Topic: CHECK ENGINE LIGHT

[crawlerdan]

while driving to work lately, ive had the heater on, and after a few mins, the check engine light will come on. if i shut the heater off, the light will go off. then i will turn the heater back on, and in a few mins, the light is back on??
any ideas?? no performance loss, i dont think, but really annoying!!

[WHITE_TRASH]

Bad temp sender near the thermostat housing would be my guess.

[BigMike]

No, on the older efi systems, the temp sender will not throw a code.

I bet it is something related to your charging system, because the blower fan operates off of a 50 Amp fuse, so it's expected to have a huge draw. Possibly the blower fan motor is getting old and it's taking so many amps that the alternator can't keep up or something?

It might also be related to your A/C system, but I doubt the older ecu's would notice that either...


Jump your diag box (T1 to E1) and see what the code is.

[GrimReaper]

while driving to work lately, ive had the heater on, and after a few mins, the check engine light will come on. if i shut the heater off, the light will go off. then i will turn the heater back on, and in a few mins, the light is back on??
any ideas?? no performance loss, i dont think, but really annoying!!

Ask your truck nicely whats wrong with it. Its smart enough to tell you if you know how to ask.