My Story about The JATCO Transmission on early 90s ISUZU NPR
This applies specifically to ISUZU NPR and NQR chassis with AUTOMATIC TRANSMISSION with the 4BD2 - 4BD2T - 4BD2TC diesel aspirated of turbocharged motor with any of the following ATSG or JATCO ELECTROMATIC TRANSMISSION with either of the following AK002 - AK006 - 4L30e - JR40e - JR403E transmission types ;AND that specifically use theTCM model 31036 - with ANY of the following sub-types:AK002 or AK 003 or AK004 or AK 005 or AK006 or AK007 or AK008 or AK012 .The following PART NUMBERS also apply for additional info and cross-checking for the correct TCM ; They are 8970655790, 8970123221, 8970949400, 8971288470, 8970122970, 8971000322, 8971354160, 8971278710.
The respective vehicles ranging in years of use from 1991 1992 1993 1994 1995 1996 1997 thru to 1998 .
Within these range of years, the GMC model W4 - W5 - W400 - W500 with their respective isuzu mechanicals also applies ...
To the story now:i own a 1992 Motorhome that developed a chronic and permanent issue / a Problem with the Automatic JATCO ELECTROMATIC TRANSMISSION; more specifically with the onboard TRANSMISSION CONTROL MODULE, often abreviated as TCM or TCU -. or ECU
After a series of three TCMs becoming defective - one after the other, my Motorhome was rendered useless. Only the 3rd gear default and selectable lower gearing was available, as per the Shift Selector.
i proceeded to spend several weeks of research, and about 25 various short test rides.After a month of R&D , YES, i determined and developed a way and a system to operate the transmission electronically by overriding / and -or / 'piggybacking' (interpolating / or splicing intothe unit with a 3 gang toggle set) into the TCM itself, but still using the remaining function of the module.
The result was the return of the full use of all the gears on my motorhome...
if you think you have a defective TCM, and / or are not sure that the rest of the Tranny works well, this 'might'be usefull to diagnostic your problem. In essence, this is a system that 'manually overrides' the gear-shifts of the TCM in order to troubleshoot / determine / or confirm the function of components within the Transmission.
Please Contact ME for Specific instructions for the TROUBLESHOOTING / DIAGNOSTIC KiT .You must be somewhat mechanically inclined, with at least a Basic understanding of Auto mechanics in general, and must also have (very basic) understanding of auto wiring and being able to read wiring diagrams and the respective on-board components involved.The Specific instructions and Researched background info costs $250 usd The respective hardware, and wiring , and minor electrical components needed should cost about $25 usd ... Special Notice / Disclaimer: this KIT be used for the purpose of verifying the fuction of certain components of the transmission and is to be done entirely AT YOUR OWN RISK !
You can CONTACT ME via my email,which is : shaunsmachines ( ...followed by... ) @gmail.com
