newprotest.org: Dodge Grand Caravan

Dodge Grand Caravan

Wrenching on the family minivan


This is a collection of repairs or modifications I've done on my 2000 Dodge Grand Caravan Sport.

BODY CONTROL MODULE

2011-03-27 21:10:09
by: jovial_cynic


In addition to the transmission issues that Dodge Caravans are known to have, having the instrument cluster go out is another common problem which I had the luck of experiencing. And similar to the transmission problem not actually being a transmission issue, the problem with the instrument cluster has nothing to do with the instrument cluster.

On the Dodge Caravans (and many other Dodge vehicles, apparently), the Body Control Module (BCM) controls several functions of the minivan:


Automatic door locks
Battery protection
Chimes
Compass/mini-trip support
Courtesy lamps
BCM diagnostic support
Door lock inhibit
Headlamp time delay
Ignition key lamp
Illuminated entry
Instrument panel dimming
Mechanical instrument cluster support
Power door locks (with/without remote keyless entry)
Sliding door memory lock
Vehicle Theft Security system (VTSS)
Windshield wipers / washers (front and rear)


I read through as many forums as I could to see if I could trace down the root of the problem. If I could avoid buying an expensive part for the van, that would be ideal.

The first thought that was that I'd have to replace the BCM outright, which I could pick up for about $100 on eBay. However, the problems with the instrument cluster not showing anything was intermittent. Sometimes, I could tap on the cluster and it would kick back on. That didn't sound like a computer issue. It sounded more like a loose wire, so I pulled the BCM plugs and checked everything to make sure that there wasn't anything amiss. After that, I pulled the instrument cluster to see if anything seemed loose back there, but I couldn't identify any problem.

After a little while of dealing with the intermittent gauge cluster problem, I noticed that there was also a problem with the heating/AC controls. I could turn the air on and off, but the temperature and direction (face, floor, defrost, etc.) was stuck on defrost. This didn't seem like it was related to the BCM, but the problems started at the same time, so I decided to see if I could find a common ground between the two that could be causing the problem. I was going at this blind, because the wiring diagram in my manual didn't show any common grounds.



Pulling the heater control panel was a matter of removing four screws: two shown above the CD player, and two down below, under a cover above the cup holder.



There are three plugs to deal with. The plug with the 21 pins turned out to be interesting.



Unfortunately, my wiring diagram pin-out only explain what pins 1 through 19 control.



It's hard to see in this photo, but the bottom-right pin was brown, in contrast to the other shiny silver-colored pins. I didn't think much of it, but then I looked at the plug itself.



Yup. The spot that held pin #21 is melted. There is a loose connection at that location, and the repeated arcing heated up the plug and ended up coating the pin, severing the connection entirely. After a couple of minutes of scrubbing the pin and tightening up the plug, I put it back together and my instrument panel worked perfectly.

Weird, right? Why would a break at the heater control have anything to do with the instrument cluster, via the BCM? Wiring efficiency, I guess. Having common grounds across different circuits saves on wires, but it sure make it seems like there are gremlins in the system. On the other hand, it did make it a little easier to trace down the bad ground, because I went into it assuming that the problems were related. The forums I've read on this problem have never linked the gauge cluster and the heater controls. In fact, the responses I read to someone else with the exact problem stated to view the two systems separately, and to start with replacing the BCM. In this case, that wouldn't have helped.

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SECOND TRANSMISSION ISSUE

2009-12-27 15:48:49
by: jovial_cynic
I recently started having issues with the Dodge Caravan transmission again. Previously, the problem was traced down to a bad speed sensor; the symptoms included an erratic speedometer and cruise-control that kept hunting for the right speed. (That's an output speed sensor issue, by the way).

This time around, the check-engine light came on, and while driving on the freeway, the transmission went into neutral (free-revving). I pulled the van over, turned the car off, and then turned it back on again to see what would happen. If the van was going to remain stuck in neutral, I knew I was going to need a tow truck to come get me. Fortunately, the Dodge transmissions are able to go into "limp-mode," which basically puts the transmission into second gear and leaves it there while you're driving it. This makes for rather high-RPM free-way driving, but at least you can get it home so you can work on it.

