Diagnostic Code 48
My truck is displaying a 48 which, as I understand it, indicates a faulty idle speed stepper motor. Now it only does this when it is cold. Mine touches 2000 rpms before hesitating for about 5 seconds at 1500 then about 1250. It settles in at 1100 and gradually drops to normal idle speed as it warms.
What is the behavior of your D90 on cool, let say 60 degrees, start up?
Could a faulty temp sender cause this?
It has, on occasion, hung out at 2000 and 1500.
94D90 NAS 3.9 LT77 LT230T Soft Top
There are no guarantees expressed or implied of the accuracy or correctness of the contents of this message, and the Author is not liable for the taking of any action in reliance upon the contents of this message. As always, do your own research. To the extent that opinions are expressed in this message, they are not necessarily the opinions of the Author.