06 International RE300 DT466 NEXIQ scanner questions

SKOOL-E-O · 10-09-2021, 11:26 PM

Hello all. I've searched through the site and have not found any answers.

I bought a NEXIQ scanner from chinacardiags.com and it came with 4 discs. Ive installed the Allison DOC software on a Windows 7 pro laptop, but I CANNOT get it to connect.

The International master diagnostics is also installed on the same laptop. It connects, and I can check codes but nothing else.

My bus has the 9pin deustch data link in the rear of the bus, in the engine compartment.

I am trying to do 2 main things.

1) unlock 6th gear on my Allison 3000PTS

2) Raise the bus governed speed "engine retarder" - currently it is governed at 62mph

Any help or links I may have overlooked would be greatly appreciated!

cadillackid · 10-10-2021, 05:44 AM

engine retarder isnt the speed limiter.. when you have your accelerator punched to the floor and reach 62, what is your RPM? if its close to 2600 then you are out of gears, 6th gear would net you a few more MPH.

which navistar software do you have? ServiceMaxx ? if so then when you connect it, click the 'P' button in the toolbar and then you can look for speed limiting function 'enable / disable'. click the box and it will let to change it to 'disable' then you click program engine.

if you need Servicemaxx, just search for Servicemaxx J1708 download. since Snap-On handles all navistar software now, it will take you to a Snap-On page to download it for free.

this is done with Key On, Engine Off (normal run posituon on key but engine not spinning). it will as ktoy to cycle the key a couple times during the process.

unlocking 6th gear you need a new calibration file for your TCM that has 6th gear open. there iare multiple threads on getting 6th turned on through this forum. a guy that does it for people remotely that have the Nexiq or clone device was found by member Bapos and he has been a great go-to from everyone who has used him.

-Christopher

SKOOL-E-O · 10-11-2021, 12:04 AM

I'm at around 2200 rpms at 62 mph.

I have the International Master Diagnostics software that came with the NEXIQ. It connects, and shows it has the engine retarder activated. I figured this was the speed limiter.

Ill do some searching here for the unlocking 6th gear. Thanks for the help!

Ill check out that Navistar software you mentioned also.

cadillackid · 10-11-2021, 05:01 AM

that looks like a cool 3rd party program, i might have to find a copy of it..

the Retarder is normally a function of the transmission whicbh helps you to slow down on hills.. the ECM can control it from a switch or oftentimes the brake pedal input.. if that parameter was on when you got it, Id turn it back on, probably means your bus is equipped with a retarder which is a fantastic thing to have if you plan to drive in the mountains..

there should be a couple other speed related parameters.. there is a maximum vehicle speed when speed limiting active parameter. and then there is another for setting the speed limiting feature to enable or disable. and then there are a couple paramneters for enabling cruise control and the min / max speed for cruise to operate..

they are unprotected parameters so id think that software would have the ability to alter them

Booyah45828 · 10-11-2021, 10:37 AM

Christopher got it.

You'll need someone familiar with allison's to enable 6th. It isn't just a switch you can flip in allison doc. There are several ways to do it, search the threads on here for them, as some are easier then others.

Engine retarder isn't in the trans, and it's not keeping your speed at 62, the speed limiter is. The engine retarder simply closes the vgt turbo down to create an exhaust brake when you're decelerating. You need to raise the vehicle governed speed, and like chris said, there are a handful of different speed limits that might be enabled in the ecm. With basic levels of servicemaxx you might not be able to deactivate them, but you can raise the value to a speed the bus won't attain, which essentially does the same thing.

I've never used International Master Diagnostics, so I can't tell you the capabilities of it. But servicemaxx is free and has the ability to do what you're after.

cadillackid · 10-11-2021, 06:24 PM

I keep forgetting his bus is new enoug hto have the VGT turbo. figured he had a J1939 capable retarder.. OOPS..

does the VGT turbo retarder make a differemce? or is it about like when people used to try and close the EBPV on the 7.3 as a makeshift "retarder" ?

SKOOL-E-O · 10-11-2021, 07:23 PM

"that looks like a cool 3rd party program, i might have to find a copy of it.. "

I'd be happy to send you a copy of all 4 discs I got with my NEXIQ. It has software for Bendix antilock, International, Perkins, Ford, Volvo, Cummins, Allison, Cat, and other stuff. Just send me a message if you are interested. I cannot post it all here as it is several dozen gigs of files.

I did some searching last night and found a much newer version of Allison DOC than I have so maybe that will help me connect to my trans.

I also found the link you mentioned about Bapos for the Allison reprogram for 6th gear.

Ill check tonight on the servicemaxx software also.

Thanks for all the help you two!!!

Booyah45828 · 10-12-2021, 07:18 AM

Quote:

Originally Posted by cadillackid

does the VGT turbo retarder make a differemce? or is it about like when people used to try and close the EBPV on the 7.3 as a makeshift "retarder" ?

Depends on the application and the transmission. All of your exhaust retarders require RPM to work, so if the shift schedule in the transmission is aggressive at keeping the rpm's up, then they work extremely well. The older buses weren't very good at it, because with your foot off the accelerator, engine load is 0, and the transmission won't downshift to keep the engine rpms up. Newer ones have a switch on the dash that will alter the shift points at 0 load, keeping the rpm up, and making the brake actually work.

Most of the newer cummins equipped rams have a similar feature and switch.

With the switch on, it's a very noticeable "throw you forward" deceleration. But it definitely requires a switch, as that's not something you want on slick road conditions.

cadillackid · 10-12-2021, 09:05 AM

While I don’t have an engine brake I’ve been playing with decel control on my own allison. Allison relies heavily on TPS.. and you are right at 0 TPS the trans is in 6th before you know it .. so my computer program surmises if you let off the gas you aren’t looking to speed up, I can inject some TPS into the mix as the vehicle speeds up.. or even inject a kick down request which will trigger the trans to drop a gear if it’s not over speed for the new gear.

The mode switch is a “wire” in the TCM. Which can also be induced via data link commands so the data link can activate hill descend mode, tow haul, or alternate shift pattern.

Running with cruise on is the easiest way for me to determine when to trigger shifts as I have a target speed .. so my raspberry pi box can trigger the radiator fan on, kick down etc..

Stuff the new trucks do from the factory now..

Booyah45828 · 10-12-2021, 09:52 AM

Right. You got the gist of it.

Without the tcm keeping the rpms up, the brake is no good. The trick is getting the tcm to know when and when not to keep the rpms up. In some scenarios coasting with minimal engine rpm/load is desired, others you want max engine rpm/load for the exhaust brake to work.

I've done minimal modifications to the old tcms, and haven't looked at all into the new ones. So I couldn't tell you what terminal the switch inputs to. Might be mode switch, I don't know. My experience is more into repair then modifications.

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