the torque converter also replaced?

Other than a linkage or other issue, could be the overdrive shift solenoid is shot or has a loose electrical connection.
Or the torque converter's locking clutch is faulty.
 

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Discussion Starter · #5 ·
It's not been lifted and all the wire harness are tight and in the right spot the only reason I some else was I didn't have the time and it is making me crazy I think some one didn't disconnect the wires and pinched them. I can understand some one saying it could be this part or the other but they have a computer and kept saying it's this it's that and not getting any where so I brought it home and will check the ohms on the wires if needed. But I think it's a senior I am over looking I can't find a good wire diagram. This is why I don't like new cars all computer
 

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I agree with these computer on wheel vehicles which can be a royal PITA to trouble shoot.
Before diving into a wiring diagram, check each and every connector going to the tranny for looseness, corrosion and spread pins.
Barring a wiring issue, sure sounds like a solenoid issue.
 

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To answer your question on testing the shift solenoids, with most transmissions the pan has to be dropped to gain access to the solenoids. Then the leads to the solenoid coils are disconnected and then the solenoid energizing coils are ohm'ed out per spec. for shorts or opens.
No clue about the WJ but my old Dodge Neon had the solenoid module mounted on the engine firewall. Easy to check and/or replace!

However a p0700 is an all encompassing code meaning anything other than the solenoids could be the root cause including the TCM or its failed communication to the PCM.

When it comes to transmission issues if i don't find anything obvious, i'll take it to a trusted qualified shop and have it sorted out good or bad.
 

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Discussion Starter · #10 ·
Yeah I put it in a shop they said it was the transmission so they put in a new one and the same problem. They said it was the transmission so they transmission company sent it to another shop to find out they said it was the computer the TCM so they put one in. Same problem they said the tps so they put one in they said it was the ECM so they put one in same problem. They said it was bad transmission sensor so they put them in again. I have spent 4500 in this so I brought it home because they can't tell me what is going on. If two garage's keep fighting with each other I will never get this figured out I know a lot but don't have the computer to check it out.
 

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If misery loves company read on.
I hear your pain as i had a similar money pit with my old Dodge Neon.
It had a totally rust free body with no dents. Looked showroom fresh for an '05 so decided to freshen it up.

I replaced the struts to fix a thumping issue, brake job, battery, tune up, etc and then all of a sudden out of nowhere it developed a strange rough idle in gear at a stop only. No CELs either.

Replaced all the motor mounts which wasn't fun, pulled out the engine sensor parts cannon, cleaned the TB, etc.
Still rough idle only in drive at a stop.
Even had a trusted tech at a Jeep dealership check it out with his fancy engine diag. scanner tool.
He was also stumped as everything checked out including a cylinder compression test.

I was convinced the rough idle was somehow related to a PCM software bug coupled with 130K mileage from doing some research.
Why?
Because the rough idle was due to a drop in engine rpm.
At a stop if i shifted into neutral and back into drive = no rought idle.
Also if at a stop in drive if i just tapped the accelerator pedal = no rough idle.

Decided to live with it as it ran fine otherwise for a long while then out of nowhere the CEL came on with a p0700 and i think it was a p0740 and the transmission would not shift into over drive.
Sound familiar?
I was gonna replace the shift module located on the firewall myself but got so dam tired of working on that POS, i decided to have a local trusted tranny shop that specializes in Mopar transmissions freshen it up.
I was also hoping that the new torque converter would also fix the rough idle issue...wishful thinking!
Some $1500 later the tranny rebuild fixed the p0740 issue but still had the rough idle in drive at a stop.

Long story short i should of cut my losses much earlier instead i dumped almost as much money and time into it as you did.
Finally sold that POS at a basement bargain price making sure the buyer was well aware of the rough idle issue.


Anyhow back to your not shifting into overdrive issue.
Rebuilt tranny, new TCM, new PCM, new transmission sensors and still a no fix?
Whats somewhat strange is your only getting a p0700 code which i mentioned is a general transmission malfunction code which is typically followed up by one or more detailed codes.

IMPORTANT: Did they replace the torque converter with the transmission rebuild?

I'd guess that all might point to a wiring harness or connector issue.
Possibly even a bad ground somewhere.

Only thing i'd suggest is to disconnect the battery then carefully check each and every harness and connector going to the transmission. The connectors actually need to be disconnected making sure there are no spread pins or corrosion.
I'd also clean each and every ground terminal i could find.
Other than that i'd find a sharp trusted tech with a good engine diagnostic scanner tool and who knows how to use it.

Good luck and keep us updated.
 

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If the transmission, TCM, PCM and speed sensors have all been replaced not much is left to go wrong.
Have the overdrive button and wires been tested or replaced? How is the ground strap to the transmission? Bad grounds are notorious for causing all kinds of issues in the WJ. Make sure the grounds are connected to clean bare metal.
 
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