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).
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:
WTEC III – Has two functions of:
1) Oil level
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 Gen 5 Display Designators
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:
⇒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.
III. Shifter will display 99%
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
II. To reset filter life monitor after servicing main and lube filters, hold mode button down for 10 seconds.
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 Monitor – Transmission 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.
II. If transmission health shows low, Allison DOC software must be used to troubleshoot and reset Transmission Health Monitor.
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.
II. Display for WTEC III and Gen 4 will display DTC’s with flash codes.
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
DTC’s can be also be viewed and cleared with Allison DOC software under the DTC page.