Ecm?????

[cobo351]

I have a 92 Tracker, 2 door, 1.6L 8V, 5 speed, just got it so I have very little history. shortly after having it I started to find out why the CEL was on. Jumping the diagnostic terminal will sometimes give me a couple of CEL flashes before going solid, sometimes its solid as soon as I turn the key on. I only get about 6 volts at the diagnostic terminal. I have a 5-volt reference. Sometimes I can start the engine and it runs very well no CEL than after a couple of mins. Click, CEL on, rough idle, poor acceleration. The p.o. said that he replaced the ECM and I have opened the ECM the caps have been replaced and I see where there has been some cleaning around one of the caps. Based on the little I have stated can my problem be a bad remanufactured ECM or likely some other problem?
Thanks, Cory

[jtgh]

Originally Posted by cobo351

I have a 92 Tracker, 2 door, 1.6L 8V, 5 speed, just got it so I have very little history. shortly after having it I started to find out why the CEL was on. Jumping the diagnostic terminal will sometimes give me a couple of CEL flashes before going solid, sometimes its solid as soon as I turn the key on. That is normal and MUST happen every time you key on. if not ECU is sick.

I only get about 6 volts at the diagnostic terminal.(so?) I have a 5-volt reference. GOOD !

Sometimes I can start the engine and it runs very well no CEL than after a couple of mins. Click, CEL on, rough idle, poor acceleration.
but why dont you place the jumper and get the codes, why no t?

The p.o. said that he replaced the ECM and I have opened the ECM the caps have been replaced and I see where there has been some cleaning around one of the caps. GOOD new caps, bad if traces are damaged.

Based on the little I have stated can my problem be a bad re-manufactured ECM (no such thing, they are just refurbished.or likely some other problem?
Thanks, Cory

most shops just replace caps. 3 of them.
then repair any physical damage. and acid neutralization.
then test all inputs and output for proper ops, (if you are lucky)
on a running vehicle and a TEST JIG.

the CEL must come on, every time key on.
this is a indication that it booted and passed rudimentary self checks and tests the lamp.
if it can do this simplest of tasks, the ECU is bad or , power feed to it is bad.
the Main relay can be bad. (or wiring to same.)

hope that helps you .

cheers.
and welcome !

[jtgh]

make reals sure.
dome fuse is good, (memory to ecu)
FI fuse is good.
and
Cig./radio fuse.

all three must be at 12.5vdc at all times or more. (except while cranking)

[cobo351]

When I say that I sometimes only get a couple of flashes from CEL with the diagnostic terminal jumped its like this: flash, pause flash, solid light. I know that normal flashing acts like: Flash, pause, Flash, Flash, pause, repeat. I should see code 12 then other codes if there are any other problems. Shouldn’t each code show 3 times? My understanding is that each code will show 3 times going through all the codes over and over with 12 being the beginning and if no other codes are stored 12 should flash until you turn the key off. I have never got a code 12 to flash more then once or twice. The CEL will not flash when jumping the diagnostic terminal after engine has been running poor with the CEL on. The only time the CEL will attempt to flash is after the neg cable has been disconnected for a little while. Info on your page says I should have 10 to 14 volts at the diagnostic terminal with key on and not grounded but I only get about 6 volts. I have 11.8 to 12 volts to the ECM with engine not running and key on. All fuses are good both under dash and under hood. I have cleaned ALL of the grounds.
Jtgh, what concerns me is p.o. needed to replace ECM and something is still not right.

[jtgh]

that is a bad ECU.

10 to 14 volts at the diagnostic terminal

<< this is FSM voltage page.
id ignore that for now ,as the CEL is sick.

this car, when running correct. you can place the diagnostic jumper , key on
get 12, and drive for weeks with cell flahing code 12. over and over forever.
yours is crashing , MID TRANSMISSION .

this is the sign of. ( since it fails not running. then its not noisy Alternator with shorted diode bank, rare)
a bad ecu,
bad power. to same.


sorry for my questions ,as understanding the ECU , while it is crazy , takes careful looking.
ive seen only 1 post this forum with that exact condition.
and it was a bad ECU. but one must be careful , and be sure power is present.

Flash , then solid, is crashing. ( it never completed its sequence)

id send it to DAVID. He does great work and at a very fair price.

eBay My World - mandigital

keep in mind, not all things can be fixed. (horrible burned up boards , water damage, lightning damage. ive seen the worst , and it can happen)

[cobo351]

Thanks for your help jtgh, I was very sure the ECM was bad thanks to the helpful info I read on your Tracker page. What concerns me is the prevous owner got it durning this past winter. He got it needing a ECM he says he paid $300 to replace. Now it needs a ECM again. If what he told me is true thats 2 ECM changes in a very short time with a 3rd to happend very soon. Can something with the tracker be killing the ECM as soon as its plugged in? I am having a buddy replace caps and if that doesn't work off to David it will go.
Thanks again, Cory

[jtgh]

be sure to repair any trace damage ,under those caps.

i wonder did he exhange it , buy it outright or have his repaired.
maybe the replacment was worse. been known to happen.

if you need the fsm flow chart for ECU, i have it. it just says same thing.
no codes, bad ecu. (check power, check diag and diag ground put are good)


i know this will help. ask questions.?
ive played with this all winter, sucking its brains out for Megasquirt , adaption.

the corner cap is tops for bad. near pin B8 ,loves to
dry out
blow its guts (boric acid) , split, crack and go completely dead.
i have one here, has a volcano on side.
the ECU goes quit nuts with it dead. crashing over and over.

under that cap are traces. I have photos of them, nice ones.
and a macro camera to do it.

cheers.

PS:

one can power up this ECU on a bench.
and guess what? few wires need attachment, to get a string of valid codes.
open , TPS, open ECT, open IAT.. come screeming out.
no dizzy, no coil, nothing but.
3 powers, all grounds.
and the CEL lamp and that diag pin grounded.

it it dont to that , it aint worth crud.

i have a test jig.

I am sure I have no spark

here is my spark jig , one of 2.

note , it dont take much for spark.
now imagine all those spark parts missing. Cross them of schematic. see?
add CEL lamp
add diag pin, (grounded)
and it will spit out codes all day. never ending.

if it does that , ECU passes its first test.

[cobo351]

A friend of mine found cap 101 bad and replaced looked for any trace damage. I plugged it in today. It ran with no check engine light for about 20seconds before check engine light came on then went out and engine died. Now no check engine light with key on. What do you think?

[jtgh]

oops,
(assuming CEL didnt just die, filament burned out)

you have lost a fuse (3 of them. Radio, Dome and FI)
or the MAIN relay is not pulling in.

I must pull in or it (relay) is bad or the ECU is not plugged in.

the cig radio fuse (top left)
must send power to ECU first. and to Main.
or the Main can never pull in (energize)
see blk/white wire at coil, it must be 12v at key on.
if not , ecu will be dead as a brick.

http://www.kick-fix.com/ECU/91-95-TB...matic-base.jpg

cheers.