OK, I looked more into 6E and found that the MAT does indeed affect all kindsa stuff for startup enrichment and that sort of thing. So now I'm looking into alternate analog inputs. I came up with this for ARAP/6E: Original: ECFF: 86 80 : LECFF LDAA #$80 ; A/D Ch 8, MAT ED01: BD F2 F7 : JSR LF2F7 ; To A/D subroutine ED04: 43 : COMA ; INVERT TEMPERATURE ED05: B7 01 30 : STAA L0130 ; A/D MAT VALUE ED08: 97 61 : STAA L0061 ; MAT ED0A: DE 19 : LDX L0019 ; ENG RUN TIME (Sec) ED0C: BC C1 : CPX LC1FA ; 120 SEC'S MIN RUN TIME FOR ERR 23/25 ED0F: FA 23 : BLS LED6E ; BR IF RUN TIME GT 120 SEC'S, else... ED11: D6 66 : LDAB L0066 ; MPH/1 Continue /w/ ARAP MAT error checking... Modified: ECFF: 86 80 : LECFF LDAA #$80 ; A/D Ch 8, MAT ED01: BD F2 F7 : JSR LF2F7 ; To A/D subroutine ED04: 43 : COMA ; INVERT TEMPERATURE ED05: 97 61 : STAA L0061 MAT ED07: 86 X0 : LDAA A/D Channel ‘X’ ED09: BD F2 F7 : Call A/D routine ED0C: B7 01 30 : Store A/D value into 0130 for datastream pickup in place of MAT2(?) ED0F: D6 66 : Redundant filler (same as code that follows) ED11: D6 66 : LDAB L0066 ; MPH/1 Continue /w/ ARAP... In terms of pinout, there's 0-5v being looked for at MAP (C11 on connector) and MAP2 (D8). Looks like they are both relatively high impedance /w/ a 51k pulldown along with an 18k resistor on the way to the AI. Is this right thinking? Help me out here if I'm misguided. Now what analog channels correspond to what inputs on the 165? I've got the following: 1 = Batt voltage 2 = ? 3 = ? 4 = CTS 5 = TPS 6 = ? 7 = Start/run V, diag volts 8 = MAT 9 = ? A = MAF B = ? So that's 5 mystery inputs, candidates include: MAP MAP2 Others? Any help would be appreciated... -Craig

and to think all i wanted to do was rewrite the o2 sensor lookup routines to read the WB-02 as if it were supposed to be there. in all thoery shouldnt be that hard.

move the o2 input to the 0-5v a/d converter. repoint the ldaa command for the sensor read.

then reworks the scalar for reading the a/d counts. this way it would be truly wideband. the ecm does the sampling not the sensor.

Well, I know the pin to use and the patch to apply as shown above, it will work fine I'm sure. What I need to know is what A/D channel corresponds to what on the 165. This should be a generic GMECM question I think...

http://www.cruzers.com/~ludis/1227165schematic.html

Just a suggestion, you may want to move the code to a spot in the factory test area. No diag code will need to be bypassed.

RBob.

That's a good idea. I guess the only thing I'm bypassing right now is the 120s check to see if the MAT diagnostic test should be performed, but still...

Works great!

Brought the WB signal in on MAP2 (Pin D8), which is A/D channel '0'. Did the volts-to-AFR conversion in the logging software. I think this is going to be ultra-sweet...