Dealer installed latest computer updates!!

[madmax7]

Should I be worried?
Dropped my truck off for oil change and asked about 5th gear lockout.

Next thing I know, the dealer scanned for updates and installed on their own! They claim that most customers are happy when they do that!

I mentioned that I thought the truck was running great and didn't have a problem.

Is this reversible if I don't like it? Why would there be a problem. I know I have read on this page that their has been some disatisfaction in updates that have been installed. :confused:

[pullinpower]

Did they do a full switch install also? Or did they just program your TCM to accept it?

[madmax7]

They said they couldn't find anything on the 5th gear lock out. Any help on what or where they can go to see this? I haven't picked the truck up yet.

[2K2AD]

MADMAX7,

I could not get the link to work, so I cut and pasted the article (as well as the pub title). It is a little long, but here goes nothin':

A monthly publication for GM Dealership Service Professionals
July 2002
Volume 4, No. 7

TAC Tips
Allison LCT1000 M74 Automatic Transmission 5/4/5 Shift “Busyness”

CONDITION/CONCERN
Allison LCT1000 (M74) may experience a condition of shift “busyness” or frequent shifting from 5th to 4th to 5th while towing or under heavy loads.

RECOMMENDATION/INSTRUCTIONS
A new TCM calibration has been released to improve the shift busyness. The TCM calibration is available on TIS 2000 version 3.50 or later (released 3/24/02). The calibration also contains a feature which allows 5th gear to be disabled/inhibited if desired.To make this feature operable, the following items must be
obtained and steps performed:

FOR VEHICLES WITHOUT AIRBAG DISABLE SWITCH
Parts needed
Momentary push button switch (normally open), qty 1 – obtain locally
LED and 10k resistor wired in series, (if an indicator is desired), qty 1 – obtain locally
Accessory switch opening cover, P/N 15734687, qty 2
Accessory switch housing, P/N 15040483, qty 1
18 gauge wire (bulk) – obtain locally
3 Micro-Pack 100 W Terminals, P/N 12084912
Installation Instructions
Install the switch (and LED / resistor in series if desired) in the accessory switch opening cover.
Using the bulk wire, route the wires from the switch through the cowl to the TCM, using approved methods.
Connect one lead of the switch to TCM connector C1 pin 12 and the other to TCM connector C1 pin 28, using the Micro-Pack 100 W Terminals. If an LED / resistor is used, connect one lead to TCM connector C1 pin 20, using the Micro-Pack 100 W Terminal and the other lead to a 12-volt switched power source.
Install the accessory switch cover and accessory switch housing into the dash.

FOR VEHICLES WITH AIRBAG DISABLE SWITCH
Parts needed
Momentary push button switch (normally open), qty 1 – obtain locally
LED and 10k resistor wired in series, (if an indicator is desired), qty 1 – obtain locally
18 gauge wire (bulk) – obtain locally
3 Micro-Pack 100 W Terminals, P/N 12084912
Installation Instructions
Install the switch (and LED / resistor in series if desired) in the small, blank panel to the left of the passenger airbag shutoff switch. Using the bulk wire, route the wires from the switch through the cowl to the TCM, using approved methods. Connect one lead of the switch to TCM connector C1 pin 12 and the other to TCM connector C1 pin 28, using the Micro-Pack 100 W Terminals. If an LED / resistor is used, connect one lead to TCM connector C1 pin 20, using the Micro-Pack 100 W Terminal and the other lead to a 12 volt switched power source.

OPERATION, ALL VEHICLES
Depress the momentary switch once to inhibit 5th gear operation. Depress the momentary switch again
to allow 5th gear operation. The system defaults to allow 5th gear operation with a key cycle.

– Thanks to GM Technical Assistances

[madmax7]

Awesome- Thanks.

From what I have been reading, it sounds as if the jury is still out on who pays for this. Has anyone been told by a dealer where this falls??

It seems to me though, if this is to address a complaint with the driveablility, then this should be covered by GM.