Post by: Donster on February 07, 2012, 07:07:08 pm
Replaced the ECM tonight with a good one and also got a DKY1888 PROM in it. Drove the car over 35 mph to teach the ECM, but now when I accelerate, the CE light blinks??
Any idea what would cause that?
Won't throw any codes
\D
Post by: Raydar on February 07, 2012, 07:52:10 pm
There are a couple scenarios.
One is that the ECM may be operating in some sort of a test routine. I don't really know how to access it. It's been a long time. (It may be pins A and B jumpered, with the engine running, and driving. I also may very well be wrong about this, however.)
Having said all that, one of the results of this "test mode" is that the Check Engine light will flash at different speeds, depending upon whether the exhaust is rich or lean. (Slow for lean, Fast for rich?)
I'll have to do some reading.
The other scenario is that the ECM is losing sight of the PROM. That will also cause the Check Engine light to flicker rapidly.
It should set a Code 51 if this happens, however.
I may have an 84 ECM. I'll try to remember to dig it out and bring it to the meeting.
It probably doesn't have a PROM in it, however.
Post by: Donster on February 07, 2012, 08:50:35 pm
First I thought it might be a short somewhere in the instrument pod, so I wiggled around but couldn't detect anything.
I also have a software program called L4 ScanConverter (See sample picture for V6 below) and a USB connector, which I connected to the ADLD. It reads everything correct, even tells me PROM IDs and such, but not telling me any error codes
\D
Post by: Roger on February 09, 2012, 10:02:02 am
Post by: Donster on February 09, 2012, 10:03:58 am
\D
Post by: Roger on February 09, 2012, 10:08:46 am
Because on the vacuum leak in my car, the CE light comes on for high idle but goes off soon afterwards and never sets a code.
Your's only comes on briefly when accelerating?
Post by: Fierofool on February 09, 2012, 10:33:29 am
Don't know what the blinks twice thing is. Don, you might try phonedawgz on PFF for that answer.
Post by: Raydar on February 09, 2012, 10:06:17 pm
blinks twice when accelerating, let of the gas, hit it again, blinks twice
...but not telling me any error codes
Yes it is.
Look at the bottom left of the pic. "Trouble codes"
Code 22 - Low TPS voltage.
Code 34 - Low MAP sensor voltage.
You might have a bad 5V feed that is common to both of them.
You're getting two blinks. That might be that code flashing.
But that certainly doesn't explain why it's flashing without the A and B pins shorted. Odd.
(OTOH... I've heard that if a code is "happening" the light may flash. I didn't realize that it would flash the code, however. I may be totally off base, here. But even so, something isn't right.)
Post by: Raydar on February 09, 2012, 10:11:23 pm
Key on but engine off?
Lots of nonsensical sensor readings there.
Post by: Donster on February 09, 2012, 10:57:44 pm
Was using it for demonstration only
\D
Post by: Crash 86GT on February 12, 2012, 02:09:52 pm
Post by: Donster on February 12, 2012, 07:05:07 pm
Instead of shorting out/resetting the ECM, I installed a new (new to the car) one, which essentially should have the same affect.
Now when shorting/jumpering pin A & B, it won't even go into maintenance mode (error code 12)!
I checked all wires and ground and can't find anything wrong there.
Then I put in a 3rd (third!) ECM and it has the same issue!
However, I am using the same PROM on all of them, as I only have one automatic PROM, the DKY1888. Could a bad PROM be the issue?
As long as I can't get it to go into maintenance mode, it's useless to try and set the timing, which Shanine's car really does need, as it is running like a heap of dirt right now and sucking up lots and lots of gas, about 15 mpg!
Stumped!
\D
Post by: Roger on February 12, 2012, 07:29:09 pm
That means your Diagnostive Mode is ACTIVE and the ECM is okay.
I'll stop by late tomorrow afternoon with a timing light if you need one.
Post by: Donster on February 12, 2012, 07:47:06 pm
Engine NOT running...error Code 12 is correct.
That means your Diagnostive Mode is ACTIVE and the ECM is okay.
I'll stop by late tomorrow afternoon with a timing light if you need one.
Roger -
Diagnostive Mode is NOT ACTIVE and the ECM is NOT okay.
It WON'T go into maintenance/diagnostic mode, that's what has got me stumped!
Anne and I just checked all wiring again, but can't find any issues
\D
Post by: Roger on February 12, 2012, 07:59:22 pm
Post by: Roger on February 12, 2012, 09:36:10 pm
My computer won't flash any codes. Could there be a bad connection somewhere, or is the computer shot?"
