3.1b) How to check and fix crankshaft position sensors How to check? If the CKP has died completely there will be very high resistance between the device's electrical connections associated with the open circuit. Furthermore spark delivery to the plugs will be absent. First check that the electrical connection is clean and secure; dirt or corrosion can impair an otherwise healthy CKP signal from getting through. If the CKP suffers from a drop in voltage associated with heat increase this can only be detectable with a voltmeter or oscilloscope with a graphical display; an analogue display voltmeter might just be able to show needle fluctuations due to voltage variation output. 2 pin socket (magnetic - sine wave output). One pin is 'ground' the other is 'signal'. A voltmeter set to 2 volts AC should measure a signal in the 0.2 to 2 volts range on the 'signal' pin. 3 pin socket (Hall effect, magneto - square wave form output).One pin is 'reference' (5volts), one pin is 'ground' and the third pin is 'signal'. A DC voltage should be detectable in the 0.5 to 1.5 volt range from the 'signal' pin. It is important that the voltage measurement take place at start up when the engine is cold and again, 20 minutes later, when the engine has fully warmed up to operating temperature. Often the voltage output from faulty sensors declines with temperature rise. How to fix? Check the wiring for continuity and that the electrical connection is clean and secure. Remove the CKP and clean off any dirt build up on the tip. If you strongly suspect the crank sensor as being at fault it is a relatively inexpensive device to replace. NEXT 3.2) CMP - Cam shaft position sensor

Crankshaft position sensor , possibly !
Crankshaft Position (CKP) Sensor
The crankshaft position (CKP) sensor is a three wire sensor based on the magneto resistive principle. A magneto resistive sensor uses two magnetic pickups between a permanent magnet. As an element such as a reluctor wheel passes the magnets the resulting change in the magnetic field is used by the sensor electronics to produce a digital output pulse. The PCM supplies a 12-volt, low reference, and signal circuit to the CKP sensor. The sensor returns a digital ON/OFF pulse 24 times per crankshaft revolution.
There are a lot of videos on youtube on testing crankshaft position sensors an Cam sensors !
There

P0385 - Crankshaft Position Sensor B Circuit Malfunction
The crankshaft position sensor (CKP) measures crankshaft location and relays this information to the PCM (Powertrain Control Module). Depending on the vehicle, the PCM uses this crankshaft position information to time the spark properly or on some systems it is only for misfire detection and does not control spark timing. The CKP sensor is stationary and works in harmony with a reluctor ring (or toothed ring) that is attached to the crankshaft. As this reluctor ring passes in front of the CKP sensor, the magnetic field created by the CKP sensor is interrupted and this creates a square wave voltage signal that the PCM interprets as crankshaft position. If the PCM detects that there are no crankshaft pulses or if it sees a problem with the pulses on the output circuit, P0385 will set.

Symptoms:

NOTE: If the crank sensor is used only for misfire detection and NOT spark timing (this varies with the vehicle), the vehicle should start and run with MIL (Malfunction indicator lamp) illumination. Also, some vehicles require several key cycles to illuminate the MIL. If this is the case, there may be no MIL illumination until the problem often enough over time. If the crank sensor is used for BOTH misfire detection and spark timing, the vehicle may or may not start. Symptoms may include:

Vehicle may not start (see above)
Vehicle may run rough or misfire
MIL illumination

Causes: A P0385 "check engine light" code could be caused by:
Damaged CKP sensor connector
Damaged reluctor ring (missing teeth or not turning due to sheared-off keyway)
Sensor output open
Sensor output shorted to ground
Sensor output shorted to voltage
Failed crank sensor
Failed PCM

Possible Solutions:
* Using a scan tool, check if, when engine is running or cranking, that there is an RPM signal.
* If there is no RPM reading, then visually inspect the crank Sensor Bnd connector for any damage and repair as necessary. If there is no visible damage, and you have access to a scope, you could check the CKP 5 Volt square wave pattern. If you do not, then, obtain a resistance reading of your crank sensor from a repair manual. (There are so many different types of crank sensors that there's no way to put here which resistance reading is correct). Then check the resistance of the CKP sensor by disconnecting the Sensor Bnd measuring resistance of the sensor. (It is best to check resistance readings from the PCM connector. This rules out any wiring problems from the start. But it does require some mechanical skill and shouldn't be performed if you\'re not familiar with automobile electrical systems). Is the sensor within resistance specs?
* If not, replace the CKP sensor. If so, recheck resistance reading from the PCM connector. Is the reading still okay?
* If not, repair open or short in the wiring to the crank Sensor Bnd re-check. If the reading is okay, the problem is intermittent or the PCM may be at fault. Try reconnecting and checking for RPM signal again. If there is now an RPM signal, wiggle test the wiring harness to try and induce the fault.

