Volkswagen Repair: !998 Jetta OBD Codes 411 and 1450, amp fuse, fuel pump relay

Question
My wife has a 1998 Jetta with 120,000 mile. The check engine light came on and I went to Autozone. They got codes 411 and 1450. I cleaned the 50 amp fuse and changed the secondary air pump relay. The codes were cleared, but only lasted a day. Went back to Autozone and got same codes. The secondary air pump relay does not to be getting enough trigger voltage. I can only get about 6 volts, not enough to trip the relay. Primary power is 12 volts. I applied 12 volts to the Secondary air pump and it does spin. I am going to change the secondary air solenoid, but I don't feel this is the answer. I also changed the fuel pump relay about a year ago. What direction should I go in? Thanks. Armand  

Answer
A secondary air pump fault has multiple reasons. Check voltage at the pump whole running. The pump will run when the engine is cold. The If the pump runs then you got power and ground. Voltage at the pump should be running voltage 13.5-14.5VDC. Check the vacuum hose to the secondary air combination valve. The mechanical metal valve attached to the exhaust. If this is a turbo engine check the Turbo bypass regulator valve at the intake pipe and see if it holds vacuum at the vacuum port. If it does not then replace then re test. Does the pump run when cold? Check the vacuum lines from the solenoid and see if the solenoid is clicking when cold. The pump will not always run with the fault until the fault is erased and the problem is corrected. If the front oxygen sensor is bad and not reading right then it will throw a secondary air fault and some times the  o2 Sensor fault. If your pump has rivets on it the rivets can break and air can leak out. Tell me after you erase the fault and check when cold if the pump runs. With out the proper scan tool the activation of the system is very hard to duplicate.