2002 Chrysler Town and Country Town and Country not shifting

Now I'm going to have to refer you to a transmission specialty shop. I don't know if those codes set because the solenoids didn't respond due to the jumper wire wasn't in yet when the self-tests were performed, or if there is a problem with them or their wiring. You might want to measure the resistance on those wires to see if one is grounded or if there's an open circuit to one of them.

That's an interesting site that I'm going to explore further later.

There's a few issues I have with the tests. That test is real basic and an open circuit is going to be one of the least likely defects to occur. First, besides testing for continuity between the two terminals, you have to consider that you're testing a big coil of wire and there's two things that can go wrong with it. They're having you measure for continuity but anywhere along that wire it can be grounded to the housing. Without researching a lot further, I don't know if that will set the same fault code, set a different code number, blow a fuse, or simply shut the computer down. So, ... In addition to testing continuity, measure between either terminal and the housing. That should read infinite, (open circuit). If one reads open, the other terminal is going to read the same, but you can test it anyway to prove it to yourself.

The next thing to be aware of is they're saying normal resistance is between 0.5 to 9 ohms. That seems like an awfully broad range. If 9 ohms is normal, the coil could be half shorted and read 4.5 ohms, which they say is okay. A coil of half strength won't engage a valve reliably.

Next, remember that your meter leads will have perhaps as much as two to five ohms of resistance so you have to add that to your readings. A totally-shorted coil with 0.0 ohms resistance will appear to be okay if you don't factor in four ohms of resistance in the meter's leads.

I've never actually measured the resistance when diagnosing a problem like this. I have Chrysler's DRB3 scanner, and under the "Actuator Test Mode" it allows the solenoids to be activated by pressing a few switches. If you hear the solenoid click, or if you feel something happen when the engine is running, you know the 12 volt feed circuit is okay, the control circuit is okay, the solenoid is okay, and the computer's switching circuit has control over it. It isn't until there's no response with the scanner that you have to dig into the individual parts of the circuit.

The solenoids also have a mechanical side where it moves a valve. Just because the winding is okay electrically, the plunger might be sticking or the valve could be plugged and fluid can't get through. Since those are not electrical in nature, the computer won't detect an electrical problem and set an electrical-related fault code. Instead, when it activates a solenoid, it expects to see a corresponding rise in pressure from a sensor. If that doesn't occur, a different fault code related to that mechanical problem will be set, but it still requires the operation of an electrical sensor.

Yippee! One in a row! Happy to hear it's solved.

You're right about the relearn procedure. If you had the Chrysler DRB3 scanner, there is a relearn sequence that can be done in the shop, but few mechanics use that because it's easy to do the normal way. After any transmission work, the vehicle gets a test-drive, and that's enough miles for the relearn to take place.

There are four clutch packs with steel and fiber plates that wear out over time just like in all transmissions. The difference is with the old ones, slipping between shifts gradually increased as those fiber plates wore out, and you'd have two or three years notice that was taking place. The shifts were just a little more mushy as the months went by. Chrysler was the first to use this design where the computer watches how many CCs of fluid it takes to apply each clutch pack. As the plates wear down and get thinner, it takes more and more fluid to fully apply the packs. It takes time to fill those assemblies with fluid, so to maintain the nice crisp shift quality, the computer learns to apply third gear, for example, just a fuzz sooner before releasing second gear. That gives third gear time to get fully locked up just as second gear is releasing.

Depending on the amount of wear in the clutch packs, before the relearn takes place, the transmission could feel like a dragster with a real hard shift quality, or it could be real soft and mushy. It takes about a dozen up-shifts over a few miles to complete the relearn process. Most people don't even know that's taking place. The Transmission Computer goes through the same relearn procedure after simply disconnecting the battery, at least that was the case in the '90s. Most newer computers retain much of their learning and programming when the battery is disconnected.

If you're interested, the DRB3 scanner will display the "clutch volume index", (CVI) to show how much life is left in the clutch packs. The updating of the shift schedules as you drive is what makes the shifts feel like when the vehicle was brand new, but since you can't go by feel anymore to get an idea of the wear, this set of four numbers shows the volume, in cubic centimeters, of fluid it takes to apply each clutch pack. An experienced transmission specialist can tell by those number how much life is left in the transmission. A lot of independent shops have the Chrysler DRB3 scanner because with an extra plug-in card, they could do emissions-related diagnostics on any brand of vehicle sold in the U.S. Starting with '96 models. I suspect a lot of the better aftermarket scanners have this capability too.

The big disadvantage to this computer-controlled system is the shift feel is always nice and solid, ... As long as the computer can keep updating when to apply and release each clutch pack. The time will come when it can't update any further because the plates are so worn, there is no amount of fluid that will make that clutch pack lock up solidly. You would never get that far with the older transmissions because the severe amount of slippage would be horrendously annoying. That slippage would cause a lot of excess heat to be generated which would damage a lot of other components. Once this computer can't update further, slippage occurs, that is detected by the computer, it sets a diagnostic fault code related to "gear ratio error", and defaults to "limp mode" which gives you second gear, neutral, reverse, and park. The problem is you go from shifting fine yesterday to limp mode today with no warning. You can get an extra couple of years out of the transmission, but try selling that as an advantage to the family in the middle of a cross-country vacation!