Ford Taurus 2000 Code P1413

[Don1]

I am a new member. I have spent two days on this problem. HELP!

Secondary air pump does not turn on. Pump is good. It works with 12V directly to motor. Voltage to air pump is low. Fuse is good. Air pump relay is good. There is 12 volts to coil of relay but there is also 12 volts on the ground side. The same exists even when the relay is removed. The negative side of the relay goes to the PCM (computer). I assume the PCM grounds this during startup. The pump motor is supposed to runs for a short time after starting (20 to 120 seconds) . It appears to be a bad ground wire or a bad PCM. I don' t know how to check this as I can't follow the wiring harness to the PCM.

Can any body help?

Don