ECU replacement

[geauxbear]

Can you change out a 1990 geo tracker 4X4 automatic 8V ECU with a 1989 geo tracker automatic 8V ECU. The only difference I see is that it is not 4X4 and not sure if that really matters. the numbers of course will not match but was wondering if it is an option.

[jtgh]

have you changed the caps yet?
My ECU is bad now what?

89/90 are same pn 60A42 ,
mt and At , are diff, but 89 has 1.3L engine option, so watch out that wont work.

1.3L car. 63a10 ecu for carbi?, dont buy that.

what dont it do.

see ebay for repair centers, cheap.

[geauxbear]

I pulled this one out of a 1989 tracker and went back to junk yard to check to see if it in fact had 4wd and it did. the other thing that I noticed is that the numbers on it were 33920-60a41 but the other parts such as the intake manifold was taken and put on my 1990 but do not remember if the engine was 1.3L or 1.6L. It was an LSI model. Any insight if this will work or not?

[ranger88den]

Get the VIN, the 8th digit will tell engine size,at least on my 95. U=1.6,8v 6=1.6, 16v

[jtgh]

ok , no location , so i had to guess, and so you are in canada ,
that PN is Canada 1990 E28 export ECU MT only.

they only have mt and at , ecu's in 89-90. in Canada .

vin will tell year of body (engine ,etc), ecu's tend to get changed ,like floor mats after 19 years.

that pn is easy to take, once you tell general location.

[jtgh]

the only issue on 4wd , besides some lamp, is if you have RWAL, it cuts out in 4wd.
and ecu could care less about 4wd. (i think ,but i could be wrong as Dennis Miller says)

89 schematic prints are rare.

e28 ecu's can be different than in other countries, even though all the parts look the same.
E28 is canada export rules (smog )

[geauxbear]

I am in FL and had someone say that they thought the ecu was malfunctioning even though I haven't really noticed anything funny with the car. This actually was an a/c tech who noticed that the brand new compressor had sprayed oil all over the hood and was not working. I have replaced the compressor but he said that the condenser fan was not working properly and the ecu was malfunctioning. I am not sure how to check the operation of the condenser fan since it seems to be working properly to me. I picked up the ecu from a 1989 geo tracker lsi model with AT and 4wd. Mine is 1990 geo tracker 1.6L with 4wd and ATM.

[jtgh]

to bad he didnt tell you why he thought this ecu was malfunctioning.
does the check engine light glow at key on and not started, then go out after starting and running?

do you get good MPG?
the only relation ship between the ecu and the ac is when you turn on the A/C , a signal goes to the ECU commanding a higher idle.
so long as engine doenst stall when A/C is on , then all is well.
you have a bad compressor or its fittings. as you said.

maybe he is confused between the A/C amp module behind glove box and the ECU that runs the engine. (other side of car)?
the A/C amp has logic in it, that controls the A/C under a bunch of rules.

It may well be a bad ECU.
he might have noticed it will not idle correctly.
but that is almost never an ECU problem.

I hope he is not building his ticket.

if car drives ok, has power, gets over 25mpg and you have not bogging.
then ECU is mostly ok,

I do not know the exact rules on 90 AC amp, because I dont have print for it.

air-conditioner-repair

I could be wrong,as I am not 100% sure ,about all the functions on pin colored Y/B.
that is the idle pin.
the ecus
89-90, -dash 60a32 manaul tran
89-90 -dash 60a42 auto tran <<<<< only choice.
your spare is a canadian ECU. i have no idea what is different on that.

could be it is better or could be something quite missing.

but make your mechanic state exactly why he thinks its bad.

Just because the CEL lamp is happy doesnt mean ECU is good, some people driving them
around in Limphome mode for years. ( horrible mpg)

ok, see my link above. see 91 schematic.
yours is the same, cuz i looked up the partnumber of 89,90 and 91 and all 3 are the same.
so the logic is the same.
engine over heat, shut down compressor and AC.
low or high freon pressure (below 30psi ) shuts down compressor.
freezing if evap coil , shuts down compressor.
A/c must be turned on.
A/C fan must be turne on.
and last car must NOT be cranking.

show this print for 91 off my web page and your mech, might be helped.
cheers