Last week my truck threw a code, P0506 (Valve duty cycle lower than expected) Any one know what could be the cause of this? My truck idles down really low when I come to a stop, its actually turned off a couples times. Any one know what the problem could be?

 

Also when im stopped my AC stops cooling, and my compressor goes on and off non stop (Regardless, stopped or while moving)! Don't know if the problems are related?

 

My 98 F150 had the same symptoms as what you are saying, the trucks RPM's would rev up and down at a stop. This was because the truck was low on AC refrigerant....Once I added the freon the truck worked perfect and cooling was back.

 

Nope, already checked the freon levels and there good, whats up tuff?

 

nice to see im not the only 1 awake in the valley at this hours

 

Anyone up for Whataburger?

 

P0506 in my book is called out as "idle air control system rpm lower then expected"

I'm assuming your "Valve duty cycle lower then expected" refers to an old IAC valve setup which our trucks don't have.

This code could be because somehow extra air is getting into your engine. Like lose connections or holes. Have you messed with the intake at all?

-ii

 

No I haven't, I have an AirAid Intake but its never caused this problem before Im thinking maybe its the Idle Control Sensor, It might be dirty due to the oil from my airaid.

 

Air leaks usually cause a high idle. You'd probably start getting lean codes as well if that were the case. That being said, I looked up the code and it says the throttle body or a vacuum leak. So......

 

Reread my first post my truck doesn't idle high, it idles low, it jumps between 2-300 RPM's

 

Bump

 

Off topic, but why do you have a SD truck in your signature? Is that your truck?

 

No the truck in my sig isnt mine but im gonna order one this month, hence the "MODS TO COME" Gonna order a 08 SD, 4 Door, FX4, Dually, black, and install the Big Rig Wheels and Tires. So its more of a soon to come pic.

 

Replace the throttle body and reprogram the PCM to it's latest calibration. That's what I'd do anyways.

 

I DID read your post. Someone else said air leak. Usually , they cause high idle. Sorry you missed that.