Help with idle re-learn.
Team Owner
Joined: Sep 2001
Posts: 23,283
Likes: 906
From: Lake Elsinore, CA
Re: Help with idle re-learn. (low98vette)
Automatic Transmission
1. Turn OFF the ignition.
2. Restore the PCM battery feed.
3. Turn OFF the A/C controls.
4. Set the parking brake and block the drive wheels.
5. Start the engine.
6. Ensure that the engine coolant temperature is more than 80°C (176°F).
7. Shift the transmission into Drive.
8. Allow the engine to idle for 5 minutes.
9. Shift the transmission into Park.
10. Allow the engine to idle for 5 minutes.
11. Turn OFF the engine for 30 seconds.
Manual Transmission
1. Turn OFF the ignition.
2. Restore the PCM battery feed.
3. Turn OFF the A/C controls.
4. Set the parking brake and block the drive wheels.
5. Place the transmission in Neutral.
6. Start the engine.
7. Ensure that the engine coolant temperature is more than 80°C (176°F).
8. Allow the engine to idle for 5 minutes.
9. Turn OFF the engine for 30 seconds.
1. Turn OFF the ignition.
2. Restore the PCM battery feed.
3. Turn OFF the A/C controls.
4. Set the parking brake and block the drive wheels.
5. Start the engine.
6. Ensure that the engine coolant temperature is more than 80°C (176°F).
7. Shift the transmission into Drive.
8. Allow the engine to idle for 5 minutes.
9. Shift the transmission into Park.
10. Allow the engine to idle for 5 minutes.
11. Turn OFF the engine for 30 seconds.
Manual Transmission
1. Turn OFF the ignition.
2. Restore the PCM battery feed.
3. Turn OFF the A/C controls.
4. Set the parking brake and block the drive wheels.
5. Place the transmission in Neutral.
6. Start the engine.
7. Ensure that the engine coolant temperature is more than 80°C (176°F).
8. Allow the engine to idle for 5 minutes.
9. Turn OFF the engine for 30 seconds.
Melting Slicks
Joined: Jan 2001
Posts: 2,635
Likes: 2
From: Aloha, Oregon
Re: Help with idle re-learn. (low98vette)
do NOT disconnect the battery with key in on position. This has the potential to surge the PCM and fry it. If you desire to disconnect the battery to reset the static registers in the PCM (to zero the fuel trims, for example)-
1. remove both PCM fuses at the fuse panel by the battery (#16 and 23, i believe?)
2. disconnect the battery, let sit for 5 minutes
3. Reconnect battery
4. reinstall fuses
5. drive in variable traffic, stop/go, some wide open throttle sprints on freeway where safe, hills, with some engine shutdown and restarts in between for 50 miles or so.
PCM will be effectively 'relearned' at this point. Of course, the more miles you put on the more the Long Term trim registers will average out and stabilize. If you are scanning your runs with a tool, you will see this happen as you put more miles on car.
Again, I emphasize not to have key in On position and disconnet battery. Hope this helps!
Robert Judd
GenIII Motorsports, Portland, OR
1. remove both PCM fuses at the fuse panel by the battery (#16 and 23, i believe?)
2. disconnect the battery, let sit for 5 minutes
3. Reconnect battery
4. reinstall fuses
5. drive in variable traffic, stop/go, some wide open throttle sprints on freeway where safe, hills, with some engine shutdown and restarts in between for 50 miles or so.
PCM will be effectively 'relearned' at this point. Of course, the more miles you put on the more the Long Term trim registers will average out and stabilize. If you are scanning your runs with a tool, you will see this happen as you put more miles on car.
Again, I emphasize not to have key in On position and disconnet battery. Hope this helps!
Robert Judd
GenIII Motorsports, Portland, OR
Team Owner
Joined: Sep 2001
Posts: 23,283
Likes: 906
From: Lake Elsinore, CA
Re: Help with idle re-learn. (low98vette)
It means, "Reconnect the battery." That's if it's disconnected.
The only time an idle relearn has ever helped my idle is when I first started the car after doing a heads/cam job. The idle was extremely rough before the relearn and magically smooth after. It was a little eerie.
:cheers:
The only time an idle relearn has ever helped my idle is when I first started the car after doing a heads/cam job. The idle was extremely rough before the relearn and magically smooth after. It was a little eerie.
:cheers:
