Dodge Repair/automatic trans: accessory temp sensor, port location
QUESTION: Hi i have a 2008 dodge grand caravan 3.3L v6 i want to order a transmission temp gauge. the instructions on the gauge say that i can install the sensor in the transmission test port. I dont know if my car has one and if so where is it located. please let me know i would greatly appreciate it. thanks
ANSWER: Hi Albert,
You didn't happen to mention whether this is a 4-speed or 6-speed transmission. But for example in the 4-speed there is already a temperature sensor built-in to the transmission which is a thermistor attached to the transmission range sensor which is located inside the transmission, attached to the valve body. That sensor is a temp-variable resistor attached to electrical 'ground', and that resistance value is observed by both the trans control module and the powertrain control module and those computers are programmed to modify the functioning of the trans and engine and cooling system in response to any overheating issues affecting the transmission. Are you sure you want to add this accessory gauge? I can check out the 6-speed model to sure it also has such a thermistor.
There are 6 test ports where measurement of the clutch fluid pressures can be made and those are located in a line along the side of the transmission, just above the edge of the trans oil pan. I am not certain if the temp that would be measured at one of those ports would be equivalent to those that are measured by the already built-in thermistor described above.
It may be that you could tap into the wire for the thermistor and use an ohmmeter meter to measure the temperature that way.
I would believe that if there were a problem with the temperature control of the transmission that there would be a fault code for that which would alert you.
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QUESTION: Thank you Roland for the quick reply, i will be towing a boat so i wanted to have a gauge that will monitor the tranny temp. i googled that the port to put it to is the tcc apply port (i think it means torque convertor clutch apply, do you know which of those 6 ports is the tcc apply port? and what size it is ?
There is a torque converter clutch apply electrical connector on the 4-speed transmission but I see no 'apply port'. Are we dealing with that transmission or a different one? Does the vender mean the electrical plug connector or does he mean a hydraulic fluid port of some sort?
Again, I can tell you where to find the sire for the thermistor to which you could probably attach an ohmmeter if you wanted to monitor the temp that way.
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