P0488 Code

[07flatbed]

Anyone had to deal with engine code: P0488, Airflow throttle control circuitry.

The truck seems to accelerate slower than normal, until a certain point when the acceleration "breaks free" and seems excessive relative to throttle position. It idles at a lower RPM than normal and sounds as if the exhaust brake is on.



I'd appreciate hearing from anyone who has had experience with this problem.

thanks, Eric



Truck is a 2007 3500 C&C.

 

[HBarlow]

The symptoms you described but not the code are consistent with what you might experience when the engine is in the regeration mode.

 

[MullenaxM]

P0488 DTC is a EGR Airflow control valve circuit performance code. The most likely cause of this code is the EGR air flow valve is sticking. One easy way to check the valve is to remove the air intake hose from the throttle valve and take a mirror and place it under the air intake at the throttle valve and have someone turn the key from the off position to the on position (dont start the engine) and then back to the off position while you watch the trottle plate with the mirror. You should see the throttle plate move from the open position to the closed position and then back to the open position at key off. This should be a smooth transition with no binding or stoppage of the throttle plate. Every time the key is turned to the on position the throttle plate will cycle from the open position to the closed position as a performance check of the throttle valve. The normal default position of the throttle valve is the open position.



Sometimes if the throttle plate is sticking we can pull the EGR Airflow Control valve off and clean the throttle plate and reinstall and repair this condition, But most of the time we end up replacing the EGR Airflow Control Valve.



Mike

 

[07flatbed]

Mike,

Thank you for the information, sounds like that is probably what's happening. I'll inspect the plate, or maybe since I'm still in warranty I'll just take it to the local dealer.

Thanks for taking the time to respond to my question.

Eric