Tuesday, November 16, 2010

Allison Transmission Codes & How To Retrieve Them

If you have ever wondered about Allison transmission codes and what they mean or how to retrieve them....look no further. Read the explanation below and leave a comment here on this post and I will reply with the code details. This is the first procedure a Mechanic carries out when there is a transmission complaint.

How To Retrieve an Allison Transmission Code

With the key on run... press the 2 arrows on your shift pad. You will get a D1 then 4 digits after that. The 4 digit number is the code you're after. To check for more codes press "mode" and D2 will show up with the second code (4 digits). Press Mode again D3 will come up with the fourth code and so on.

For Example: A Speed Sensor code is 2214 2212 or 2223. There are various checks you can perform. If you have a code let me know and I will post detailed transmission code troubleshooting information to help you out.

Allison transmissions come in different series, the 1000, 2000 and 3000 series depending on the size of your vehicle. The electronics is labeled as WTEC 1, 2, 3 and now 4. These are generations of the electronic systems built through the years. WTEC 3 is very common for older trucks, the tell tale sign of this type of system is the 3 plug-ins at the Transmission ECU.

This is a quick overview of Allison Transmission Codes and will be followed with a video demonstration on how to retrieve codes. Newer WTEC 4 systems require software called Allison Doc using a laptop. The video will be focusing on a WTEC 3 system using the shift pad to get codes. If you're a Mechanic, owner operator or truck enthusiast this procedure is the first step to take if you run into problems.

Check out all my Allison Automatic Transmission posts HERE  Full of Troubleshooting and Repair advice. Many faults can be repaired by running a new coaxial wire from the sensor to the ECU. If there is any interference or resistance issues with a signal to the ECU you will end up with a code.


Here are 3 quick videos I made on how to use the trans shift pad to find codes. I set up a code by disconnecting the output speed sensor at the transmission. This will demonstrate what happens when a fault code occurs and what you can do to find out which code it is and how to clear it.

Video 1 - I'm purposely setting a fault code by unplugging the output speed sensor at the transmission.

Video 2 - Retrieving the transmission fault code using the shift pad.

Video 3 - Hooking the speed sensor back up to simulate the repair being completed and clearing the code using the shift pad.

As you can see Allison transmission codes are easy to read and clear using the shift pad. At the very least you can find out what the fault is and relay that information to your mechanic or use it to troubleshoot the problem yourself. I had a service call once in the middle of the winter, the bus was stuck in 1st gear.

Sound familiar? What had happened was the connector and harness accumulated so much ice around it the weight actually pulled the connector out of the output speed sensor socket. That was weird but made for a happy ending. Another common code is '3500' which is the battery voltage feed to the ECU, battery voltage is hard wired to the ECU so if their is any interruption you're going to get that code number.

Please post your comments and questions below and I will get back to you. thanks!

NOTE: This is for a 2009 4th generation Allison Transmission.


vehicles said...
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Anonymous said...

You seem like a knowledgable guy. I would like to pick your brains for a minute. I was recently assigned to a new IC FE300 which is like a Cadillac. The first bus I've driven that didn't squeak or rattle what so ever. The question I have is for my old bus which was a 2006 Thomas Saf-T-Liner EF with a Cummins 5.9 engine and Allison AT545 trans. The problem is when driving the bus sometimes jerks or "scoots" as if you were tapping excessively on the accelerator. It seems to do this when the transmission is about to shift into the next gear and doesn't usually stop until you let off of the accelerator. Other times it runs just normal. The district technician told me it was normal and I was either giving it too much gas or not enough. However, he could not explain why the other buses I have driven which are identical don't have this issue. The transmission went out about a year and a half ago and it still does this with the new one!...The reason I am asking about it even though I have a new bus is because now my cousin is the driver assigned to it and she is also concerned. THANKS! for any insight you may have!

lineman said...

got a f800 with allison trans wont shift out of service mode codes are d1 4522, d2 4515, d3 4514 not sure where to start any ideas, thanks

