Where is my ECM located ? I know it's either on the passenger side or driver's side underneath the dash ..I dont wanna stand on my head taking one side off then it be on the other side . Thanx guys . Im checking for a bad ECM or bad ECM wiring . Doing Tom's "CODE 34 CHART " .....THANX ALOT TOM FOR TYPING ALL THAT FOR US !!!!

 

On my 1985 Firebird,
ya remove the panels on the PASSENGER SIDE front dash area.
IT's kinda behind, and UP.
Not "easy to see" ya just follow the HUGH wire bundle that you put our hand on.
It is removed by several nuts, to lower it to work on.
FYI
MAKE SURE ya keep yourself GROUNDED so you DO NOT fry it out by a "short"
HOW?
Maybe sneakers with rubber soles and ONE FOOT ON THE GROUND not on the GROUND of the interior of the car.
What's kinda clumsy is "putting it back into position" for rebuttoning up the interior panels.

 

could do what those computer tech geeks do, have a wire velcro'd to their wrist & the other end of the wire gator clipped to the computer frame. always grounded then. just a thought.

 

could do what those computer tech geeks do, have a wire velcro'd to their wrist & the other end of the wire gator clipped to the computer frame. always grounded then. just a thought.

I AGREE ALSO.
Is my suggestion for "grounding" wrong?
I assumed it's a good "idea"

 

Thanx for the help guys !

I went out there just then to look for the connections to te ECM .This brown/white wire which go's to the maf sensor that Tom said to check . In his code 34 chart he says to check it for openings are shorted areaus . Does this mean , I have to trace this wire threw the dash and under the hood and check the whole damn wire out ? If so , what would be the best way to do this ? Thanx guys

 

Do you have a DVM (digital volt meter)?

If so, you really dont have to trace, but will need an assistant.

Plug one end of DVM in plug under hood, plug other end in proper place buy ecm end. Turn to ohm reading. Have assistant start shaking wires while you watch metter. If it fluctuates (sp?) then you have short/bad wire.

Meter reading stays same, your good.

 

Oh $hit . I checked that wire by the maf sensor , probed it , it fluctuated . Did not stay steady . This was with my digital voltmeter . That's ganna be a hell of a wire to change .

BUT , your saying to plug the other end by the ecm under the dash at the same time ??? How is that possible ?

I'm wondering though , if my ECM is bad because my air condition blows cold air sometimes but not all the time , that seems wierd to me but , that may have nothing to do with the ecm .

Also , this miss problem Im having , which gave me the 34 code , the car mainly starts to miss when the car is warmed up after awhile , and the more I drive it , it gets worse . Everything else has checked out ok , fuel pressure , all ignition componets , MAF sensor is good . It even backfires a little with it sometimes , but not bad ...

Thanx for the help Dale and guys !

 

ttt

 

ttt

 

Wayne, you just made my day!! It's so rare that code 34 chart gets used!

I'd shoot myself too, if I had to dig that wire out and replace it. Do what the master techs do; they run a brand new wire to the engine compartment. 'Fact, since that usually is a fast operation (compared to trying to undo harnesses), if they suspect the wire is bad, they'll just run a new wire anyway. Patch it in as close as you can to the computer... preferably with solder and heat shrink; then run the new wire in.

How's the connector to the MAF? Maybe the problem is just the connector; I think I mentioned that I had that problem in the chart.

 

Ok, you probley tested the power side correct??

Does it have 3 wires??
1. Power
2. Ground
3. Signal

I was refuring to the return signal (#3) to the ecm.

I don't have a maf, so their somewhat "new" to me.

However, in my experence, if you get any major fluxation in signal (it will have a "little" naturaly), wire has issues.

 

Tom , I printed that sucker off and its sitting in my toolbox ! I also e-mailed it to myself incase I lose it ! I was thinking about just leaving the old wire in there and replacing it with a new one , but i though , that just sounds crazy , maybe not sence the mechanics do it ! I think Im ganna try the connector to the maf sensor first . Is this basically cutting it off and soldiering a new one on ?

 

Tom , I feel like and idiot though , What's a test light ?

 

Nevermind , I remember my neighbor walking over once before with his test light and testing some wires . I rememberd I had one in this emergency kit Dad got me for Christmas years ago . I pulled it out and used it . I FINALLY FOUND out what was wrong with my car . No one has been able to find what was wrong with it for a year . It's had this miss , not bad , but bad enough , I've mentioned it on here several times before to you guys . I thought sence the mechanics never figured it out Id never figure it out .I had some vacumn lines that werent hooked up right , the shop had un-hooked them for some reason . And thought that was causing my miss and code to show . I thought they were pain to fix , but I fixed those last week however ,it did not fix my "miss " problem . But today , I FOUND IT , its the ground wire from the MAF sensor . I can't see the wire being sliced , torn anywhere , it's good where it grounds to , but I guess it's still a bad wire because that's what TomP's code 34 chart is showing .

 

LOL! I actually have to buy one of those computer-safe test lights one of these days; I just use my dad's 20-odd year old light. You can actually use a multimeter as a test light, too... just set the meter for voltage. Only annoyance is that with a test light, you don' thave to worry about a negative or positive. Actually; with digital multimeters, you don't really have to worry about that either; the display just shows a negative voltage. But with the old analog meters, if you hooked one up backwards, it would pin the needle backwards, and could screw up the meter.

Could the ground pin in the connector be corroded?

Yeah, it's basically cut/strip/splice/solder. You might have problems with the solder melting against the old wires. Corrosion seeps thru the wire insulation over years, and can get onto the copper strands, making them feel very stiff. Solution? Flatten the strands out. Slide a very fine grit sandpaper over the flattened strand bunch. This will remove the corrosion, and makes the wire easier to solder.

Glad to hear you fixed another problem (vac lines) at the same time!

 

Is this a special kinda wire I need to buy , or what ? Thanx guys . And do I take the wire out of the connector or cut it and soldier it back together there or what ?

 

ttt

 

Not sure on size. Autozone sells it in little spools. My local w-m does also.

I would cut the wiring leaving a little "pigtail" and solder new wire onto end.

I also suggest heatshrink tube, rather then electrical tape.

 

OBTAIN HEAT SHRINK TUBING FOR PENNIES FROM ELCTRONICS STORE!
Get the size LARGER than ya think ya need!
It's about $1 a section from Radio Shack.