Allison Transmission Shifter Functions and Prognostics

Allison Transmission Shifter Functions and Prognostics



Type: Allison Transmission
⇒Models: B400R & B500R
⇒Versions: WTEC III, Gen 4 and Gen 5




⇒Vehicle should be on level ground and wheels chocked.
⇒Wear personal protective equipment.




Allison Gen 4/5 transmissions have an optional feature called Prognostics. Prognostics is a diagnostic feature that alerts the operator when the transmission service is needed thru the shifter. Prognostics information can be also accessed with Allison DOC software.
It alerts service in these fields:
1. Transmission Oil life
2. Transmission Filter Life
3. Transmission Clutch life
When service is needed, the shifter will illuminate a wrench icon in the display. Along with these features, the shifter will display the standard features of oil level and DTC (Diagnostic Trouble Codes).

Allison Prognostics Service Arrow
Allison Prognostics Service Arrow   


Shifter functions, can be accessed by pushing the up and down arrows simultaneously, each time the up and down arrows are pressed the next function is accessed:

Allison Shifter Accessing Functions
Allison Shifter Accessing Functions                        

WTEC III – Has two functions of:
1) Oil level
2) Codes
Gen 4/5 with no Prognostics -Has two functions of:
1) Oil level
2) DTC (codes)
Gen 4/5 with Prognostics – Has 5 functions of:
1) Oil Level
2) Oil Life Monitor
3) Filter Life Monitor
4) Transmission Health Monitor (clutch life)
5) DTC (codes)
WTEC III, Gen 4 and Gen 5 can clear DTC’s (codes) by holding the “Mode” button down for 10 seconds while in DTC function.
To exit out of any function, press the neutral button.




1.    Oil Level Check – Preparing for oil level check:

⇒Make sure vehicle is on level ground
⇒Before starting vehicle, use dipstick to verify transmission oil condition (not burnt) and that there is sufficient oil in transmission ( that dipstick shows oil )
⇒Engine is at idle (no fast idle)
⇒Transmission is in neutral
⇒Transmission fluid temperature must be between 140º F and 220º F to get an accurate reading.
⇒Vehicle has been stationary and idling for approximately for two minutes for oil to settle to sump.


The transmission oil level sensor has a max reading of 3 quarts high and 4 quarts low. Any higher than these limits the limits will not be shown.

Oil level sensor will compensate for fluid expansion when oil is at operating temperature, this may cause a deviation between dipstick and oil level sensor readings. The oil level sensor readings should be used to achieve the correct oil level and not the dipstick.


A.  Oil Level Check – 
 I. Push up and down arrows once

Allison Shifter Accessing Functions
Allison Shifter Accessing Functions
 If vehicle has just been was just driven, and oil level is selected, the shifter will go into a countdown mode to allow the oil to settle to the sump (approximately 2 minutes).    

Allison Oil Countdown


Shifter will display transmission oil level status.

Allison Oil Level Display
Shifter Displaying Oil Level Status
Depending on the version of Allison, the shifters will display oil level in different ways –
Oil level reading low:

Allison Shifter Oil Low

Oil level reading high:
Allison Shifter Oil Display High
Oil level reading Ok:
Allison shifter Oil Level OK


If oil level check does not meet ECU / TCM requirements, the shifter will display an alert designator or alert of condition not allowing an oil level check. The following are the alert designators:

Allison WTEC Gen 4 Shifter Codes



Allison Gen 5 Display Designators

Allison Gen 5 Shifter Messages


Oil level can be also viewed with Allison DOC software.



2.  Oil Life Monitor – This feature gives a count down 99% to 0% of the oil life. At 2% it will activate the service wrench icon on the shifter display. It is based on the vehicle’s duty cycle of operation. Which are:
⇒Operating hours
⇒Output revolutions
⇒Shift density (shifts per mile)
⇒Retarder accumulator applies

If the oil life monitor is not reset at 0%, the shifter will read a negative percentage of up to -100%. The negative percentage indicates how far past due the oil change is. And DTC P0897 will be logged with a check transmission light.


