[ImperialCrown]

Because the crank and cam sensors are inter-related (one can set the fault code for the other), it would be very unusual for 2 or more sensors to fail at once.
I would more suspect a common thread between all 3 sensor fault codes which would be the 5 volt supply or sensor ground from the PCM and its wiring. TPS-low could be a short to ground in the 5v power or signal return circuit which could affect all 3 sensors.
Once the PCM goes into protection because of a 5v short to ground, the battery power must be lifted from the PCM momentarily to resume 5v supply operation after re-connection. This will also erase the fault codes. The Vt/Wt wire should be your 5 volt sensor supply.
What are the wire colors to this sensor that appears to be the wrong one?
The tach/ign spark is driven from the crank position sensor. Fuel injector sync is driven from the cam sensor.
Any aftermarket security alarm or remote start on the car?

P0340-CAMSHAFT POSITION SENSOR CIRCUIT
When Monitored: Engine cranking/running. Battery voltage greater than 10 volts.
Set Condition: At least 5 seconds or 2.5 engine revolutions have elapsed with crankshaft
position sensor signals present but no camshaft position sensor signal. One Trip Fault.

POSSIBLE CAUSES
INTERMITTENT CRANKSHAFT POSITION SENSOR SIGNAL
INTERMITTENT CAMSHAFT POSITION SENSOR SIGNAL
5 VOLT SUPPLY CIRCUIT SHORTED TO GROUND
5 VOLT SUPPLY CIRCUIT OPEN
5 VOLT SUPPLY CIRCUIT SHORTED TO VOLTAGE
CMP SIGNAL CIRCUIT SHORTED GROUND
CMP SIGNAL CIRCUIT OPEN
CMP SIGNAL CIRCUIT SHORTED TO VOLTAGE
CMP SIGNAL SHORTED TO 5 VOLT SUPPLY CIRCUIT
SENSOR GROUND CIRCUIT OPEN
PCM - 5 VOLT SUPPLY
PCM - CMP SIGNAL
CAMSHAFT POSITION SENSOR

P0335-CRANKSHAFT POSITION SENSOR CIRCUIT
When Monitored: Engine cranking.
Set Condition: No CKP signal is present during engine cranking, and at least 8 camshaft
position sensor signals have occurred.

POSSIBLE CAUSES
CHECKING INTERMITTENT CMP SIGNAL WITH LAB SCOPE
INTERMITTENT CKP SIGNAL
5 VOLT SUPPLY CIRCUIT SHORTED TO GROUND
5 VOLT SUPPLY CIRCUIT OPEN
5 VOLT SUPPLY CIRCUIT SHORTED TO VOLTAGE
CKP SIGNAL CIRCUIT SHORTED GROUND
CKP SIGNAL CIRCUIT OPEN
CKP SIGNAL CIRCUIT SHORTED TO VOLTAGE
CKP SIGNAL SHORTED TO 5 VOLT SUPPLY CIRCUIT
SENSOR GROUND CIRCUIT OPEN
PCM - 5 VOLT SUPPLY
PCM - CKP SIGNAL
CRANKSHAFT POSITION SENSOR

 

[lbrowne]

Should I check voltage to one of the sensors to see if I got 5 volt while the car is sitting with the key in the RUN position?

 

[ImperialCrown]

Yes. The Vt/Wt is 5 volts with the ign on. One wire should be signal voltage (usually between 0.5 and 4.5 volts) and the Bk/* should be ground.

 

[lbrowne]

If there were an aftermarket security system I would think the locksmith guy would have found it. He had the key programmed rather quickly but he then spent about 1-1.5 hours searching for anything like that and came up with nothing. I'm leaning towards one of these sensors. Thanks for the tips so far.

 

[lbrowne]

Here is the sensor on the driver side of the motor, I don't think it's my prob but :

These ground wires are just hanging there, looks like they have been for a while. Two looms and the ground post is against the side of the passenger strut tower wall.

What is this connector for with the blue dot? Also note the nub of a ground wire below it:

 

[lbrowne]

In the run position the camshaft pos sensor is getting a strong 5 volts, and the signal voltage is .5 or a tad bit higher.

Also, I removed the plastic around the steering column to confirm no remote starter or anything like that. Only thing there is the factory immobilizer unit.

