Questionmy 2001 dodge ram van 2500, service engine light comes on with dtc fault po740 tcc failure??? my local shops can't identify the fault, any sugesstions?
AnswerHi Rich,
I got a similar question from the owner of a '98 van a couple of weeks ago. Here is my response:
"The trouble shoot for this code points to the following steps before concluding the need to replace the torque converter clutch (not necessarily the entire torque converter but just that part, which I believe nonetheless requires removal of the trans):
fluid level OK?
electrical connectors?
do shift lever test
verify flash level of trans controller for need to upgrade the software
check for technical service bulletins that might apply
drive the van and see if the torque converter clutch will engage (you should note the rpm drops about 5% when you pass through the speed of about 40-50 mph, and feels like a slight decrease in the overall gear ratio)
if it does, then try wiggling the wires and check for shorted circuits.
if the clutch doesn't come into play then do a hydraulic pressure test on the trans
on the basis of that test decide what needs to be done.
I might mention that the lack of a torque converter lock up capability just means that you would lose about 5% in the mpg figure on the highway as compared to if it worked. There are many vehicles than don't have this feature. This malfunction will not meaningfully affect the function of the transmission just the marginal affect on fuel economy it is probably not going to be a repair that is worth it to you. It can be repaired later when the trans suffers an inability to shift properly or even to drive the van which commonly requires a total rebuild. The clutch for the torque converter is purely for gas economy."
Roland