A. Oil Life Monitor Checking and Resetting – 
I. Push up and down arrows twice.

Allison Shifter Oil Life
Shifter Displaying Oil Life Remaining
II. To reset oil life monitor after performing service, hold mode button down for 10 seconds. This will reset oil life back to 99%.
Allison Oil Life Mode Reset
Using Mode Button to Reset Oil Life

III. Shifter will display 99%

Allison Oil Life Reset


Oil life can be also viewed and reset with Allison DOC software.



3.   Filter Life Monitor – Filter life is sensed by the PS2 (Pressure Switch 2) which is a Normally Closed (N.C.) switch located in the valve body. When the PS2 switch receives pressure, it signals the TCM that the filters need servicing. The switch takes a pressure difference between unfiltered main pressure and filtered lock up (TCC). When the pressure difference is great enough the Normally Closed switch goes open and signals TCM that filter service is needed.

A. Filter Life Monitor Checking and Resetting –
I.  Push up and down arrows three times

Allison Filter Life Shifter
Display Showing Filter Life Status

II. To reset filter life monitor after servicing main and lube filters, hold mode button down for 10 seconds.

Allison Filter Life Reset Shifter
Filter Life Reset with Mode Button


Filter life monitor on B400R and B500R will reset automatically if TCM receives no signal from PS2 filter switch.

Filter life monitor can be also viewed and reset with Allison DOC software under the Prognostics tab.



4.  Transmission Health MonitorTransmission health monitors the running clearance of clutches C1, C2, C3, C4, and C5 to determine clutch plate wear. Clutch running clearance is based upon clutch fill volume, which indicates remaining clutch life. Lock-up clutch (TCC) is not monitored. When 10% of clutch life is reached, the wrench icon on the shifter will illuminate.


If the wrench icon is ignored for over a 100 hours indicating transmission health problem, DTC P2789 Transmission Clutch Life Expired will be logged active.

Transmission Health Monitor cannot be reset with the “Mode” button. It can only be reset with Allison DOC software under Prognostics tab.


A. Transmission Health Monitor Check –
I. Push up and down arrows four times.

Allison Transmission Health shifter
Transmission Health Displayed

II. If transmission health shows low, Allison DOC software must be used to troubleshoot and reset Transmission Health Monitor.

Allison Transmission Health Low
Transmission Health Low Status



5. DTC (Diagnostic Trouble Codes) Checking and Clearing – The shifter will show up to five DTC (Diagnostic Trouble Codes) active and inactive. The shifter will also clear active and inactive DTC’s. 

A. DTC Checking and Clearing –
I. With Prognostics feature: Push up and down arrows five times.
Without Prognostics Feature: Push up and down arrows two times.

Allison Shifter Accessing Functions
Allison Shifter Accessing Function

II. Display for WTEC III and Gen 4 will display DTC’s with flash codes.

Allison DTC Shifter


Allison Shifter Mode Button

Allison Shifter Mode Button

Allison Shifter Diagnostic Levels

III. Clearing DTC’s for WTEC III, Gen 4 and Gen 5, hold the mode button down for 10 seconds while in DTC mode. This will clear all “ACTIVE” and “INACTIVE” DTC’s

Allison ShifterMode Button Clearing


DTC’s can be also be viewed and cleared with Allison DOC software under the DTC page.


3 Comments on “Allison Transmission Shifter Functions and Prognostics

  1. We just purchased a motorhome with the MH2100 with prognostics. In speaking with a Allison dealer in Fort Wayne concerning the inability to climb hills during our adventure to West Coast, he spoke about our transission having economic and performance mode. Can you provide information regarding the feature?

    1. Glen,
      The shifter allows you to select from an economy mode and a performance mode. In economy mode the transmission shifts gears at a lower engine speed to allow the engine to operate in a more fuel efficient range. But, the draw back is that you get less power. On the other hand, in performance mode, you get more power but sacrifice fuel economy. This is because the transmission will shift at a higher engine speed which gives you more power. My suggestion is to drive in economy mode in flat areas. And in performance when you are driving on hills, towing, passing other vehicles or whenever quick acceleration is needed.
      Remember, that the Allison transmission is an adaptive learning transmission, it learns and adapts to your driving style. I’ve included some links that might help. Hope the information is useful to you.
      Best wishes,

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