Help! Broke down now in a parking lot

[Peterjk]

We stayed overnight at a cracker barrel.
This morning, the thomas saftliner catc7 started fine.
When i hit the Allison Reverse button i feel it going into gear
But there no throttle.
Meaning when I hit the throttle the rmps do not invrease
Also my fast idel button does work either.
My scan gauge is showing one code

[Peterjk]

I found a local place they will tow me in, I dont think this iis fixable.

[ewo1]

Originally Posted by Peterjk

I found a local place they will tow me in, I dont think this iis fixable.

Wrong way to start out a beautiful day....

I know squat about Cat's but I do know wiring....

That code is for a J1939 communication to ECM problem....maybe a chafed/broken wire ???

I found this schematic, hope it helps you out somewhat...

[ennonne]

Where are you?

[Peterjk]

Hi all, we just made it to a mechanic via a 600$ tow, its Precision Diesel Repair. Were in Shepherdsville KY.
Yeah, what a way to start a vacation indeed. But everythinig happens for a reason, I just don't know yet the reason for this one yet

I did swap/replace all the fuses, bosh type, and still nothing. Im betting its a bad electronic throttle, but its a guess. I didn't see any disconnected wiring anywhere.

Were now in good hands I think, Im just glad we were close to a diesel repairer shop.
Ill update once this gets figured out.

[Peterjk]

Here we are at the mechanic, thank you to Ellis Towing and Brian for the fine job in scraping us of the road.

[Peterjk]

Mechanics are stumpted. No more codes other then what I posted and that cleared itself.
Still no throttle either. They hooked up a diag tool, not Cat ET.
Throttle position is being seen by the ECM, so its not the throttle, they think.
What sensor can fail without the ECM seeing it that would cause this ?


The one day I left my laptop at home which has Cat ET! Grrrr : /

[ewo1]

Again, i know nothing about cat but I'll try to help as if it was me on the road stuck...

you stated that the problem happened when you pressed the "R" button on the transmission.

I am going to guess you have an Allison 3000 ??

The J1939 data circuit is what is used to transmit that request from the pushpad.

I am going to go on a wild goose guess here and say that either you got a bad connector or a broken wire on that circuit.

what I would do, go under the bus and locate all you tranny connections.

Starting from the TCM, unplug, inspect and re -connect.

My personal experience with my MD3060, 2 broken wires INSIDE the connector which made the bus not start. My bad connector was the cable that comes out of the tranny, first plug on that line.

yours is starting but if the ECU gets a confusing message from the TCM via the data link then that might just be why you have no pedal response ???

I am just wild guessing but it makes sense to me and worth the simple labor of unplugging, inspecting and testing.

Also, is your pushpad still lighting up? no cat eye's ?

will it shift into all the gears....with or without pedal response ?

[Peterjk]

TCM Interesting, it could be.
I did have the TCM reprogrammed recently to unlock 6th at a reputable Authorized Alliison dealership. So it was removed and put back in.

Issue started when I shifted into R and tried to back up. I had to back up as there was a tree in front of me.

I will let the techs know what you said. Thank you!

Yes I can shift the Allison into all the gears. No cat eyes, although Im not sure what that is.

[ewo1]

If you take a look at the doc I uploaded, second page, bottom right...

Look in the purple box, ECM...

Just about in the middle you will see the datalink inputs...

It shows a 9 pin cab connector...

Maybe there is a problem there ????

[ewo1]

Originally Posted by Peterjk

TCM Interesting, it could be.
Issue started when I shiifted into R and tried to back up. I had to back up as there was a tree in front of me.


I will let the mechs know what you said.


Yes I can shift the Allison into all the gears. No cat eyes, although Im not sure what that is.

If you could shift into all the gears then the ECU and TCM are talking, this is good!

Cats eye look like this "-/-" on the pushpad.

so if she is starting and going into gear, wierd for sure...

I would check on the integrity of the datalink cable and all it connections...

since it an Allison, there should be terminating resistors on the data link cable. Ask the mechanics to verify they are still good.

If I am not mistaken that can be checked with an ohmmeter, and should reflect 120 ohms.

[Peterjk]

Got it:
terminating resistors on the data link cable. Ask the mechanics to verify they are still good.
checked with an ohmmeter, and should reflect 120 ohms.
I crawled under the bus and made sure all the connectors were tight on the TCM.
RE:
It shows a 9 pin cab connector...
Is that under the front dash? I have a ScanGauge connected there thru a 9 pin Y connector and a NextIQ usb adapter.


Will do, stand by and thanks again.

[ewo1]

I'm not able to copy n paste but look here for more info

https://www.scribd.com/document/5277...D-231-9-Copiar

[Peterjk]

front dash pic with my connectors

[ewo1]

Originally Posted by Peterjk

Got it:
terminating resistors on the data link cable. Ask the mechanics to verify they are still good.
checked with an ohmmeter, and should reflect 120 ohms.
I crawled under the bus and made sure all the connectors were tight on the TCM.
RE:
It shows a 9 pin cab connector...
Is that under the front dash? I have a ScanGauge connected there thru a 9 pin Y connector and a NextIQ usb adapter.


Will do, stand by and thanks again.

I do not know where the connector is as I am not familiar with Thomas bodies but I would venture to say that you got it!

Don't just look at and ensure the connections are tight...

Mine were tight but water got inside the connector and right at the pin crimp, my wires were compromised.

open up the connectors, check for loose wires/pins.

With the bus running...

in neutral, is there pedal response??

If no, then have someone wiggle/jiggle the cables, data link and tranny cables...does pedal response return at all ? intermittent ???

[ewo1]

https://www.skoolie.net/forums/f33/m...nel-24837.html

Look at the pic in post #2, you will see what I found, broken pin inside the connector.

You cannot test/ohm this out with a meter...!!!
You can test with a light bulb !

[ewo1]

Originally Posted by Peterjk

front dash pic with my connectors

look like thats it!

when I had my troubles, both times, bus was rested first time one week, second time overnight...meaning that there were no codes just a simple broken wire and would not start.

[ewo1]

Do your mechanics have access to this ?

J1939 Data Link Diagnostic Tool

What is the J1939 Data Link Diagnostic Tool?

It is a tool that displays basic J1939 component information and J1939 voltage that can help trace J1939 malfunctions in the Cummins proprietary data link to a particular location in the harness and down to the exact wire.

The Cummins INLINE 7 adapter needs to be connected at the 3-pin service connector in order to successfully trace the malfunctions

https://quickserve.cummins.com/info/...stic_tool.html

[Peterjk]

With the bus running...
in neutral, is there pedal response??

No pedal response. Ive reseated every connector inside the cab. The engine is hot after it was running, so I cant touch the block.

Under, the bus, I found the TCM, connectors look good. Ive not touched them.

They all left for the night, and told me they are going to try and replace the ECM tomorrow maybe. Emphasis on the maybe. So were spending the night here.

They dont thiink its the TCM, why, IDN.

Seems your problem was a no start from the link you sent. Mine is a start, but no go on the throttle.

[Peterjk]

RE the 1939 tool, they have a generic tool looks like an Ipad. Not CAT ET for sure.


RE
"when I had my troubles, both times, bus was rested first time one week, second time overnight...meaning that there were no codes just a simple broken wire"
Again, our bust starts fine, just there's no pedal

Well, I reseated the connectors inside, where can I check next ?