Anyhow, I got the van home and picked up another set of speed sensors (still under warranty through Schucks Auto (Kragen Auto, locally), hoping that the issue was the input speed sensor. That, and it's always best to start with the least expensive repairs first, or you may end up spending lots of money on parts you don't actually need. Free is rather cheap, which is why I started with them.

After swapping out the sensors, the van was still in limp-mode, so the next thing I wanted to rule out was a possible wiring fault between the sensor and the transmission computer.


Not wanting to spend a lot of time trying to trace down shorts in the wiring, I figured the easiest way to check for faults was to run back to Kragen and borrow their diagnostic scan tool. They keep an Innova scan tool for rentals, and that seems to be a pretty good product.

The sensor reported two codes: 755 ("Shifter Solenoid B") and 700 ("General Transmission Fault"). This was good and bad news. The good news was that the problem was unrelated to the speed sensors, so I probably wouldn't have to try to trace down a shorted or disconnected wire somewhere. The bad news was that I had no idea what "Shifter Solenoid B" was, so I had to do some research.

A couple of quick google searches pointed to the following diagram:


The shaded section is the solenoid pack.


Wanting to rule out a connection problem (as opposed to a faulty device), I popped off the 8mm that held down the gray plug cap.


The plug was covered in oil - transmission fluid. There's no good reason for transmission fluid to get onto this connector.


The terminal was also wet. Somehow, an internal leak on the solenoid pack was forcing oil into the connector, which meant I'd have to replace the pack.


Here's the bad solenoid pack. Because the fault is internal, you can't tell that there's something wrong with it by looking at it.

NOTE: Dirt builds up behind the solenoid pack on the transmission. Try to clean that off before removing this part, or the dirt will loosen up and fall under the solenoid pack while you're removing it, and you'll end up with dirt in the oil passages on the transmission. I spent a lot of time with Q-tips extracting dirt. Not fun.

I checked on the local auto store websites, and found that Auto Zone could order the part for $179 with a 3-month warranty. I didn't want to wait for a special order, so I called up the Dodge dealership, who carried the part for $240. After talking with the Dodge guy a bit, I learned that this particular part was on its third version, due to known defects and leaks. Not knowing if Auto Zone or the other sites carried the latest version, I decided to go with the Dodge part.

Three bolts later, the new solenoid pack was installed. I ran the scan tool on the van again, and the 0755 code was gone. I still had to clear the 0700 codes, which apparently don't go away by themselves, and three days later, the check engine light has not come back on, and the transmission is changing gears just fine.


NOTE: In the event that your Dodge is stuck in neutral, I believe that you can force it into limp-mode by removing the plug to the shift-solenoid pack, which is bolted down with an 8mm bolt.

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TAIL-LIGHTS

2009-12-19 10:20:10
by: jovial_cynic


Back in June of 2009, I solved the Dodge transmission problem after a bit of research and wrenching. From the comments on that post, it looks like a lot of Caravan owners found that post useful, and as a result, I've committed to posting any Caravan repairs that I do.

On the way down to California, I noticed that my minivan's left tail-light was out. I figured that the problem was likely a blown bulb. However, the lights came on when we hit the brakes and when the turn-signals were used, so that ruled out the bulb. Driving around with a single tail-light out wouldn't be a big deal, except that were were pulling a little trailer behind the van, and the wiring on the trailer apparently depended on the left tail-light. Ie., with no left tail-light, we didn't have any trailer lights. Driving through the night with no lights on the trailer didn't sound like a safe way to go, and since I didn't have the tools handy to do the repairs, we ended up driving through the night with the hazard lights flashing.


Because the problem was electrical in nature, I figured that picking up a repair manual for the minivan was probably a good idea. A few weekends later (after my wife got pulled over for the tail-light), I picked up a Haynes repair manual and tackled the problem.

I was originally confused about the problem, because it didn't cross my mind that the lights would be on separate fuses. I assumed incorrectly that they should have been on a single circuit, so I thought that the problem was a bad connection or failed ground. This is why it's handy to have a repair manual with a good wiring diagram.


After flipping through several diagrams, I found the one on exterior lighting, and zeroed in on the left-light assembly.


I followed the brown/yellow (BRN/YEL) wire up to the fuses and was surprised to see the wire meet a 15a fuse. Just to confirm, I followed the right-light assembly and saw that it met up with a separate 15a fuse.


