PO495 - Fan Speed High
PO410 - Sec Air Inj System
PO526 - Fan Speed Sensor Circuit

Suggestions so far are: Fan Clutch, Air pump and hose, relay????
So many possibilities it cost prohibitive to replace everything. Is there a way to narrow in on what the problem actually is? Sometimes really hard to diagnose the problem, so I hoping someone has ideas how to troubleshoot.

Thanks,

-mapsurfer
Cordova, TN

 

For the secondary air injection system you can readily remove the air pump. It is located on the frame under the drivers side of the vehicle. Check to make sure the hoses are dry and the pump operates smoothly. Apply some 12 v current to the contacts to check its operation.

There is also a check valve on the exhaust manifold that is an integral part of the SAR system. Remove and check the valve to make sure it is operating. Both parts can be replaced in less than an hour if needed.