J. E. Whelan said...

Hey Lineman,
These codes are opens in the shift solenoids. They are located inside the transmission control module (The bottom part of the trans.)
I would check wiring first, each solenoid has a ground and power wire. You have three different solenoids at fault so I would check the wiring going into the trans bulkhead connector. I don't know if you have a schematic but it would really help. You could check for resistance or opens. Definitely check the connector going into the trans. If it's getting any moisture the signals will get crossed. Do a search on my homepage for allison transmission and you will get all my posts on troubleshooting. There's some wiring schematics there as well.

J. E. Whelan said...

You have to check the trans for codes. This is done with a laptop with the Allison Doc software. It could be many things but could be narrowed down with a code reading.
Good luck.

Alex said...

I think anonymous is right, to be verified for the transport codes, I've seen something ... congratulations for your post, your site is excellent!

lynngars said...

Dear JE You are a genius! My husband does not type. He has been working for DAYS and DAYS trying to figure out why our Safari Motorhome transmission froze up after changing the engine batteries. OMG what a nightmare in diagnosing this. We were so worried and only saw dollar signs. We couldn't even have it towed because it was frozen in the driveway with no lights on the tranny touch pad. We had to cancel our favorite trip of the year to the Desert Hot Springs. Then he read your blog that spoke about the VIM fuses. That was it!!! A few minutes ago, I heard the sound of my motorhome starting up in our driveway. It was music to my ears! YOu should have seen the look on my husband's face....PRICELESS! Thank you SOOOOOO much for your time and willingness to share your knowledge! Lynda & Garry from CALIF

J. E. Whelan said...

I'm Really glad I could help you out! I hope you'll get to holiday soon..

Calvin Wallace said...

I have a motor home with a Cummins 6BT engine coupled to an Allison MD 3060 transmission. I started-up to depart on vacation in the driveway and the light on the dash said: "Do Not Shift". The digital readout on the pushbutton shift selector blinked erratically and then went blank. I was able to get it into the diagnostic mode and the codes are: D1= 45-15, D2=45-12, D3=--, D4=--, D5=--

If I am reading the code manual correctly, 45-15 means D solenoid circuit open and 45-12 means A solenoid circuit open. It seems odd that two solenoids would fail at the same time. How can I get better diagnostics? I cannot clear the codes. Is there a way to override so I can get the coach to the service provider?

cam said...

1993 spartan gulf stream allison code 2112, any help?

John Whelan said...

I'll get back to you on that code. It could be a sensor, I have to refer to my code list and description at work. (just finishing some days off)

John Whelan said...

code 2112 is the Throttle Position Sensor. In 1993 the sensor is mechanical and basically is a cable that is attached to the throttle linkage. Following it back you will find the TPS where there is a rheostat that reads the resistance and sends that information to the trans ECU. You will have to check the cable and make sure it isn't damaged and then check the wiring resistance and condition. You need the Prolink to check the counts which should be between 50 and 200. I'll find a post and get on back here with the link for you.

John Whelan said...

Cam, Here is a post on the TPS with a schematic. There's not much to this system. You have to do the copy and paste in your browser again or do a search on my blog for "allison TPS"

Alex said...

Hi John ,you know what is this code P-0847 thank you

Anonymous said...

Hey John, I have a 1993 coachmen with md 3060 Allison had been working fine then do not shift light comes on and key pad freezes up and will not change ,let it sit and can start and get to work for about a minute in and out of gear then do not shift light flickers and then locks up,any ideas

Danny said...

Hello, My RV Trans was working fine when parked about 3 months ago. Went to start it now and it started then the trans key pad light came on for a couple of minutes then blinked and went out. I let it set awhile and tried again, same thing. What can I do to check it? It's a 1993 Europremier with MD 3060 Allison transmission and this was my first time to use it.

John said...

