Here's something I found in a old post over on TT, maybe this will be of some help. Oh, I don't think you want to try to MOD the laser over on to an Armada, it would be way more fun to do than you could imagine. I had to rewire a Qx56 for one once, a lot of work!!!!!!!!
For all you tech geeks, here is a break down of all the different entries in diagnostic mode. There is a oil pressure, entry, but unfortunately the output is in Hex, so that's not very natural too look at..
COMBINATION METER SELF-DIAGNOSIS MODE FUNCTIONS
Self-Diagnosis Mode functions Table
-------------------------------
DISPLAY: nrXXXX
Displays hex ROM rev as
stored in NVM.
-------------------------------
DISPLAY: GAGE
Performs sweep of all
gauges, then displays
present gauge values.
Performs checksum tests
on ROM and EE.
Gauges sweep within 10 seconds
-------------------------------
DISPLAYAll segments illuminated)
Lights all odometer/trip
meter, fuel, and engine
temperature display segments.
Initiating self-diagnosis mode
complete
-------------------------------
DISPLAY: bulb
Illuminates all micro-controlled
lamps/LEDs
regardless of SW configuration.
-------------------------------
DISPLAY:EE XX, FAIL
-------------------------------
DISPLAY:Sc1XX
Displays 8-bit software
configuration value in Hex
format.
Bit Coding
7-3 = reserved for future use
2 = TCS/VDC 0 = not present
1 = present
1 = Shift type 0 = Column shift
1 = Floor shift
0 = ICC 0 = not present
1 = present
-------------------------------
DISPLAY:Sc2XX
Displays 8-bit software
configuration value in Hex
format.
Bit coding
7-0 = Reserved for future use
-------------------------------
DISPLAY:EprXX
Displays 8-bit software
configuration value in Hex
format.
Bit Coding
7-2 = reserved for future use
1 = A/T Oil Temp (gauge)
0 = not present
1 = present
1 = Odo Units 0 = kilometers
1 = miles
-------------------------------
DISPLAY:1nFXX
Displays 8-bit market info
value in Hex format.
$31 = USA
$2A = Canada
-------------------------------
DISPLAY:cYLXX
Displays 8-bit engine configuration
value in Hex
format.
$08 = 8 cylinder
$06 = 6 cylinder
-------------------------------
DISPLAY:FFXXXX
Displays 16-bit fuel flow
constant "Q" in tenths of
cc/min in Hex format.
$0000 - $FFFF
-------------------------------
DISPLAY:tF
Displays 16-bit tire factor
"A" in hundredths in Hex
format.
$0000 - $FFFF
-------------------------------
DISPLAYt1XX
Displays oil pressure telltale
"on" threshold in A/D
counts in Hex format.
$00 - $FF
-------------------------------
DISPLAYt0XX
Displays oil pressure telltale
"off" threshold in A/D
counts in Hex format.
$00 - $FF
-------------------------------
DISPLAY: XXXXX
Raw uncompensated
english speed value in
hundredths of MPH.
Speedometer indicates
present speed.
Will display "-----" if message is
not received. Will display
"99999" if data received is
invalid
-------------------------------
DISPLAY: XXXXX
Raw uncompensated
metric speed value in
hundredths of KPH.
Speedometer indicates
present speed.
Will display "-----" if message is
not received. Will display
"99999" if data received is
invalid
-------------------------------
DISPLAY: tXXXX
Tachometer value in
RPM. Tachometer indicates
present RPM.
Will display "-----" if message is
not received.
-------------------------------
DISPLAY: F1 XXXX
Present ratioed fuel level
A/D input 1 in decimal format.
Fuel gauge indicates
present filtered level.
000-009 = Short circuit
010-254 = Normal range
255 = Open circuit
--- = Missing 5 seconds
-------------------------------
DISPLAY: XXXC
Last temperature gauge
input value in degrees C.
Temperature gauge indicates
present filtered temperature.
Will display "---"C if message is
not received.
Will display "999" if data
received is invalid.
-------------------------------
DISPLAY: BAtXX.X
Estimated present battery
voltage.
-------------------------------
DISPLAY: rES -X
Seat belt buckle switch
LH status.
1= Buckled
0 = Unbuckled
-------------------------------
DISPLAY: PA -XX
Hex value port A.
-------------------------------
DISPLAY: Pb -XX
Hex value port B.
-------------------------------
DISPLAY: PE -XX
Hex value port E.
-------------------------------
DISPLAY: PL -XX
Hex value port L.
-------------------------------
DISPLAY: P6 -XX
Hex value port K.
-------------------------------
DISPLAY: Pn -XX
Hex value port M.
-------------------------------
DISPLAY: PP -XX
Hex value port P.
-------------------------------
DISPLAY: PS -XX
Hex value port S.
-------------------------------
DISPLAY: Pt -XX
Hex value port T.
-------------------------------
DISPLAY: Pu -XX
Hex value port U.
-------------------------------
DISPLAY: P4 -XX
Hex value port V.
-------------------------------
DISPLAY: Puu -XX
Hex value port W.
-------------------------------
DISPLAY: A01XXX
A/D port A/D value (nonratioed).
0-255
-------------------------------
DISPLAY: A02XXX
A/D port A/D value (nonratioed).
0-255
-------------------------------
DISPLAY: A03XXX
A/D port A/D value (nonratioed).
0-255
-------------------------------
DISPLAY: A04XXX
A/D port A/D value (nonratioed).
0-255
-------------------------------
DISPLAY: A05XXX
A/D port A/D value (nonratioed).
0-255
-------------------------------
DISPLAY: A06XXX
A/D port A/D value (nonratioed).
0-255
-------------------------------
DISPLAY: A07XXX
A/D port A/D value (nonratioed).
0-255
-------------------------------
DISPLAY: A08XXX
A/D port A/D value (nonratioed).
0-255
-------------------------------
DISPLAY: A09XXX
A/D port A/D value (nonratioed).
0-255
-------------------------------
DISPLAY: A10XXX
A/D port A/D value (nonratioed).
0-255
-------------------------------
DISPLAY: A11XXX
A/D port A/D value (nonratioed).
0-255
-------------------------------
DISPLAY: A12XXX
A/D port A/D value (nonratioed).
0-255
-------------------------------
DISPLAY: A13XXX
A/D port A/D value (nonratioed).
0-255
-------------------------------
DISPLAY: A14XXX
A/D port A/D value (nonratioed).
0-255
-------------------------------
DISPLAY: A15XXX
A/D port A/D value (nonratioed).
0-255
-------------------------------
DISPLAY: PA0-XX
Hex value representing
state of A/D ports 0-7.
-------------------------------
DISPLAY: PA1-XX
Hex value representing
state of A/D ports 0-7.
Event Odometer Display Description of Test/Data Notes:
-------------------------------
DISPLAY: Thr-XXX
Decimal value of thermistor
A/D reading.
0-255
-------------------------------
DISPLAY: D-HI Meter/LCD Illumination.
Full daytime brightness all
LCD segments active
-------------------------------
DISPLAY: N-HI Meter/LCD Illumination.
Full nighttime brightness all
LCD segments active
-------------------------------
DISPLAY: N-LO Meter/LCD Illumination.
Min. nighttime brightness all
LCD segments active
-------------------------------
DISPLAY: GAGE
Return to beginning of selfdiagnosis.
Hex EE level. If EE
checksum fault exists,
display alternates
between "EE XX" and
"FAIL".
-------------------------------
DISPLAY: dtXXXX
Hex coding of final manufacturing
test date.
