What is the protocol to obtain misfire data on cylinders for a '99 Cad Deville?

Thread view:

Enable EMail Alerts

Start New Thread

Thread rating:

Rich - 20 Dec 2005 02:59 GMT

Does anyone know how to query the PCM computer to give a count of
misfires on each cylinder? My OBDII system is just an interface to my
laptop and apparently the GM recommended scantool is capable of
showing counts of misfires on each cylinder. That would be very
useful.

This is on a 1999 Cad Deville 4.6 liter Northstar. The misfire codes
for each cyl are P0301 thru P0308.

TIA, Rich

Reply to this Message

Stephen H - 20 Dec 2005 18:22 GMT

You really need a scanner capable of giving that data.
There are about 9 current channels (Modes f-1 through f-9) that give out
data or take requests on the cars computer (More are out there but reserved
for later use) A basic scanner is only accessing one or two of these modes,

Signature

Stephen W. Hansen
ASE Certified Master Automobile Technician
ASE Automobile Advanced Engine Performance
ASE Undercar Specialist

http://autorepair.about.com/cs/troubleshooting/l/bl_obd_main.htm
http://www.troublecodes.net/technical/

> Does anyone know how to query the PCM computer to give a count of
> misfires on each cylinder? My OBDII system is just an interface to my
[quoted text clipped - 6 lines]
>
> TIA, Rich

Reply to this Message

Woody - 20 Dec 2005 20:44 GMT

What scanner are you using? Does it support Enhanced data? The laptop based
unit I use shows it....

> Does anyone know how to query the PCM computer to give a count of
> misfires on each cylinder? My OBDII system is just an interface to my
[quoted text clipped - 6 lines]
>
> TIA, Rich

Reply to this Message

Rich - 20 Dec 2005 21:47 GMT

I'm using the Elm 322 chip in the circuit marketed by Scantool.net.
It translates from the GM flavor OBDII to a serial port. So far as I
know, this circuit is not limited in the mode or type of data that it
can transmit or receive.

What is enhanced data? I do know that my software will not show
HISTORY codes, but only current codes. I have several of the free
OBDII software packages- Scantool.net, Digimoto. OBDII Logger, etc.

Do you know where the software developers get the commands in order to
produce the ODB software?

>What scanner are you using? Does it support Enhanced data? The laptop based
>unit I use shows it....
[quoted text clipped - 9 lines]
>>
>> TIA, Rich

Reply to this Message