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View Full Version : Tranny Swap Now No Cruise Control In 6th Gear???



Southern Speed
April 23rd, 2007, 09:10 AM
We did a tranny swap from a 5-speed to a T-56 in an 2006 Silverado. I corrected to speedo and VSS pulses but for some reason the cruise control will not engage in 6th gear. It works fine in 4th and 5th though. I'm new to EFI Live so is there something else I need to change?

Thanks for any help.

Paul

ChipsByAl
April 23rd, 2007, 01:58 PM
The powertrain control module (PCM) inhibits the cruise control operation when any of the following conditions exist:

• A Cruise Control System related DTC has been set.

• The vehicle speed is less than 40 km/h (25 mph).

• The vehicle is in PARK, REVERSE, NEUTRAL, or 1st gear.

• The engine RPM low.

• The engine RPM is high.

• The vehicle speed is too high.

• The system voltage is not between 6-16 volts.

• The Antilock Brake System (ABS)/Traction Control System (TCS) is active for more than 2 seconds.


How low is the engine speed in 6th?
Al

Southern Speed
April 23rd, 2007, 02:46 PM
It has 4.56 gears with a 30.5" tire. At 72mph it running 1800 and the customer even tried it at 85 which is about 2150. Doesn't seem like any of the conditions you listed would fit since it works fine in 4th & 5th, other then maybe the computer not picking up something in 6th gear but How does the computer know what gear it's in other then R with a manual trans? Looking through the program I can't see anything else about transmission that looks related. This was a manual transmission to start with as well.

Thanks for the help so far Al.

Paul

ScarabEpic22
April 23rd, 2007, 03:00 PM
Have you changed the transmission tables so it knows it is a 6spd not a 5spd trans? I dont know if it applies to your truck at all, but I have seen a few tunes where that is an option.

Southern Speed
April 23rd, 2007, 03:06 PM
No I didn't see anything for that but maybe I missed something. The only thing I changed is the gear ratio, tire hieght, and 17 VSS pickup from the factory 40.

Southern Speed
April 25th, 2007, 10:43 AM
I looked back over the program and nothing that I missed is jumping out at me. Any other suggestions???

OH AND BTW IT'S AN '04 NOT A '06.

Paul

ScarabEpic22
April 25th, 2007, 01:31 PM
Can you post your tune up? Dont know if I can help much, but I can try. :)

Southern Speed
April 25th, 2007, 03:07 PM
Yep I'll try and do that tomorrow.

Paul