Sometimes, if I switch from neutral or park to drive, the check engine light will turn on and the D will start flashing. However, the flashing D will go away after next startup and the check engine light just goes away a bit after that. I'm not sure if its the park neutral switch that is at fault or if it is just because I have some other weird electrical issue, since sometimes the "tighten fuel cap" light will come on and go away in a very similar manner, but this is new.
Any tips on what to test to see what I need to replace / check?
154206 miles.

 

Likely contacts are worn and now intermittent contact causing the issue.

Best bet would be to replace.

https://acurazine.com/forums/3g-tl-p...7-code-968913/

There's two links to threads in there to reference as well.

 

Thanks.

 

A few days ago I got a check engine light on my 08 TL, replaced the neutral safety switch but the check engine light was still on, I tried resetting the check engine light with a scan tool but still wouldn't go away, also checked the transmission fluid level and it was fine. Any suggestions on where to go from here?

 

So, just to clarify, your check engine light from a few days ago was a P1717, you changed the neutral safety switch and your ECM keeps throwing a P1717?

 

Yeah thats correct

 

Transmission Range Switch Test

1.Make sure you have the anti-theft codes for the audio system and the navigation system (if equipped).
2.Remove the battery trim and the left upper fender cover.
3.Disconnect the negative cable from the battery, then disconnect the positive cable.
4.Remove the battery hold-down bracket, and remove the battery and the battery tray.
5.Remove the intake air duct and the air cleaner assembly.
6.Remove the battery base.
7.Disconnect the transmission range switch connector.


8.Check for continuity between the terminals at the switch connector. There should be continuity between the terminals in the following table for each switch position.

9.Transmission range switch test is finished if the test results are OK. If there is no continuity between any terminals, check that the transmission range switch installation. If the switch installation is OK, replace the switch.
10.Check the connector for rust, dirt, or oil, clean or repair if necessary, then connect the connector securely.
11.Install the battery base.
12.Install the intake air duct and the air cleaner assembly.
13.Install the battery tray, the battery, and the battery hold down bracket, then connect the battery terminals.
14.Install the left upper fender cover and the battery trim.
15.Enter the anti-theft codes for the audio system and the navigation system (if equipped). Set the clock (on vehicles without navigation).

 

I disconnected and reconnected the negative battery terminal and the check engine light went away away. I'll drive the car for now, if the check engine light happens to return I'll proceed with the intructions you gave. Thanks