Need Help Hardest Dodge code To Crack P1698!!!!!
 

I have a 2000 Dodge Dakota sport and for a long time now I have been
dealing with this code, I have replaced the TCM, PCM checked all of the
grounds replaced the battery.
And now I'm stumped I want this code fixed as it's annoying for a daily driver.
I did scan it and the code reader said the TCM was not communicating. is it
possible for corrosion to be in the port? as I have checked the wiring and it
looks like it was from the factory not fresh but looks usable.
the symptoms are, I'm having is that it shifts hard into gears but is fine when
driving, gives it a rough idle on start but normals out after 5 to 10 minutes as
well as I can not see on the speed cluster what gear I am in. The dome lights
in the cluster will not turn on even though the bulbs are fine.

Please any help with code would be appreciated

No Ans

That's a serious code for a computer not working/reading properly. If you've checked all wires and have proper power, how about grounds? Any loss of ground will cause problems. Could also be low voltage. Maybe the alternator is weak and as you drive it charges up enough. Any crack or pin hole in a wire will cause issues too. The issue with dome lights also sounds like a ground.

Mods: This is a Dakota question

You posted in the Ram section and it sounds you have the 4.7 which wasn't available on the 2nd gens. The 4.7 indeed has a separate TCM unlike the older 3.9/5.2/5,9 engines where the TCM is integrated in the PCM. What scan tool did you use ? As this is a pre-CAN bus vehicle you need something that can talk on different pins in the diag port. There is some sort of diag junction block that connects all the different modules, see if the tool can talk to ABS and Airbag modules. P1698 indicates no communication between TCM and PCM. Either a basic problem with power or ground at the TCM or with the communication bus itself.

You said you checked grounds but have you added grounds just for giggles?

Granted, it's unlikely to cure your problem but it's easy, quick and very low cost

P1698 No Bus Message From TCM
Don't know how many wires go between the two but they are the ones to check.

Thank you for the advice guys, does anyone know where I can get the ground layout?

I assume this is a 4.7 truck?

Extra grounds are good I've installed 2 extra not that I need them in Arizona no rust and salt problems.

I have the same issues as described, but i chose for it this way :)

I have a 2000 Dodge Dakota 4.7L V8 with the 45RFE Automatic and upgraded with the 2002 Jeep Grand Cherokee TCM, to a 5-45RFE Automatic.
By doing this, you have a TCM and PCM who can't communicate with each other, that way you get the P1698 code, because the 2000's run on a CCD Bus communication.

I don't know if you had this one from new, maybe the previous owner made the TCM upgrade ? and that's what you're dealing with.
Don't know which TCM change you've made to solve the problem ?
If you have changed out to original 45RFE TCM, or changed out to the part number ( Probably 545RFE TCM ) which is in there now ?

v8cowboy comment... he brings up a good question in do you have a durango/dakota tcm installed? 1 wire ecm vs 2 wire tcm (?), going to make it hard to communicate. which makes me wonder about that 2nd wires function...

technical talk... if the single wire setup was sensitive to noise a fix would have been to use a differential driver and twisted pair setup. if the tcm is expecting it and you have a jeep tcm, may just need an 1999-2000 jeep tcm for the 5 speed function. would need to investigate.