P 1693 Code points to MAP Sensor
All,
Returned from the dealer this morning; their diagnostics pointed toward the MAP Sensor not returning sufficient voltage, which triggers the 'check engine' light, but has allowed the truck to run fine since this condition first set in. The dealer didn't have the part on-hand but will replace this part under warranty, which they see in this case as an 'emissions' issue.
Learned a couple things from this visit to the dealer. First, it is very helpful to know enough about your vehicle to ask smart questions. Second, it's important to ask if a given situation is covered under warranty, and if not, why not. In this case, I was initially given a $300 bid to replace the sensor, since the truck is beyond 3-36 warranty period. After asking a few questions of the maintenance rep, and learning that this was actually an emissions issue, I then was able to ask why it wasn't then covered. Bottom line is that TDR keeps the education curve ahead of dealer complacency. Thanks all.
griggsd