In another thread posted a few weeks back, there was a discussion concerning whether to decommission and remove an OBD I first generation computer? subsystem, based on a question and posting from a member.
While digging through one of my file binders for the paperwork on a pair of Magnaflow mufflers that I had plans to rehab and return back to service in my Monte, I came across this:
A long time ago, back before I was able to locate and score a complete service manual of my own, I discovered that my local library actually had copies of the service manuals on file. That and a whole bunch of change let me selectively copy the most important pages and diagrams that, at the time, I had most need of.
What you see above is the complete wiring diagram for the first generation OBD I Electronic Control Module, aka the "computer". Everything shown on this diagram provides or returns input back to the module. For anyone contemplating the elimination of a malfunctioning or dead module, these are all the sensors and circuits that would have to be deleted or edited as well.
Me? Been there-done that, burnt the T-shirt years ago. All this was what I had to personally wade through just to get my own car to run properly when I first scored it.
Although not present on this diagram, as it has been edited to remove application titles and captions, it is relevant to both Monte Carlos and El Caminos that came with the first gen system. The diagram itself should be clear enough that someone reviewing it can identify both the various sensors used in the system as well as the color of wires in the various harnesses and where they plug in as part of the sockets that communicate with the board. Power to the module is not directly shown but, for reference, comes from the battery via that large copper stud on the solenoid. I elected to load this diagram in as a j-peg so anyone can grab it and download it for themselves. Once you have it, you can enlarge it to get a better view or create clearer text.
As was noted earlier, If the plan is to get rid of this whole mess, do be aware that you will also have to address both the distributor and the carb as they both depend on the module for input and guidance as well. Neither unit works too well on its own. The easiest solution for them is to locate and buy either older versions that can be tuned and tweaked manually, or go brand new. aftermarket hi-po.
One suggestion, if the plan is to delete this system, don't do it with a pair of side cutters and a trash can. While you may have no use for what you see as worthless crap, someone else on the board might be looking for all this stuff, particularly the various wiring harnesses and plugs and could easily be willing to pay to take it off your hands. Sure the stuff is old and might be sketchy but even a dead sensor or plug is useful for show and tell at the local parts store or on line.
Nick
While digging through one of my file binders for the paperwork on a pair of Magnaflow mufflers that I had plans to rehab and return back to service in my Monte, I came across this:
A long time ago, back before I was able to locate and score a complete service manual of my own, I discovered that my local library actually had copies of the service manuals on file. That and a whole bunch of change let me selectively copy the most important pages and diagrams that, at the time, I had most need of.
What you see above is the complete wiring diagram for the first generation OBD I Electronic Control Module, aka the "computer". Everything shown on this diagram provides or returns input back to the module. For anyone contemplating the elimination of a malfunctioning or dead module, these are all the sensors and circuits that would have to be deleted or edited as well.
Me? Been there-done that, burnt the T-shirt years ago. All this was what I had to personally wade through just to get my own car to run properly when I first scored it.
Although not present on this diagram, as it has been edited to remove application titles and captions, it is relevant to both Monte Carlos and El Caminos that came with the first gen system. The diagram itself should be clear enough that someone reviewing it can identify both the various sensors used in the system as well as the color of wires in the various harnesses and where they plug in as part of the sockets that communicate with the board. Power to the module is not directly shown but, for reference, comes from the battery via that large copper stud on the solenoid. I elected to load this diagram in as a j-peg so anyone can grab it and download it for themselves. Once you have it, you can enlarge it to get a better view or create clearer text.
As was noted earlier, If the plan is to get rid of this whole mess, do be aware that you will also have to address both the distributor and the carb as they both depend on the module for input and guidance as well. Neither unit works too well on its own. The easiest solution for them is to locate and buy either older versions that can be tuned and tweaked manually, or go brand new. aftermarket hi-po.
One suggestion, if the plan is to delete this system, don't do it with a pair of side cutters and a trash can. While you may have no use for what you see as worthless crap, someone else on the board might be looking for all this stuff, particularly the various wiring harnesses and plugs and could easily be willing to pay to take it off your hands. Sure the stuff is old and might be sketchy but even a dead sensor or plug is useful for show and tell at the local parts store or on line.
Nick
