Trying to ID a PROM, Could YOU possibly help me ?

[1980 Buick]

OK: I'm committing Sin, "but I haven't a choice".

I have an 1984 "G" Body "Hurst Olds" with a 307 "9" Engine,

Cutting to the chase, I'm trying to find out IF the PROM in the car NOW (& it Scan's "813") , is the CORRECT one.

That's it !

The Broadcast code is: 0810, "DFC". *I can't find it anywhere in the published "tables", and wondered if someone alot sharper then me ("not a tall order") COULD.

The reason why is that I have no TCC "apply" (when the proper "criteria" is met). After that, I have a "yes" to a knock signal while running / driving, ... and a "no", with just the KEY-ON. *The car has NO Knock Sensor !

Along with this, I have an "A/C Clutch "on" (when it's off on the panel) ... and a "no" for A/C on . what's interesting there is a "no" when I TURN IT ON as well.

The A/C works fine BTW ...

All this information's off a GM "TECH-ONE" Scanner.

There are other "gremlin's", (or "strange parameters) ... but those are what bother me.

Originally, I found that someone added a 2 terminal switch too the TCC (inside the Trans.) Eliminating (or "bypassing" this), along with a new Torque Converter corrected that. *The funny part is, (with ALL that I preface above) is the fact that the T.C.C worked after I did the above, on it's OWN for TEN MILES ! *I "felt" the T.C.C. go "in & out" with each touch of the brake Pedal.

THEN, I came to a stop, "turned around" ... (too go back home that same ten miles)... and then NOTHING !
NO T.C.C. after (or during that 10 mile gaunt all the way back home).

Grounding "A to F" on the ALDL gets me T.C.C. ALWAYS.

W H Y ?? ... "that's where I am".

Any help would be much appr. !

Thanks for reading !

 

[mikestertwo]

It sounds like you have the correct computer and chip for an 84' Hurst Olds. It matches the original computer out of my 84' Hurst. Computer service number is 1226457. Chip code is DFC. It should scan 860813. Your intermittent problems are most likely the edge connector on the computer where the harness plugs into it. They are notorious for going bad. That's why GM changed to a different connector on newer models. Try reseating the edge connector. BTW tying "A" to "F" on the ALDL will lock the converter always unless you are in first gear.

 

[1980 Buick]

Understood. ** I will check that Sir ! (It's the correct # then ? ) .... < GREAT > !!!

GESE: THANK'S A MILLION !!!!!!!!!!!!!!!!!!!

 

[1980 Buick]

I verified the ECM is as YOU say (and the PROM) ... I removed the ECM and cleaned the edge-boards, (The connectors looked like new).

Anyway, still no TCC after the above. It again; works every time (with a switch across "A to F") ... I guess it's ECM Time ?

Thanks loads Mike ! ;- )

 

[mikestertwo]

Make sure you have +12v at pin "P" on the computer. If you do and you are sure the connector is good, the VSS is working, the park/neutral switch is adjust correctly, and the 4th gear switch is working properly (should open when in 4th gear), then I would say the computer is bad. I would verify all sensors and connections first.

 

[1980 Buick]

I have a "Tech-1" Scanner , and: VSS, TPS, P/N, coolant, closed loop, MAP, "it's all there" ... (all's OK) ... *I'll bet "Pin P" is a pink wire ?
Anyway, I'd sure love finality with this dam thing, as I'm getting burned out with all this ! ;- )

I "see" no 4th gear 'parameter' ... (on the menu) , just "hi gear". That too NEVER changes.
If I pull the pan "again" that would make 7 times out ! (R & R).

A bit too much reality.

I need it to work before it's put away, as I haven't any interest in driving it.
"It just has ta work" ! after that it's on to the next car.

THX again Mike !

 

[mikestertwo]

I have a "Tech-1" Scanner , and: VSS, TPS, P/N, coolant, closed loop, MAP, "it's all there" ... (all's OK) ... *I'll bet "Pin P" is a pink wire ?
Anyway, I'd sure love finality with this dam thing, as I'm getting burned out with all this ! ;- )

I "see" no 4th gear 'parameter' ... (on the menu) , just "hi gear". That too NEVER changes.
If I pull the pan "again" that would make 7 times out ! (R & R).

A bit too much reality.

I need it to work before it's put away, as I haven't any interest in driving it.
"It just has ta work" ! after that it's on to the next car.

THX again Mike !

It's common for those switches to go bad. They blow through (leak) when they go bad. Remove the switch from the valve body and see if you can blow air through it. If you can the switch is bad. That most likely is your problem. Pin "P" I think is a tan wire with a black stripe.

 

[1980 Buick]

It's common for those switches to go bad. They blow through (leak) when they go bad. Remove the switch from the valve body and see if you can blow air through it. If you can the switch is bad. That most likely is your problem. Pin "P" I think is a tan wire with a black stripe.

Mike would you happen to know which pin # / color is the "4th gear met message" ? *ALSO, I had that switch out (remember there were two of them ?),... and NOW one remains, and that IS the single pole "4th" gear switch (as you say). Anyway, I had that one out, & IF I RECALL it was N.O. and it "closed" after using shop air pressure ("a heck of alot of pressure") *I watched it close*.

