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ALDL Port

PFloyd36069PFloyd36069 Posts: 135
edited 2008-04-25 23:00 in BASIC Stamp
Hi,

Is there anyway to interface the BS2 to the ALDL(Assembly Line Data Link) on my 1984 Chevy Caprice? I know that there is serial·data being output from the port at either 12 or 5 volts depending on the ECU. The Baud rate can either be 160 or 8192. I am trying to make a guage that interfaces and gets the info from the port.

Thanks,

Bryan

Comments

  • FranklinFranklin Posts: 4,747
    edited 2008-04-20 14:18
    If it's serial data you can probably read it but then you need to translate it into something you can use. Do you have documentation on what is being output and in what form?

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    - Stephen
  • PFloyd36069PFloyd36069 Posts: 135
    edited 2008-04-20 18:05
    hi franklin,

    I found the following information on the ALDL port on my car


    ······················· DATA STREAM A6··· SPECIFICATION

    ······ SPECIFICATIONS FOR· DATA STREAM INFORMATION
    ······

    ······ ENGINE· USAGES:
    ············· 5.0l V8 CLCC (LV2) - (Y) - 84
    ············· 5.0l V8 CLCC (L69) - (G) - 84
    ············· 5.0l V8 CLCC (LG4) - (H) - 84
    ············· 5.0l V8 CLCC (LG8) - (9) - 84
    ············· 5.0l V8 CLCC (LM1) - (6) - 84


    ······ DATA PIN· : READ DATA ON PIN "D" OF ALDL CONNECTOR

    ······ BAUD RATE : 160 BAUD

    ······ MODES···· : DIAGNOSTIC ENABLE:
    ···················· 10K . . . . . . . YES - 20 WORDS
    ···················· NORMAL· . . . . . NO
    ···················· SHORTED . . . . . YES - 20 WORDS

    ······ DEFINITION: DATA STREAMS CONTAIN THE SAME INFORMATION
    ·················· IN THE SAME FORMAT WITH 20 WORD FORMAT.

    ..PAGE


    · DATA STREAM DEFINITION
    ·
    ··· WHERE "WORD" IS THE BYTE OF DATA STREAM AS IT IS READ FROM THE VEHICLE
    ··· AND "BIT" IS THE BIT OF THE BYTE, WHERE 0 IS THE LEAST SIGNIFICANT BIT.

    ··· WORD· BIT·· DESCRIPTION
    ··· ----· ---··
    ··· 1·········· PROMID BYTE 1
    ··· 2·········· PROMID BYTE 2
    ··· 3·········· BATTERY VOLTAGE
    ··· 4·········· COOLANT TEMPERATURE
    ··· 5·········· VEHICLE SPEED
    ··· 6·········· MANIFOLD ABSOLUTE PRESSURE
    ··· 7·········· MODE WORD 1
    ··········· 0·· ADVANCE FLAG··························· 0 = ADVANCE
    ··········· 1·· WARM FLAG······························ 1 = WARM
    ··········· 2·· TIMING ERROR - 100 MSEC LOGIC FAILED TO COMPLETE
    ··········· 3·· HOT ENGINE MODE························ 1 = HOT ENGINE
    ··········· 4·· TCC ROAD SPEED 1ST PULSE FLAG
    ··········· 5·· REAR VACUUM BREAK SOLENOID ON·········· 1 = SOLENOID ON
    ··········· 6·· EST ENABLED FLAG
    ··········· 7·· ENGINE RUNNING FLAG···················· 1 = RUNNING
    ··· 8·········· THROTTLE POSITION SENSOR
    ··· 9·········· OXYGEN SENSOR
    ··· 10········· MIXTURE CONTROL SOLENOID DUTY CYCLE
    ··· 11········· MALFUNCTION FLAG WORD 1
    ··········· 0·· C24 VEHICLE SPEED SENSOR
    ··········· 1·· C23 AIR FUEL SOLENOID
    ··········· 2······ NOT USED
    ··········· 3·· C21 THROTTLE POSITION SENSOR
    ··········· 4·· C15 COOLANT SENSOR LOW TEMPERATURE
    ··········· 5·· C14 COOLANT SENSOR HIGH TEMPERATURE
    ··········· 6·· C13 OXYGEN SENSOR OPEN
    ··········· 7·· C12 NO REFERENCE PULSES (ENGINE NOT RUNNING)
    ··· 12········· MALFUNCTION FLAG WORD 2
    ··········· 0·· C42 EST MONITOR ERROR
    ··········· 1·· C41 TAC INPUT ERROR
    ··········· 2······ NOT USED
    ··········· 3·· C34 PRESSURE SENSOR
    ··········· 4······ NOT USED
    ··········· 5·· C32 BARO SENSOR LOW
    ··········· 6······ NOT USED
    ··········· 7······ NOT USED
    ··· 13········· MALFUNCTION FLAG WORD 3
    ··········· 0······ NOT USED
    ··········· 1·· C54 CARB. MIXTURE CONTROL SOLENOID
    ··········· 2······ NOT USED
    ··········· 3······ NOT USED
    ··········· 4·· C51 PROM ERROR
    ··········· 5·· C45 OXYGEN SENSOR RICH
    ··········· 6·· C44 OXYGEN SENSOR LEAN
    ··········· 7······ NOT USED
    ..PAGE


