[klhansen]

DTC P1280 indicates injector control signal circuit out of range low.
Possible causes:
-- biased ICP sensor/PCM
-- open ICP sensor circuit
-- short to SIG RTN or PWR GND on ICP sensor circuit
-- open in VREF circuit

I'd look at your ICP sensor, and possibly the connector and wiring. If you have oil inside the sensor connector, then it's suspect. Could be an intermittent wiring problem like a connector socket that's spread too far apart to make good contact with the sensor pin.

That's the code you'll get if you pull the ICP sensor connector off with the key on or engine running.

 

[klhansen]

Right on top of the driver's side head just behind the alternator.