Archived Caution light in 03

[dward]

I have a buddy towing his trailer through Tx right now and just had the yellow caution light come on. It's the MIL(Malf indicator light) The manual says if it stays on, it may be an engine control module issue, or maybe an emission sytem problem.

Truck is 03 4x4 6 sp man, no cat . Mods are a Smarty set on low level, and a Pac Brake. He said he had to tie into the ECM for the brake but that was over 5 yrs ago with no problems.

He is towing a 25' airstream and the temp is 97 deg. Truck is running fine with no abnormalities, but he doesn't have after market gauges.

Any thoughts or advice would be appreciated.

 

[Sticks]

Find out what the codes are. Could be a simple wheel speed sensor, could be something catastrophic on the horizon.

Does the "Key on/off x3" still work on the 3rd gens?

 

[dward]

Sticks,
Thanks for the reply. There are 3 codes showing
P0477 - exhaust pressure control relay low
P0837 - 4 wheel drive switch performance/rationality
P2122 - pedal position sensor low

The light stays on but the truck is running fine and everything is in limits (stock gauges)
Has smarty junior set on towing level.