IAC (TPS) Idle relearn procedure
My dad pulled his IAC out and now the truck is idling funny. Can anyone please post up how to do the relearn procedure for me.
Thanks in advance...
Unplug IAC
Turn key off
Wait 30 seconds
Turn key on, leave on for 30 seconds. You should see a SES light now too.
Turn key off.
Plug IAC back in.
Turn key on.
If you can, verify with a scanner ( with key ON only, not car running ) that with your foot off the gas it's reading 0%, and at WOT it's reading 100%.
Your done.
Now here's an IDLE relearn:
PCM Idle Learn Procedure:
Automatic Transmission:
1 Turn off the ignition
2 Restore the PCM battery feed
3 Turn Off the AC controls
4 Set the parking brake and block the drive wheels
5 Start the engine
6 Allow the engine coolant temperature to reach 176 degrees F
7 Shift the transmission selector into the drive range
8 Allow the engine to idle for 5 minutes
9 Turn on the AC controls (Omit for 2000-01 model)
10 Allow the engine to idle for 5 minutes (Omit for 2000-01 model)
11 Shift the transmission selector into Park
12 Allow the engine to idle for 5 minutes (Omit for 2000-01 model)
13 Turn off the AC controls (Omit for 2000-01 model)
14 Allow the engine to idle for 5 minutes
15 Turn off the engine for 15 seconds
Manual Transmission:
1 Turn Off the ignition
2 Restore the PCM battery feed
3 Turn Off the AC controls
4 Set the parking brake and block the drive wheels
5 Transmission in neutral
6 Start the engine
7 Allow the engine coolant temperature to reach 176 degrees F
8 Turn on the AC controls (Omit for 2000-01 model)
9 Allow the engine to idle for 5 minutes (Omit for 2000-01 model)
10 Turn off the AC controls (Omit for 2000-01 model)
11 Allow the engine to idle for 5 minutes
12 Turn off the engine for 15 seconds
Your procedure worked it idles perfectly. First bump of the key and it’s BAM right on idle, no chasing the idle up and down until it settles on 900 rpm. Solidly goes to 900 instantly.
So…..as we all know, these PCMs are not all the same, they have minds of their own. If in fact that was a TPS idle relearn, I’m here to tell everyone they can try it for an IAC valve also, because their PCM might like it.
Thanks.






