Important info. For bad idle in p (idle jumping from 500 to about 1500 rpm

[3100]

Hello everyone, I did small research on this big idle issue that some of us have so if you experience problems with idle jumping as mentioned above only in park, and when you shift to D it goes to normal or sometimes engine even stalls. For this problem many times I recommended replacing O2 sensor, I even replaced it on my own and was OK. for a while, but then, it started again. To make the long story short, the problem is in the shifter module, (the one that lights up p r n d 1 2 3 ) it is the white plastic box held by two 7mm or the prndl on the trans below the power booster is unadjusted. What happens is that something goes bad inside of that white box and then pcm is not sure if the trans is in p or d and therefore does not know what to do with the iac, egr and evap system control. This will set DTC if pcm sees that highs and lows in prndl switch do not match with their normal table of operation for more than 10 seconds, after 10 sec DTC will be set however, MIL will not be iluminated nor the freezeframe will be available for this.

[xeroinfinity]

Almost sounds like an upshift or neutral flare, what DTC was it showin ?
Your transmission is a 4t60e isnt it ?