Just picked up my 98.5 last week. It appears to have the Trans TC lock up problems. I changed all of the fluids (only 6 quarts ATF), filters and adjusted the AT bands, reset the Apps, cleaned the IAT sensor. A sticker showes the ecm was update 5/12/00 to 333037303J. I would think that the flash from TSB 18-02-99 would be included in this. It will still go in and out between 35-55 mph. Causing about a 100 rpm surge.

Question:

Is the OBDscan (universal USB interface) tool @ aprox $170.00 what I need to pull/check the computer codes?

Or is there a better model or a add on power modual that would do this also?

The TC is driving me crazy. I'm afraid to drive my new truck.

I'm planning on checking the wiring/connectors, TPS next...

Thanks,
L

 

ECM update would not effect trans issues as that is controlled by the JTEC controller. I would have the part number checked with the drb and run it through the mds and see if there is an update. Updating the JTEC would be the first thing I would do.

 

Go to any good tranny shop, they will hook a laptop up to it and take it for a drive and tell you whats wrong. Most will do it for free.

 

All the scan is going to show is that IF there is an electronic command for the lock up clutch to engage/disengage. If it does show let the games begin on finding whats causing it. First thing and easiest if a signal is shown is to update the JTEC. I've taken care of a ton by doing this.

 

Dodge does not show the jtec was flashed.

Dealer # 1 $154.00
Dealer # 2 $ 90.00

Hmm.... I still want to buy a scan tool.


Thanks

 

TSB Flash didn't change anything. $ 500 parts and labor for TPS quoted.

I'm thinking I should isolate the wire from the loom first? They said I have an old style tps pre tsb.

???

Also what do you think of resetting the apps and placing a block under the pedal to change the range the tps operates in. (assuming it is toast in one spot)?

 

Picked up my truck. Should I see a sticker showing the PCM was flashed and a code number? My receipt said they did flash it per my request.

Thanks

 

Well yes you are supposed to "by law " put on the update sticker, but that doesn't always happen. I'm not familiar with "an old style" APPS, but I'll look through some bullitins applying to the 98-99 and see what there is. I'm also not familiar with the "wire isolation" but I'm assuming that is the same as the "Happy Box" that is on the market. Something you can do to play around with your situation. If this lock unlock is happening all the time, unhook all connections from your alternator and then go test drive the truck and see what happens. I have repaired a couple by cleaning all these connectors. I've also had a couple positive experiences using foil tape to cover wiring harnesses, and even currently have a truck that we replaced the lift pump on that was affecting the lockup. All of these situations took quite a bit of time and test driving to conclude that a change or repair had been made.

 

After further searching the web on this Torque Converter lock/unlocking issue. I came up with the following solution and am now getting very solid TC lock up at 1500 rpm under normal acceleration. With no more jumping around in any gear under acceleration!

What i did:

1) Cleaned the PCM socket and connector with electric parts cleaner. (electricity 101)

2) Grounded the PCM directly to the passenger side battery lead with a jumper. ( more electricity 101)

3) Clamped on a RF Choke around the Orange / Blue stripe wire from the APPS to the PCM at the PCM connector. (see attached picture) I will wrap it with tape to keep it in place and from disturbing the connector.

FYI: Chokes, like this one, are used to filter electrical noise from +- 5 volt data cables ( like printer or USB cables attached to your computer). So why not the APPS circuit on my CTD. Glad I had an extra one handy.

Thank you for your input ( and everyone else that took the time to post their problem/solutions.)

 

Thanks for keeping us up to date and letting know what worked for you. Is that filter something that would be available at Radio Shack?

 

Things have changed a lot sense I've step into a radio shack. I searched the entire store. Including something to buy to remove it from ... they had no idea what it was. Maybe a better stocked (or old) store? I know I've seen them there just not sure how long ago... If you are near a Fry's electronics or even a local computer shop(talk to a tech). They may come up with something .

I'm looking for I source (reasonable) as I wish to place a few more on other critical circuits. Including right at the APPS / TPS end.

BTW my next step would have been a 220 uf capacitor @ the PCM straight to my ground strap. I just hate to cut/splice wires and was looking for a water proof tap, to make it easy. There is a electronics supply house I'll check at when time permits they should have both.

Sure is a great Truck. I'm sure the PO was sick of driving it that way.

 

i had mine in the shop yeterday for this same kind of thing i was thinking of pulling the starter and fixing the cps plug that has workrd for some but the dealer said they changed a pcm to ecm wire and now it shfts good.