Transmission Input Speed Sensor Replacement 1997 Plymouth Voyager

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. Might as well replace both sensor and will take less then 30 min from start to finish.

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.

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 transmission. On the left is the input sensor behind the Transmission Solenoid pack by the transmission dip stick tube , 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.

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. 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 most 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 98% of the time will completely be 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. Good luck and merry xmass