Holden Jackaroo / Isuzu Trooper - 4L30-E Automatic Transmission with Torque Pro OBD-2

  A few things I have done to improve the Holden Jackaroo (aka Isuzu Trooper) UBS-26 4WD. Holden Jackaroo is built by Isuzu Japan, which is owned by General Motors. Hence, the 6EV1 engine designed by GM, but fortunately it is built in an Isuzu factory in Japan. 

January 2023 - I finally got the Torque Pro OBD2 App to give me the Automatic Transmission information, most importantly, the Automatic Transmission Fluid Temperature (ATFT)  data, I been mucking around with it for a couple years, but finally got it to work, I found some extra clues on the IzuzuPlanet discussion forum, there been talk for a long while, but some details were misconstruded, I guess some people quote  details, as generalizations without making specific  and exact references to specific models/year ranges etc.

For my vehicle, a 2002 build,  with a 3.5litre V6 petrol (6VE1 32bit) built in Japan, with a Borg Warner 4speed (4L30-E 32bit) Automatic Transmission, built in Strasbourg, France, there were slight variations of the OBD2 codes. Anyway, I can now measure the ATFT and see how it behaves under different driving conditions. Under extreme 4WDing on very hot days, it was hard to tell if I pushing the auto to its limits or past its limits, but in testing during summer I got  to do some road tests, put it under heavy load on hot days to get the tests results I needed to see, to then know what I needed to do to improve cooling performance of both engine and automatic transmission. I can now get the Air Fuel Ratio (AFR) data as well.  You don't want unnecessary extra fuel being consumed.

Basically, I learnt from the specifications that this 4WD designed to  cover a wide range, but realistically, in terms of engine cooling  and auto transmission cooling, it is really meant to be used in cold climates,  that running in hot climates like Australia, you pushing it to the limits and shortening the life of the engine and auto transmission and I think this is probably the case for most cars and 4WD's, the operating range and emissions controls are designed specifically for cold climates like Siberia, or northern Japan, or Canada, you can pick the deliberate things they did.  So for running this in above Zero degree C conditions (0-50degreeC) is a good range  for Australian conditions, then you can modify things to work better for this range.

What did I do:

1. cold boxing the air intake system to reduce manifold air intake temperature, running 20 degrees above ambient is ridiculous in Australia,  pre-heating the air is great for Siberia, but is bad for Australian conditions  causing the engine to chew more fuel.

2. replaced the ageing radiator, with a full aluminum radiator with dual tube, 40mm core, instead of 26mm core. Using two x 12inch high power Davies Craig fans (22amp @ 13.8V each) pulling air, giving 2500CFM, controlled via thermostat control box.

3. added Plate and tube oil transmission cooler from Davies Craig with 8inch fan pulling air, fitted in series with radiator feedline. This is recommended for towing, but equally important for 4WD'ing, as climbing mountain tracks causes a big load on the transmission and raises the fluid temperature very fast.

The engine temp sits in low 80's driving along open road, the fans kick in at 85 deg C, pulling it straight back to 80deg C within a minute,  The ATFT runs in the 70's deg C on flat open road,  the fan kicks in at 88deg going up hills and pulls the temperature back to the low 80's. Now I should not need to keep stopping when driving up mountains.

on this day, is after installing new 40mm core radiator, ambient temperature was 35degreesC,  the engine doing great, but ATFT shot up to 114 degreesC after coming up a long hill at 70km/h  it took 10minutes on flat road before it dropped again. AFR 14.7%  good, considering it was hot & humid day.

this is testing on another hot day, after installing the auto transmission oil cooler,  it was only a short trip to find some steep hills to get the ATFT up, got to 88degreesC  and 8inch fan kicked in.

here is PID Editor in Torque Prod app,  to get ATFT  you need a PID of 221940, Min is 0 degC, Max is 200degC, Equation is A-40   and Header value is 6c18f1(hex) 

NOTE: depending on the Holden Jackaroo model and year, (same applies to Holden Rodeo) you may need to use  Header code of 6c18f1   or  try 6c10f1 (hex)

In summary, if you have a 4WD and using it for off road activity where you driving  on bush tracks and mountains and doing a lot of low speed driving and it has a auto transmission, then I recommend you add an transmission oil cooler, preferably with a fan and thermostat control to reduce the heat build up. If the 4WD is older then radiator may have reduced efficiency due to clogging of tubes due to build up, then when its times to replace it, get a higher performance radiator with thicker core.