I'm getting an ECT voltage too high and MAP sensor error. The voltage at the sensors is normal at 5v. Continuity b/w sensor and PCM also w/in specs. I replaced the sensors w/ no change. The truck idles and runs well until I connect the ECT sensor. Once connected, the idle drops and the engine quits. When disconnected, idles/runs fine again. In desperation I replaced the PCM today - no change at all. Any ideas??

Ernie[/align]

 

You may have a ground issue. Check your ground and make sure your pos. wire is not shorting out somewhere.