Question
Unknown connector, wit
QUESTION: Greetings Roland.
1991 Caravan 3.3L AWD. No speedo past couple years, no problem shifting gears until recently. Have observed bucking and being stuck in 2nd. Which I usually resolve this going into limp mode by carefully shifting into neutral and restarting while rolling.
Have replaced output speed sensor, which has had no effect. Is the TCM smart enough to realize sensor was changed or does it need to be reset??? I don't yet own a scanner, did the key check, only code shown is Thirty-Six.
How does one test the output and input sensors, with a vom, oscilloscope or another method???
Also how do I get to the input sensor, there is something in the path, I believe a solenoid pack, does it first have to be removed???
On a different subject, (could be related for all I know), attachments enclosed, black wire with green tracer, do you know after looking at the connector what this wire attaches to???
Thanks
ANSWER: Greetings Duane,
I suspect that the speedo failure may not be due to the output sensor since you didn't have a problem with the trans for a couple of years without the speedo. If it had been the output speed sensor the trans would have acted up.
The TCM doesn't have to be reset because you changed the output sensor.
I suspect that the sensors are pulse rate generators, but I am not sure which type of meter will accurately reflect its output.
I don't believe the solenoid pack has to be removed to remove the input speed sensor. But why do you want to change it? Unless you have a fault code I wouldn't do that (see below).
On the overall situation, my suggestion would be to have a readout of the trans computer memory via the blue data link connector 6-pin plug under the dash, at the dash reinforcement on the left side. A Chrysler DRB II or similar professional OBD-I code reader will do it.
I would try an independent non-franchise trans shop for that. Ask for the two digit code number(s), what they mean, what they suggest and for how much. Then let me know and we can compare that to my '92 trans shop manual.
The 36 code you observed by the check engine lighe appears to just say that there is a trans fault that it detected just after a shift, but there is another code in the trans memory that can't be read out with ignition key. I say that even though there is no listing of a engine fault code with that number, rather the 36 code is only applicable to the transmission code series.
Can you tell me something about which harness (what other wires) are grouped with that mysterious wire? I would otherwise have to go thru the '91 van wiring diagram manual (125 pages) I have looking for such a wire. I will do that but if you can give me anyother hints it would make it easier.
Roland
PS Use the 'thank/rate' tab below to get back to me quickly, without having to wait for me to be 'available' to answer a question. There is a space for comments.
---------- FOLLOW-UP ----------
Unknown black wire/gre
QUESTION: I've looked at several websites and several folks replaced input and output and experienced success. I figured if both sensors are the same, then nothing was wrong with the output sensor I removed so I should be able to swap it with the input sensor and see what happens. That's only if they are the same, I haven't gotten around to calling an autoparts store to see if they have the same part number. But with solenoid pack sitting in front of it, I cannot see it, I cannot even feel if there is a firmly fitting connector on it.
I am going to purchase a ODB-I and II code reader, I have looked at them at Meijer, Napa, and Murrays, but the selection is very limited. The unit I think I want isn't in stock for me to look at but can be ordered. So I'm still looking.
On that wire/connector, I will have to get back to you, it's between the 3.3L rear and firewall. And is long enough to drag on the ground, that's why that chunk is out of it. I will try to determine which harness it is grouped with. I will also try sending another picture from a different angle.
Duane
AnswerHi Duane,
The sensor is between the top of the solenoid box and the two transmission fluid cooler lines. That is probably why you can't see/feel it. There is little space in between the top of the box and the nipples for the cooler lines. Maybe you would do well to get a Chrysler DRB-II (which is an OBD-I reader). Watch for them to come up for auction on EBay.
The attachment for pictures function at the site is pretty limited so don't spend to much effort on a photo.
Roland
I purchased a InNova model 3120 OBD 1&2 reader. It found, DTC:15 No Vehicle Speed Sensor Signal Detected During Road Load Conditions. I visited trans shop, TCM was canned with a Snapon scanner, 7 errors found 36, 54, 52, 53, 51, 22, 35. In addition some other numbers were written on paper, I could scan them and send them if you would like. He tells me the trans needs a rebuild from fluid smell, and clutches doing strange things that we could feel during the test drive. Cost $1,500-$1,800 he will know more of course when it is taken apart. I guess that's about right, last rebuild cost $1,400 and lasted 11 years. Was informed both input and output sensors were working, he was able to look at data they were sending. I'm told the Vehicle Speed Sensor drives the speedometer directly. Where is it located??? It's going to take a while on that wire, I have another vehicle in the garage at present, it has run in about three years, I'm figure it a blow head gasket or holes through the tops of the pistons. Duane
Hi Duane,
All those codes, taken together means a rebuild is necessary.
The '91 manual's wiring diagrams that I have shows that the speedo is 'driven' by the output speed sensor when you have that transmission and an electronic digital dash (all handled on the digital data bus). I could imagine there would be a separate speedo sensor if you had the 2.5L with a conventional trans and conventional cluster, but that is not the case here.
Best of luck on the rebuild, and thanks for the kind evaluation and nomination.
Roland
