ECM Problem
Thread Starter
Heel & Toe
Joined: Aug 2005
Posts: 20
Likes: 0
ECM Problem
Hi everyone, I am a newbie here if I have posted this in the wrong area I am sorry.
I have a early 86 vette. The other day it started overheating and the SES light came on. I shut it down and had it towed home. I started checking things out for the heating problem and found that a plastic grocery had been sucked up in between the A/C condenser and radiator.
The only sensor I undone was the MAF so I could remove the top of the radiator cowling to remove the bag. I put things back together and took it for a test drive. Ever thing worked great. The next day went for a short drive and the SES came back on. This time the car started running bad. No overdrive for the 4+3 etc. I took it to a shop and they put it on the scanner. I was told that the scanner and ECM were not talking and that the next step was guess and check (Ya right at $90 bucks an hr
). Is there a way that the codes can be checked with out using the connector under the dash to read the codes? And is there away to check the MAF sensor? The car is in limp home mode.
I did a search for this and found a few posts but I do need help.
Thank You
I have a early 86 vette. The other day it started overheating and the SES light came on. I shut it down and had it towed home. I started checking things out for the heating problem and found that a plastic grocery had been sucked up in between the A/C condenser and radiator.
The only sensor I undone was the MAF so I could remove the top of the radiator cowling to remove the bag. I put things back together and took it for a test drive. Ever thing worked great. The next day went for a short drive and the SES came back on. This time the car started running bad. No overdrive for the 4+3 etc. I took it to a shop and they put it on the scanner. I was told that the scanner and ECM were not talking and that the next step was guess and check (Ya right at $90 bucks an hr
). Is there a way that the codes can be checked with out using the connector under the dash to read the codes? And is there away to check the MAF sensor? The car is in limp home mode.I did a search for this and found a few posts but I do need help.
Thank You
Team Owner
Joined: Dec 2000
Posts: 90,675
Likes: 304
From: SE NY
Cruise-In II Veteran
Hopefully you were gentle handling the MAF when it was off as the sensor wires can be damage by rough handling.
Verify that the MAF connector is well seated and even clean the contacts.
To pull the stored code:
-remove the ALDL cover, if present
-insert a bent paper clip into ALDL pins A&B (upper right)
-turn the key On
-count the SES flashes; first there will be three "12"s, followed by each trouble code flashed three times, terminated by three more "12"s.
-record the trouble codes
-turn the key Off
-remove the paper clip and install the ALDL cover
-bring the codes here
If you want to clear the codes, just open the connector in the Orn wire near the battery for a minute or so.
Verify that the MAF connector is well seated and even clean the contacts.
To pull the stored code:
-remove the ALDL cover, if present
-insert a bent paper clip into ALDL pins A&B (upper right)
-turn the key On
-count the SES flashes; first there will be three "12"s, followed by each trouble code flashed three times, terminated by three more "12"s.
-record the trouble codes
-turn the key Off
-remove the paper clip and install the ALDL cover
-bring the codes here
If you want to clear the codes, just open the connector in the Orn wire near the battery for a minute or so.
Le Mans Master
Joined: Aug 2003
Posts: 9,884
Likes: 3
From: Magnolia Mississippi
St. Jude '03-'04-'05-'06-'07
Originally Posted by 65Z01
Hopefully you were gentle handling the MAF when it was off as the sensor wires can be damage by rough handling.
Verify that the MAF connector is well seated and even clean the contacts.
To pull the stored code:
-remove the ALDL cover, if present
-insert a bent paper clip into ALDL pins A&B (upper right)
-turn the key On
-count the SES flashes; first there will be three "12"s, followed by each trouble code flashed three times, terminated by three more "12"s.
-record the trouble codes
-turn the key Off
-remove the paper clip and install the ALDL cover
-bring the codes here
If you want to clear the codes, just open the connector in the Orn wire near the battery for a minute or so.
Verify that the MAF connector is well seated and even clean the contacts.
To pull the stored code:
-remove the ALDL cover, if present
-insert a bent paper clip into ALDL pins A&B (upper right)
-turn the key On
-count the SES flashes; first there will be three "12"s, followed by each trouble code flashed three times, terminated by three more "12"s.
-record the trouble codes
-turn the key Off
-remove the paper clip and install the ALDL cover
-bring the codes here
If you want to clear the codes, just open the connector in the Orn wire near the battery for a minute or so.
Thread Starter
Heel & Toe
Joined: Aug 2005
Posts: 20
Likes: 0
Thank for the replies
I tried the paper clip trick the light will not flash the codes. I went and bought a scanner still no codes. It appears the ecm is not communicating the codes. Any other tricks to pull the codes or is it my ecm?
Thanks
Thanks
Le Mans Master
Joined: Dec 2000
Posts: 7,839
Likes: 22
From: San Diego, Ca
There's always the possibility that your Year just won't communicate with whatever brand scanner you purchased, but if it won't let you pull the codes, either the serial data feed is open, or the ECM is dead. Do you have Instant and Average Mileage readouts? Is the Range readout working? Both rely on the serial data line which is spliced into the Display. If they're gone too, but you get a Check Engine Light, sounds like the ECM needs to be replaced.
