1227747 to 16197427 Conversion PCM Swap with Wiring Pinout Directions!

[In-Tech]

00004000 0000 FFFF FFFF EC11 0D01 E10C 93A5 0098 ................

L4000:  FDB $23AF   ; ID BYTE, 9135d
                    ;
L4002   FDB $FFFF   ; Platform ID  
L4004   FDB $FFFF   ; Platform ID   
                    ;
L4006   FDB $0000   ; CK SUM 
                    ;
L4008   FCB $0D     ; CK BYTE   Change to AA to disable checksum check

This is line 4000 in a hex editor, at 4008 is the mask id, the checksum is at 4006,7 and is calculated from 4008-FFFF

[Rob 689]

00004000 0000 FFFF FFFF EC11 0D01 E10C 93A5 0098 ................

L4000:  FDB $23AF   ; ID BYTE, 9135d
                    ;
L4002   FDB $FFFF   ; Platform ID  
L4004   FDB $FFFF   ; Platform ID   
                    ;
L4006   FDB $0000   ; CK SUM 
                    ;
L4008   FCB $0D     ; CK BYTE   Change to AA to disable checksum check

This is line 4000 in a hex editor, at 4008 is the mask id, the checksum is at 4006,7 and is calculated from 4008-FFFF

oh nice i didnt know you could figure out the mask like that, thankyou

[Rob 689]

So my truck is running quite well on the new pcm now but theres one weird issue left. My speedometer does weird things only key on engine off. It likeises up and floats around in the 45 50 mph range and holding the brake lights on or turning the headlights on makes it move around somewhat sporadically and then slowly rise up some. You start the engine and it snaps down to zero no problem. Im confused

[Rob 689]

Also speedo functions normally while driving around. Its just key on engine off

[Rob 689]

Also i set minimum tps for PE to the max anc the minimum speed to the max and the minimum temperature to the max. It still comes on if i put my foot in it. Im also getting alot of knock counts and i think its stuck in high octane spark but i deffinatly have a fullass tank of 87. The highest at the pump in my state is only 90 as well.

anyone got any ideas on where to look in the bin?