95 pontiac sse computer

Reply

  #1  
Old 10-22-06, 04:59 PM
Member
Thread Starter
Join Date: Oct 2006
Posts: 24
95 pontiac sse computer

I am repairing a 95 pontiac sse and cannot get the computer codes (there are probably several) to read on my scanner. Continues to say cannot link. I ASSUME the problem is the ECM itself. Is there a definitive way to KNOW when the ECM needs to be replaced?
 
Sponsored Links
  #2  
Old 10-22-06, 06:44 PM
HotxxxxxxxOKC's Avatar
Banned. Rule And/Or Policy Violation
Join Date: Jul 2006
Location: USA
Posts: 8,044
What type of scanner are you using? OBD II will only work on 96 and higher model years.
 
  #3  
Old 10-22-06, 06:49 PM
HotxxxxxxxOKC's Avatar
Banned. Rule And/Or Policy Violation
Join Date: Jul 2006
Location: USA
Posts: 8,044
If you are using a OBD 1 tool and still receiving those errors, it may be the ECM/PCM
 
  #4  
Old 10-22-06, 10:34 PM
Member
Thread Starter
Join Date: Oct 2006
Posts: 24
I am using an ODBII Actron brand scanner.
The Chilton's AND Haynes books said Pontiac
used OBDI till 94 and SOME 94 models (those with 16 pin connectors) were OBDII. ALL 1995 pontiac's used OBDII. This is a 95 with 16 pin connector so I feel relatively sure it is OBDII.
Further, I have used this scanner several times on other cars so I don't feel it could be the scanner.
 
  #5  
Old 10-22-06, 11:01 PM
Member
Join Date: Dec 2001
Posts: 2,538
95 was usually a switch over year some models were obd2 some were not but if it has an obd2 connector under the dash would expect it to be obd 2 does your scanner have different keys have you tried the generic obd 2 key?
if you have access to a manual they do have flow charts for testing a no communication problem to determine if its ecm or other problem such as ground or power to the connector.
 
  #6  
Old 10-22-06, 11:27 PM
Member
Thread Starter
Join Date: Oct 2006
Posts: 24
the manual has a typical flow chart- check grounds, fuses, tight connections etc. The car has no listing of which fuse goes where, printed on the lost cover I suppose, so it is possible that a fuse is missing which could connect the ECM and scanner together. With all the other problems the car has, a fried ECM would be par.
Example- after 1/3rd throttle, the rest of the pedal is useless. There is no RPM increase in the top 2/3rds of the pedal. Cable and connections are good. Bad ECMs in "limp-in" or "backup" mode are supposed to be enough to get you home but little else. This fits that description. And when you hold the pedal STILL at say 1/2 throttle the RPMs pulse from maybe 2000-5000, engine revving up and down over and over, all by itself. The computer HAS to be doing this

The scanner has only 1 connector, no keys to plug in.
The manual does not show a scan code for "ECM in backup mode" and I am not sure they have one. I have always heard that you try everything else and replace the ECM if nothing else works.
 
  #7  
Old 10-23-06, 08:27 AM
HotxxxxxxxOKC's Avatar
Banned. Rule And/Or Policy Violation
Join Date: Jul 2006
Location: USA
Posts: 8,044
Does this car have a MAF (Mass Air Flow Meter)? If this part is bad, it will not allow your motor to go over a certain RPM. Also, this vehicle can take a OBD II connector but is not OBD II compliant.
 
  #8  
Old 10-23-06, 10:52 AM
Member
Thread Starter
Join Date: Oct 2006
Posts: 24
It DOES have a mass airflow meter. However, as the ECM is not reading to my code reader, I can get no info on it. I now have a pullout ECM on order. Ebay-60 bucks-7 day return policy.
Car won't even start right now. I'll check the airflow meter soon as I get it in.
 
  #9  
Old 10-23-06, 11:44 AM
Banned. Rule And/Or Policy Violation
Join Date: Oct 2004
Posts: 120
does it have OBD I or II ?

looks like 94 and up bonneville/sse are OBD II


different scanner needed between these two systems

it is hard ot keep track of what year make models were still OBD I and which changed to II and when

it was pretty random and i forgot how ot identify them

some google research should come up with some good info
 
  #10  
Old 10-23-06, 01:12 PM
Member
Thread Starter
Join Date: Oct 2006
Posts: 24
going by the haynes and Chilton's manuals, they both say it is OBDII. Has the right connector for it.
New ECM should be here wednesday.
I'll find out then i suppose.
 