 

[ImperialCrown]

It looks like someone made a generic aftermarket MAP sensor work. The correct part would be fastened with 2 screws.
A bad MAP could cause a no-start and you might try seeing if it starts with the MAP unplugged Sometimes a MAP won't set a fault code. The PCM will substitute a default MAP value and set a fault code (MAP voltage high) with it unplugged. I don't think it is the problem either as the cam/crank sensor codes have to be solved first, but it is possible that it's related.
Repair the ground straps. Ground wires will work if you don't have straps.
The extra 'blue dot' connector laying by the intake may be for an optional MTV (manifold tuning valve) that came on some engines.

 

[lbrowne]

It looks like someone made a generic aftermarket MAP sensor work. The correct part would be fastened with 2 screws.
A bad MAP could cause a no-start and you might try seeing if it starts with the MAP unplugged Sometimes a MAP won't set a fault code. The PCM will substitute a default MAP value and set a fault code (MAP voltage high) with it unplugged. I don't think it is the problem either as the cam/crank sensor codes have to be solved first, but it is possible that it's related.
Repair the ground straps. Ground wires will work if you don't have straps.
The extra 'blue dot' connector laying by the intake may be for an optional MTV (manifold tuning valve) that came on some engines.

Where are those two looms supposed to be secured? I can tell by the look of them that they've been hanging there a looooooooooooong time. But they do reach to the engine or there abouts. Is there anyone that can take a look at their car to see for me? It's one strap with branches into two, and it's secured to the strut tower sheet metal, not quit halfway down.

 

[lbrowne]

Well fellow experts I found the problem. I crawled underneath and noticed that the harness for the crankshaft pos sensor was stuck to the cat converter. I plucked it off, good and melted. All three wires were now one black mess lol.

So I cut the bad section out, spliced and crimped them back together, and IT'S ALIVE!

The only code I got now is for an O2 sensor.

 

[ImperialCrown]

Good work on the investigation and for repairing the real issue instead of just replacing parts.
What is your 'P' code for the O2 sensor?

 

[Combat Missionary]

If you haven't actually jumped time, then...
Apparently a lot of Chrysler 300M's at one point or another go through a problem similar to this. The symptoms include (often in this order):

Acting like the rev limiter is turning on at greater than approximately 2,500 RPM
Rough idle followed by engine shutdown and inability to start
The Fuel Shutdown and/or Automatic Shutdown Relay clicking on and off multiple times per second or every couple of seconds
Intermittent spark when cranking the engine
Trouble codes for crankshaft position sensor fault, camshaft position sensor fault, or both

People will try replacing the crankshaft position sensor, the camshaft position sensor, or both, followed by the ECM (Engine Control Module), and the car may start up, then stop working again. This will make you pull your hair out.

I just went through this problem myself, and I was finally successful in correcting the fault. If you follow this procedure, you will be too.

1. 
   Pull the battery and clean and tighten the terminal clamps. Clean the negative cable jump terminal on the passenger side fender under the hood. Clean the terminals connected to the positive jump terminal in front of the air cleaner assembly. Clean the positive cable terminal feeding power into the power distribution center (PDC). Test your battery and make sure it is charged. Lack of power due to a discharged or bad battery or corroded terminals will prevent adequate spark and will stop cranking. After cleaning these terminals, try starting the car. If the car still doesn't start, proceed to step 2.
   
2. 
   Test fuel pressure at the fuel rail while having an assistant crank the engine. Upon startup, the fuel pump will pressurize for approximately 3 seconds, so this test is simply to eliminate a bad fuel pump as the cause of your non-start. You will probably read in the neighborhood of 50-60 PSI if the fuel pump is working.
   
3. 
   Test for spark at one of the coil packs. If you have no spark, your ASD relay is probably not getting a ground.
   
4. 
   Following the procedure outlined in the Haynes or Chilton's repair manual for your car, test your camshaft position sensor and your crankshaft position sensor. One wire feeds approximately 8 VDC to the sensors, one wire grounds the sensors, and one wire sends a square wave (approximately 5 VDC) to the ECM. This test involves “backprobing” the connectors, but you can simply use a voltmeter and push GENTLY through the wire insulation (if you push too hard, you'll break the copper wires inside and create a high resistance wire which will be more of a pain to fix) and test for power and/or ground as specified by the manual.
   
