I'm digging into this for ya Bob.
- Bernd
-----Original Message-----
From: owner-dakota-truck@bent.twistedbits.net
[mailto:owner-dakota-truck@bent.twistedbits.net] On Behalf Of Bob Tom
Sent: Wednesday, July 14, 2004 7:49 PM
To: dakota-truck@dakota-truck.net
Subject: DML: Looking for highly tech. info. about OD
Hi,
I've been experiencing an "intermittent" problem with OD on the track :-( I
set OD to OFF with the OD ON/OFF switch at the end of the gear shifter. I
use 1-2 5200 and 2-3 5500 shift points when bracket racing. If the problem
does not occur, the Dak will cross the 1/4 mi. line at around 5700 rpm.
When OD comes on by itself, it always happens just past the 1000' marker
when in 3rd gear and revs approaching around 5300. When this happens, rpm
drop to 4000 and I might as well put my dial up on a minivan :-)
The FSM says that the wire from the OD ON/OFF switch to the computer
"toggles" a memory location which the computer reads as OD ENGAGE or OD
DISENGAGE. The computer monitors this location and, if it sees OD ENGAGE
and some other inputs are met, it energizes the OD solenoid in the tranny
via another wire from the computer. If it sees OD DISENGAGE, the solenoid
cannot be energized and therefore no overdrive.
My question is: Are there any "fail safe" inputs that the computer monitors
that will activate overdrive and override the OD DISENGAGE "mode". I haven't
been able to anything on this :-(
Because the problem is intermittent in nature (and assuming for the moment
it is an electronic/wiring problem and not a "mechanical/hydraulic" one),
I've been thinking of putting in a switch so that I can manually control
when OD will come on.
The first possibility that I thought of was to put manually control the wire
that energizes the solenoid. The problem that I see with this is that with
OD engaged, the computer goes through a sequence where the torque converter
is unlocked, OD solenoid is energized and then the torque converter is
locked up again.
The other possibility is the wire from the OD switch. This way I can set OD
to OFF the normal way, manually interrupt this circuit so no further pulse
signal can be sent to the computer and thus leaving the computer in the "OD
DISENGAGE mode". Unless, the computer looks at other "fail safe" inputs and
overrides it :-(
I am careful not to hit the switch during the race. OD operates perfectly
on the streets/highways and about 50% of the time on the track.
Sorry for the length and the complexity of the query, especially being so
close to BBQ time :-)
Bob
This archive was generated by hypermail 2b29 : Sun Aug 01 2004 - 00:46:14 EDT