It is 4.7L V-8 gasoline engine.

So I guess I can check to see if there are any loose connections or frayed wires going to or from the PCM?
There are 3 connectors on the PCM, any suggestions which set of wires to pay attention to?

What does AA00 or 00 00 mean?

Appreciate the help by the way!

 

Cluster codes, probably whining about no communication on the bus. That's standard for the test though. I don't have the chart for those codes here handy.

Well, the PCM is obviously getting power, since you can talk to it. Are you getting power to pin 30 on the ASD relay? (do you even have one? What's your power distribution center look like?

 

This is where things will slow down for me. This is where I need to look things up and where they are...
Hope to have more info by tomorrow.

 

Ok, ASD relay pin 30 is 12 volts (no key in ignition) - in other words, hot all the time.
We will try to check the CCD bus tomorrow.

What do you mean by Power Distribution Center... fuse box or PCM? We did remove the fuse box and looked for bad connections and bare wires. It looked good.
We have not removed the PCM or checked wires near PCM.

 

Fuse box under the hood.

 

We looked under the fuse box 2 days ago and nothing gets our attention. No burned spots, frayed wires, etc...

I downloaded a 2002 Ram manual last night. After looking at the schematics, since there are no blown fuses, I am almost convinced there is an open wire somewhere related to the PCM or the PCM is partly damaged.
Or there is a signal that the PCM is supposed to receive before turning on the instrument panel and fuel pump etc..., but is not getting this signal to turn everything on.

I am temped to do some tests. For example, the fuel pump never comes on whether the key is on or trying to start. I am thinking about pulling the fuel pump relay and jumping pin 30 to pin 87.
If the pump runs, then I know the pump is good, and therefore, the relay is not getting a charge from the PCM. If the pump does not run, then I guess I'll have to drop the tank and test the pump.

Then I can check other pins where the signal is supposed to come from the PCM and work backwards and see why the PCM is not sending power to the relays.

Any other suggestions?

 

Pull the relay, install your test light across the terminals on the control side of the relay, turn the key on, does the light come on for about three seconds? If it does, then that part is working as it should. If it doesn't, verify you get power to the control wire, then check and see if you get ground. Test the ASD relay the same way. See if the PCM is actually trying to control them.

 

We jumped pin 30 to pin 87 on the fuel pump relay and the fuel pump runs.
We checked for voltage on pin 86 and there is no volts when we turn the key.
Same thing with the ASD relay.. no volts coming from the PCM.

So, how can we tell if the PCM is waking up or not?
Next thing we plan to check are the wires to ground and the 12 v and 5v to the PCM when the key is on.

We are thinking either the PCM is bad, but is there a way to see if the PCM went bad on it's own, or did s sensor short out and damage the PCM?

 

PCM provides ground path for the control side of those two relays. Ignition switch should provide the power. So, with ignition on, you should see power on pin 86, (I think it's 86.....) In any event, with ignition on, you should see 12 volts on two wires in the relay socket.

 

Ok, we plan to check the wires going to the PCM on Tuesday. I will double check the 2 pins that are hot on the relays. If I remember right, pin 30 is hot all the time and 86 is hot when you turn they key.

Other than that, I plan to check that all the ground wires on the PCM are still grounded and none are open.
And on the other hand, make sure the other wires are not shorted. Only trouble here is that we won't be able to tell if it is "open". In other words, we are checking for shorts, but just because there is no short, doesn't mean the wire is good.
Which pin wakes up the PCM?