E38 stuck in 4lo..??? Pls help...

[harascho]

There is thread in the T42 tranny section about this but I thought I'll better bring it to a point in here:

Summary:
2hi ok -- 2wd tun in TCM -- 4lo not ok
2hi not ok -- 4wd tun in TCM -- 4lo ok

Conversion:
'97 NP241 electric shift TC. VSS in TC tailshaft. This VSS signal wired to the VSS inputs of the TCM.

Important:
parallel to the TCM's VSS inputs is a '95 VSSB to get the necessary signals for the '97 antilock (128.000 pulses/mile) . The signals look ok.

speed limit 4lo:
intermittent works on 4lo and 2hi
intermittent doesn't work on 4lo and 2hi this happens without changing anything

Facts:
4wdlo input ECM C1,2 PIN is grounded when in 4lo, circiut checked and ok

guesswork:
1st guess: The OS (2007 Tahoe with NP8 option) isn't reading the C1,2
2nd guess: the VSSB parallel to the TCM's VSS inputs confuses things.. sometimes.. which could explain those non conclusive results I have when testing.

help:
how can I check/activate the 4wdlo C1,2 input on the E38. My OS and tune supports option NP8 which should activate that pin. ( At least in my schematics I have a (NP8) behind C1,2 4wdlo).. Could anyone agree to the option NP8 (automatic trans case) supporting that C1,2 4wdlo input pin ????

Can I programm the E38 VSS output to get my '97 antilock working with it.?

[harascho]

Last question to the E38's VSS pin:

if H0159 is activated, can I adjust that output with H0105 and is H0105 only acting on the ECM's VSS output ( I think pin 57..) and not on all the other VSS values on the GMLAN?

[harascho]

this is was the GM docs say about the TC options and the C1,2 input of the E38, could be correct but must not be correct...

Harald

[harascho]

Hey folks.. nobody here with any thoughts to this matter???

Harald