Low idle after batt replacement
Thread Starter
Racer
Joined: May 2009
Posts: 253
Likes: 38
From: Austin Tx
Low idle after batt replacement
The batt died in my 2000 coupe (stock eng with auto tranny and 90k miles). After replacing the batt, I now have an odd idle problem.
When I come to a stop, the RPMs drop to 400 and eng shutters a bit. After abt 2 sec, the RPMs climb back to 600 and idles very nice. It happens every time I stop at a light.
The IAC compensates for the A/C being on or off just fine.
I thought the computer might need to re-learn something, but it has been a couple of months now and it still does it.
It didn't happen before batt replacement.
Other than this issue, the car runs perfectly.
Any ideas?
When I come to a stop, the RPMs drop to 400 and eng shutters a bit. After abt 2 sec, the RPMs climb back to 600 and idles very nice. It happens every time I stop at a light.
The IAC compensates for the A/C being on or off just fine.
I thought the computer might need to re-learn something, but it has been a couple of months now and it still does it.
It didn't happen before batt replacement.
Other than this issue, the car runs perfectly.
Any ideas?
Tech Contributor
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
Have you tried an Idle Relearn Procedure?
C5 Idle Relearn Procedure
Purpose
This page basically shows you step by step how to do an Idle Relearn. You would want to do this if you have done any intake modifications. If you do not do this, you may have hesitation or other issues.
Tools Required
None.
Do the Job
Follow these procedures EXACTLY or you will have to start from scratch.
Insert key into ignition and turn to the "On" position but, DO NOT START THE ENGINE.
Pop open the engine fuse block box cover and remove the two 10amp fuses from position numbers 16 & 23.
Your DIC will now display "check" messages for ABS, etc...
Turn ignition to the "Off" position.
Re-insert both 10amp fuses for positions 16 & 23.
Start your engine
Allow engine coolant temperature to reach a minimum of 176 degrees F and run at this minimum temperature for at least 5 minutes.
Shut down engine
Let rest for a minimum of 30 seconds.
Restart engine - check for DIC error codes (there should be none).
Drive car for a minimum of 30 miles at varying rpm settings and speeds. PCM will now re-learn and adjust for the new air flow and air temperature at the intake.
C5 Idle Relearn Procedure
Purpose
This page basically shows you step by step how to do an Idle Relearn. You would want to do this if you have done any intake modifications. If you do not do this, you may have hesitation or other issues.
Tools Required
None.
Do the Job
Follow these procedures EXACTLY or you will have to start from scratch.
Insert key into ignition and turn to the "On" position but, DO NOT START THE ENGINE.
Pop open the engine fuse block box cover and remove the two 10amp fuses from position numbers 16 & 23.
Your DIC will now display "check" messages for ABS, etc...
Turn ignition to the "Off" position.
Re-insert both 10amp fuses for positions 16 & 23.
Start your engine
Allow engine coolant temperature to reach a minimum of 176 degrees F and run at this minimum temperature for at least 5 minutes.
Shut down engine
Let rest for a minimum of 30 seconds.
Restart engine - check for DIC error codes (there should be none).
Drive car for a minimum of 30 miles at varying rpm settings and speeds. PCM will now re-learn and adjust for the new air flow and air temperature at the intake.
Thread Starter
Racer
Joined: May 2009
Posts: 253
Likes: 38
From: Austin Tx
Thx for the replies guys!
I'll give the idle re-learn a try tomorrow.
After a bit more reading, I discovered I have no IAC. Oops!
Guess I been under the hood of my 3rd gen Camaro too long...
I'll give the idle re-learn a try tomorrow.
After a bit more reading, I discovered I have no IAC. Oops!
Guess I been under the hood of my 3rd gen Camaro too long...
Last edited by zz28zz; Jul 23, 2012 at 11:55 PM.
Tech Contributor
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
The PCM Tune is written to NONVOLITILE MEMORY. SO,, NO, removing power to the PCM or Car for that matter will not effect the TUNE or PCM Operating System. The IDLE is a learned function that changes with many functions. The PCM has a basic idle that it defaults to and the PCM will LEARN the new correct idle in a short period of time.
BC
BC
Last edited by Bill Curlee; Mar 19, 2019 at 10:38 PM.
