code reader for GM

J

Jon G.

Guest
I have a 94 Pontiac Bonneville. The check engine light goes on
sometimes. At idle, the oil pressure oscillates up and down.
The check engine light usually goes on after going high speed
and slowing down to a stop.

I have tried to find a code reader for it. The connector is
trapezoid (D-shaped). This is supposed to mean that the
computer is OBD II, but since the car is a 94, it was during a
hybrid year and needs a OBD I to OBD II adapter.

Can anyone tell me a way to read the codes?

Jon
 
Jon G. wrote:
I have a 94 Pontiac Bonneville. The check engine light goes on
sometimes. At idle, the oil pressure oscillates up and down.
The check engine light usually goes on after going high speed
and slowing down to a stop.

I have tried to find a code reader for it. The connector is
trapezoid (D-shaped). This is supposed to mean that the
computer is OBD II, but since the car is a 94, it was during a
hybrid year and needs a OBD I to OBD II adapter.

Can anyone tell me a way to read the codes?

Jon
Click to expand...
They both have rounded edges. obd2 is truncated trap - 16 pins.
obdi is D shaped - 12 pins. A 94 should be obdi.
 
Dick C wrote:
Ť Paul ť wrote in alt.autos.gm

Jon G. wrote:

I have a 94 Pontiac Bonneville. The check engine light goes on
sometimes. At idle, the oil pressure oscillates up and down.
The check engine light usually goes on after going high speed
and slowing down to a stop.

I have tried to find a code reader for it. The connector is
trapezoid (D-shaped). This is supposed to mean that the
computer is OBD II, but since the car is a 94, it was during a
hybrid year and needs a OBD I to OBD II adapter.

Can anyone tell me a way to read the codes?

Jon

They both have rounded edges. obd2 is truncated trap - 16 pins.
obdi is D shaped - 12 pins. A 94 should be obdi.

The problem is that in 94-95 GM used the OBDI system with an OBDII
connector. Dealers usually have the scanner, but that, of course,
costs alot of money just to have the codes read.
Click to expand...
Hmm.. I'm probably wrong but I thought GM did not start using the
obd 1.5 until the 95 model year?
 
Jon G. wrote:
Hi,

thanks for your help all.

My OBD II connector has pins 4,5,8,9,14,16 populated. This
doesn't match *any* of the standard configurations for OBD II
scanners (there are 4 protocols). From what I can determine,
the pinouts are,

pin 4 chassis ground
pin 5 signal ground
pin 8 ?
pin 9 signal ?
pin 14 CAN Low (J-2284)
pin 16 battery power
Click to expand...
How do you know your aldl is what you have described above?
You cannot jump pins to flash codes. You need a reader capable
of reading obd 1.5. In other words, some of your car is obd 1 and
some is obd 2. Call around and find a shop with a reader.
 
Ť Paul ť wrote in alt.autos.gm

Dick C wrote:


Ť Paul ť wrote in alt.autos.gm


Jon G. wrote:

I have a 94 Pontiac Bonneville. The check engine light goes on
sometimes. At idle, the oil pressure oscillates up and down.
The check engine light usually goes on after going high speed
and slowing down to a stop.

I have tried to find a code reader for it. The connector is
trapezoid (D-shaped). This is supposed to mean that the
computer is OBD II, but since the car is a 94, it was during a
hybrid year and needs a OBD I to OBD II adapter.

Can anyone tell me a way to read the codes?

Jon

They both have rounded edges. obd2 is truncated trap - 16 pins.
obdi is D shaped - 12 pins. A 94 should be obdi.


The problem is that in 94-95 GM used the OBDI system with an OBDII
connector. Dealers usually have the scanner, but that, of course,
costs alot of money just to have the codes read.

Hmm.. I'm probably wrong but I thought GM did not start using the
obd 1.5 until the 95 model year?
Click to expand...
Late 94 I think.

--
Dick #1349
"They that can give up essential liberty to obtain a little temporary
safety deserve neither liberty nor safety."
~Benjamin Franklin

Home Page: dickcr.iwarp.com
email: dickcr@comcast.net
 
Ť Paul ť wrote:
Jon G. wrote:

Hi,

thanks for your help all.