5. 
   Test the ASD relay.
   
   Resistance test terminals 85 and 86. You should read about 75 ohms of resistance.
   
6. 
   Resistance test terminals 87 and 30. They should read open (infinite resistance).
   
7. 
   Jumper terminal 86 of the relay to 12 VDC, and jumper 85 to ground. Resistance test terminals 87 and 30. You should read continuity (roughly 0 ohms of resistance).
   
8. 
   If the relay meets these specifications, the relay is good. If not, replace the relay.
   
9. 
   Test the Fuel Pump Relay using the same procedure as with the ASD relay (the terminal numbers are the same and the relays operate the same, even thought the Fuel Pump Relay is narrower).
   

At this point, you'll have established that you have a good battery, good power distribution, a good fuel pump, a good crankshaft position sensor, a good camshaft position sensor, and good ASD and Fuel Pump relays. If your car still won't start, and you're still reading bad crankshaft and camshaft position sensor codes, and you're still getting “chattering” ASD and Fuel Pump relays, it's because the relays are getting an intermittent ground through the ECM. Most likely your problem is that there is a fault in the engine wiring harness that has shorted and ruined your PCM. The harness must be repaired and then the ECM must be replaced. If you just replace the ECM without repairing the harness, odds are you'll just fry the new one.


To remove the harness, first remove the upper intake manifold. Place clean rags in the intake holes on the lower intake manifold to prevent debris from entering the manifold. Disconnect the C1 connector from the ECM (this goes to the engine, the C2 connects to the PDC). Follow the harness and disconnect it from the PDC connectors, the alternator, fuel injectors, coil packs, upstream O2 sensors, throttle body, etc. Note the portion of the engine harness that passes under the upper radiator hose connection at the lower intake manifold. On my 300M, the insulation on about half of the wires at this point had been melted due to the heat from the engine coolant passing through the hose.

Repair the harness. Separate the individual wires from each other. Wire by wire, cut out any parts that have melted or brittle insulation. Solder and heat shrink replacement wires into place.

After repairing the damaged portions of the wiring in this section of the harness, inspect the rest of the harness for cracked, brittle insulation, melted insulation, chafed insulation, etc. Repair the wires as necessary (this part took me a couple of evenings in my shop). Inspect all of the connector plugs for damage, missing lock tabs, or any other damage. You can still get most of the connectors at a dealer, so replace them as necessary (I found about half a dozen wires that were chafed at the connector plug and were probably grounding out on my harness; any of these could have fried my ECM), although if you need a C1 connector, you're going to have to go to a junkyard and splice it in (I didn't need one). Use solder and heat shrink, or you'll just end up redoing the job when your crimped splices corrode out.

After repairing all the wires in your engine harness and replacing any connectors as necessary, chafe wrap your rebuilt harness. Between Auto Zone, O'Reilly's and Harbor Freight, I got plenty of 1/4”, 3/8”, 1/2” and 3/4” plastic anti-chafe corrugated tubing (or whatever it's called). Chafe wrap every sensor lead right down to the sensor and secure the chafe wrap with zip ties. After chafe wrapping the entire harness, use plenty of electrical tape where sections of chafe wrap meet to secure the sections together.

At this point, you have a harness that's probably better than factory. Reinstall the harness, rerouting it ABOVE the upper radiator hose and pushed forward more so you don't get melted wiring again anytime soon from radiated manifold heat. Reconnect the harness to your ECM (you might get lucky and NOT have a fried ECM). Try to start the car. If you're still getting the chattering relays, your PCM is shot. I recommend going to Auto Zone for a new one. Dodge wanted $500 for the part, plus another $100 to flash program the ECM; they wanted $900 to install and program the ECM themselves. O'Reilly's wanted $130 for the ECM, $20 to ship it in from out of state (plus a three-day wait), and then I'd have to take it to Dodge to flash program it. AutoZone had the part I needed for $130, and when I went in, I brought in my VIN and my mileage, they got me the part in three days already flash programmed from the remanufacturer. It works like a charm, plug-n-play. Just install the part and you're ready to go.

 

[chuzz]

Why would someone revive a 19 month old thread where the issue was located and fixed?