The BCM pretty much runs the show. You could have a dirty connector where a plug connects to the BCM, or at the IP. At such low voltages and in such extreme environments it's a wonder more problems don't crop up in humid weather! Last week after a torrential storm came through on a 95* day, dropping a couple inches of rain in a few hours and knocking the temps into the 70's, my car started up and the following messages/lights came on:
Service ESC
Traction Control disabled
Check engine light
Message: "Engine at reduced power"
My V6 acted like it had less than 3 cylinders! Called service the next day and all the lights/messages had turned off. He said it was probably a "soft code" and wouldn't set any permanent codes, and not to worry about it. I took it in for a door needing adjustment (right front dragging on latch). They kept it overnight for "check engine light", put me in a rental, and never told me anything more than the RO stating they replaced my gas pedal, referred to as an APP sensor.
I believe that the sudden drop in temp caused the extremely muggy humidity to condense out on anything it could and the connections to the BCM and/or TCM, ECM, etc. were compromised, but I have no evidence other than the symptoms. But as the car's interior cooled and dried the symptoms disappeared, just not all at once. When I got home the TC light was off but the CEL was on. The next morning it "fixed itself" I guess.
You may have experienced a similar condition as what I believe mine did. (Again, no hard evidence, just conjecture.) If you are past warranty then remove the negative battery cable, then pop the front console covers (both sides), then unplug and plug-in the BCM connectors several times. If you have some non-conducting (I think it's called dielectric) grease, use it after cleaning the terminals with the plugging/unplugging. There is another BCM connector facing the driver's side behind the others facing the passenger's side.
Service ESC
Traction Control disabled
Check engine light
Message: "Engine at reduced power"
My V6 acted like it had less than 3 cylinders! Called service the next day and all the lights/messages had turned off. He said it was probably a "soft code" and wouldn't set any permanent codes, and not to worry about it. I took it in for a door needing adjustment (right front dragging on latch). They kept it overnight for "check engine light", put me in a rental, and never told me anything more than the RO stating they replaced my gas pedal, referred to as an APP sensor.
I believe that the sudden drop in temp caused the extremely muggy humidity to condense out on anything it could and the connections to the BCM and/or TCM, ECM, etc. were compromised, but I have no evidence other than the symptoms. But as the car's interior cooled and dried the symptoms disappeared, just not all at once. When I got home the TC light was off but the CEL was on. The next morning it "fixed itself" I guess.
You may have experienced a similar condition as what I believe mine did. (Again, no hard evidence, just conjecture.) If you are past warranty then remove the negative battery cable, then pop the front console covers (both sides), then unplug and plug-in the BCM connectors several times. If you have some non-conducting (I think it's called dielectric) grease, use it after cleaning the terminals with the plugging/unplugging. There is another BCM connector facing the driver's side behind the others facing the passenger's side.
