Allison 5sp: Allison trans throwing codes

[Rawash]

First of all hello to everyone. My 2003 D/A started throwing codes yesterday. The codes that I have are P0500, P0700, P0717, P0721, and P0726. This started after I let my wife use it for a few hours. The Transmission feels like it is slipping, and the speedo shows 10 mph while in park or stopped at traffic light. I also got a message indicating that their was some kind of shift problem, sorry I didnt write it down when it happened. I purchased a Input speed sensor which I replaced on the bell housing and an output speed sensor that I replaced on the transfer case. cleared the codes, started it up, cycled through the gears and came up with codes P0500, P0700, P0717 and P0721 again. I am a little stumped at this point and looking for help.

P0500 - VSS speed sensor circuit condition
P0700 - Transmission Control System Malfunction
P0717 - Input/Turbine Speed Sensor Circuit No Signal
P0721 - Output Speed Sensor Range/Performance
P0726 - Engine Speed Input Circuit Range/Performance

 

[Mike L.]

Check wheel speed sensors and wires first.

Then check output speed sensor wires at the transfer case and turbine sensor on trans case.

 

[Rawash]

Thanks for the reply. Visually checked both wheel speed sensors they looked good so did the wires, plug contacts did not look corroded. Is there a process to check them further? I was also able to duplicate the message on the display panel it read "Range Shift Inhibited". I need to check the Input/Turbine speed sensor as well, I'll do that tomorrow. Is there any way to check these sensors to tell if they are bad, or do you just replace them.

 

[Mike L.]

Thanks for the reply. Visually checked both wheel speed sensors they looked good so did the wires, plug contacts did not look corroded. Is there a process to check them further? I was also able to duplicate the message on the display panel it read "Range Shift Inhibited". I need to check the Input/Turbine speed sensor as well, I'll do that tomorrow. Is there any way to check these sensors to tell if they are bad, or do you just replace them.

You need a Tech 2 to watch the turbine and output sensors. Watch for a drop out or a glitch.

 

[Rawash]

Wow, no offense here, but I just looked up the Tech 2 that is quite a pricey little tool. are there any other, options other that taking it to a dealer.

I can buy a lot of chickens at that price.

 

[BLKLMM]

find someone in your area to check it for you. Sorry I cant help further maybe someone on here will chime in !

 

[rgullett83]

where abouts in michigan you at?

 

[Rawash]

Rgullett83, I am in Trenton, Michigan. I talked to the dealership yesterday they are pretty much useless, they wanted me to bring in the truck for service and would'nt give me the time of day for any questions. I've got a couple of calls out to other connections, and waiting for their response. Already looked up an Allison service center if it comes to that.

 

[Redbowties88]

mike couldn't you also log that data with efilive?

 

[Mike L.]

mike couldn't you also log that data with efilive?

I would think you could. I don't play with EFI so I don't know for sure.

 

[Redbowties88]

i believe so, input and output speed at least and i believe thats the issue hes having....

OP.. perhaps start a thread and see if anyone local to you has efilive so you can use the scan tool and see if its getting an accurate reading

 

[Builtlngbd]

iam goin to do this also. with efi. what do i need to open in the scan tool?

 

[Redbowties88]

do you have V2? you can monitor it on the remotely. its in the standard PID files on the V2 or at least with the LLY

 

[Builtlngbd]

yes i have a v2. i need to monitor the turbine speed and also the speed the sensors are reading to see if the sensors are working properly

 

[Redbowties88]

is it setup for BBL?

 

[Rawash]

Redbowties, that sure is an interesting pic. Im not sure what an EFI is, and I do not know anybody with a Tech 2 scanner. Of the two connections I had both said to replace the NSBU switch. I also replaced the Input turbine sensor today as well, neither had promising results. Do to this truck being a daily driver, I found myself in a situation were I needed to get this fixed and running in a sort time frame. I took the truck to an Allison service center to evaluate this afternoon, told them what parts I had already replaced, they were going to look at it tomorrow morning and call me with an update on what they find. I greatly appriciate the help form everyone who replied, I will keep you guys updated on what they find. Thanks again!

 

[rgullett83]

Well I hope they get it figured out for you keep us updated

 

[Rawash]

Well the Allison Service Center said it was not a transmission issue, a good thing I guess, they did not have the capability to work on the Duramax, and reccomended that I take it to the dealer. Dropped it off Friday afternoon, of course they are closed for the weekend so hopefully I here something Monday or Tuesday, I'll keep you guys posted on what they find. Thanks for everyones help.