kevin,
maybe i chose an incorrect term for that
yes ohming is a form of resistance checking but i use another method that was mentioned, a continuity check which also can show any resistance in the circuit. A good clean circuit will read close to 0 but if there is any anomaly in the path it will show a value greater than 0, basically the same as ohming does.

and as far as the A04 test it is there, when you get into the menu you can go to each segment and should be able to change it till it reads A04. I think when it first comes up it might read I00 or something like that if i remember correctly. Since i'm not looking at a manual right now or have one in front of me i'm trying to go from memory here.

joe,
and as far as the comment about not trusting the analog 'in-truck' tests? well this is what the truck is seeing and it reads that voltage to calibrate itself and guage the values on which the truck runs. The TMM is monitoring this voltage the way you see it there, so why wouldnt you trust it? Speaking of being bit, i've set many a potentiometers with a vom only to have to reset/readjust it after i installed it because the system was seeing it differently. Part of adjusting this and calibrating it to the system is having the test mode up on the console before you even remove the control handle from the circuit, if you try and set the pot externally and then start up the truck afterwards to go into setup mode to calibrate the system to it, the system will see this and will not start up correctly because it is not seeing the right voltage range and you will play **** trying to gain access. Sometimes the 'old school' ways just do not work, especially on these trucks.

Of course if this has the later system on it the access keypad/display is on the dash and not like the ones that have the remote display box mounted over the crossbar on the mast like the older ones, those require input solely from the control handle horn button and pot's, this being the only way to control the input to navigate the menu system. I'm farily certain they revised that keypad input to eliminate this problem that the older units had to simplify the calibration.