Expert: Roland Finston - 11/11/2009

Question
Hi,

My son-in-law, Matt, has a 94 Dodge Intrepid with a 3.5L engine. The engine idles smoothly and seems OK when you run the RPM up and down.  As soon as you shift it into gear, Drive or Reverse, it dies.  If you rev it up some and drop it into gear, it will move a very short ways and die.

He said it happened while he was in town.  He got home by revving it up, shifting into gear, and giving it a lot of gas.  Once it got up to 30 or 40MPH, it ran OK.  Acts, to me, like it's stuck in a high gear or is in the lock-up mode.

Checked the fuel rail and it looked like it was in spec.  Spark seems OK.  My Auto-XRay code reader will not connect to the blue diagnostic connector under the dash, so I can't read any codes and we can't drive it to anywhere that could do it for us.  I'm not sure what kind of code reader is required for this car.

He doesn't have a manual for the car, as of yet, and from my experience it probably wouldn't help him.  I have an Alldata account for my wife's Jimmy, so I would probably just add his car to my account if you think it might help us.

I don't know much of anything about this car so any ideas would be appreciated.  I don't have much experience with the electronic controls on modern automotive transmissions, even though I'm an electronic tech.  I'm better at missiles and computers.

Thanks in advance,
Dan...  

Answer
Hi Dan,
It sounds like the torque converter lock-up is engaged when it shouldn't be. That could be due to the piston which actuates the lock-up feature being stuck, or the solenoid fluid valve that controls the piston is stuck in the engaged position. The former unfortunately would require removal and servicing the piston, the latter only requires servicing the valve body which is accessed after opening up the pan on the bottom of the trans, draining the fluid, and removing the valve body for inspection. If the trans fluid seems to be burnt smelling that might warrant a drain and refill with ATF+4 (power flush if you want to remove all the old fluid/drain flush only removes 2/3 approx).
On the codes: any engine fault codes can be obtained with the ignition key:"on-off-on-off-on and leave on" doing that in 5 seconds or less elapsed time. Then count the flashes of the check engine light, which are separated by pauses. The last two sets of flashes are 5 in each. Then repeat the process to be sure of an accurate flash count set. Group the counts in pairs in the order of appearance to form the 2-digit fault codes. Go to www.allpar.com/fix/codes.html for a translation. The 55 code means end of readout.
The trans codes are found via the blue plug using an OBD-I code reader (such as the Chrysler DRB-II with the 'data link' connector to match the blue plug). I have that device if you happen to be in the San Francisco Bay area.
Let me know if you want to get into the trans to inspect the valve body and I can xerox copy and mail you the pages from the '94 shop manual. You can re-imburse me for copy and postage costs after you get the pages (10 cents/side).
Roland