  #11  
Old 10-28-06, 01:11 PM
Member
Thread Starter
Join Date: Oct 2006
Posts: 24
well,
for those interested...
I got the new (pullout) ECM and installed it.
No change whatsoever!!

Still can't read anything with my OBDII scanner.
Keeps saying link error.
Found a ECM fuse under the hood on the firewall.
checks good. replaced it anyway.
same thing. Chilton's says there is a ECM harness ground by the ignition control module
(3 distibutor looking thing). Cannot see ANY grounds near that point.
Engine still acts EXACTLY the same as it did before. Revs up and down by itself if the throttle pedal is more than 1/2 way down. Bell rings every 30 seconds or so as if you just put the key in. Security light on. Several gauges acting strange.
I'm WAS thinking the ECM was in backup (broke ECM). New one acts identical so I doubt that is the problem.
What's the chances 2 bad ECMs are glitching in exactly the same way?
Checked EVERY fuse box (4) for bad or missing fuses, 1 missing - put in a 15 amp, 1 bad, replaced it.
No change. Don't know what those fuses went to.
Fuse panels not labeled. No owner's manual.

Is there a fuse for the code reader connector?
Checking the code reader on my 96 truck next.
I'm sure it is NOT the reader.

New (pullout) ECM from a Lumina. EBAY'd.
Same numbers on box. Looks the same.
What's the chance the MEM-CAL or EEPROM needs reprogramming? Or replaced?
 
  #12  
Old 10-28-06, 02:02 PM
Member
Join Date: Dec 2001
Posts: 2,538
would reinstall your old ecm as your new one may need reprogramed to match your car.
what exactly is the car doing if you atttempted to start it without appling any gas pedal will it start and idle will it stay running.
 
  #13  
Old 10-28-06, 02:41 PM
Member
Thread Starter
Join Date: Oct 2006
Posts: 24
starts and runs fine at idle.
without ever touching the pedal.

check this out.
Just checked my scanner on my 96 truck.
Reads fine. Scanner good.

So I looked at the pins in the ends of both connectors. All pins straight and clean but they
DON'T ALIGN WITH EACH OTHER.
And before you ask - yes I realized they are mirror images when looking at the face of each.

So, the plugs plug into each other but only a couple of the pins match up.
8 total pins (actual metal pins) on the reader,
6 total on the car.
Both have the 16 pin OBDII plastic connector.
2 rows of 8 HOLES.

SO, I went to the ACTRON website and saw that
there is an adapter for the 94-95 GM cars (as the OBDI/OBDII changeover was taking place).
However, the adapter shows one end, which will fit the reader, (2 rows of 8 with ODBII shape)
and the other end made for ODBI shape.
THAT end is smade to fit on the car but it I do not have and OBDI connector on the car!!

What the heck?

I know there was a lot of problems in the changeover years with conformity but this is getting rediculous.

Gonna check some other scanner websites and see if THEY can read a 95SSE with "1" type supercharged motor.
 
  #14  
Old 10-28-06, 03:06 PM
Member
Thread Starter
Join Date: Oct 2006
Posts: 24
My oh my.
I just found the problem

This thing is OBDI

It IS one of the changeover cars.
It uses an OBDII connector with OBDI technology.
Although several people asked if it was OBDI or OBDII, no one ever mentioned ODBI came in OBDII packaging.
Guess I should have read between the lines.
So much for the obvious.

Now to figure out which 2 leads to jump
and I can start counting flashes...

I hope.

The info was on a torn emission label on the radiator cover. Very small writing, very messy label.
 
  #15  
Old 10-28-06, 07:10 PM
HotxxxxxxxOKC's Avatar
Banned. Rule And/Or Policy Violation
Join Date: Jul 2006
Location: USA
Posts: 8,044
I told you in earlier posts that your car was OBD1 and not II.
 
  #16  
Old 10-28-06, 09:23 PM
Member
Thread Starter
Join Date: Oct 2006
Posts: 24
Rereading the posts- you were the only one convinced it was ODBI. Rock on.

Everyone else - including myself quessed ODBII

OBDII connector meant it was an OBDII as far as I knew. Books seemed to say it was OBDII, though they left a margin of error saying it was a changeover year.
I did not know it was possible to have OBDII connector with OBDI technology installed in it.

