I'm considering replacing my aux trans fluid pump as well. Curious to see what your resolution is, and a parts list for everything needed.
I've already replaced the control module and wiring to eliminate the bump/jerk. Now I have problems with a stall coming out of hybrid. I believe my pump is weak and not holding pressure on the clutch plates and causing the trans to slam and stall the motor. 2008 yukon, 228k miles.
Battery cables has not stalled since polish them good. with steelwool 0000 as fine as possible( don't press hard) and electrical cleaner plastic safe WEAR GLOVES well ventilated area... COLD engine is a must this stuff is flammable Disconnect the 12v battery before working on it
i'm getting 14.7v at the battery i suspect bad wires since controller modules are still seeing 14.0-14.3 (even though the mutimeter says 14.7-14.8v at the battery terminals) there is still several ground that need cleaning
before the major deep cleaning it was barely 13.1-13.3v the battery was completely discharged to 12.1v 10-20% charge
also i suspect the thin wire( the positive to the AUX fuse box the one near the radiator ) (this houses the Pump fuse) might be undersized causing voltage drop these are 60amp fuses two of them plus a few others it's quite misleading that two thick wires are going to that fuse box(it's just for the 200AMP MEGA fuse also clean or replace the fuse)
#2 Copper wire should be used to the battery to the aux box i'm assuming these fuses are using at lest 40-45amps ea
( i'm sure u can find replacement lugs on ebay)
also no CEL for the Battery cooling performance so far ....
have not had any stall outs I'm really looking into getting a capacitor thing
i found one on ebay with 375F(rebranded xs power) for 200$ used it's solely designed for start/stop cycling 1100 CCA
Ioxus 12v as it's called
on a resume it uses a lot of power to fire up the ignition system run the computers Aux pump steering etc.... this can cause a NO check engine stall (may see loss of steering and electric braking system etc..)
My gas mileage has been restored i'm getting 19.8 around town... before i was getting 11 to 13mpg
i would take the Aux box off and check for internal corrosion as it's in a spot were it might happen