    · DATA STREAM DEFINITION CON'T
    ·

    ··· WORD· BIT·· DESCRIPTION
    ··· ----· ---··
    ··· 14········· CLCC MODE WORD
    ··········· 0·· BLENDED ENRICHMENT FLAG················ 1 = BLENDED
    ··········· 1·· COLD START····························· 1 = COLD START
    ··········· 2·· IDLE LOAD CONTROL WIDE OPEN THROTTLE··· 1 = WOT
    ··········· 3·· WIDE OPEN THROTTLE····················· 1 = WOT
    ··········· 4·· NOT USED
    ··········· 5·· O2 RICH/LEAN FLAG······················ 1 = RICH
    ··········· 6·· NONVOLATILE MEMORY BOMBED·············· 1 = BOMBED
    ··········· 7·· CLOSED LOOP FLAG······················· 1 = CLOSED LOOP
    ··· 15········· I/O STATUS WORD 1
    ··········· 0·· NOT USED
    ··········· 1·· NOT USED
    ··········· 2·· REAR VACUUM BREAK······················ 1 = ON
    ··········· 3·· TCC···································· 1 = ON
    ··········· 4·· NOT USED
    ··········· 5·· HIGH GEAR SWITCH······················· 0 = 4TH GEAR
    ··········· 6·· LOW/MID GEAR SWITCH···················· 0 = 3RD GEAR
    ··········· 7·· E-CELL INPUT··························· 0 = TIMED OUT
    ··· 16········· I/O STATUS WORD 2
    ··········· 0·· AIR DIVERT SOLENOID···················· 1 = SOLENOID ON
    ··········· 1·· AIR SWITCH SOLENOID···················· 1 = SOLENOID ON
    ··········· 2·· NOT USED
    ··········· 3·· IDLE LOAD CONTROL SOLENOID············· 1 = ON
    ··········· 4·· NOT USED
    ··········· 5·· P/N SWITCH····························· 1 = PARK OR NEUTRAL
    ··········· 6·· AIR CONDITIONING······················· 1 = A/C ON
    ··········· 7·· AIR/FUEL SOLENOID TEST················· 1 = SOLENOID ON
    ··· 17········· MODE WORD
    ··········· 0·· AIR CONDITIONING SWITCH ON············· 1 = ON
    ··········· 1·· MOUNTAIN COAST MODE ON················· 1 = ON
    ··········· 2·· STACK OVERRIDE ON RAM FLAG············· 1 = OVERRIDE
    ··········· 3·· ESC MALF 43 DISABLE···················· 1 = DISABLE
    ··········· 4·· EGR ON SOLENOID OFF···················· 1 = ON
    ··········· 5·· ESC DELAY FLAG························· 1 = ENABLE
    ··········· 6·· WARM· FLAG····························· 1 = WARM
    ··········· 7·· AIR CONDITIONING CLUTCH RELAY ON······· 1 = ON
    ··· 18········· ENGINE RPM
    ··· 19········· BAROMETRIC PRESSURE
    ··· 20········· TOTAL CROSSOVER COUNTS

