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Check engine light wont flash by greener37
Started on: 04-02-2014 09:29 PM
Replies: 12 (469 views)
Last post by: greener37 on 04-06-2014 11:53 AM
greener37
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Report this Post04-02-2014 09:29 PM Click Here to See the Profile for greener37Send a Private Message to greener37Edit/Delete MessageReply w/QuoteDirect Link to This Post
Check engine light is on but when i cross terminal A and B on the ALDL it doesnt flash a code. It starts up but only runs at like half power. Iv replaced the ecm and prom but still the same problem. 87 2.5l auto
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James Bond 007
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Report this Post04-03-2014 12:13 PM Click Here to See the Profile for James Bond 007Send a Private Message to James Bond 007Edit/Delete MessageReply w/QuoteDirect Link to This Post
Try disconnecting the battery for 5 minutes to reset the memory...otherwise bump to the top for any other responses.
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Formula88
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Report this Post04-03-2014 12:23 PM Click Here to See the Profile for Formula88Send a Private Message to Formula88Edit/Delete MessageReply w/QuoteDirect Link to This Post
Just to cover the obvious - you have the key ON, but the engine is NOT running, correct?
Make sure you're using the right pins. The ALDL plug may be upside down from what you're expecting, so you may be in the wrong location.

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84fiero123
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Report this Post04-03-2014 01:00 PM Click Here to See the Profile for 84fiero123Click Here to Email 84fiero123Send a Private Message to 84fiero123Edit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Formula88:

Just to cover the obvious - you have the key ON, but the engine is NOT running, correct?
Make sure you're using the right pins. The ALDL plug may be upside down from what you're expecting, so you may be in the wrong location.



ya I was thinking that as well, I have never had one not flash anything.

Steve

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and one big pain in the ass when it doesn't



Detroit iron rules all the rest are just toys.

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greener37
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Report this Post04-03-2014 01:27 PM Click Here to See the Profile for greener37Send a Private Message to greener37Edit/Delete MessageReply w/QuoteDirect Link to This Post
Ya the ignition is on an the engine not runing an no its not plugged in upside down becaus iv flashed codes off this numerous times before
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Gall757
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Report this Post04-03-2014 05:34 PM Click Here to See the Profile for Gall757Send a Private Message to Gall757Edit/Delete MessageReply w/QuoteDirect Link to This Post
How is the ECM ground? I don't know what the default is for an open connection....maybe it's what you have.
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greener37
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Report this Post04-04-2014 01:22 PM Click Here to See the Profile for greener37Send a Private Message to greener37Edit/Delete MessageReply w/QuoteDirect Link to This Post
If its the ground just off to the left of the ecm its fine. Iv been having troubles with this for awhile an i just wana fix it
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phonedawgz
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Report this Post04-04-2014 03:07 PM Click Here to See the Profile for phonedawgzClick Here to visit phonedawgz's HomePageClick Here to Email phonedawgzSend a Private Message to phonedawgzEdit/Delete MessageReply w/QuoteDirect Link to This Post
Pin B of the ALDL connector is the White/Black wire. At the ECM try grounding that wire (Key on) Does the light now flash? If so your wiring to the ALDL connector is bad.

Did you try two PROMs or did you swap the prom from one ECM to the other? Since the power is way down the ECM might be running on limp mode because the PROM is bad.

Since this really sounds like either a bad ECM or bad PROM, that is the way I would lean. Perhaps two bad ECMs. $40.00 for a working used 7748 ECM if you are interested email me. I have three so most likely I can supply you one with the correct PROM.

gofast@reddevilriver.com - email

[This message has been edited by phonedawgz (edited 04-04-2014).]

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greener37
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Report this Post04-04-2014 07:12 PM Click Here to See the Profile for greener37Send a Private Message to greener37Edit/Delete MessageReply w/QuoteDirect Link to This Post
Iv only had two proms the originally wich if you were to push on it it would run fine and the one i had someone burn but when you push on the one the guy burned it doesnt do anything so idk if its just that or what. He said he did it corrextly and checked so.
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greener37
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Report this Post04-04-2014 07:17 PM Click Here to See the Profile for greener37Send a Private Message to greener37Edit/Delete MessageReply w/QuoteDirect Link to This Post

greener37

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Now how do you go about testing this ground wire caus even if it was a bad prom it should still flash a code for that
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84fiero123
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Report this Post04-05-2014 08:48 PM Click Here to See the Profile for 84fiero123Click Here to Email 84fiero123Send a Private Message to 84fiero123Edit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by greener37:

Now how do you go about testing this ground wire caus even if it was a bad prom it should still flash a code for that


if you just want to test the ground wire in the plug you just need a test light and a live + power supply. take your cigarette lighter out, its always live and put the point of the test light into the center of the lighter all the way to the back, make sure you don't touch the side of the lighter casing. then put the alligator clip on the ground wire. the light should light as soon as you make contact, if not you ether have a bad lighter socket or the ground is bad, or you didn't get a good connection on one of the places.

Steve
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greener37
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Report this Post04-06-2014 01:26 AM Click Here to See the Profile for greener37Send a Private Message to greener37Edit/Delete MessageReply w/QuoteDirect Link to This Post
I just checked it an the green light on the continuity tester turned on which means it doesnt have continuity.
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greener37
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Report this Post04-06-2014 11:53 AM Click Here to See the Profile for greener37Send a Private Message to greener37Edit/Delete MessageReply w/QuoteDirect Link to This Post
Wait never mind its grounded right
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