The PCM is detecting too much or too little current in the primary of the ignition coil. This is done when the coil is saturated (before the plug fires) so it wouldn�t be the secondary (plugs or wires). You need to check the low voltage harness and connector for shorts or opens. A quick way to do this (if is there is such a thing) is to pull the connector from the PCM and use an ohm meter to check the resistance reading from ground to each primary coil pack. You will likely find #3 reading higher or lower then the others.
For the ECT problem it could be the harness but it�s likely the ECT. With the engine cold pull the connector off and measure the resistance. Compare it to the cold values listed in the manual. If it�s correct the check the harness (voltage below value indicates the ECT resistance is to low (out of range) or on open/dirty/short in the ECT wiring. You can also check this at the PCM connector.
jeff
