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MarvinMACK

Mack Truck not moving forward

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Hello All,

I have a Mack e tech 2001, which gives me grief. The transmission allows us to place it into "R" at which she reverses fine. The problem is "D", with that mode we only move forward in a crawling speed. As soon as we apply acceleration she shuts down. 

What is my problem???  

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Where would I be able to see that? On the board computer or do I have to read it out?

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Is the shifter a push button or stick?

if it’s a push button simultaneously push the up and down buttons. I believe that will display the code one digit at a time. First it will give you a “D”, to let you know it’s into the diagnostics, then the code number “1”(if it’s the only code), or 2 if you have another registered, 3 etc. the four follow up digits that make the code.

If you have a 2 digit display it will give you them as two digit increments. 

Edited by Mack Technician

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The shifter is a button. Allison Gearbox.

I will try and attempt your recommendation. I presume based on the code(s) one is able to identify the problem? 

 

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I believe 2214 is saying the transmission isn't reading engine speed? Do you have any engine faults? Electronic malfunction light on dash lit up?

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6 hours ago, steeler said:

I believe 2214 is saying the transmission isn't reading engine speed? Do you have any engine faults? Electronic malfunction light on dash lit up?

^ Yup, Trans wants to know engine RPM and can’t function without it.

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On 2/13/2020 at 8:26 PM, steeler said:

I believe 2214 is saying the transmission isn't reading engine speed? Do you have any engine faults? Electronic malfunction light on dash lit up?

Well, thanks for the response. We had checked all three sensors. Engine speed, transmission and I think pressure sensor. 
We replaced all sensors, and we had a faulty wire and the reading on a diagnostic laptop disappeared. 
The Allison gearbox selected swiftly and responded great. 

However, as soon as we  moved 30ft the engine shot down. I applied the same arrow up and down that Pedigreed Bulldog recommended. We now have an error code 12511. 

I am getting frustrated guys, the garbage truck pays for my living, and at the moment both my trucks are giving trouble. 

What am I not seeing???

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Your 2511 code is for the output speed sensor on the rear of the transmission. 

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Thanks much Big Dog. Appreciate the fast response and clarification.

So this is clearly all sensor related. I tested all sensors and they worked, except one, which had a faulty wire. 

But I am thinking of buying a new lumen wiring. Would you recommend me buying a spanking new one, or is there maybe a scrapmetal yard that has used new lumen available? 

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If I were getting a harness I would go new. I'm not sure you could find a good one from a scrap yard, those seem to get chopped when they remove other components. 

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Gents, all sensors have been repaired, rewired and the truck runs beautifully again. Thanks much Pedigreed Bulldog and Big Dog!!!!

 

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