1995 Chevy S-10

1995 CHEVROLET S-10
181,000 MILES • 4 CYL • 2WD • AUTOMATIC
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RRFIELS65
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16 pin aldl obd1.5

To any body else that owns one of these

and any other 94-95 car or trck model with PCM OBD1.5 located under glovebox/kick panel,true OBD2
PCM's are located in engine compartment.
They also have a knock sensor mounted atop of it.
along with a MAF and a extra heated O2 sensor at
back of the CAT/Convt.
OBD1,OBD1.5 have a removeable PROM - OBD2 has
a EEPROM and is not removeable.

OBD1 was flashed with 160 baud/8192baud(J2234)
OBD1.5 with 160/8192 w/UART(J1849vpw)
OBD2 with 160/8198 w/UART-CAN H+/L-(J1850vpw)

OBD1 12 pin / A=Blk.w/Wht. wire(ECM signal grd.)
B=Wht.w/Blk. wire(160)
D=Wht. wire (UART) ABS
E=Tan w/Blk. wire (8192)
M=Orange wire (12vdc)
Jump A+B get code flashout,clear codes by unhooking Neg.post on battery.

OBD1.5 16 pin / pin4=Chasiss Grd.(Blk. wire)
pin5=PCM Signal Grd.(Blk.w/Wht.wire
pin6=160/canh+(Wht.w/Blk.wire)
pin9=8192 (Tan w/Blk.wire)
pin12=UART(Wht. wire)ABS
pin14=UART(pink wire)canL-
pin16=(12vdc)Orange wire
Jump 5+6 get code flashout,to clear out codes a scan
ner w/ OBD1/OBD2 protocals is needed with a GM
Specific (16 pin connector-Blue plug-in) or go to junk
yard and get a 12 pin ALDL and wire it like so.

( A to pin5 ,B to pin6 ,E to pin9 ,M to pin16)
Use the OBD1 connector on the 12 pin ALDL.
Sep 25, 2009 at 7:07 PM
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95SONOMADRIVER
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I have a 1995 Sonoma also 4cyl 2WD but stick and I seem to have a similar problem. But this post is the first I have ever heard of OBD1.5

I have an ODB2 data port under the dash on the driver side. I haven't climbed under it to look really close at the pins that are present/absent.

A couple of questions...

1) By "true OBD2 PCMs are located in the engine compartment," are you saying that all unless you're directly connecting to the computer, your system is NOT an OBD2 design?

2) Can I take an ODB2 cable and hook it up to an OBD1 scanner to read ODB1 and OBD1.5 codes (whichever my truck has)? Or do I have to use the ALDL cable and a PC/laptop?

Thanks!
Oct 22, 2009 at 9:51 PM
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RRFIELS65
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Answer: 1 You have a 16 pin ALDL-if your pcm is inside the engine compartment , you should be OBD2
1996 EPA compliant.Any scanner with OBD2 protocals
w/a yellow 16pin ALDL plug should access computer.
If Computer is up under glovebox-you have a 1.5 OBD
it has a removeable PROM/MEM-CAL which can be re-
flashed(programmed) for performance.

Answer:2 YES to both, as long as you have the blue
16 pin ALDL GM Specific plug and your scanner has
OBD1/OBD2 protocals. (I use a AutoXray2500)
The yellow 16 pin ALDL plug is only for vechicles aft.
1995(1996 to present)

I hope this puts some light to this dark area
Oct 23, 2009 at 8:20 PM
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