1995 Oldsmobile 88

Tiny
SDECGREEN
  • MEMBER
  • 1995 OLDSMOBILE 88
  • 6 CYL
  • FWD
  • AUTOMATIC
  • 65,000 MILES
I cannot get my 1995 olds 88 to scan for a diagnostic code. Trouble light comes on when car is accelerated in the mid range, lifgt comes on and car appears to chug and skip. When connected to scanner output reads "unable to establish connection" have tried several different scanners with same results. Impossible to make a diagnosis without a trouble code. Why cannot scanner communicate with computer?
Monday, April 5th, 2010 AT 2:14 PM

12 Replies

Tiny
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Do you have 16 pin datalink connector? If so, at the least, you need an obd2 code reader. If you have the 12 pin datalink connector, you may be able to access trouble codes, without any special tools. 95 is a cross-over year between obd1 and 2, can be a a pain.

If your fully obd2 compliant, pin 16 is voltage, pins 4 & 5 are grounds. The scanner or code reader need both voltage and ground or it won't work. If what you have is a hybrid connector, not sure how to help?
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Monday, April 5th, 2010 AT 3:18 PM
Tiny
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It surely is obd2 what are you suggesting that I check 16 for voltage and 5 & 6 for ground? If so how?
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Monday, April 5th, 2010 AT 6:34 PM
Tiny
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Use a testlite on pin 16, see if there is voltage? If no voltage check the fuse, 9C--10amp-- left instrument panel fuse block. I believe it is pin 5, ground for the scanner. Both, 4 & 5 are grounds. To check any ground you can use a testlite connected to battery voltage, then touch the testlite to the terminal, if ground is good, the testlite comes on. I'm just talking about chassis grounds.


https://www.2carpros.com/forum/automotive_pictures/512072_olds88_data_link_connector_1.jpg

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Tuesday, April 6th, 2010 AT 9:07 AM
Tiny
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All wires check ok, 4 and 5 grounds fine. #9 only reads 4 volts appears to be data link wire to computer, tan wire. Checked wire at data link connector and other end at pcm with a sounder, appears ok. Still cannot read computer with scanner. I am baffled. A friend suugested I try to find an older scanner, claims new scanner may not recognize computer because " it may be to updated" does that sound like it makes sense. At this point I am willing to try anything even dynamite, lol. Whats your opinion.
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Thursday, April 8th, 2010 AT 9:10 PM
Tiny
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I'd have to use your scanner on a similiar vehicle, see if it works. Pin 16 has voltage?

All I can do now, is show you what MOD said about terminal 9. I had to look it up, because I don't know. Databases are not always correct.


https://www.2carpros.com/forum/automotive_pictures/512072_olds_88_1.jpg

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Friday, April 9th, 2010 AT 10:07 AM
Tiny
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I am having difficulty reading diagrams, when I try to enlarge they become fuzzy, any suggestions. I think I am getting beyond my ability, do you think the dealer can scan car and get a reading for trouble codes. I have been trying to avoid this but I am getting nowhere. Like I said all wires appear to check ok, can you simplify.
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Friday, April 9th, 2010 AT 2:22 PM
Tiny
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Are there any driveability issues? Right now, I don't know why the scanner won't work? With the key on, does the mil come on? I did enlarge, may not make any difference?


https://www.2carpros.com/forum/automotive_pictures/512072_95_olds_88_2_1.jpg

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Friday, April 9th, 2010 AT 3:34 PM
Tiny
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Yes there are driveability issues, check engine light keeps coming on and car skips and chugs when acclerating, that is why I am trying to scan to get a diagnostic code for this problem. You ask if mil comes on, what does "mil" stand for?
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Saturday, April 10th, 2010 AT 8:54 AM
Tiny
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Malfunction indicator lamp, mil, sounds like it is working. How long since a tune-up? A tune-up is a maintenance issue, it may or may not fix the problem. Use a gage and check fuel pressure.
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Saturday, April 10th, 2010 AT 10:24 AM
Tiny
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Full tune up recently, no help. Have not checked fuel pressure, will this trip check engine light?
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Sunday, April 11th, 2010 AT 12:32 PM
Tiny
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Fuel pressure by itself, no. If the fuel issue caused a misfire, obd2, yes, a misfire can cause a code to set.
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Sunday, April 11th, 2010 AT 12:56 PM
Tiny
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Replaced o2 sensor no help. Could not deal with this much longer, brought it to dealer, their scanner immediately read some codes, replaced cam shaft and crank shaft sensors, no help, told them I replaced both of those sensors 10,000 miles ago, they just called me and told me they are now getting some different codes, going to get back to me in a little bit. I am lost, least they are able to communicate with their scanner. What do you think?
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Monday, April 12th, 2010 AT 12:20 PM

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