-- Press and hold dash odometer button in, then turn key from off to on. Continue to hold button while all odometer display segments light up, then mileage shows up...then release it when the display says "teSt". -- Each press of the button steps through the following readings. Values shown are with truck in park and engine off; where known, notes describe different possibilities for readings. GAGE - all gauge needles sweep to full range, then sweep back to low range, then go back to current readings. ******* - all display segments on buLb - all dash bulbs illuminated PF 3346 - ? SF 0E02 - ? 0017430 - ? IgnIn b - ? r 0302 - ? nr 0302 - ? EE 01 - ? dt 3E39 - ? CF1 b0 - ? CF2 00 - ? CF3 00 - ? CF4 00 - ? dtC - display alternates between "dtC" and number(s). Diagnostic 9201 Trouble Code. (9201 is fuel sender circuit failure!) EnG 000 - ENG(lish) units for speed - MPH riC 000 - (met)RIC units for speed - kM/H tAC0000 - Tachometer - reads 625 or so when idling, but highly erratic within a range of a few RPMs. The dash tach and AIC tach sure do stabilize these readings before showing them to you! F 252 - Fuel sender reading. 255 is max value, presumably 0 is min. FP 077 - Fuel pressure? Reads steady 115 with engine idling. 171 later. 255 C - ? oiL 234 - Oil pressure - reads 000 when idling! Another fake gauge? 062 tF - ? (possibly coolant temp in Fahrenheit?) br 123 - ? batt12.3 - Battery voltage - reads 13.5 when idling rhEo FF - Dash illumination rheostat value. FF when clicked to "on" position, 28 at dimmest position. 00 when headlights off. Prnd 40 - Auto trans lever P=40, R=01, N=80, D=10, 3=08, 2=04, 1=02 (so port bits are wired NP-D321R ) PAr o - Parking brake: "o" = off, "g" = engaged. door 00 - Door ajar codes. Port bits: LF RF LR RR - - - - (Ex: 80 = Driver's door open, F0 = all 4 crewcab doors open) (Excursion rear door bit is ???) Stbt b - ? CHE 02 - ? (01 when idling) PA 80 - ? (Port A raw data?) Pb 53 - ? (Port B raw data?) (13 when idling) PE 1C - ? (Port E raw data?) (18 when idling, 0x when dash button is pressed) PG 04 - ? (Port G raw data?) (00 when idling) PH 90 - ? (Port H raw data?) PP 98 - ? (Port P raw data?_ PS 8F - ? (Port S raw data?) (sometimes reads 9F) Pt A5 - ? (Port T raw data?) (25 H/L off, 27 park/Hl on) PCAn 5F - ? (CANBus port raw data?) Ad0 000 - ? (Analog-Digital Converter input pin?) Ad1 250 - ? (ADC input pin? 255 when idling) Ad2 050 - ? (ADC input pin? 255 when idling) Ad3 075 - ? (ADC input pin? 083 when idling) Ad4 142 - ? (ADC input pin? 000 when idling) Ad5 255 - ? (ADC input pin?) Ad6 156 - ? (ADC input pin? 174 when idling) Ad7 154 - ? (ADC input pin? 170 when idling) ...and then back to "GAGE" again...