My OBD II connector has pins 4,5,8,9,14,16 populated. This
doesn't match *any* of the standard configurations for OBD II
scanners (there are 4 protocols). From what I can determine,
the pinouts are,

pin 4 chassis ground
pin 5 signal ground
pin 8 ?
pin 9 signal ?
pin 14 CAN Low (J-2284)
pin 16 battery power


How do you know your aldl is what you have described above?
You cannot jump pins to flash codes. You need a reader capable
of reading obd 1.5. In other words, some of your car is obd 1 and
some is obd 2. Call around and find a shop with a reader.
Click to expand...
If it's OBD I, you can jump two of the pins. Under the hood it
says the car is OBD I compliant, but under the dash it has and
OBD II connector.

the female looks like,

----------------------------
\ 1 2 3 4 5 6 7 8 /
\ 9 10 11 12 13 14 15 16 /
-----------------------

the following pins are populated:

pin 4 solid black
pin 5 black with white stripe
pin 8 black with white stripe
pin 9 tan
pin 14 green
pin 16 orange

compare this with the OBM II protocols:

J1850 VPW pins 2,4,5 and 16
ISO 9141 pins 4,5,7,15 and 16
J1850 PWM pins 2,4,5,10 and 16

Short-circuiting pin 4 and 15 of an SAE J1962 connector for 3
sec gets the check engine blinking.

The pin configuration on my car doesn't match any of the OBD II
scanner protocols. Will a code scanner still work? If the car
is and OBD I with an OBD II connector, then which pins do I jump
to pull a code from the blinking check engine light?

Jon
 
I've got a 94 bonneville SSEi. Bought an Actron OBDI reader and a cable to
connect to the car with the OBDII type connector, works great.

Look on Ebay.

Or take it to the dealer and pay 'em a few bucks to tell you the code.
Cheaper than trying to guess the problem and buying unnecessary parts.
My dealer charges about $30 to just read a code. Sometimes they do it for
free. If I need them to diagnose the exact problem they charge me about
$55. Which applies to the repair cost if I let them make the repair.
"Jon G." <jon8338@peoplepc.com> wrote in message
news:hxyhd.14900$5i5.1496@newsread2.news.atl.earthlink.net...
I have a 94 Pontiac Bonneville. The check engine light goes on sometimes.
At idle, the oil pressure oscillates up and down. The check engine light
usually goes on after going high speed and slowing down to a stop.

I have tried to find a code reader for it. The connector is trapezoid
(D-shaped). This is supposed to mean that the computer is OBD II, but
since the car is a 94, it was during a hybrid year and needs a OBD I to
OBD II adapter.

Can anyone tell me a way to read the codes?

Jon
Click to expand...
 
Ť Paul ť wrote in alt.autos.gm

Jon G. wrote:

I have a 94 Pontiac Bonneville. The check engine light goes on
sometimes. At idle, the oil pressure oscillates up and down.
The check engine light usually goes on after going high speed
and slowing down to a stop.

I have tried to find a code reader for it. The connector is
trapezoid (D-shaped). This is supposed to mean that the
computer is OBD II, but since the car is a 94, it was during a
hybrid year and needs a OBD I to OBD II adapter.

Can anyone tell me a way to read the codes?

Jon

They both have rounded edges. obd2 is truncated trap - 16 pins.
obdi is D shaped - 12 pins. A 94 should be obdi.
Click to expand...
The problem is that in 94-95 GM used the OBDI system with an OBDII
connector. Dealers usually have the scanner, but that, of course,
costs alot of money just to have the codes read.



--
Dick #1349
"They that can give up essential liberty to obtain a little temporary
safety deserve neither liberty nor safety."
~Benjamin Franklin

Home Page: dickcr.iwarp.com
email: dickcr@comcast.net
 
Jon G. wrote:
If it's OBD I, you can jump two of the pins. Under the hood it
says the car is OBD I compliant, but under the dash it has and
OBD II connector.

the female looks like,

----------------------------
\ 1 2 3 4 5 6 7 8 /
\ 9 10 11 12 13 14 15 16 /
-----------------------

the following pins are populated:

pin 4 solid black
pin 5 black with white stripe
pin 8 black with white stripe
pin 9 tan
pin 14 green
pin 16 orange

compare this with the OBM II protocols:

J1850 VPW pins 2,4,5 and 16
ISO 9141 pins 4,5,7,15 and 16
J1850 PWM pins 2,4,5,10 and 16

Short-circuiting pin 4 and 15 of an SAE J1962 connector for 3
sec gets the check engine blinking.

