ecu alt control

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10-31-2006, 11:11 PM

#11

HMTguy

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Re: ecu alt control

Quote:

Originally Posted by MADMAX

LOL, I did the same ----. Ya ELD disable doesn't work in UD.

Do you get the hesitation at around 10inHg too. That's because the O2 disable was coded really fucked up. It was done by bypassing some code with a jump. There is actually a byte option that can disable it. It modified my misc script to change the byte option not the jump around code crap.

Nope, running closed loop

11-01-2006, 01:21 PM

#12

turbohf

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Join Date: Dec 2002

Posts: 6,656

Re: ecu alt control

Quote:

Originally Posted by BLACKSI

seems like i remember hearing somwere that at wot the ecu turns the altenator output off or down for less engine load? any body know if this is true or not specificly on 88-91 civic/crx.

Beau

i think we talked about that with the race car... anyway in the serivce manual for the 92-95 Civic it was saying that as electical loads go up the alternator would put out more amparage.

im pretty sure Honda does this to lessen the prostectic drag from the alternator so your car will get better gas mileage, like in crusing conditions on the freeway in 5th were your not really gonna have any loads on unless its at night/raining/cold... not sure about WOT though...

and yes its called the Electrical Load Detector (ELD), it should be the extra/4th wire from the alternator and goes directly to the ECU....

11-01-2006, 05:07 PM

#13

BLACKSI

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Posts: 2,101

Re: ecu alt control

well i tested the alt harnes from the racecar on my daily driver useing the charging system tester and as long as you power up the blk/yel wire everything work fine voltage and amp wise. but what im wondering is on my old harness with the zdyne ecu is if the ecu was turning down the alt causing battery voltage to drop during a run especily with the super small gay battery i was running

Beau

11-01-2006, 11:31 PM

#14

iceracercrx

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Join Date: Nov 2005

Posts: 478

Re: ecu alt control

I also did a race car harness. So I looked into this matter pretty hard. Yes the ecu changes the voltage. The regulator is inside the ecu. What you did by hooking up the power wire is bypassed the ecu and put the car into full charge mode. I raced like that last year and it didn't work so well, but drag racing it maybe just fine.

small batteries=problems also

Randy

11-01-2006, 11:34 PM

#15

HMTguy

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Re: ecu alt control

I remember reading a thread on H-T that did the exact same thing you did Beau, he blew 2 alternators in a few weeks time.

But in a race car, maybe that'll last 2-3 seasons

11-02-2006, 12:18 AM

#16

BLACKSI

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Posts: 2,101

Re: ecu alt control

the thing is it does not put the alt into full charge mode the amps increase only with load. the regulater is not in the ecu at all if you look at the wiring harness it shows wires going from the ecu to the regulater inside the ecu. basicly the alrt in the racecar acts just like the 1 wire alt in my chev pickup.

Beau

11-02-2006, 12:58 AM

#17

BLACKSI

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Re: ecu alt control

ok
taken from the honda service express

The alternator generates an AC voltage in its
windings as it is belt driven by the engine. The integral
rectifier converts this AC voltage to DC.
The voltage regulator, a component which is included
in the alternator frame, has as its primary
function the control of alternator output to meet
electrical system requirements. The regulator
controls the charge warning light and the charging
signal (FR) and can be turned on or off by external
control.
Fuse 14 supplies battery voltage to the charge
warning indicator. With the engine not running
and the ignition switch in RUN, terminal L of the
regulator is grounded internally and the indicator
lights. With the engine running and the alternator
charging, terminal L voltage rises and the indicator
will go out. If the alternator fails to charge, terminal
L will remain below battery voltage and the
indicator will remain lit.
The charging (FR) signal is supplied to the PGMFI
electronic control unit (ECU). The ECU detects
whether or not the alternator is charging by
evaluating the changes of the charging signal.
The ECU then knows to compensate for the
charging load on the engine by adjusting the idle
control, which results in a more constant idle
speed.
The external control feature allows the ECU to
turn the alternator on and off. The electronic load
detector sends a signal to the ECU. The signal is
proportional the system’s electrical demand. The
ECU turns the alternator on or off depending
upon several factors including electrical demand
and system voltage. When the alternator is off, it
reduces engine load and improves fuel economy.
The ECU regulates the alternator so that is provides
the best combination of fuel economy and
electrical system operation.