Based on my research on these helpful forums, I am now convinced that this is the same issue as the GX model. Attached are the highlighted technical service bulletins for both the 2003 GX 470 and LX 470, where Lexus has clearly acknowledged the problem with the GX but not the LX. I plan to write a relatively strong letter to Lexus "suggesting" that they resolve this problem. I hope that you and others do the same. Maybe I should post my letter here so that others may see it.
Kind regards,
Jason Havens
Destin, FL
TSB for your 2003 Lexus Truck GX 470 V8-4_7L.pdf
Find Technical Service Bulletins for your 2003 Lexus Truck LX 470 V8-4_7L.pdf