2007 hummer h2 oddity, autostart as-6850

The equipment installed is an autostart AS-6850 alarm/starter combo with a BypassKit XK01 module. The issue - Once in a while (totally random) when remote starting everything lights up but when the starter engages it only turns over for a half second or so. On the second (automatic retry) attempt it fires right up. Out of the past 15 or 20 remote starts it has done this twice. The XK01 is handling the databus for all functions via the D2D cable. Tach, door locks, door status, OEM alarm disarm/rearm etc.. Any ideas?

try getting the tach from from an injector. the tach signal through data and modules can be very weak at times.

If the signal was weak wouldn't it overcrank instead of short cranking? Also, is it possible to pick up an outside tach signal while the databus is connected to the XK01?

sorry, very weak i guess is not the right term. its more like inconsistant and varrying.  yes, you can get another tach signal while the XK01 is connected. just disconnect the tach wire from the module, tape the cut lead, and connect the tack input from the RS to the correct wire at the injector. check this out.... https://www.the12volt.com/installbay/forum_posts.asp?tid=99278&KW=tach 

The XK01 module picks up the tach signal from the vehicle databus and sends it along the D2D cable to the RS module. There is no wire to disconnect on this one. On another note now... The heated seats are randomly going on and off in the vehicle after the driver takes control by turning the key on and driving away. Oddly, the short starter problem seems to have gone away and this has taken its place. Although it sounds like a faulty XK01 on the surface I want to be 100% sure. I don't want to tell the customer that a new bypass module will fix it just to have him come back a day later. The installed XK01 has firmware AMDL 6.00 on it. I have also emailed the manufacturer to gather their insight. I wish there was a way to just turn off the heated seat feature, but there isn't.

im surprised that the D2D cable does the tach function, if i remember correctly i thought they only do power, ground, and GWR. the rest of the connections(triggers, tach etc) had to be done manually. i believe that module turns the heated seats and mirrors on through databus depending on the temperature in the vehicle. Most GM modules do it. the temperature has to be something like -3 degrees.

The XK01 with the AMDL firmware does it all on the databus and D2D, quite an amzing piece of hardware. The heated seats are automatically turned on when the cabin temperature is below 0 celcius. I just learned that the owner was turning on the heated seats at the switch before inserting the ignition key and turning it on. Apparently this creates a databus fight between the XK01 and the BCM. The XK01 is trying to turn the seats off while BCM is trying to turn them on because of the status of the switch. Once the owner was advised to leave the heated seat switch alone until after turning the key the problem went away. Makes sense to me now.

make sure the AS6850TWFM is firmware version 2.1Shaughn Murley

Install Manager, Dealer Services

Visions Electronics

Red Deer, Alberta

The heated seat function is a part of the XK01, not the AS6850, or am I missing something?