2009 f150 tow haul function fails when transmission comes up to temperature
Asked by Guru9LFR9 Jun 28, 2017 at 01:14 PM about the 2009 Ford F-150 Lariat SuperCrew 4WD
Question type: Maintenance & Repair
the tow haul functions works when the transmission is cold but once it comes
up to temperature it no longer will work. once it cools down it will again work
and so forth.
11 Answers
not sure of actual temp but once the the transmission gauge shows it has come up to temp
as thought - electronics are subject to this type of failure, ckt boards, caps, etc. Could this be related to the tcm? is there some other component in the circuit that might be subject to temperature failure?
I also suspect a control issue. This is a job for a good transmission shop.
transmission if in great condition where is the control fuse located - in fuse panel under what name or #
by control issue to you mean the tcm or is there an other component that is in the ckt/
transmission if in great condition since the tow haul button is basically a gnd to the tcm which then changes the shifting algorithms . This signal once the temperature gets hot does not get sensed or that portion of the tcm ckt has a failure. is there a way to test the tcm to determine if it is ok?
Testing transmission controls is past my pay grade which is why I suggest a transmission pro.
The tow/haul feature is electronic. What it does is it alters the shift patterns of the transmissions. It also prevents the overdrive feature from kicking in. When engaged, the vehicle will also not coast, meaning the transmission is used as a braking feature. What you will need is someone with a live data recorder to check the perimeters of the transmission under driving conditions and under load.
