Whats the difference between OBDI and OBDII
Thread Starter
Teching In
Joined: Nov 2002
Posts: 20
Likes: 0
From: Los Angeles, Ca
Whats the difference between OBDI and OBDII I have a 1995 (production 11/94 on door) chevy camaro, and was wondering what the differnce is? My car has a lable in the radiator shroud that says its OBDI but it also has a plug under the dash thats made for the OBDII scanner.
Is one better than the other? Can you still run LT1 edit on this car? Any help is appreciated. thanks.
Is one better than the other? Can you still run LT1 edit on this car? Any help is appreciated. thanks.
TECH Resident
Joined: Jan 2002
Posts: 754
Likes: 0
From: USA
Re: Whats the difference between OBDI and OBDII OBD-I of course means the 1st generation of cars required to support functions in engine being monitored by the ECM (engine's computer)
In 1996 OBD-II became a requirement by EPA and monitors/controls many more functions due to tighter rules as to smog laws and what had to be controlled by the PCM ( next gen engine computer)
GM began shifting over to OBD-II in '96 but began using the 16 pin ADLC connector in all '94 MY cars since EPA was requiring all carmakers use a common connector but car models that would not exist pat 1995 like the ZR-1 Corvette kept using the older ECM but still had to have the standard 16 pin ADLC connector and those models that would need to comply to new EPA standards for 96 switched to a PCM.
94 and 95 MYs got caught in the shift from OBD-I to OBD-II but there are scanners and PCM programmers on the market for them.
<small>[ December 09, 2002, 10:55 PM: Message edited by: Team ZR-1 ]</small>
In 1996 OBD-II became a requirement by EPA and monitors/controls many more functions due to tighter rules as to smog laws and what had to be controlled by the PCM ( next gen engine computer)
GM began shifting over to OBD-II in '96 but began using the 16 pin ADLC connector in all '94 MY cars since EPA was requiring all carmakers use a common connector but car models that would not exist pat 1995 like the ZR-1 Corvette kept using the older ECM but still had to have the standard 16 pin ADLC connector and those models that would need to comply to new EPA standards for 96 switched to a PCM.
94 and 95 MYs got caught in the shift from OBD-I to OBD-II but there are scanners and PCM programmers on the market for them.
<small>[ December 09, 2002, 10:55 PM: Message edited by: Team ZR-1 ]</small>
Re: Whats the difference between OBDI and OBDII There are numerous differences between OBDI and OBDII. Hardware level (voltage signals), protocol level (acutal data bits and rates), and parameter values. OBDII was a way for the gov't to force a little bit of standardization on car manufacturers. A P0300 on a Chrysler means misfire - just like it means it on a Chevy (in OBDII).
Under OBDI, there was no such restriction or standardization. Codes were placed wherever manufacturers wanted to put them. GM has over 200 OBDI protocols. <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" />
As for your LT1, it is a true OBDI PCM, but it got the OBDII connector. Why did GM do that? I have a feeling it has to do with some of the other devices in your car, but not the PCM. The 94-95 F-body PCM (p/n 16188051) has no OBDII functionality in it. The 94-95 Corvette was a true hybrid OBDI-OBDII PCM, but the F-body (which has a different part number, and has fewer components inside the PCM) is not.
As for LT1Edit for OBDI, yes, you can use it. For some more info, go here: http://www.akmcables.com (shameless plug <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" /> ).
-Andrew
Under OBDI, there was no such restriction or standardization. Codes were placed wherever manufacturers wanted to put them. GM has over 200 OBDI protocols. <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" />
As for your LT1, it is a true OBDI PCM, but it got the OBDII connector. Why did GM do that? I have a feeling it has to do with some of the other devices in your car, but not the PCM. The 94-95 F-body PCM (p/n 16188051) has no OBDII functionality in it. The 94-95 Corvette was a true hybrid OBDI-OBDII PCM, but the F-body (which has a different part number, and has fewer components inside the PCM) is not.
As for LT1Edit for OBDI, yes, you can use it. For some more info, go here: http://www.akmcables.com (shameless plug <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" /> ).
-Andrew
