Mechanical Issue Question - 1999 DodgeCaravan 3.0L AT

[jake75]

Just thought I'd ask here - son has this Caravan - about 90,000 miles. Routine transmission fluid changed about 5,000 miles ago. He says that it suddenly drives as if the transmission might be slipping and the speedometer stays at zero. Of course it is Sat night and the independent auto shop we use is closed. Anyone have any ideas?

[joatmon]

Sounds like either the tranny needs fluid or the tranny needs repair

edit - I misread, and interpreted the speedometer reading always 0 to mean the car never moved, which is not the same thing.

[ColonelPanic]

Speedometer staying at 0 sounds like a speed sensor... A failed speed sensor will cause some awful shifting issues as well. Hopefully that is all it is.

Did the shop use the correct fluid for the transmission?

[jake75]

Didn't know the speed sensor would screw up the shifting - would not think transmission failure would also involve no speedo reading so that is a logical diagnosis.
Son is underemployed and penniless so I'll be paying for the repair. I have a lot of work this year (more than I want) for a semi-retired lawyer so I can handle it o.k.

[journeyforce]

First off did the folks doing the trans fluid change use the correct Chrysler fluid?

The trans is controlled by the TCM and is 100% computer controlled so if the VSS(Vehicle Speed Sensor) took a dump the trans would not work because the computer cannot tell the vehicle speed. While the A604 transmission is pure and utter junk, I would think that for it is a computer/sensor/electrical issue. Check out this webpage. It may have the answers you seek
http://www.newprotest.org/details.pl?1410" onclick="window.open(this.href);return false;
Here is the second page
http://www.newprotest.org/details.pl?1457" onclick="window.open(this.href);return false;
Good luck

[jake75]

The shop that did the transmission fluid change has a good reputation so I assume they did that job right. Did find a big screwdriver in the engine compartment probably from the folks at Valvolene that did a recent LOF but I don't think that caused the problem. Supposedly they had to move something to get at the Oil FIlter - can that be right?

[jake75]

Word from the independent shop is that the issue is the speed sensors. Cost to fix about $350 including tow. Didn't want to risk driving it and this shop has its own towing so not a major expense for that.

[joatmon]

Way to go journeyforce, you nailed it.

[jake75]

Thank you very much for the quick info that confirmed my belief that the entire transmission was not shot - though I knew the speedo signal came from the transmission I did not know that failure would cause "awful shifting issues". For future reference would there have been any potential fir damage if it was drive the 10 miles or so to the repair shop - or is this a better safe than sorry situation.

[jimincalif]

I don't know myself, but it seems to me you make the right decision to tow it, I would have done the same. "Transmission" + "awful" usually means "expensive". Glad to hear it's a reasonable fix.

[journeyforce]

I am glad it worked out and the repair was relatively cheap to do.

You did good to get it towed and that was the best approach as there was no use stressing the engine and trans unneeded.

To answer your question about would it have been safe to drive it that short distance, most likely as long as it was driven slow. The van was in limp mode because of the sensor issue. The computer lost the signal of the speed sensor and put it in a safe mode to protect the drivetrain and also to allow the driver to be able to get it home or to a shop. This is something Dodge programmed into the computer. Basically it is stuck in second gear and the speed is governed to be no greater then 30-35 mph. This allows you to slowly get the vehicle home without damaging it

As much as I think that model of trans is utter garbage, at least Dodge put all the things that go wrong with it on the outside(the shift sensors and the speed sensor) instead of the inside so you can repair it easy

By the way when you bought the van did you get the timing belt changed? That engine is known for eating them. It is a dual overhead cam engine set so far back changing the thing is a royal pain.

Good luck with the Dodge

[jake75]

In that engine if the timing belt fails is it good-by engine? I had a timing belt fail in a relatively low mileage 1978 Chevette - car just wouldn't start - no engine damage.

[jake75]

As the Transmission reliability - had a 1998 4 cylinder Plymouth Voyager that went 200,000 miles with no major repair aside from replacing a head gasket. So it is the luck of the draw I guess.

[ColonelPanic]

3.0L was a Mitsubishi engine, I believe... I would guess it is most definitely interference, so it's probably write-off time if it breaks.

Ahh, the joys of timing belts.

[CharlesinGA]

I see you resolved it. I had a '99 Breeze with a 2.0L and AT and drove straight thru, Plover, WI to Atlanta, about 19 hrs. Parked the car and it sat for two days. Next time I drove it, it would shift to second and no more, and sometimes work OK for a couple of minutes after you restarted it. Turned out both speed sensors failed. Without the sensors the tranny has no idea what gear its in or if it needs to shift. I think 2 ed is the limp mode. Dealer relieved me of $250 and about an hour of my time and off I went. Worked OK after that till I sold it early this year at 234K mi.

Sensors are easily replacable from outside the tranny.

Charles