Honda CRX Forum banner
1 - 13 of 13 Posts

·
Registered
Joined
·
6,568 Posts
Discussion Starter · #1 ·
So, Ive been looking into the differenced between USDM and JDM ecus and one of the major ones is the lack of ELD and ALT on the JDM ecus.

So i started looking into what these actually are. Ill start with a summary of what each does.

ELD: this is an amneter in your fusebox. it tells the ecu what sort of load is on your electrical system. It meters any current draw through the fusebox. (so, if you have ABS, amplifiers, etc etc this is NOT metered)

ALTC: this is an output on the ecu that tells the alternator to relax, like at idle. for some reason though, if you apply a large load this output is triggered for about half a second, like for example, when you flash your high beams.

now, if the ELD sees alto of load, its supposed to keep ALTC from kikcing on. BUT if you circumvent the fusebox in any way, the ELD doesnt see that loud. hence the problems with dimming lights with bumping systems, etc etc.

My simple fix was to cut the ALTC wire on my ecu (pin A16 obd1, B5 obd0). Now my alternator works like normal (governed by its internal voltage regulator) and my voltage is much more stable. its very obvious with my larger fuel injectors when there is a voltage fluctuation, as my AFRs change, as well as my voltage gauge, causing a funky idle.

Also, one more point, to those of you looking into upgrading your alternator to a high output unit, make sure you ask to see a graph of output vs RPM. youll be surprised to see that most of the high output alternators actually have less current capabaility at low rpm then a stock one! they need to be revved up to acheive their full capcabilities.

anyway, hope this was informative, just wanted to put it out there.

[email protected]
 

·
Registered
Joined
·
953 Posts

·
Registered
Joined
·
2,302 Posts
mattminerDOTcom said:
fine :rolleyes1:

ill cut b5

[email protected]
*walks ot the gargare to cut b5*

*thinking about being 5 again and how simple it was back then...*

now what was that again... 5 ... yes, 5 blue wires...

*clip clip clip clip clip* All done.

*screaming* MATT HELP, IT WONT RUN!
 

·
Registered
Joined
·
953 Posts
mithuth said:
mattminerDOTcom said:
fine :rolleyes1:

ill cut b5

[email protected]
*walks ot the gargare to cut b5*

*thinking about being 5 again and how simple it was back then...*

now what was that again... 5 ... yes, 5 blue wires...

*clip clip clip clip clip* All done.

*screaming* MATT HELP, IT WONT RUN!
:lol: LMAO :lol:
 

·
Registered
Joined
·
1,061 Posts
A bit off topic I think, but would this explain also why when ur car has a bouncy idle caused by the IACV (for me at least) if I turn my lights on and off or my heater (sometimes both) it stops bouncing and resumes regular idle?
 

·
Registered
Joined
·
9,754 Posts
Shadow_d15 said:
A bit off topic I think, but would this explain also why when ur car has a bouncy idle caused by the IACV (for me at least) if I turn my lights on and off or my heater (sometimes both) it stops bouncing and resumes regular idle?
The increased draw on your engine in that case causes it to make more torque and idle smoother. The real solution is to fix the IACV.
 

·
Registered
a CRX
Joined
·
2,609 Posts
actually, on my 95 GSR the ELD is a completely separate unit from the fusebox. it sits in the upper-left corner near the bulkhead (facing the car) that little gray thing had me confused for a while until I figured it out.
 

·
Registered
Joined
·
1,061 Posts
downest said:
Shadow_d15 said:
A bit off topic I think, but would this explain also why when ur car has a bouncy idle caused by the IACV (for me at least) if I turn my lights on and off or my heater (sometimes both) it stops bouncing and resumes regular idle?
The increased draw on your engine in that case causes it to make more torque and idle smoother. The real solution is to fix the IACV.
Ok, yea I figured I needed to deal with that anyway, I was just curious about the workings behind it, think I might just not mess with it since I'm swapping in my b18 soon anyway. :p Thanks for clearing that up tho.
 
1 - 13 of 13 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top