Operation: ACPGI-0 Continuious send ISO-9141-2 to rs232 Transciever.
At power up a continuiously send log in sequence for ISO 9141-2 initialization is started and repeated until connection established. Default data request ID 4 or other is continuiously made to prevent time out. If correct ISO-9141-2 response is recieved from vehicle, then the requested ID and 2 byte data value is returned at rs232 19200 baud. The gateway program then delays the ISO-9141-2 minimum time betwen responses of 55 ms. at which time a rs232 1 byte request can be made to change the ISO-9141-2 data recieved. If no rs232 request is received the last rs232 request or default will be sent in a continuious run mode until the next rs232 input request. Upon ISO-9141-2 error or no response within 50 ms the gateway program will perform the SAE error protocol routine, if this fails the ISO-9141-2 initiation sequence will be restarted. Upon device software crash the initiation sequence will be restarted in 288 ms. At power down communication will stop.
Operation: ACPGI-1 one shot ISO-9141-2 to rs232 Transciever.
At power up a continuiously send log in sequence for ISO 9141-2 initialization is started and repeated until connection established. A ID 1 or other data request is continuiously made every 2 seconds to prevent time out. If correct ISO-9141-2 response is recieved from vehicle, then the requested ID and 2 byte data value is returned at rs232 19200 baud. 1 byte request can be made to change the ISO-9141-2 data recieved. If no rs232 request is received within 2 seconds the time out data request will be made until the next rs232 input request. Upon ISO-9141-2 error or no response within 50 ms the gateway program will perform the SAE error protocol routine, if this fails the ISO-9141-2 initiation sequence will be restarted. Upon device software crash the initiation sequence will be restarted in 288 ms. At power down communication will stop.
Operation: ACPGV-0 or ACPGP Continuious send VPW or PWM to rs232 Transciever.
At power up a continuiously send log in sequence for VPW or PWM initialization is started and repeated until connection established. Default data request ID 4 or other is continuiously made to prevent any diagnostic time out. If correct VPW or PWM response is recieved from vehicle, then the requested ID and 2 byte data value is returned at rs232 19200 baud. The gateway program then delays a minimum time betwen responses of 30-200 ms. at which time a rs232 1 byte request can be made to change the data recieved. If no rs232 request is received the last rs232 request or default will be sent in a continuious run mode until the next rs232 input request. Upon vehecle network error or no response within 30-200 ms the gateway program will perform the SAE error protocol routine, if this fails the VPW or PWM initiation sequence will be restarted. Upon device software crash the initiation sequence will be restarted in 288 ms. At power down communication will stop.
Pin Description ACPGI 1 5 volt 2 auxillary input or output 3 ISO output 4 ISO input internal pull-up 5 rs232 input Schmitt trigger 6 auxillary input or output 7 rs232 output 8 ground (other pin outs available)
rs232 19200 baud 1 stop no parity ISO 9141-2 10400 baud 1 stop no parity ISO 9141-2 10400 baud 1 stop odd parity ISO 9141-2 5 baud 1 stop no parity
232 in xxxxxxxx xxxxxxxx 232 out xxxxxxxx ISO in xxxxxxxx ISO out xxxxxxxx xxxxxxxx
typical times ACPGI
t0 ISO initiation log in 2340ms t1 ISO message transmit 50ms t2 IS0 message receive 60ms t3 IS0 response to ISO request 35ms t4 IS0 delay before ISO request 55ms t5 acquistion (sum t1 thru t4) 200ms t6 SAE delay before log in 300ms t7 watch dog time-out 288ms
previous transception 400ms = 2*t5 no response to requested PID 2840ms = t6+t0+t5 terminated or not possible 7920ms = 3*(t0+t6) software or firmware crash 3128ms = t6+t0+t5+t7
typical operation ACPGI-0
With power applied to pin 1 the ISO log in initiation sequence will begin and repeat until response is received. A internal default data value will be requested such as load Parameter Indentification (PID) number 04 hexidecimal. Upon response the return data bytes will be parsed and then output as rs232 2 byte unscaled value. The default PID will be sent until a rs232 1 byte PID input is received during period t4 of duration 55ms begining at end of last rs232 output. The new PID value will then be transceived until another rs232 input. If the network does not respond to a request within 50 ms the request will be resent. If no response to 2nd request the log in will be repeated and the default PID will be sent upon correct log in.