The pin configuration on my car doesn't match any of the OBD II
scanner protocols. Will a code scanner still work? If the car
is and OBD I with an OBD II connector, then which pins do I jump
to pull a code from the blinking check engine light?

Jon
Click to expand...
I have never heard of anyone ever jumping pins on obd 1.5 and
getting more than a burned out ecu. It has always been my understanding
that you need a obd 1.5 reader - which is a obd 1 serial reader
that can interpret some obd 2 data.
You could try it. There are many people who would like to know how to do it.
If you can figure it out, please let alt.autos.gm know.
 
I would suggest going out and getting a copy of the CHILTON manual for that
particular car.

I have a '94 Chevy Blazer and have to read the codes myself. For my
particular model
I just jumper pins 1-2 with the ignition OFF. When I turn the key to the ON
position, the
'check engine' will start to blink giving you the error code. The pattern
varies with the
problem, and the Chilton's manual will have the codes listed.

This is a quick way to determine what the computer has in it's memory.

Craig
"Jon G." <jon8338@peoplepc.com> wrote in message
news:hxyhd.14900$5i5.1496@newsread2.news.atl.earthlink.net...
I have a 94 Pontiac Bonneville. The check engine light goes on
sometimes. At idle, the oil pressure oscillates up and down.
The check engine light usually goes on after going high speed
and slowing down to a stop.

I have tried to find a code reader for it. The connector is
trapezoid (D-shaped). This is supposed to mean that the
computer is OBD II, but since the car is a 94, it was during a
hybrid year and needs a OBD I to OBD II adapter.

Can anyone tell me a way to read the codes?

Jon
Click to expand...
 
Hi,

thanks for your help all.

My OBD II connector has pins 4,5,8,9,14,16 populated. This
doesn't match *any* of the standard configurations for OBD II
scanners (there are 4 protocols). From what I can determine,
the pinouts are,

pin 4 chassis ground
pin 5 signal ground
pin 8 ?
pin 9 signal ?
pin 14 CAN Low (J-2284)
pin 16 battery power

Then someone wrote,

"Yes, some OBD-II equipped vehicles have a hybrid system where
the PCM is OBDII and the other modules in the vehicle are
pre-OBDII, 8192 baud UART. The vehicle will typically have a PIM
(Powertrain Interface Module) that converts the OBDII to 8192
UART and back again to facilitate comms between the two
different systems.

The OBD-II connector uses pin 9 to provide access to the 8192
UART data of the non-OBDII modules."

Can I jump 2 of the pins for a flashing Check Engine light code
readout? If so, which ones?



Dick C wrote:
Ť Paul ť wrote in alt.autos.gm


Jon G. wrote:

I have a 94 Pontiac Bonneville. The check engine light goes on
sometimes. At idle, the oil pressure oscillates up and down.
The check engine light usually goes on after going high speed
and slowing down to a stop.

I have tried to find a code reader for it. The connector is
trapezoid (D-shaped). This is supposed to mean that the
computer is OBD II, but since the car is a 94, it was during a
hybrid year and needs a OBD I to OBD II adapter.

Can anyone tell me a way to read the codes?

Jon

They both have rounded edges. obd2 is truncated trap - 16 pins.
obdi is D shaped - 12 pins. A 94 should be obdi.


The problem is that in 94-95 GM used the OBDI system with an OBDII
connector. Dealers usually have the scanner, but that, of course,
costs alot of money just to have the codes read.
Click to expand...
 
Jon G. wrote:
Ť Paul ť wrote:

Jon G. wrote:

Hi,

thanks for your help all.

My OBD II connector has pins 4,5,8,9,14,16 populated. This
doesn't match *any* of the standard configurations for OBD II
scanners (there are 4 protocols). From what I can determine,
the pinouts are,

pin 4 chassis ground
pin 5 signal ground
pin 8 ?
pin 9 signal ?
pin 14 CAN Low (J-2284)
pin 16 battery power



How do you know your aldl is what you have described above?
You cannot jump pins to flash codes. You need a reader capable
of reading obd 1.5. In other words, some of your car is obd 1 and
some is obd 2. Call around and find a shop with a reader.


