Checking ECM Codes and clearing soft/history
Thread Starter
Drifting
Joined: Aug 2002
Posts: 1,857
Likes: 0
From: Yakima WA
Checking ECM Codes and clearing soft/history
Can anyone tell me where to buy a scanner to ck codes? (and a code-book) Also, can these scanners clear old codes? I hear Autozone will ck codes for free, but they don't have an adapter for 86 Vette. Can I just buy one of those and bring it to them?
Melting Slicks
Joined: Nov 2000
Posts: 3,388
Likes: 1
From: X
Re: Checking ECM Codes and clearing soft/history (dbwade36)
Safety Car
Joined: Aug 2002
Posts: 3,842
Likes: 230
From: SANTA CRUZ CA
Re: Checking ECM Codes and clearing soft/history (dbwade36)
Try page 4-25 of the MIDAMERICA catalog. There are two options: $40 & $80 (top and bottom of the page). For $80, the device clears your codes, the $40 unit does not. Or, the paper clip will do the trick, now that JonL has provided the codes.
THANKS JONL FOR THE THREAD/LINK ! :cheers:
THANKS JONL FOR THE THREAD/LINK ! :cheers:
Pro
Joined: Jul 2002
Posts: 729
Likes: 4
From: Yukon OK
Re: Checking ECM Codes and clearing soft/history (dbwade36)
If you use the paper clip trick, or one of the jumper plugs: In order to clear the codes just pull the ECM fuse and leave it out for about a minute.
Safety Car
Joined: Aug 2002
Posts: 3,842
Likes: 230
From: SANTA CRUZ CA
Re: Checking ECM Codes and clearing soft/history (LaVidaLoca)
LaVidaLoca (Rick), I have tried removing the ECM to reset the codes, and it didn't reset the DTCs. It is possible the system is still reading a fault. The GM manual suggests disconnecting the positive battery terminal, or the in-line fuse holder that originates at the positive terminal of the battery. The manual further reads that the negative terminal may be disconnected, but you will lose your on-board memory data. I was not aware that the on-board memory data was polarity sensitive. Maybe some member can enlighten us.
Pro
Joined: Jul 2002
Posts: 729
Likes: 4
From: Yukon OK
Re: Checking ECM Codes and clearing soft/history (Oldman)
I have reset my with the fuse several times. Could be you are still getting a fault. Try resetting it and scan for codes before running the engine. It should be clear. Then run the engine and check again to see if the code comes back.
I use the AutoXray code reader/scanner. It is nice because you can monitor the engine parameters in real time while you drive.
I use the AutoXray code reader/scanner. It is nice because you can monitor the engine parameters in real time while you drive.
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Safety Car
Joined: Aug 2002
Posts: 3,842
Likes: 230
From: SANTA CRUZ CA
Re: Checking ECM Codes and clearing soft/history (LaVidaLoca)
Thanks for the response, Rick. I have tried pulling the fuse several times, rechecking the code without starting the engine, and the code remains. I believe the system performs an electrical check with the ignition on, even with the engine off. The fault code is 23 (IAT sensor), which was created when I left the sensor unplugged after cleaning my throttle body. I'll try the battery disconnect next. It's no "biggie", as the vette doesn't seem to care if the IAT sensor is plugged in, or not.
Melting Slicks
Joined: Nov 2000
Posts: 3,388
Likes: 1
From: X
Re: Checking ECM Codes and clearing soft/history (dbwade36)
You can clear codes by just disconnecting the pigtail on the possitive battery cable...You will see a connection under the break booster...disconnect it for 10 seconds...If you need a pic, let me know.
Safety Car
Joined: Aug 2002
Posts: 3,842
Likes: 230
From: SANTA CRUZ CA
Re: Checking ECM Codes and clearing soft/history (JonM)
Thanks for staying up so late to respond, Jon. I'll try the positive side disconnect. Have you had any success with resetting codes by removing fuses? Others responding to this post seem to have succeeded with the fuse removal process.
Melting Slicks
Joined: Nov 2000
Posts: 3,388
Likes: 1
From: X
Re: Checking ECM Codes and clearing soft/history (Oldman)
I never tried...I don't think I ever had a code stored. But the little pigtail coming off the pos battery cable is the easiest. Late?? Its only a little past midnight...almost time for the dancing girls to show up.
Thanks for staying up so late to respond, Jon. I'll try the positive side disconnect. Have you had any success with resetting codes by removing fuses? Others responding to this post seem to have succeeded with the fuse removal process.
Safety Car
Joined: Aug 2002
Posts: 3,842
Likes: 230
From: SANTA CRUZ CA
Re: Checking ECM Codes and clearing soft/history (JonM)
Resetting codes on MY '93 seems to be accomplished only by disconnecting the battery, or by a code reader that has reset capabilities. Removing the ECM fuse did not reset MY codes.
The negative side of the battery was disconnected only because of the immediate access to that post. Accessing the "pigtail" off the positive post required disconnecting the positive side
of the battery first, so I took the path of least resistance.
The negative side of the battery was disconnected only because of the immediate access to that post. Accessing the "pigtail" off the positive post required disconnecting the positive side
of the battery first, so I took the path of least resistance.
