Dodge Repair Questions? Ask a Mechanic for Answers ASAP
Hi Mike, welcome to Just Answer!.
Overwhelmingly, the most significant code you have is the P0320 (CRANK SENSOR CIRCUIT), but P0381 (possibly 1391) indicates an intermittent crank sensor signal. Sorry, was unable to locate a P1381 code...
Chances are good that it's an actual sensor failure, but the inhospitable environment the sensor and wiring harness live in makes it a definite possibility for your problem.
The engine harness to the crank sensor disappears down the back side of the engine in the engine/ transmission area, just to the rear of the cylinder head. This section of the loom becomes heated by the exhaust manifold and can cause the individual wires of this section to become melted together, sometimes sharing circuits. Oil in the area somewhat complicates matters, softening the individual wire insulation and making a short between wires that much more likely.
The loom also passes over a section of driveshaft, the right side half-shaft which can grind the harness if it comes into contact with it and cause intermittent loss of signal. It's something that needs to be checked in person (of course), because the loom doesn't always drape dangerously like this.
I'd suggest doing some harness "wiggle testing", where the engine is idling and you manipulate any section of harness available to you in a manner that would suggest the vehicle being driven. Push, pull, whatever, but watch carefully for a result that might indicate the harness movements are at fault, then locate the problem based on your actions.
If nothing can be found, I'd suggest simply replacing the senosr, located on the back side of the engine, near #1 cylinder off the crankshaft. Replacement of the cranks sensor connector may be required, depending upon the version presently being used.
Write back if you have any questions.
Actually, no. P0743 is a transmission torque converter lockup code, something that isn't going to affect engine starting. If your transmission is a 3-speed, the torque converter electrical connector will be very close to the point on the trans where the dipstick enters the trans casting. Look for a round, two wire connector and push it down toward the trans if it's migrated upward.
Code 0117 tells us that the engine coolant temperature (ECT) sensor signal is shorted to ground or is very near zero volts. It may have some impact on starting the engine, depending upon whether the engine controller (PCM) is using the low voltage signal as an actual engine temperature (not likely). Once coded, the ECT signal should be thrown out, but we can't count on that assumption 100%. If left hovering in the region between setting a code and actually being BELIEVED, it will cause the PCM to set a hot restart program in place. Cold engines need extra fuel, not less... as the hot restart program would supply.
Disconnecting the ECT sensor on the back (transmission) side of the cylinder head should push the voltage high and set a P0118 code (circuit high) if the circuit is OK and the sensor is at fault. If nothing changes, the problem will be with the harness or the PCM itself.
But beyond a shadow of doubt, the P0320 and (presumptive) P1391 codes will be the front-runners in getting the engine running again.
Once you get to the connector, the voltages will read as such if they're OK (disconnected)...
Grey/ black.... Ignition reference signal wire, has a 5v pull-up voltage on the circuit when not grounded by the sensor.
Black/ light blue... sensor ground, should have no more than .1v on the circuit at any time. Should have good continuity to ground if checked with an ohm meter.
Orange.... power source to the hall swtich, that IS the crank sensor. 8v to 9v should be present at any time the key is on.
Good luck in finding your problem... don't forget that it may be in the section of harness that drops down back of the cylinder head!
Those all appear to be "hard" codes... electrically open or shorted and set immediately. The exception is the P1684, which simply means the battery has been disconnected or PCM memory has been lost in the last 6 weeks or so. The crank sensor signal code problem requires the PCM seeing a cam sensor signal (but no crank) for a period of time. It just takes a while to set a P0320 sometimes.
I'd suggest doing some electrical testing at the crank sensor connector to see what kind of voltages you have there. If you see the two voltages as I described to be OK, check the sensor ground for good continuity with battery negative/ engine block... somewhere in the 10 ohms department is expected.
It could be a bad crank sensor or harness problems, Mike. Because the cam and crank sensors share the same power feed, the crank sensor might short the orange wire and take the cam sensor out with it at times, preventing the P0320 from setting. With both sensors down, no problem at all is seen by the PCM concerning signals, strangely...