This code is basically identical to P0335. This code P0385 refers to Crankshaft Posistion Sensor "B", whereas P0335 refers to Crankshaft Position Sensor "A". If you have the code P0385, your vehicle is equipped with two crank sensors (CPS). Other crank sensor codes include P0016, P0017, P0018, P0019, P0335, P0336, P0337, P0338, P0339, P0385, P0386, P0387, P0388, and P0389.

Hope this helps (remember to rate this answer).

Crankshaft Position Sensor Engine speed is a very important input to the Engine Management System (EMS). Crankshaft speed and position are the basis for many calculations made by the computer. Crankshaft position values are transmitted to the computer by pickup coils also known as Permanent Magnet (P/M) generators, hall-effect sensors or optical sensors. The Crankshaft Position Sensor (CKP) also known as engine speed sensor is located in close proximity to the crankshaft.
In addition, the EMS uses minute variations in the CKP sensor data to determine engine misfire. The EMS uses this information in conjunction with the camshaft position sensor to perform misfire diagnostics.
Related Symptoms No Start / Intermittent Start Condition - Can be caused by a faulty crankshaft position sensor due to loose connections, bad grounds, high resistance in the circuit, or opens in the circuit.
NOTE: For procedures on the position sensors, please refer to Driveability and Emissions.
Removal & Installation To Remove:

1. Before servicing the vehicle refer to the precautions at the beginning of this section
2. Raise and support the vehicle
3. Remove or disconnect the following:
   • Air deflector
   • Oil filter adaptor
     
     
   • CKP sensor electrical connector
   • CKP sensor retaining bolt
   • CKP sensor

To Install:

1. Lubricate the CKP sensor O-Ring with clean engine oil
2. Install or connect the following:
   • CKP sensor and the retaining bolt
     1. Torque to: 89 lb-in. (10 Nm)
   • CKP sensor electrical connector
   • Oil filter adaptor
   • Air deflector
3. Lower the vehicle to the ground.
4. Operate the engine then inspect the CKP sensor for engine oil leaks.
5. Perform the CKP System Variation Learn Procedure.
6. Test drive the vehicle.

Operation

The CKP sensor is a magnetic transducer mounted on the engine block or timing cover and is adjacent to a pulse wheel located on the crankshaft. By monitoring the crankshaft mounted pulse wheel, the CKP is the primary sensor for ignition information to the PCM. The trigger wheel has a total of 35 teeth spaced 10 degrees apart with one empty space for a missing tooth. By monitoring the trigger wheel, the CKP indicates crankshaft position and speed information to the PCM. By monitoring the missing tooth, the PCM uses the CKP signal to synchronize the ignition system and track the rotation of the crankshaft.

Removal & Installation

3.0L (VIN S) Engine

1. Before servicing the vehicle, refer to the Precautions section.
2. With vehicle in NEUTRAL, position it on a hoist.
3. Disconnect the battery ground cable.
4. Remove the accessory drive belt.
5. Remove the nut and position the power steering pressure line, muffler and bracket assembly out of the way.
6. Remove the right front fender splash shield.
7. Remove the screws and the generator splash shield.
8. Remove the left-hand upper stud bolt and the lower generator bolt. Loosen the right upper stud bolt.
9. Pivot the generator away from the engine block.
10. Remove the engine-to-transaxle support bracket.
11. Disconnect the electrical connector.
12. Remove the bolt and the CKP sensor.
13. To install, reverse the removal procedure.
    