The computer should flash a 1-2 code three times before and after any stored trouble codes. Since yours does not, I'll put my money on a bad computer.
However try this to make sure:
Remove the connector (it was a white connector in 84) from the computer. The Check engine light should go off. If it does not, there is a short on the wire leading to the light. Fix the short and don't read on :)
Reconnect the ECM connectors. Make sure there is a good ground to the diagnostic terminal (B). You might also want to try putting a ground at the ECM connector wired to terminal (B) (white connector pin #3 in 84). If either of these gets you a 1-2 code, your computer is good, but the wiring ECM to diagnostic gounding terminal A or bad wiring from ECM to terminal B.
If all this fails to give you a 1-2 code, open the ECM and carefully remove the PROM. Be careful not to bend the pins, and remember which way it was installed.
Make sure the ignition is _OFF_ before you remove the PROM.
After the PROM is out, turn on the key, ground the diagnostic terminal and look for a 5-1 code. If you get the 5-1, you need a new PROM, it not, you need a new ECM box. However, you should check for low resistance between the ECM box and various solenoid terminals before replacing the ECM: TCC solenoid (if automatic), A/C relay (if equiped) and Cooling fan relay. If these measure less than 20 ohms, they will kill the new ECM box very quickly. If they all measure more than 20 ohms, just replace the box.
Post by: Donster on February 12, 2012, 10:44:02 pm
You have an email.
You also forgot your baseball cap at our house
;D
\D
Post by: Raydar on February 12, 2012, 11:17:28 pm
Steve! I said the picture below is a sample! Look more closely and you'll see it's actually a screenshot from a V6! ;D
Was using it for demonstration only
\D
Oooops.
Okay... You did mention that. I had my head up... in a dark place.
Post by: Roger on February 13, 2012, 08:46:44 pm
Thanks to the Fiero On-Line Service Guide, we tracked the problem to a broken ground wire, right at a GM splice!
Happy Happy Joy Joy!!!
Don and Anna did all the hard work, and I stumbled on it.
Now if I could only figure out why I can't get my GT started??? again.
Post by: Donster on February 13, 2012, 09:02:01 pm
You are fabulous!
But of course a 1984 Fiero wouldn't be a 1984 Fiero, if something new hadn't poped up. Replaced the Temp-Fan switch and the fan still won't kick in! @!$$!&$%!
Shorted the low speed side for right now so at least it cools down.
Thanks for the tip with drilling the hole in the thermostat - worked like a charm without burping.
Put the PurplHaze back together and checked timing again, seems right on the mark and runs nice and even.
Thanks a million Roger. Now please get me the contact info of the welder/muffler/exhaust guy so we can get her leak taken care of.
\D
Post by: Roger on February 13, 2012, 09:48:09 pm
Take that DMM and check for continuity between the case of the fan switch and the block. If there's 0 ohms there then that switch either closes at a higher temp than required or is just kaput. We both know that the rest is okay.
Here's the muffler stuff:
Mega Muffler
151 N Broad St (Hwy 53)
at West New St.,
2 blocks east of Quality Foods on the left
Winder, GA 30680 (770) 867-7728
I think he's closed Sunday and Monday.
Post by: Roger on February 14, 2012, 12:04:46 pm
So,
The following part numbers can be found (or ordered)
at Advance Auto Parts in the GP Sorensen line.
These sensors all have a 3/8"-18 NPT thread.
FS6 - Closes at 204*-220* F- Retail $21.59
FS4 - Closes at 211*-227* F- Retail $8.69
FS1 - Closes at 222*-238* F- Retail $9.49
Then, Rodney sells one for $24 that has a lower switching temp that may be more applicable to the situation.
You'll have to change the connector (which can be had at boneyards for next to nothing).
I'd hook it up to the low speed wire just to keep the fan noise down or, use 'bullet' type connectors so in an extreme summer or a lot of in-traffic driving you could switch over to the high speed wire easily.
Post by: Donster on February 14, 2012, 03:12:18 pm
Sounds like a bad ground at the ADLA connector.
Missed that. Robbie was actually right all along
\D
Post by: Donster on February 15, 2012, 11:14:24 am
Anne calls me and says the fan won't turn off, even with the ignition off! ??
Had them disconnect the battery. As soon as they reconnect the battery, fan kicks back in!
Stumped
\D
Post by: Donster on February 15, 2012, 10:33:24 pm
Battery is charged
I can understand our daughter's frustration now, this is hard for a young adult that needs her car to get to work and hang out with freinds with her (currently not so) cool little car. I truly understand her and feel sorry for her and I am getting frustrated too
Argh!!!
\D