SAE J1979 mode 01 continuious data
Request Return PID DESC byte 1 byte 2 00 PID supported(01-20) xxxxxxxx xxxxxxxx 01 Number of DTC xxxxxxx- 01 MIL ON -------1 01 MIL OFF -------0 01 Misfire support -------x 01 Fuel support ------x- 01 Component support -----0-- 01 Reserved ----x--- 01 Misfire status ---x---- 01 Fuel status --x----- 01 Component status -x------ 01 Reserved status 0------- 02 03 open loop 1------- 03 closed loop -1------ 03 open loop driving --1----- 03 open loop fault ---1---- 03 closed loop fault ----1--- 03 reserved -----0-- 03 reserved ------0- 03 reserved -------0 04 load % b/255*100 05 coolant temp. F (b-40)*1.8+32 06 short fuel trim b/128*100-100 07 long fuel trim 1 b/128*100-100 08 short fuel trim 2 b/128*100-100 09 long fuel trim 2 b/128*100-100 0A fuel pres. psi b*3*0.14504 0B intake pres. inHg b*0.29613 0C engine rpm (b<<8+b2)/4 0D vehicle speed mph b*0.6214 0E ignition time (b-128)*0.5 0F intake air F (b-40)*1.8+32 10 air flow 1b/min (b<<8+b2)*0.132275 11 throttle % b/255*100 12 air upstream cat 1------- 12 air downstream cat -1------ 12 air off --1----- 12 air reserved ---00000 13 O2 location 11 1xxxxxxx 13 O2 location 12 x1xxxxxx 13 O2 location 13 xx1xxxxx 13 O2 location 14 xxx1xxxx 13 O2 location 21 xxxx1xxx 13 O2 location 22 xxxxx1xx 13 O2 location 23 xxxxxx1x 13 O2 location 24 xxxxxxx1 14 shrt fuel trim 11 b/128*100-100 14 shrt fuel trim NA 11111111 14 O2 V 11 b*0.005 15 shrt fuel trim 12 b/128*100-100 15 shrt fuel trim NA 11111111 15 O2 V 12 b*0.005 16 shrt fuel trim 13 b/128*100-100 16 shrt fuel trim NA 11111111 16 O2 V 13 b*0.005 17 shrt fuel trim 14 b/128*100-100 17 shrt fuel trim NA 11111111 17 O2 V 14 b*0.005 18 shrt fuel trim 21 b/128*100-100 18 shrt fuel trim NA 11111111 18 O2 V 21 b*0.005 19 shrt fuel trim 22 b/128*100-100 19 shrt fuel trim NA 11111111 19 O2 V 22 b*0.005 1A shrt fuel trim 23 b/128*100-100 1A shrt fuel trim NA 11111111 1A O2 V 23 b*0.005 1B shrt fuel trim 24 b/128*100-100 1B shrt fuel trim NA 11111111 1B O2 V 24 b*0.005 1C OBDII CARB 10000000 1C OBD Fed 01000000 1C OBDII and OBD 11100000 1C OBD I 00100000 1C None 00110000 1D O2 location 11 1xxxxxxx 1D O2 location 12 x1xxxxxx 1D O2 location 21 xx1xxxxx 1D O2 location 22 xxx1xxxx 1D O2 location 31 xxxx1xxx 1D O2 location 32 xxxxx1xx 1D O2 location 41 xxxxxx1x 1D O2 location 42 xxxxxxx1 1E Power take off On 0------- 1E Power take off Off 1------- 1E Auxil input Reserved -0000000
current release no collision detect resend, watchdog timer = 2304ms
data return of 3 bytes: pid request and 2 data bytes
request byte 122 returns mode 02 pid 02 trouble code
request byte 144 clears DTC
DOS development terminal program with timer for continuious send and ISO
Development board box, connectors and cables $92 (includes one chip, assembled and tested)
Copyright © 1999-2001 Alex C. Peper. All Rights Reserved.
