Can you please tell me where the PCM is located on a 1997 Crown Vic, base model, gas, 4.6? Also, I am getting OBD codes PO112 and PO113 when I run the diagnostics, they seem to be saying the opposite of each other. Could this mean that the IAT sensor is bad, or maybe even the PCM? Frustrated with this one, please help.
Answer: The ECM on your Crown Vitoria is located to the left of the brake pedal under the drivers side of the dash. You will have to lay on the floor and look up at that location to see it.As for the codes P0112 and P0113 for the intake air temperature sensor, these codes are most likely a bad IAT sensor and not the PCM. With a volt meter with the key on, check one of the wires for 5 volts and the other is a ground. If these are OK, set then meter to ohms and check the sensor terminals. You should get some kind of reading, not an open circuit.
Another common problem is that one of the wires to the temp sensor is broken right at the sensor connector. Give each wire a little tug to see if one stretches. If so, this means the wire is broken inside the colored insinuation and need to be repaired.
It is not too likely that the PCM is the problem, more a bad sensor or wiring.