Low Slope and Breakpoint Patch
Posted: 2026 Aug 31, 15:30
I successfully implemented a low slope and breakpoint patch for J1X that is adapted to A1C below. I have not tested on A1C yet but here are the details if anyone is interested. The only thing may need to be worked out is the conversion math for breakpoint. I adjusted it by feel until I was happy with the results.
Code: Select all
Address: 508E
Original Hex: A3 F4 08 3A
New Hex: EF 6F 52 FFCode: Select all
Address: A300
Original Hex: FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF
New Hex: 89 9A 0A B4 D1 06 A3 F4 08 3A 20 04 A1 E0 E6 3A F0Code: Select all
; --- A1C Hardcoded BKPT & ALOSL Patch (Unscaled 39.5 psi Deka 80s) ---
; Direct Compare
a300: 89, 9a, 0a, b4 cmpw Rb4, 0a9a ; Compare Commanded Fuel Mass (Rb4) to 0A9A (BKPT: 0.00002714)
a304: d1, 06 jleu a30c ; If Mass <= BKPT, jump to Low Slope logic
; High Slope Path
a306: a3, f4, 08, 3a ldw R3a, [Rf4+8] ; R3a = AHISL (Original factory load from A822)
a30a: 20, 04 sjmp a310 ; Jump to Return
; Low Slope Path (Hardcoded)
a30c: a1, e0, e6, 3a ldw R3a, e6e0 ; R3a = E6E0 (Hardcoded ALOSL: 101.46 lbs/hr)
; Return
a310: f0 ret ; Return