According to the diagram, this fuse was located in the "junction box" which is the fuse panel below the steering column. Removing the cover was a matter of turning a plastic screw and pulling the clear plate, after which I looked for the 15a fuses. As it turns out, there's only two of them - one labeled "RT PARK" and one labeled "LT PARK."


As expected, the "LT PARK" fuse was blown. Fortunately, I had an extra fuse available which fully solved the problem.

Near as I can figure, if the trailer lights draw everything from the left circuit, I should probably consider throwing a 20a fuse in there instead of the 15a fuse. The trailer hookup was an after-market add-on, and the original 15a fuse didn't account for an additional set of lights. Now, overfusing isn't generally a good idea (it can overheat your wires), but I believe that the 20a and 15a circuits in the van use the same size wiring, so I shouldn't have any concerns about the ability for the wires to handle the additional current.

Anyhow, problem solved. The tail-lights are working just fine now.

comments [6]


DODGE CARAVAN TRANSMISSION

2009-06-15 07:02:53
by: jovial_cynic


A few months ago, my wife and I started to notice that our minivan transmission was acting a little funny. When slowing down to a stop, the transmission would drop from second to first (we have the 4-speed automatic) with a clunk, sometimes so forcefully that the car would shudder as a result. Additionally, I noticed that the cruise control had gone all wonky -- I'd set the cruise, but the engine would fluxuate around the speed I set, as though it couldn't find the correct speed once I set it. Lastly, my wife noticed that the speedometer needle started acting up, and would shoot out to 120mph and back down to 0mph with no actual change in engine speed. Very weird.

Having heard for years that Dodge transmissions were notorious for failure (especially on the minivans), I braced myself for the cost of repairs. Between the transmission, the cruise control, and whatever was causing the speedometer to race around, I expected to end up with a repair bill that would be greater than the value of the van. However, I wanted to see if anybody else had experienced similar problems with their transmissions, and wondered if the cruise and speedometer issues were connected in anyway.

Transmission:

The first thing I needed to do was to identify my transmission. The 2000 Dodge Grand Caravan Sport (3.3 L) has the A604 transmission, as did any Caravan from 1989 to 2006. As it turns out, this transmission is entirely computer controlled.

A604 / A606
The transmissions above are 4 speed front wheel drive automatics that are all computer controlled. If your transmission starts shifting erratic or stays in second gear only, then make sure you or a shop run a scanner on the vehicle. You want to see if you have a sensor that has gone bad causing your problems. Also make sure you check the clutch volume index (c.v.i.). This helps determine the condition of the transmission. Chevy's and Ford's do not have this neat little feature.

Vehicle's with A604 transmissions have chronic input and output speed sensor problems and also with the little wire connectors to those input and output speed sensors. The dealer offers a repair kit for these wires instead of buying a whole new wire harness. On most of these vehicles, If you have a code 41-44 you should check for weak battery voltage first. now the shop needs to check the wiring for poor grounds. I have seen that The transmission controller often goes bad causing these same codes, so be careful.


Reading that a common fail-point on these transmissions is the input and output speed sensors, I kept researching to see if the other issues with my van could be caused by the same sensors.

Cruise Control:

This article I found referenced a 1988 Dodge transmission (which is a generation prior to the one in my van), but the reference to the speed sensors caught my attention:

Q. Now I have a few problems with my 1988 Dodge Caravan, 3.0 liter engine, is equipped with cruise control, A/C and has 141,000 miles. I have a Maintenance Required light coming on with a Code 15. I had this for about two months or so. During that time the cruise control worked just fine!

A few days ago I turned on the cruise control to set it at 55 mph and when I did the car started to accelerate more and more!!! It would not stay at 55 mph. Could code 15 cause this problem?

A. Code 15 is the Vehicle Speed Sensor and a bad VSS would most certainly cause the problem you're having with the cruise control.


Speedometer:

The last issue was the speedometer, and sure enough, the issues with the speedometer can also be linked to the speed sensors on the van.