    

    Fig. Engine-to-transaxle support bracket-3.0L (VIN S) Engine
    
    
    

    Fig. CKP sensor-3.0L (VIN S) Engine
    

3.0L (VIN U, 2) Engines

1. Before servicing the vehicle, refer to the Precautions section.
2. Disconnect the battery ground cable.
3. Raise and support the vehicle.
4. Disconnect the electrical connector.
5. Remove the bolts and the CKP sensor.
6. To install, reverse the removal procedure.
   
   

   Fig. Crankshaft Position sensor-3.0L (VIN U, 2) Engines
   

Testing

Fig. Crankshaft Position Sensor Connector

1. Before servicing the vehicle, refer to the Precautions section.
   WARNING Use only a high-impedance multimeter, otherwise damage to the PCM and/or sensors can result.
   
2. Visually check the timing cover, CKP sensor and external trigger wheel (outside the timing cover) for obvious physical damage.
3. With the key OFF , disconnect the CKP sensor harness and measure the resistance of the CKP sensor. Standard value is 250-1000 ohms.
4. If the resistance is outside the limits given, replace the CKP sensor.

P0385 - Crankshaft Position Sensor B Circuit Malfunction

What does that mean?
The crankshaft position sensor (CKP) measures crankshaft location and relays this information to the PCM (Powertrain Control Module). Depending on the vehicle, the PCM uses this crankshaft position information to time the spark properly or on some systems it is only for misfire detection and does not control spark timing. The CKP sensor is stationary and works in harmony with a reluctor ring (or toothed ring) that is attached to the crankshaft. As this reluctor ring passes in front of the CKP sensor, the magnetic field created by the CKP sensor is interrupted and this creates a square wave voltage signal that the PCM interprets as crankshaft position. If the PCM detects that there are no crankshaft pulses or if it sees a problem with the pulses on the output circuit, P0385 will set.

Symptoms
NOTE: If the crank sensor is used only for misfire detection and NOT spark timing (this varies with the vehicle), the vehicle should start and run with MIL (Malfunction indicator lamp) illumination. Also, some vehicles require several key cycles to illuminate the MIL. If this is the case, there may be no MIL illumination until the problem often enough over time. If the crank sensor is used for BOTH misfire detection and spark timing, the vehicle may or may not start. Symptoms may include:
* Vehicle may not start (see above)
* Vehicle may run rough or misfire
* MIL illumination

Causes
A P0385 "check engine light" code could be caused by:
* Damaged CKP sensor connector
* Damaged reluctor ring (missing teeth or not turning due to sheared-off keyway)
* Sensor output open
* Sensor output shorted to ground
* Sensor output shorted to voltage
* Failed crank sensor
* Failed PCM

Possible Solutions
1. Using a scan tool, check if, when engine is running or cranking, that there is an RPM signal.
2. If there is no RPM reading, then visually inspect the crank Sensor Bnd connector for any damage and repair as necessary. If there is no visible damage, and you have access to a scope, you could check the CKP 5 Volt square wave pattern. If you do not, then, obtain a resistance reading of your crank sensor from a repair manual. (There are so many different types of crank sensors that there's no way to put here which resistance reading is correct). Then check the resistance of the CKP sensor by disconnecting the Sensor Bnd measuring resistance of the sensor. (It is best to check resistance readings from the PCM connector. This rules out any wiring problems from the start. But it does require some mechanical skill and shouldn't be performed if you\'re not familiar with automobile electrical systems). Is the sensor within resistance specs?
3. If not, replace the CKP sensor. If so, recheck resistance reading from the PCM connector. Is the reading still okay?
4. If not, repair open or short in the wiring to the crank Sensor Bnd re-check. If the reading is okay, the problem is intermittent or the PCM may be at fault. Try reconnecting and checking for RPM signal again. If there is now an RPM signal, wiggle test the wiring harness to try and induce the fault.

This code is basically identical to P0335. This code P0385 refers to Crankshaft Posistion Sensor "B", whereas P0335 refers to Crankshaft Position Sensor "A". If you have the code P0385, your vehicle is equipped with two crank sensors (CPS). Other crank sensor codes include P0016, P0017, P0018, P0019, P0335, P0336, P0337, P0338, P0339, P0385, P0386, P0387, P0388, and P0389.

Hope helps (remember rated this).