Seeing Double Vision-Part 2

Here is a 2008 Dodge Nitro 3.7 Liter with 81,738 miles on it. Shop owner call me with a complaint of MIL on and O2 heater codes that come right back when erased. He is pretty sure it will need a PCM replacement. So sure that he has already ordered the replacement PCM. I told him I will do some quick checks before setting up the replacement PCM. So lets pull some codes.

Again, we are seeing all four oxygen sensor heater codes active. Lets look at some data.

Looking very familiar isn't it? We use the same testing procedures.

Here we actuated Bank 1 Sensor 1 oxygen sensor heater circuit with the WiTECH application at 25%. Again, I want to look at the command and amperage. We are flowing about 2 amps of current when activated. Lets look at static reading as well.

Same testing procedure as on the Jeep. We are checking resistance.

Here is the resistance of Bank 1 Sensor 1 oxygen sensor heater circuit-the whole circuit.

Here is the replacement PCM. Again, this is not a plug and play unit. Same procedures as Jeep.

Here I used the WiTECH application to program the replacement PCM.

The data after the PCM replacement. Now, are we to assume that whenever we get all O2 heater circuit codes at the same time that it is always the fault of the PCM? You better not. I try to treat each instance as brand new. If you don't you could make a wrong turn on your diagnostic path. Do the testing and confirm.