I wish you would have elaborated on your comment "this vehicle can take a OBD II connector but is not OBD II compliant." That made no sense to me at all.

I thought changeover year meant SOME cars were fully OBDI for a given manufacturer and the rest were fully OBDII.
This is some kinda frankenstein.

So what connector do I use?
The GM 94-95 OBDI/OBDII adapter sold for
my ACTRON will not hook up to the car.
It hooks to my scanner but has an OBDI style plug for the car. My car has a OBDII plug?
 
  #17  
Old 10-29-06, 12:11 AM
Member
Join Date: Dec 2001
Posts: 2,538
you might want to take it to a shop to have the codes read while im not familiar with your brand most shops will have a fairly expensive scanner that will do almost all models just by changing out connectors or cartrides never really had a problem scanning 95 models, this will also tell you if there is an actual problem with the car if another scanner will not communicate with it you may have a wiring problem.
 
  #18  
Old 10-30-06, 12:04 PM
Member
Thread Starter
Join Date: Oct 2006
Posts: 24
went to pontiac. talked to 2 technicians.
In the end they said pin 9 was the data link for the check engine light. either 5 or 8 for ground.
So, as you do for OBDI, I crossed them together to get the engine check light to blink and - nothing.

Light would not blink at all.
Still no codes.

Being this is an OBDI computer, is the engine check light supposed to blink to retrieve codes?
Or does this Frankenstein have to be read with a computer?
GM wasn't sure - and of course they throw away all books after 10 years...
 
  #19  
Old 11-14-06, 10:48 AM
Member
Thread Starter
Join Date: Oct 2006
Posts: 24
o.k.
with a snap-on computer ( a friend's) I was able to retreive codes QDM 640 and QDM 670.
According to the snap-on manuals this translates to codes 26 and 56 for OBDI.
According to a couple websites these codes are
QDM A and QDM B systems.
Can anyone tell me which circuits QDM A and B control?
 
  #20  
Old 11-14-06, 04:41 PM
HotxxxxxxxOKC's Avatar
Banned. Rule And/Or Policy Violation
Join Date: Jul 2006
Location: USA
Posts: 8,044
QDM A will always come up if the brakes are on and/or the engine is not running.

Quad-Driver Modules (QDM) are used to control certain components in some engine management systems. When the ECM is commanding a component "ON," the QDM closes the switch completing the circuit to ground. Each QDM output has a sense line. When a component is commanded "ON," the voltage potential on the sense line is low, and when the component is commanded "OFF" the voltage potential on the sense line is high. DTC 26 will set when the ECM is commanding a component "ON" and the voltage potential on a QDM "A" sense line is high, or if the component is commanded "OFF" and the voltage potential on a QDM "A" sensor line is low.

Either of these conditions will cause the QDM "A" fault line to display HIGH and set DTC 26. On all vehicles, the QDM "A" fault status on the scan tool will display HIGH with the brake applied or if the engine is not running. On vehicles with a 3T40 transmission, the QDM "A" fault status on the scan tool will read HIGH until the TCC in-line switch is closed. These conditions will not cause DTC 26 to set even though the fault line displays HIGH. To simulate driving in second gear and change the QDM status to low, disconnect TCC connector and connect a test light between harness terminals "A" and "D."

DTC 26 will set if:
The system is running in "CLOSED LOOP."
Brake switch is closed (brake not applied).
Transaxle in mid or high gear.
The ECM detects an improper voltage level on a QDM "A" controlled circuit for 10 seconds.
The ECM does not know which controlled circuit caused DTC 26, so each and every QDM circuit has to be tested to see which one caused the code to set.
 
  #21  
Old 11-14-06, 04:46 PM
HotxxxxxxxOKC's Avatar
Banned. Rule And/Or Policy Violation
Join Date: Jul 2006
Location: USA
Posts: 8,044
You will need wiring diagrams for this troubleshooting. If the problem isn't cured, then there is a good chance that the problem will cause the ECU to be damaged.
 
  #22  
Old 11-14-06, 06:29 PM
Member
Join Date: Feb 2006
Posts: 361
Post

91-95 GM OB1 Use jumper from ground to diagnostic terrninal but do not start car in this test mode. A terrninal is ground and b terrninal is diagnostic terrninal , Last two terrninals top right-
 
Reply

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Thread Tools
Search this Thread
Display Modes