engine system check

[Tom Thompson]

Hi there i own a ‘09 Rav 4 diesel and recently the engine system check warning light came on as well as 4 x 4 system check - the EGR valve was replaced but warning light will not go - have tried diagnostic check and Battery reset but to no avail - any help out there? PS i am not a mechanic 

[flash22]

have you had the codes read ?

[Tom Thompson]

Yes - yes keeps coming up with EGR error code 

[Tom Thompson]

P0488

[Devon Aygo]

P0488 is not an EGR issue :

P0488    Exhaust Gas Recirculation Throttle Position Control Range / Performance

DESCRIPTION

The ECM opens and closes the throttle valve using a DC motor type actuator. Due to the opening and closing of the valve, the exhaust gas recirculation volume can be properly controlled. Also, engine vibration and noise will be reduced by closing the valve when the engine is stopped.
Although the DTC title says "Exhaust Gas Recirculation Throttle Position Control Range / Performance", this DTC indicates that the throttle valve is malfunctioning.

 

P0488 

DTC Detection Drive Pattern	DTC Detection Condition	Trouble Area
Perform the following repeatedly for 1 minute: gradually raise the engine speed to 3000 rpm from an idling over approximately 10 seconds, and then release the accelerator pedal to return to an idling state.	The throttle motor activation duty is more than specified value for 30 seconds (1 trip detection logic).	Throttle valve stuck Throttle valve does not move smoothly Open or short in throttle control motor circuit ECM

 

There is actually a Technical service bulletin from Toyota regarding a P0488 issue:

Bulletin: EG-0167T-0311-EN

Subject: AD-08 engine: A broken diesel throttle body gear is causing an abnormal noise and DTC P0488.

Models: AVENSIS, AURIS / COROLLA, RAV4, VERSO

Model codes: ADT270, ADT271, ADE150, ADE157, ALA30, ALA35, AUR20, AUR21

DESCRIPTION OF PHENOMENON: Some customers may complain about an abnormal noise coming from the diesel throttle body. And /or the MIL is on combined with a loss of engine power, DTC P0488 (Exhaust gas recirculation throttle position range / performance) is stored in the memory of the engine ECU.

PRODUCTION CHANGE: The software of the engine ECU has been improved

PARTS INFORMATION:  26100-0R020  Venturi assy 1*

*: Only replace the “venturi assy” when the customer complaint is abnormal noise. In all other cases updating the engine ECU software is sufficient.