Reprinted with permission from SAE J1930, J1962, J1978, J1979, J2012, J2190, J1850, J2178 © 1997-1999 Society of Automotive Engineers, Inc.
California Air Resource Board
Equipment and Tool Institute
International Standards Organization
United States Code of Federal Regulations
Software name: Alex C. Peper OBD-2 ISO 9141-2, VPW or PWM to rs232 smart client written by Alex C. Peper
b.) "Hardware" shall mean a physical communication circuit device that transceives data on network.
Hardware device name: Alex C. Peper OBD-2 ACPGI ACPGV or ACPGP programmed and external circuit design by Alex C. Peper
c.) "Registered" shall mean a software and hardware combination purchased from Alex C.Peper
The software and or hardware is licensed to you by Alex C. Peper. You will own the media on which the above software files is recorded, but the author Alex C. Peper retains ownership, copyright, title, and exclusively reserves all rights to the software. The software is not in the public domain. The software and or hardware and any copies which this License authorizes you to make or subject to this License. You are not granted any rights to patents, tradenames,copyrights, trade marks franchises, or licenses rather registered our unregistered in respect of the software/hardware.
3. Permitted Uses and Restrictions This license allows you to install and use the software/hardware on a single network at a time. The license does not allow the software to exist on more than one computer at a time. Copies of software from one computer to another over a network or other means are not allowed. You can not distribute the software/hardware or any copy. You can not replicate and reproduce the hardware/software.
THE SOFTWARE/HARDWARE IS NOT INTENDED FOR USE IN OPERATION OF MOTOR VEHICLES, AIRCRAFT, MASS TRANSENT, LIFE SUPPORT,NUCLEAR, CHEMICAL AND OTHER FACILITIES AND OR MACHINES WHERE IN WHICH CASE THE USE, FAILURE OR MISUSE OF THE SOFTWARE/HARDWARE COULD LEAD TO DEATH, PERSONAL INJURY OR PHYSICAL AND ENVIRNOMENTAL DAMAGE AND OR VIOLATE ANY ENVIRNOMENTAL, SAFETY, TRANSPORTATION OR OTHER LAWS AND REGUALTIONS
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THE SOFTWARE/HARDWARE IS NOT INTENDED TO BE USED AS A DEFEAT DEVICE OF ANY DIAGNOSTIC SYSTEM OR CONTROL SYSTEM. IT IS USER RESPONSIBILITY TO OBTAIN ANY CERTIFICATION, RECERTIFICATION OR NEW CLASSIFICATIONS PERTAINING TO USE.
4. Limited warranty If software was obtained in a physical chip ROM medium it is warrant to be free of defects for 30 days from original purchase. Your exclusive remedy will be to receive a chip replacement. The hardware/software has a warranty of 30 days from orginal purchase to communicate with vehicle. Your exclusive remedy is to return hardware/software with vehicle model year, manufacturer, model name and vehicle identification number for replacement or refund at Alex C. Peper option.
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9. Government End Users If the software/hardware is supplied to US government, the software/hardware is classified as "restricted computer software" as defined in FAR 52.227-19
10. Governing Law and Severability This Agreement shall be governed by the laws of the country where the delivery is made to the orginal customer.
If for any reason a court of competent jurisdiction finds any provision, or portion thereof, to be unenforceable, the remainder of this License shall continue in full force and effect.
11. Agreement You acknowledge that you have read this agreement, understand it, and agree to be bound by its terms and conditions. Neither party shall be bound by any statement or representation not contained in this agreement. No change in this agreement is effective unless written and signed by authorized representatives of each party. By applying a potential difference to any pin or pad of hardware/software you agree to accept the terms of this agreement.