GP40 Passsenger Units

[R36 Combine Coach]

Interested in what the model designations for GP40 passenger diesels stand for, including GP40PH-2, GP40FH-2, GP40H-2.

P: Passenger package equipped
H: HEP unit
F: F-series cowl (GP40FH units)
-2: rebuilt as DASH-2 spec
-2A: ?
-2B: ? (one roster sheet mentioned "light second order", referring to the 4200 (ex-PC) series)
-2C: ?
-2CAT: Caterpillar HEP (rebuilt F40s)

[CNJ Fan 4evr]

Soon they will have dash2 third to the seventh power minus mc squared.

[CNJGeep]

Interested in what the model designations for GP40 passenger diesels stand for, including GP40PH-2, GP40FH-2, GP40H-2.

P: Passenger package equipped
H: HEP unit
F: F-series cowl (GP40FH units)
-2: rebuilt as DASH-2 spec
-2A: ?
-2B: ? (one roster sheet mentioned "light second order", referring to the 4200 (ex-PC) series)
-2C: ?
-2CAT: Caterpillar HEP (rebuilt F40s)

-2A is a designator so the new order of GP40s was not confused with the GP40PH-2s (CNJs)
-2B is similar
-2C indicates (usually) a Cummins HEP plant

[R36 Combine Coach]

-2A is a designator so the new order of GP40s was not confused with the GP40PH-2s (CNJs)
-2B is similar
-2C indicates (usually) a Cummins HEP plant

Then what is -2M?

I assume the difference between a GP40H-2 and a GP40PH-2 is lack of specific gearing for passenger service (no "P").

[CNJGeep]

-2A is a designator so the new order of GP40s was not confused with the GP40PH-2s (CNJs)
-2B is similar
-2C indicates (usually) a Cummins HEP plant

Then what is -2M?

I assume the difference between a GP40H-2 and a GP40PH-2 is lack of specific gearing for passenger service (no "P").

M could stand for Microprocessor, or Modified. Either works. And your logic regarding the H is not sound, as CDOT classifies their GP40s as GP40H-2 and they are obviously geared for passenger. The H indicates HEP.

Also, two years later and this question is still burning in your mind??

[DutchRailnut]

Conndot specifies their GP40 as :
6694-6699 6 GP40-2H AMF rebuilds