Dodge Repair Questions? Ask a Mechanic for Answers ASAP
If you have a digital voltmeter, I think we could check a few things.
The PCM in this year has very accessible connectors. We'll need to remove the wire covers on the back (visible) side of the connectors for testing and then some way to backprobe the circuits through the weatherpack while they're still connected to the controller.
Since your PCM isn't (apparently) able to perform a MIL bulb test at key-on, there may be a shorted circuit or you may have a power or ground missing. Since you've checked fuses, we can move straight to the circuit tests.
You will need to remove the connectors at least at first to find the numbering for pin positions. The red lock tabs on the connector sides just need to be slip up a bit, then you can squeeze the release tabs and pull the connectors off.
Note that one connector is numbered 1 thru 40, the other 41 thru 80.
Let's start with the connectors off. Powers and grounds are as follows...
10 Ground (tan/ black)
20 Fused ignition switch output (dark blue/ white)
46 Battery positive (red/ tan)
47 Ground (black)
50 Ground (black/ tan).
Make sure you have a good strong signal on all these pins. Use of a test light or another load device (something to actually draw a little amperage) is useful in discriminating between a weak connection and one that's OK.
As long as the connectors are off, test for continuity between these sources and vehicle ground...
32 Crankshaft position sensor signal (grey/ black)
33 Camshaft position sensor signal (tan/ yellow)
44 8v supply to cam/ crank sensors (orange/ white)
61 5v supply to MAP, TPS, A/C pressure transducer (violet/ white).
Any continuity to ground with both PCM connectors disconnected indicate an undesirable situation. You might leave the DMM connected to this circuit and begin wiggling wires and disconnecting affected circuits. Write back if this is the case.
Now connect the PCM and we can do some backprobing. The tool you use for bypassing the weatherpack around the wires needs to do so without tearing the seals. Water will ultimately find its way in and cause all kinds of havoc. A paper clip is commonly used, just make sure the end you insert to take your readings isn't sharp or rough.
The first checks will be to the 5v and 8v circuits. With the key on, you should have a very good signal from both. The 5v circuit will read extremely close to 5.0 volts, where the 8v circuit can be between 8 and 9 volts. Let me know what you find if one or both are outside this range.
If they both check out, you can check your cam and crank sensor signals from this point now. The circuit will read either zero or 5v, depending upon the sensor to reluctor relationship. It should change as you rotate the engine and a signal state change is created. If the signal remains low or high, never changing, it means either the reluctor isn't moving/ passing by the sensor or the sensor is mispositioned or just not working. The crank sensor needs to be positioned, the cam sensor is set for life. Until it dies...
That's about the extent of it. Somewhere along the line you may see a voltage reading out of line. Let me know what the circuit affected is and we'll get to the bottom of it.
If it happens to be the 5v or 8v power feed, you can disconnect the cam sensor (distributor connector, larger one), the crank sensor or the A/C pressure transducer and see if the voltage returns. If it does, that part is conclusively found to be junk at this point.
Write back when you can.
Sorry to hear that Jedd. Was the crank circuit you tested and found to always be low the same as pin 32 (crank signal)?
Disconnecting the sensor (not easy, sorry) will give you a 5v pull-up voltage at that wire if the circuit is not grounded somewhere.
If you see no 5v signal (key on, not cranking), check for continuity to ground along the way. The pin 32 should have zero continuity to ground with the crank sensor disconnected and the PCM connector disconnected.
The crank sensor IS adjustable, so it needs to be pushed inward as far as it will go to contact the flex plate with its paper spacer. They don't always peel off immediately with engine cranking, so it may have been positioned right from the start.
If the sensor is still out, you can check for ignition reference signal change by passing a steel conductor past the sensor end. Watching the sensor output, it should change as the conductor is within and then out of range. Zero and 5v.
You've done your homework Jedd. It's close to being done. If this is the only voltage source you're missing, it's likely to be an easy fix.
i will have them check this if they havent already. I still am getting no fuel? Computer codes? NO BUS on display? Does the computer shutdown when there is a problem?
I'm sorry Jedd. I focused on the crank sensor issue, missed the big picture.
NO BUS is typically an indication that the PCM isn't awake. You should not be able to get codes from the system typically in that state.
That said, there are two bus communication systems that connect to the PCM. The SCI is the factory hi-speed system for communication between the scan tool and the controller. I'm not sure they can access that. It might be an important point later.
The CCD bus is the general communication bus used for everything else. The PCM also sends and accepts information on this bus but it's on a slower rate than the SCI. Certain information is also not accessible.
But when one bus is inoperative, sometimes the other one works. It's accepted practice to try both buses when communication on one isn't available now. The CCD bus is considered the "generic" bus.
This is a tough one, Jedd. I would check each of the powers and grounds I listed above and then check for grounding of the 9v and 5v circuits. If no problems are found and no communication with the engine is available, I'd normally feel pretty confident about PCM replacement.
The complication is that they're probably using a different bus line than what I do. The CCD bus can be taken down by the radio, for Pete's sake!
I have to warn you about parts swapping at this point. It's extremely dangerous to this system to have mismatched parts exposing themselves to the original system. If you have a factory theft system, you're pretty much OK. But if you don't, the system will learn that it has theft and will prevent the engine from ever running again. It would require the replacement of both the body control module (BCM) and the PCM for it to forget what it had learned by error.
One check you might try is to check the CCD voltages. They can be accessed by going to the diagnostic link connector (DLC) below the dash, near the left kick panel. I don't have resources here now, but I believe you will find the circuits to be three spaces in on both levels (it's a 2-tier connector) from the driver's seat. The connector runs north-south on your car, so test the third pin on both rows for something close to 2.5 volts. It varies, but that's the nature of the CCD bus. Voltage variance is the signal. You'll see something between 2.4 and 2.5 volts when it's working correctly.
If the NO BUS signal is still present and you have the needed voltages and grounds specified above, I'd have to go with a replacement PCM.
I have to defer to the techs testing your car in the field, but this is what I use for go, no-go testing.
We're not done until it's running, so shoot me back any info you get Jedd.