With (and looking at) the TWO above wires (pin "P" and the 'not yet known' 4th gear pin #) , I will / could monitor these both (upon driving), and see where it goes ...

both of these "legs" are "ground" yes ?

I'll do "ANYTHING" : (except too pull that pan again Mike) !

THANKS AGAIN !

 

[mikestertwo]

The 4th gear switch goes to pin "N" on the computer. It is a green wire with a white stripe. It should open when in 4th gear according to my manual.

 

[1980 Buick]

Gese thanks again for the help Mike !!

I appr. it so VERY Much !

 

[1980 Buick]

Hi Mike: The way I see things, I'd like to INSTALL a "lamp" across "N" and "P" (I DO HAVE pwr. on "P" B.T.W.)
and this way I can (in the perfect world) "see" the T.C.C. "prerequisite's" right "then" !!

Put simply, It'd be a neat "tool" to just watch, and look at right ? ... I assume the "C" pin on the Trans. (A and B are TCC apply)
is the "4th gear" switch (in this example), or: there's the "GROUND.

Just a thought. *SO, in the "end", *** I'd be able to "see" (with a light balb) that 4th gear being "met" each time ...

*IF I don't have that "ground" (on "N") ... I'll at least be able to then SAY: OK, the 4th gear switch is "out".

"Pan off "again", but at least it's "finality" and backed with the PROOF.

Your thoughts ?

Best, Tom :- )

 

[mikestertwo]

My manual is showing the TCC solenoid is on pins "A" and "D" on the transmission connector. The 4th gear switch is on "B". It would be easier to just put a volt meter on pin "N" on the computer and see if it switches when the trans goes into 4th gear. I wouldn't recommend putting a lamp between "P" and "N" since "N" is a status input with a pull up resistor and "P" derives it's +12v through the TCC solenoid.

 

[1980 Buick]

IC ... I may have my A's & B's and C's "mixed up" ... But the conn. (on the Trans.) has 3 wires.
The Left "uppers" pwr., ... the left "lowers" the TCC controlled "ground". Then (on the right top), is the last wire
or the 4th gear "met" ground.

I will go with the balb, and put the power side to just "ign" 12 volts ... (redundant / & off the TCC 'pwr'. side ) ... that way I'll just have
(or be able to see) when (or IF) I get the 4th gear input and "watch" that ground for 4th gear.

*Easily done ... and neat to have. (The Trans. Guy says He's done this as well). *** He has a "Kent Moore" Dealer essential tool "lite"
that was used (back in the day). It just plugs in at the ALDL for this same purpose. It evened wired to "watch" the A.I.R. Solenoid !

BUT: the 4th gear "ground" however, isn't wired at (or parallel) AT the ALDL. so you can't see that ground action THERE.
I tried to buy that "tool" off Him, but he said "no-way". :- (

Man what a cool tool !



Anyway:

"I'll let you know".

 

[1980 Buick]

OK:

I'm almost positive it's the 4th gear switch Mike. *It's grounded, and never goes "open" when I meet 4th gear.
The lamp I preface above, is wired (just too test it) and I have that GROUND (or the 4th gear switch signal) at ALL times.

Again, I'm positively "IN" 4th gear ! .... and it never goes "open" (or light "out").

The other lamp is on the T.C.C. Side (ground), and the only time I get him, is when I ground "A to "F on the A.L.D.L. (on my "flip" switch).
AGAIN: That applies the T.C.C. every time ! ... *when again, I switch this "leg". (it's working fine)

This says to me, that the 4th gear switch is at fault (Trans. shifts great so don't think it's a pressure issue) and that's that.
I wondered if I "opened" that wire (too try n' prove the E.C.M.'s "on the ball") ... if I'd get APPLY then ?

*I.O.W.: "open" "B".

What say you ? ;- )

 

[mikestertwo]

You can try it and see what happens. You could also unplug the connector on the transmission and put your scanner on and see if it shows you are in high gear.

 

[1980 Buick]

So THAT'S what "Hi-Gear" means !! ... "hum", I'd of put a different "label" on on that 'flag'.

I think I'll try that before I order the 4th gear switch. I THINK it's a P/N 8683502 ?

 

[mikestertwo]

I'm not sure of the Delco part number. The part number on the Bulk Transmission Parts web site is D54411B. The scanner probably says "high gear" rather than the actual gear is it would depend if the transmission is a 3-speed or a 4-speed.

 

[1980 Buick]

Finally reached the promised land: Opening up the green pin "N" (and putting a switch in series there), turns a "no" into a "yes" ...
AND: when I drive it doing same (with a switch), I get that same "yes" and a healthy Torque Converter "apply" every time !

I'm convinced NOW, that it's the 4th gear switch Mike.

Agree ?

 

[mikestertwo]

Finally reached the promised land: Opening up the green pin "N" (and putting a switch in series there), turns a "no" into a "yes" ...
AND: when I drive it doing same (with a switch), I get that same "yes" and a healthy Torque Converter "apply" every time !

I'm convinced NOW, that it's the 4th gear switch Mike.

Agree ?

Agree. Make sure you get the correct switch. It has to be a N.C. switch.