    ..PAGE


    ······· CONVERSION FOR A/D COUNTS TO ENGINEERING UNITS
    ·······

    ··············· N = A/D COUNTS
    ·············· EU = ENGINEERING UNITS

    ··· ----
    ··························································································· ENGINEERING
    ··· WORD·· DESCRIPTION···················· CONVERSION························ UNITS
    ··· ----··
    ·····
    ···········
    ··· 1····· PROMID BYTE 1··························· NONE
    ··· 2····· PROMID BYTE 2·························· ·NONE
    ··· 3····· BATTERY VOLTAGE·······················EU = N*.1······················ VOLTS
    ··· 4····· COOLANT TEMPERATURE··············· TABLE LOOKUP
    ··· 5····· VEHICLE SPEED····························NONE
    ··· 6····· MANIFOLD ABSOLUTE PRESSURE····· EU = N * .0196··············· VOLTS
    ··· 7····· MODE WORD 1···························· NONE
    ³·· 8····· THROTTLE POSITION SENSOR·········EU = N* .0196················ VOLTS
    ··· 9····· OXYGEN SENSOR························· EU = N*(4.3403)············· MILLIVOLTS
    ··· 10···· MIXTURE CONTROL SOLENOID DUTY CYCLE· EU = N/2.56······· % DUTY CYCLE
    ···························································· EU = 60*N/256················ DEGREES
    ··· 11···· MALFUNCTION FLAG WORD 1··········NONE
    ··· 12···· MALFUNCTION FLAG WORD 2··········NONE
    ··· 13···· MALFUNCTION FLAG WORD 3··········NONE
    ··· 14···· CLCC MODE WORD······················ NONE
    ··· 15···· I/O STATUS WORD 1··················· NONE
    ··· 16···· I/O STATUS WORD 2··················· NONE
    ··· 17···· MODE WORD······························ NONE
    ··· 18···· ENGINE RPM······························· EU = N*25························ RPM
    ··· 19···· BAROMETRIC PRESSURE················ EU = N * .0196················ VOLTS
    ··· 20···· ALDL RICH LEAN CHANGE COUNTER······· SEE **


    ·** : THIS IS A ROLLOVER COUNTER (0 - 255), TAKE CURRENT DATA STREAM READING
    ····· SUBTRACT LAST DATA STREAM READING = CROSSCOUNTS.· IF CURRENT READING
    ····· MINUS LAST READING IS < 0, THEN TAKE CURRENT READING + 255 - LAST
    ····· READING = CROSSCOUNTS



    ..PAGE

    ······· COOLANT TERMPERATURE CONVERSION
    ·······

    ······· DEGREES CELSIUS·········· A/D COUNTS
    ·······
    ··········
    ············ -15···················· 252
    ············· -5···················· 249
    ·············· 5···················· 244
    ············· 15···················· 237
    ············· 25···················· 228
    ············· 35···················· 215
    ············· 45···················· 198
    ············· 55···················· 179
    ············· 65···················· 158
    ············· 75···················· 136
    ············· 85···················· 115
    ············· 95···················· 95
    ············ 100···················· 86
    ············ 105···················· 78
    ············ 110···················· 70
    ············ 115···················· 63
    ············ 120···················· 57


    Post Edited (PFloyd36069) : 4/20/2008 9:12:14 PM GMT
  • PFloyd36069PFloyd36069 Posts: 135
    edited 2008-04-24 21:31
    Anyone got any ideas?
  • allanlane5allanlane5 Posts: 3,815
    edited 2008-04-25 00:04
    I'd be amazed if the BS2 could take the data fast enough, or in enough volume.

    And be very careful -- you don't want to blow up your car computer by accident.
  • PFloyd36069PFloyd36069 Posts: 135
    edited 2008-04-25 23:00
    Is there anyway to read certain info from the data like· battery·voltage, coolant temp, and engine rpm?
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