QuestionQUESTION: Hello Sir,
It's an all too familiar story with the infamous dash gauges going dead.
1997 Plymouth Grand Voyager SE 3.3L
Months ago, the dash gauges would come and go when hitting large bumps. Now they are dead and I can't duplicate the intermittent issue. Everything works except the temp, speedo, tach and fuel gauges. When starting the vehicle, the cassette goes wild clicking. It may possibly be stuck in lower gear, aka limp mode. The ABS light is on. The engine codes are:
P1698 no CCD communication from TCM
P1695 no CCD communication from PCM
I'm not a rookie at this game. I've done this so far....
-pulled instr cluster and installed a different one
-soldered back plug pts on original instr cluster
-tried another PCM
-tried another TCM
-pulled out BCM to look at it, didn't replace because I read that when this is bad, you'll also have no power locks and windows. Mine work fine.
-checked plugs under the hood, all fuses in and out.wiring looked good too.
-tried to check grounds but I can't find another one besides the one atop the alternator. I heard there is one somewhere along the bottom, but I don't know exactly where, do you?
I tried checking the CCD bus by using a multimeter grounded and inserted into #3 and #11 terminals of the diagnostic port, but the meter is bad and waiting for another one. A friend scanned it with his up to date snap on scanner and it would not communicate with the TCM or BCM. I have been going back and forth on this and getting absolutely nowhere after alot of time spent. What am I missing here? Thanks for any help.
ANSWER:
Hi Mike,
The other battery ground is on the left frame rail lower inside edge toward the front of the engine compartment.
If it were just a matter of the cluster, then your focus on the plug pin/circuit board interface solder joints was correct. However, the communication fault codes to the TCM and PCM/ BCM and the possible limp-mode of the transmission suggest something more basic.
The manual for the codes 1695 and 1698 suggests that using the diagnostic readout box that you remove the plugs at the tcm and the pcm then by jumper ground the bus + and the bus - wires, one at a time at each plug and see whether the drb notices the grounding of each of those 4 wires by giving you a message "short to ground". If not for any one of those jumps. then trace the wiring from the plug to the diagnostic connector to find out where it is 'open'. I assume that the CCD + and - wires are never grounded in the normal state of affairs, so if you grounded pins 59 and 60 at the PCM and didn't see a ground by means of an ohmmeter to ground when you looked at 11 and at 3 of the diagnostic port, respectively, that would revel an open to be found. Similarly, if you grounded pin 4 and pin 43 of the TCM and didn't 'see' it at 11 and at 3 respectively then look for the opening in the wiring between the two points that didn't see it. Otherwise, with no other codes than those, and if you detect all the self-imposed shorts to ground, then the manual says to replace the modules whose wiring was proved to be OK. BUT:
The friend's Snap-on scanner saying no communication to the bcm appears to offer a series of possible explanations (which also might explain the presence of 1695 and 1698). The step-by-step for solving that one covers 10 pages of my '98 minivan body diagnostic procedures manual. I would be glad to xerox copy an postal mail you those pages tomorrow if you will tell me a postal mailing address. Then after you get them, if you would be so kind as to send me back four first class (44 cent) stamps to cover my cost that would be appreciated.
The bcm is the nerve center of the bus, so I suspect you will want to go over those pages to find out what is the problem.
Roland
PS Please "rate" my answer and where you see the question about "volunteer of the month" consider whether I deserve a "yes". Thanks
PPS: Thanks for the rating. To let me know your address, simply use the 'follow-up' option and check the box to make it 'private'. No one else will see it that way.
---------- FOLLOW-UP ----------
QUESTION: Roland, Here's my address if you decide to send it through the USPS.
Mike Sulton
1037 Humphrey rd
Earlville NY 13332
Or if you prefer, you can email it to me at my yahoo address nyr091994@yahoo.com and I would get it just as easy that way too. Either way would be great.
As a last thing or note, Is that battery ground on the lower frame rail also the neg battery lead? Or is there another ground there, what exactly is it by or next to? Lastly, is it possible to have a bad BCM without losing power locks etc? That was one part I didn't try swapping out because I read that the power locks would be out too and I wonder if maybe I should have tried it anyway.
Thanks again for your help. I've been banging my head against the wall for 3 weeks now and you are providing some much needed help.
Sincerely,
Mike
ANSWER: Hi Mike,
The power locks are mediated by the BCM so I presume a total failure of the bcm would stop that too. Yes the other ground is the battery cable ground. I don't have a scanner so will do the copying today and mail them.
Roland
---------- FOLLOW-UP ----------
QUESTION: Roland,
All these electronics, used to be much simpler not too long ago. Have you ever heard of a BCM going partially bad? In other words, for my particular case, would it be feasible to think the BCM is partly bad or could be, even without other major symptoms like the power locks etc? Or is that what the 10 page diagnostic is for, to determine this or not. I also tried pulling various components out to see if they affected the situation any, like the radio, heat control head, etc, but no difference.
Anyway, thanks for the info. I look forward to gaining some helpful tips.
Very much appreciated,
Mike
AnswerI haven't heard of that partial failure. The data bus includes many modules all communitcated on a pair of wires, that is centered in the bcm, so I would believe that the codes might include other components if the bcm failed totally. But that is a guess. I hope the pages will help you to sort it out.
You are welcome.
Roland
