Converting OBD1 to OBD2
#1
Pole Position
Thread Starter
Converting OBD1 to OBD2
How would I get Obd 2 readings on my 1993 lexus sc300 ? Im looking for an easy way although it may not be simple i just want to be able to plug in the obd2 and get readings off my computer
#3
Instructor
iTrader: (5)
Simple. Just replace the ENTIRE wiring harness for the motor and body plus various ECUs.
You'll be enlightened and bestowed with the incredible world of OBD2 codes that tell you virtually nothing about what's REALLY broken on the car. Wonderful codes like P0442 will make you wish you could revert to OBD1 just so you pass inspection again (welcome to NY!)
You'll be enlightened and bestowed with the incredible world of OBD2 codes that tell you virtually nothing about what's REALLY broken on the car. Wonderful codes like P0442 will make you wish you could revert to OBD1 just so you pass inspection again (welcome to NY!)
#5
Moderator
iTrader: (5)
Jwynn, regardless of the work involved to convert an OBD1 car to an OBD2 car I can't see much advantage in this, even if all you want to do is look up error codes. Yes, as SC400slide says, the paperclip method works best.
There are so many practical positives to OBD1 cars that outweigh anything an OBD2 conversion could give you.
There are so many practical positives to OBD1 cars that outweigh anything an OBD2 conversion could give you.
#6
Lead Lap
iTrader: (1)
http://www.supraforums.com/forum/sho...D2-ECU-Upgrade
this is the only way I have known hoe but never tried. I think its only to cgange fuel maps though and not get codes. but you do need a new ecu for it off a obd2 sc300, gs300, or supra.
this is the only way I have known hoe but never tried. I think its only to cgange fuel maps though and not get codes. but you do need a new ecu for it off a obd2 sc300, gs300, or supra.
#7
Lexus Champion
iTrader: (10)
as long as your car is obd1, even if you convert it to obd2 you dont have to go around advertising it to emissions stations, just keep the port in the glovebox or something.
its not that hard actually, you just need to install an obd2 ecu, wire up the new maf sensor, and there are 1-2 extra wires for the obd2 port from the ecu. you just grab a universal obd2 port and wire it up, reusing most of the wires from your current obd1 port except the 1-2 new ones mentioned above.
Grumpi is correct this thread has all the info but for a 2jzgte car.
http://www.supraforums.com/forum/sho...D2-ECU-Upgrade
the reason on your car why you have to wire up a new maf, is unlike the 2jzgte which shared the same maf between obd1 and obd2, our cars switched mafs when going to obd2, and the obd2 uses 12V and a chassis ground (obd2 maf same style as gte maf) instead of 5V and sensor ground (old obd1 maf only on 2jzge) so it must be rewired to get power from a switched 12V wire in the engine bay which there are tons, and a regular old ground.
once you do all that you will get to pull codes and read engine diagnoistics etc... via the obd2 port, but do realize that the obd2 ecu is more sensitive, and could create driving issues that you don't have right now unless you set it up pretty much factory.
so obd2 ecu, obd2 maf, obd2 maf connector, rewire the maf, wire up universal obd2 port, hope engine runs as well.
it will also throw a code for missing the second crank sensor (96-97 2jzge), but I don't think that effects how it drives its only used on those for misfire detection.
its not that hard actually, you just need to install an obd2 ecu, wire up the new maf sensor, and there are 1-2 extra wires for the obd2 port from the ecu. you just grab a universal obd2 port and wire it up, reusing most of the wires from your current obd1 port except the 1-2 new ones mentioned above.
Grumpi is correct this thread has all the info but for a 2jzgte car.
http://www.supraforums.com/forum/sho...D2-ECU-Upgrade
the reason on your car why you have to wire up a new maf, is unlike the 2jzgte which shared the same maf between obd1 and obd2, our cars switched mafs when going to obd2, and the obd2 uses 12V and a chassis ground (obd2 maf same style as gte maf) instead of 5V and sensor ground (old obd1 maf only on 2jzge) so it must be rewired to get power from a switched 12V wire in the engine bay which there are tons, and a regular old ground.
once you do all that you will get to pull codes and read engine diagnoistics etc... via the obd2 port, but do realize that the obd2 ecu is more sensitive, and could create driving issues that you don't have right now unless you set it up pretty much factory.
so obd2 ecu, obd2 maf, obd2 maf connector, rewire the maf, wire up universal obd2 port, hope engine runs as well.
it will also throw a code for missing the second crank sensor (96-97 2jzge), but I don't think that effects how it drives its only used on those for misfire detection.
Last edited by Ali SC3; 06-09-15 at 12:46 PM.
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