QuestionQUESTION: 2000 Dodge Grand Caravan with 3.3 engine and 185000 miles. Transmission rebuilt at 140000 miles 3.5 yrs ago. In the last 18 months have replaced 2 trans solenoids and Transmission Control Module. I am now in Limp mode again and have pulled the following OBD codes - P0760, P0750, P0755, P0720, P1781, P1782. Seems to point to solenoid again but seems unreasonable to have a third solenoid in 18 months. Is there some other underlying problem possible that is causing the solenoid issues? Is there any significance in the order the codes are registered in computer?
ANSWER: Hi Dave,
I answered this same question on 1/04/10 as follows:
The 0720 has to do with the output speed sensor, so you might begin by replacing that one. The rest of the codes have to do with various solenoids and pressure switches and I find it hard to believe that all the components failed concurrently. Have you checked the 8 wires between the assembly and the tcm? I can give you the interconnects if you don't have them. That would seem to be the only common underlying problem. I am not certain about the order of code question. What about transmission fluid level, is it within range?
Roland
The only other underlying problems that I find in the manual that might explain the solenoid pack related issues (all but the 0720) are:
TCM ground open circuited
Malfunction of TCM
The TCM grounding is via wires on pins 53 and 57 of the TCM plug which go through a splice and from there to the - clamp of the battery. So you could test for a flaky continuity situation from the TCM plug to the clamp while shaking the harnesses that might be involved. Otherwise, it appears to be a choice between a replacement TCM or a solenoid pack. I don't know which is the more likely cause.
Did you examine the harness that connects the solenoid pack to the PCM, and would you like to know the pin connections to check it out?
Roland
---------- FOLLOW-UP ----------
QUESTION: The transmission fluid level is fine (Was the first thing I checked).
You offered the interconnects for pin connections for the assembly (I assume solenoid) to the TCM and the pin connections between the solenoid pack and the PCM. Those would be helpful and appreciated. By any chance is there a picture that identifies the location of the pins in the plug at the end of each harness. I assume the test would be continuity between the related pins? If I get bad continuity I will try shaking/moving the harness to see if I get movement on my voltage meter. I have looked at the wiring harness and don’t see any obvious issues
If these tests eliminate that as a possibility then I will try replacing the output sensor or would you recommend doing that first..
PS: The only e-mail answer I received on the Jan 4 was that you needed to look up information in the manuals. I didn’t get your current response on that date so there must have been a problem with my ISP.
AnswerHi Dave,
I don't like throwing parts at a problem so lets check the wiring first:
solenoid pressure tcm
switch assem. pin pin
1 47
2 50
3 9
4 trans relay output (30 or 87) in power box (30='02, 87='98+)
5 59
6 60
7 20
8 19
If you examine the plugs you should find the pin numbers embossed on one side or the other, and if not let me know.
There are no connections between the assem. and the pcm
The output sensor wires: pin 1 to pin 13 and pin 2 pin 14 at tcm.
Also yes, the test are continuity or 0 ohm resistance measurements. Also check out the ground that I mentioned last time. I doubt that the speed sensor alone will solve the other codes that involve the assembly, so I wouldn't replace that until the assembly is ironed out.
Roland
PS All these interconnects are from the '02 manual, but they are identical to '98 except as shown for the pin numbering of the trans control relay's socket pins.
