Hey guys, first time posting on this site and I'm hoping to get a helping hand. (I promise I'll help when/where I can)

I have a 2001 Chrysler Voyager (3.3 FFV, NO ABS, pretty base car) with NO communications to/from the TCM, an Engine code of p1698 - No bus message from trans control module.

Here's the weird part. EVERYTHING works (Speedo, shifts gears w/o any problems, etc...) I just need the PRNDL lights to indicate what gear I'm in. My past experience with this is that when that code pops up you get Limp-In mode. I'm very lost on what to do.

New TCM, IPM, PCI wires all checked out (I CAN communicate with all the other modules [PCM, Body, etc...] and ohmed out the wire from the Diagnostic Junction Port to the IPM and than from the IPM to the TCM and everything checked out there) All my power and Grounds are good at the TCM. Double and triple checked the pins in the connector. I'm VERY confused and lost (I don't know which way is up.) When I watch the PCI wiring I do get voltage spikes from 0 volts to 7.5 and back to 0.
I have a Snap-on Solus Pro at my fingertips (I am a mechanic) and AllData. I've tried doing what Chrysler says to do, but still nothing!

I'm kinda up poop's creek with out a paddle or a bucket. Hopefully someone has come across this before and will be able to help out! Thanks in advance!

 

(Couldn't find an edit button)

There is also a code for no TCM communications in the BCM.

 

First off...By IPM, are you referring to Underhood fuse panel (Integrated Power module) or The Instrument cluster???

Perform "Cluster Diagnostics". I'll double check the procedure, but I believe you hold the trip reset down, while turning the key "ON"......It will display SoF x.xx, and go thru a cluster self test. MAke sure all segments actually work in the cluster, before condemning anything else.

At TCM, there are, if I recall, 3 grounds and 2 powers. If PCI scan doesnt Identify TCM, I would definitely start with "Buss-Comm" thoughts in mind.

Just for reference, Ive seen several TCM's come out of the box defective, so dont rule that out completely.

 

Yes, when I say IPM I do mean the Integrated Power module under hood (replaced that AND the Front Side Module attached to the IPM)

I've had 3 TCMs swapped out this car and same crap. There are 2 grounds (and 1 sensor ground) and that's it. There are 3 power spots (Don't rember the pin numbers, but one is hot in run, one is from the fuse, and one is only hot in start.)

I've done the cluster Diag and everything works on that account. Sweeps n' everything.

I'll clarify - when I say NO PRNDL display - I mean it's all lit up. Everything is boxed and lit. (Not just one letter - all of them)

I've even cut/ran my own PCI wiring from the TCM straight to the Diagnostic Junction Port just for poop n' giggles and still nothing.

What's really, really throwing me off is why does this sob shift and act normally otherwise? Should I start looking at a PCM or something?!

 

Ok.....

Check powers and grounds to the "CLUSTER". Did you recieve any error codes when doing the cluster self test?

Do you see PRNDL position on the scan tool anywhere......PCM possibly?

If it shifts, you may reasonably rule out TCM and related wiring.

However, a buss issue in the cluster itself, would explain your symptoms.

I just have to ask......Is this the original issue for replacing the TCM, and have you driven the vehicle AFTER the TCM was replaced. There is a learning process for PRNDL positions somewhere on the scan tool. (Shifter self test???)

 

When I switch gears it DOES change from P-N-- to -R-DL on the Scan Tool. I don't know if this is just some default logic (so the PCM doesn't freak out from the added load) or is it actucally seeing the gear changing but just not sending it out (As in a bad PCM.)

I don't really want to throw more parts at this car. I don't have a spare 2001 PCM (have an older pcm with the 3.0)

I'm really, really lost now...

 

One other note I paid attention to is that there is NO voltage comming from the PCI (Pin 43) from the TCM with it plugged in (but NO ground either.) I do have voltage comming from the other end of the wire. (where it goes to the IPM)

What are the odds of all 3 TCMs being bad? Is there a wake-up command that I'm missing from the PCM to the TCM? I'd really, really love to get ahold of a chrysler engineer at this point... (one can wish, right?)

I'd blame the Cluster but why does the body control module say the same thing (No communication from the TCM.) Also, everything else works on the Cluster but the PRNDL display (all lit and all letters boxed.)

The original reasion why the customer brought it in was b/c it was NOT shifting and the PRNDL display was all lit up. I found a bad power wire (the B+ wire was poked before and all the copper turned green, lol) fixed that and now I get no PRNDL selection any more

 

Hi
I had this problem once and it turned out to be two things causing it the car was at the dealers for two days first time and they found the cause as follows there was no communication with the TCM they followed the diagnosis through to no power to the TCM with the ignition on from the FCM they checked the circuit to find an open circuit and rather than try to pull the wiring out they over laid new wiring for the circuit this was a red wire from the FCM by the fuse box going to the TCM under the wing after that the fault seemed to be fixed but after a test drive the " PRNDL " lit up again so after further investigation they found that by shaking the wiring harness the could recreate the fault this led them to find two wires had rubbed against the chassis under the front wing going to the TCM and this was causing an intermittent fault the dealers did cut the damaged area of wires out and repaired then protected them from doing this again they did show me the two wires that had been a damaged which if i can remember were light white/green in colour i hope this if some help to you.

Regards
Peter

 

I have this exact same problem, but on a 1999 Chrysler Concorde....car is at the dealer now, see if they can find the problem.

 

Dealer thinks its the BCM...not about to drop $750....@#$#@$