QuestionQUESTION: i have a 1998 Dodge caravan with a 3.0 liter engine. it is an automatic transmision and it is running really rough. i took it to pepboys (they are great they didn't charge me because they couldn't help me - normally dino -$95) but It gave me the error code P0743(Torque Converter Circuit Electrical/TCC Solenoid Circuit). Is this a fuse or relay that needs to be replaced? Where is it located? thank you.
ANSWER: Hi Brett,
I doubt this has anything to do with rough running. I assume this is a 3-speed non-electronic automatic transmission, correct? The TCC is what locks up the torque converter at speeds over 40 mph to improve the fuel economy and braking. It is a simple circuit involving two wires from a black three-wire plug which is located on the side of the trans that faces the front of the van, down low at the narrow end of the bell housing. Let me know if you have a volt-ohmmeter with which to check the wire continuity and the voltage supply to the solenoid and I'll give you the specifics of the circuit.
Rough running without any other fault codes than an 0743 would leave me only with one suggestion, to check the egr valve to make sure that it isn't sticking slightly ajar at idle.
Let me know if you want to pursue either or these possibilities and I'll give you the specifics.
Roland
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QUESTION: yes i believe it is a 3 speed non-electronic automatic transmission. the rough running is because the torque converter stays ingaged and will not disengage (some times). and i would like to get it running right, but have no problem with disengaging the torque converter all together. but i think the problem is electrical problem in the tcc selenoid. i would replace it if i could find it. and i have also read that it is a good idea to change out the trans fluid with something else (not sure what it was), but it works better than the stuff chrysler puts in. do you have any recomendations for that as well?
AnswerHi Brett,
There is no specific instruction about the torque converter clutch or the solenoid that activates, it in the '98 manual. The A-413 manual (predecessor to the 31TH) says that the solenoid is mounted on the valve body transfer plate. The disassembly shows a removable valve body with two parts, one of which is the transfer plate, but no indication is given as to where the solenoid in specific is located on that plate. However once you open the trans and remove the valve body it will probably be clear which part is connected to the external electrical socket and thus a replacement of the solenoid could be affected. It is also possible that the clutch itself (presumably internal to the turbine) may be the problem. The solenoid wires at the plug on the outside of the trans are:
Orange/black to pin 56 of the pcm
White/black to fuse-like PTC #1 located on the fuse box under the dash, just underneath the 4 big plugs (there are 10 PTC sockets, #1 is the left-most).
The trans fluid you have heard of is probably the ATF+4 which is highly recommended for the etax transmissions, but also is for the 3-speed.
Roland
