Holden Jackaroo - OBDII Bluetooth Adapter and Android App
(aka Isuzu Trooper,Isuzu Bighorn,Vauxhall Trooper,Subaru Bighorn,Acura SLX,Chevrolet Trooper,Opel Monterey,Honda Horizon)

using OBDII BlueTooth reader adapter and Torque App with Holden Jackaroo 3.5L V6 petrol engine

I have purchased and experimented with four types of OBDII Bluetooth adaptors, some work better than others.
some just didnt like this Jackaroo,  I tested in other cars and they work fine.
1. the Autohil AX4 adapter is what I currently use, this has been the best and most reliable and consistent in the Jackaroo.
It has a ON/OFF button so it wont drain the battery when engine is off.
2. ELM327 Mini this was the second adapter I bought,  this was inconsistent when connecting to it from tablet.
3. KONNWEI is the third adapter I bought. inconsistent when connecting.
4. ELM327 v2.1  the first adapter I bought, inconsistent when connecting. Worked fine in a Nissan Micra.
From the discussion forums, people get different results from  different adapters, the Jackaroo, comes from Isuzu, this engine
based on a General Motors V6, therefore expecting that ECU is also from General Motors, so the Autohil AX4 adapter probably 
works well with other GM derivatives.  When mine is running it says  J1850 VPW(10.4K) Protocol ISO9141-2 5 baud
The one sensor that would have been good from the Jackaroo would be outside air temp and humdity. As then I could compare 
these against LPK, to see  relationship of temp/RH versus fuel economy.


1. types of OBDII adapters



2. screenshots using Torque App, this was testing in portrait mode, with Samsung Tab A (8inch)


3. RPM, Load, MAF, Volts, Litres/100km, Coolant temp, Manifold Intake Temp


4. driving back from Barrington Tops, outside temp was mid 30's that day. Earlier Coolant Temp reached 114degC
driving up the mountain side, so hot 39deg outside, I had to keep stopping to let automatic transmission cool down
at one point the Manifold Air Intake temp reached 44deg


5. other panel, Timing Advance, Fuel/Throttle, Manifold Air Intake pressure, O2 Sensor, STFT1


6. driving down Hume Highway, outside temp mid 30's, can be seen with lower Coolant Temp as road was flat.


7. most of these were at 100-105km/h


8. the outside temp later that day was up to high 30's


9. approaching Gundagai


10. alternate panel, Gundagai to Tumut, approx 80km/h


11. return journey to Sydney, air temp much cooler, better fuel economy with cooler Manifold Air Intake temp, 110km/hr


12. February 2021, did some tweaking to add more data options. This is engine cold, just started


13. this is engine warmup, with Aircon turned on, note PSI increased as Load increased on the engine


14. this is going up a hill, seeing how it responds accelerating , under load, temp increases, throttle open, PSI increases


15. going up another hill, accelerating under load. The PSI represents the outside PSI with open throttle


16. testing TorquePro at idle. Noted that neither Transmission Temp Type 1 or Type 2 work.


17. testing TorquePro at idle with Aircon enabled. I forgot to add fuel consumption.


18. TorquePro at idle, external temp 19deg C, a cool day, but manifold temp still high. torque 206 @ 866rpm
since cold boxng the air intake between filter and manifold, it is now only 6-7degrees higher than outside ambient
air when on the highway


19. on this day, is after installing new 40mm core radiator, ambient temperature was 35degC, the engine was doing great,
but ATFT shot up to 114 degC 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 and humid day.


20. 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.


21. here is PID Editor in Torque Pro 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)


22. automatic transmission oil cooler configuration 

Improvements :
I probably like to see Load, MAF, LPK, Intake temp, Intake Pressure together to be able to understand relationship of MAF, 
Intake Temp and Intake Pressure versus LPK.   RPM, Load and MAF  are useless as Digit displays, you need a dial to show 
what they are doing.  The Digit displays I use for Volts, LPK, Coolant, Intake Temp as they dont have a high rate of change. 
The Volts is there for a safety/reliability perspective,  if that fluctuates greatly, you might have a faulty alternator 
or battery.

I not sure if the Intake Pressure is best served by a Dial or a Digit display, but I think I need it on the main panel.
Intake temp, this seems to be 5-6 deg higher that outside air temp. We know, to lower the Intake temp will give better 
fuel economy, so I am curious to see if increasing air flow into air box, increases the manifold air pressure and if 
a higher air pressure means lower air temp.

From an Torque App perspective, I let to believe from comments that Torque is no longer updated, but I think it still is from
looking at the Google App Store, I can see a release  came out end of 2020,  I think it would be interesting, to see
dials with a colour band, a trailing colour behind the needle, think of a Pie chart,  or something like the coloured 
bar graphs on F1 GP steering wheel consoles.

If you new to OBDII, then experiment with a cheap adapter and the Torque Lite to feel out what you want to do, then upgrade
to Torque Pro to get the extra features.

I also tried OBD Mary App,  yes, it does the basic 6 x gauges,  but I could not bring any extra gauges, compared to what I found
in Torque App. At the moment I am happy with the Torque OBDII App.

February 2021, I havent done any fiddles with the settings for long time, but finally sat down, did some testing to determine what
options available in Torque for the Jackaroo and enabled them.  I not interested in the inertia options, so I have ignored them.
The Intake Pressure  I used a digit display, as it not fluctuating greatly to requie a dial.

January 2023, I now have the ATFT (AutoTransmission Fluid Temp) reading in Torque Pro for the Automatic Transmission temperature 
widget in the Jackaroo.
I created a custom widget, based on clues provided in the Isuzu Planet website, from the OBD2 PID Editor, set the PID as 221940 (hex value)
LOng Name : Isuzu ATFT,  Short Name  i.e. ATFT, Min Value is 0 (zero), Max value is 200, Scale Factor x1, Unit type  degC,
Equation A-40, OBD Header   6x18f1  (for 98-99 model) and use 6c10f1 (for 2000-2004 model) those are Hex values, Min refresh = 0  (zero),
no overides, do not store value,   turn ignition to ON state (not ACC) to get  a ATFT reading. 18hex is for 98-99 ECU version, 
10hex is for 2000-2004 ECU version.
Another custom PID is 221970 which is the PWM percentage (0-100%) the higher the number represents the grip of the Torque Converter.
If TCC is slipping, the percentage decreases. 90% is considered a good value under normal driving. I think this is the equivalent 
to GM PID 221ad0, or 221ae9. Note the 22 is the GM Service MODE  and 1970 is the PID (Parameter ID), hence MODE/PID is 221940, 229170, 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 degreesC 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. I wrapped up the
intake tube with fibreglass heat tape, covered with the silver heat tape. I still need to cover the air filter to reduce ambient heat from
the engine bay. At the moment, on the highway the air intake temp runs about 6-8degC higher than the outside ambient air temp.

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. I am adding a couple of 100Amp 12v relays to be driven by the two 40Amp relays in the Davies Craig
thermostat controller, otherwise, pulling 22Amp on/off is going to wear out the relay contacts.

The engine temp now sits in low 80's degC driving along open road, the fans kick in at 85degC, pulling it straight back to 80degC within a minute,  
The ATFT runs in the 70's degC 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. from reading the specifications and test information for my Jackaroo (3.5L 
V6 petrol and Automatic Trasnmission) the ideal engine coolant temp is 80-85degC, with transmission ATFT in the 70-80degC range for best 
reliability and longevity.

In summary, if you have a 4WD and using it for off road activity where you driving  on bush tracks and mountains, or on sand 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.
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