I have a question about a 2007 Freightliner Columbia with a Mercedes engine with an autoshift transmission. Code 25 appeared under transmission. Is this due to shutting truck off in gear? I was looking for a book of some sort listing codes, but I'm unable to find anything online. Any help you can give me would be appreciated.
Thank you,
J. Kleinschmidt

jimmy east said...

I just read your link on retrieving codes on a 1994 md3060 allison trans, when i got the motor home i would have to crank it twice to get the do not shift ligh to stay off,it has gotten worse and may have to crank it 8-10 times once the light stays off everything works fine the codes i got are 2423-2216-1313-1312-2215starting w/d1 and soon any help would be greatly appreciated thanks jimmy east

jimmy east said...

i have a 1994 dolphin with a 5.9 cummins and a md3060 allison trans, the two coes i get are 2423 and 2216 . can you tell me what they are ? thanks jimmy

John Whelan said...

Jimmy East
2216 output speed sensor
2423 sump oil temperature hot

J C said...

I have a 1992 Allison MD3060 with the same problem as the jimmy east first post (3rd post above: "DoNotShift" light on) but with just 3 error codes. When starting
the speedometer clicks, buzzes, oscillates wildly and pegs at max momentarily. The tachometer behaves OK.
While the speedometer is acting up I can hear some relay clicking maybe in the front fuse panel.
The Allison Error Codes are: d1: 2216; d2: 1312; and d3: 2214
On the shift console the Selection display is blank (the left display) and the Monitor display is "N" (right display). This "N" sometimes remains after turning off the key and fades out in a few minutes if not immediately.
Nudging the diesel generator, not even fulling starting it, when this problem occurs, will usually rectify the situation and the rv will then start properly with both displays showing "N" and the "Do Not Shift" light is out.
On the highway when running properly, the speedometer indicates 70mph when my GPS indicates 60mph.
When I last drove it on the highway with it fully warmed up, there were no starting problems, say at rest stops. I'm soon taking it on a trip and hope that will still be the case. I have not yet checked any of the wiring and contacts. I will appreciate any suggestions for repair.

Anonymous said...


J C said...

Sent me keypad and ECM to Transmission Instruments. Got it rebuilt ($495) and all now works like new. Phew!!!!!!
They have two websites:
Call to speak to John who is extremely helpful.
New replacement costs for me would have been $4K for the pad and the ECM. Refurbishment is the way to go with John at TI.
See error details in my post above. J C

Phil said...

I have a Question on a 1000 behind a 6.7L Cummin on a f-650. We have a random check trans light with a 2003 code we cant find what i code goes for but it only cames on randomly and trans works fine Wondering what the code is

John Whelan said...

For random code light warnings you need to get someone with Allison DOC software to read it. It sounds like it's not a big problem if you don't notice any changes with trans performance.

John Whelan said...

Actually you will need OBD 2 compatible reader since it's on an F650. We have a Snap On Solus and it reads our Dodge 550 trucks for powertrain problems.

Anonymous said...

hello, I have a 2002 Thomas with a md3060 that does not like to shift from 2 to 3. Also when you start the bus it doesn't like to idle for a min or so unless you rev it. Checked codes on the pad and it only comes up with D1-1313. I have started tracing wires and have not found anything as of yet. Any insite would be appreciated. Thanks!

John Whelan said...

What engine are you running? I'll check out the code and reply back here.

Anonymous said...

Help.... I have a 94 dolphin diesel pusher with trans code 6934, what does this code mean?

Scott Hoyt said...

hello I have an HD 4560 having some trouble getting my power for my reverse alarm and lights I did have 22-14 code speed control unreasonable with my nexiq but the on board computer showed nothing.. anything you have come across?

John Whelan said...

I work on the 3000 models and they have a VIM - vehicle interface module. It receives info from the transmission control unit and the VIM relays power out to the reverse lights and alarm. It's located under the dash on our vehicles and hard wired to the Transmission pad and TCU.