'91 Dodge Caravan, Speedometer Jumps

Q: I recently bought a '91 Dodge Caravan with a bad transmission. I had a Chrysler rebuilt transmission installed. When driving down the road at 30 MPH the speedometer will start jumping around sometimes will peg out at the maximum 100 MPH on the dashboard. The engine will start jerking at that point. Then the speedometer will settle down and the vehicle will run smoothly. The tachometer will remain steady even though the speedometer is jumping around. The transmission shop did not think that the rebuilt transmission would be the cause. The OBD did not show any errors. When the technician checked the dashboard, the speedometer would only go to the half way point(50MPH) instead of the full range(100MPH). What should I be looking for? Sensors, gauges, body control computer? Wiring? The problem is intermittent and seems to be affected by bumps.

A: If I'm not mistaken your vehicle doesn't have a speedometer cable. It uses a signal generator in the transmission that creates an electrical signal in relationship to vehicle speed called a Vehicle Speed Sensor (VSS). This information is processed by the vehicle's computer for engine and transmission management and provides the signal for the body computer that controls the speedometer. If the VSS is failing it will not always set a code in the computer. Why? It all depends on how it is failing (lying). Also you have to know that the computer in many vehicles have a programmed speed limiter. The computer's program uses vehicle speed as an input and if a specified speed is seen by the computer it will cut the fuel injectors to prevent the vehicle from going too fast. Knowing this, and the fact that your engine starts running rough when the speedometer flips out at 100 plus MPH, I'd say fuel cut out is kicking in. For this to happen it is likely that the Vehicle speed Sensor is on its way out. Before it quits it's going you make your life difficult. Have your technician plug into the vehicle computer and monitor the vehicle speed sensor signal. It's likely your problem is an intermittently lying Vehicle Speed Sensor.



Having put together my research, and understanding that the issue may have been caused by a bad set of speed sensors, I did my best to put my head around the problem, which I believe can be summarized this way: these transmissions receive signal about the engine speed through an input speed sensor. The transmission changes gears when the engine reaches a specific speed. The transmission, through the output speed sensor, tells the car how fast it is going, and that information is sent to the speedometer and the cruise control system.

Confident that I had figured out the problem, I checked around a few local auto stores to see if anybody had the sensors. The sensors ran about $20 each, which is significantly cheaper than having to a replace the transmission. When you get them, make sure to have the store tell you which is the input and which is the output, because I think they'll both fit in either hole. The boxes on my sensors didn't say, so I had the store just write "IN" and "OUT" on the boxes.

I found a handy image of my transmission, which shows where the sensors are located:



And then I made sure I had the parts and tools necessary to do the job.

Parts/Tool List:
10mm socket (to remove top of air intake)
1" socket (to remove/tighten sensors)
standard screwdriver (to loosen hose clamps)
Vehicle Speed Sensor - INPUT
Vehicle Speed Sensor - OUTPUT


Removal/Installation:


The first step is to remove the airbox cover. This can be removed with a 10mm socket. Under the airbox cover is the actual airbox; remove the filter by unsnapping the clamps holding the lid in place. Maybe this is a good time to see if your filter needs to be replaced.


Once you've got the airbox cover and filter off, you should be able to see where the sensors are located. On the left is the input sensor, and on the right is the output sensor.


The input sensor is located just under two little hoses; remove the clamps and get those houses of the way. Make sure that you keep track of which hose goes on the left and which one goes on the right. To remove the sensor connector, there's a tab that lifts up, probably under the sensor. It lifts very easily, and the connector slides right off. If it's not coming right off, you haven't properly lifted the tab.


Here you can see the hoses and the sensor connector removed. To remove the sensor, you need a 1" socket which should fit right over the terminal. The socket should also be large enough to clear the hose nipples.


Here's a shot of the output sensor. Note that with both of these sensors, the base is plastic. If you use anything other than a 1" socket, you'll rip the plastic to shreds and never be able to get the sensor off. USE the socket.


In my situation, the output sensor was covered in sludge, which may have been the source of the problem. Both the input and output sensors use some kind of magnetic receiving unit, and those magnets will pick up tiny metal shavings that are suspended in the transmission fluid. I suppose 10 years worth of buildup is enough to cause the sensor to throw bad signals. But maybe something on the inside caused the problem... so replacing it outright was the best decision.

Anyhow, after replacing the two sensors, the transmission problems have completely been resolved. No more weird cruise control issues, no more erratic speedometer, and no more 2-to-1 gear drops when coming to a stop. Problem solved.


NOTE: This is part 1 of the Dodge Caravan transmission issue. Part 2 can be found here: http://newprotest.org/details.pl?1457



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