If it's OBD I, you can jump two of the pins. Under the hood it says the
car is OBD I compliant, but under the dash it has and OBD II connector.

the female looks like,

----------------------------
\ 1 2 3 4 5 6 7 8 /
\ 9 10 11 12 13 14 15 16 /
-----------------------

the following pins are populated:

pin 4 solid black
pin 5 black with white stripe
pin 8 black with white stripe
pin 9 tan
pin 14 green
pin 16 orange

compare this with the OBM II protocols:

J1850 VPW pins 2,4,5 and 16
ISO 9141 pins 4,5,7,15 and 16
J1850 PWM pins 2,4,5,10 and 16

Short-circuiting pin 4 and 15 of an SAE J1962 connector for 3 sec gets
the check engine blinking.

The pin configuration on my car doesn't match any of the OBD II scanner
protocols. Will a code scanner still work? If the car is and OBD I
with an OBD II connector, then which pins do I jump to pull a code from
the blinking check engine light?

Jon
Click to expand...

Hi...

Dunno if it'll help to clarify things a bit, or just
muddy the waters more, but...

Mine is the 12 pin system. (and I have a mickey mouse
reader for it). The pins are lettered (opposed to numbered)
and according to the book that came with the reader A is ground.
B is the diagnostic test terminal. Shorting A and B
causes the check light to flash the codes.

My Haynes book says for the 12 bit type I need only
short A + B... and it works... but for the 16 bit type
I would need a reader.

Ken
 
Hi Jeff &

I think the idea was to use an OBDII scanner to read the OBDI
system, since OBDII scanners often read OBDI as well. I don't
know this for sure. Under the hood the car is labeled as OBDI
compliant, so likely it's OBDI with an OBDII connector. If this
is the case, your Actron OBDI reader would work on my 94
Bonneville as well. Thank you for your insight.

I have a friend who has an OBDI reader. Maybe all I need is the
adapter cable. I could do without the reader or cable if I only
knew what the OBDII connector wires/pins, correspond to the OBDI
connector, and jump a couple of them for a flashing check engine
light code readout.

Jeff & Carol wrote:

I've got a 94 bonneville SSEi. Bought an Actron OBDI reader and a cable to
connect to the car with the OBDII type connector, works great.

Look on Ebay.

Or take it to the dealer and pay 'em a few bucks to tell you the code.
Cheaper than trying to guess the problem and buying unnecessary parts.
My dealer charges about $30 to just read a code. Sometimes they do it for
free. If I need them to diagnose the exact problem they charge me about
$55. Which applies to the repair cost if I let them make the repair.
"Jon G." <jon8338@peoplepc.com> wrote in message
news:hxyhd.14900$5i5.1496@newsread2.news.atl.earthlink.net...

I have a 94 Pontiac Bonneville. The check engine light goes on sometimes.
At idle, the oil pressure oscillates up and down. The check engine light
usually goes on after going high speed and slowing down to a stop.

I have tried to find a code reader for it. The connector is trapezoid
(D-shaped). This is supposed to mean that the computer is OBD II, but
since the car is a 94, it was during a hybrid year and needs a OBD I to
OBD II adapter.

Can anyone tell me a way to read the codes?

Jon
Click to expand...
 
Something's going on here.

If I buy and Actron OBDI reader, complete with OBDI and OBDII
cables, then I could map how the OBDI reader converts to OBDII
pinouts, with an ohm meter, testing continuity between either
ends of the cable for each pin, and then correllating.

Jon

Jeff & Carol wrote:

I've got a 94 bonneville SSEi. Bought an Actron OBDI reader and a cable to
connect to the car with the OBDII type connector, works great.

Look on Ebay.

Or take it to the dealer and pay 'em a few bucks to tell you the code.
Cheaper than trying to guess the problem and buying unnecessary parts.
My dealer charges about $30 to just read a code. Sometimes they do it for
free. If I need them to diagnose the exact problem they charge me about
$55. Which applies to the repair cost if I let them make the repair.
"Jon G." <jon8338@peoplepc.com> wrote in message
news:hxyhd.14900$5i5.1496@newsread2.news.atl.earthlink.net...

I have a 94 Pontiac Bonneville. The check engine light goes on sometimes.
At idle, the oil pressure oscillates up and down. The check engine light
usually goes on after going high speed and slowing down to a stop.

I have tried to find a code reader for it. The connector is trapezoid
(D-shaped). This is supposed to mean that the computer is OBD II, but
since the car is a 94, it was during a hybrid year and needs a OBD I to
OBD II adapter.

Can anyone tell me a way to read the codes?

Jon
Click to expand...
 
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