This is more of a PSA than anything - I had a customer come in with a SERVICE POWER STEERING message on the DIC, after checking codes a C0450 came up "Steering Assist Control Actuator Circuit" when checking the variable effort steering data with the Tech 2 I could see that there was an outgoing signal to the rack and pinion but no incoming signal to the EBCM. So I went to check out the wiring and after removing the cover on the connector going to the EBCM this is what I found.



The wire going back to the EBCM from the rack was too short and pulled out of the connector - finally it made no contact at all and tripped the code.

Hoping that was all that happened I re-routed the wire to give it a little slack and tried plugging it back into the connector and plugging it back into the EBCM - I checked the data again but still had no incoming signal. After taking a closer look at the connector I saw this:


As you can see in the photo the third small connector from the left is discolored around that pin-out - as the wire pulled out it was arching and it actually melted the plastic around that connection - it also melted the plastic around the pin on the EBCM see pic below:




See the third pin in from the right in the picture above - the plastic is melted around the pin.

We installed a good used EBCM and after going a steering position sensor and brake pressure sensor re-learn it was back up and running.

So if you are dealing with a code like this don't assume the rack is bad - check the wiring!