What does it mean?
This generic powertrain/engine diagnostic code generally applies to all spark ignition engines, including but not limited to certain Audi, Mazda, Mercedes, and VW vehicles.
The Crankshaft Position Sensor (CKP) provides the crankshaft position or crankshaft timing to the Powertrain Control Module or PCM. This information is typically used for engine speed.
The Camshaft Position Sensor (CMP) provides the PCM with the exact location of the camshaft, camshaft timing, or distributor timing. Whenever the voltage drops below a defined level in either of these two circuits, the PCM will set code P0323. This code is considered an electrical circuit fault only.
Troubleshooting steps may vary depending on the manufacturer, ignition/distributor/engine speed sensor type, and sensor wire colors.
Symptoms
Symptoms of a P0323 engine code may include:
Malfunction Indicator Light illuminated
Engine cranks but does not start
Misfires, hesitation, stumbling, lack of power
Causes
Possible causes for setting this code are:
Open in the control circuit (ground circuit) between the ignition/distributor/engine speed sensor and the PCM
Open in the power supply circuit between the ignition/distributor/engine speed sensor and the PCM
Short to ground in the ignition/distributor/engine speed sensor power supply circuit
Faulty ignition/distributor/engine speed sensor
Possibly a failed PCM (highly unlikely)
Diagnostic and Repair Procedures
A good starting point is always to check the Technical Service Bulletins (TSBs) for your specific vehicle. Your issue may be a known problem with a known fix published by the manufacturer and can save you time and money during diagnosis.
Next, locate the ignition/distributor/engine speed sensor on your specific vehicle. It could be a crank/cam sensor; it could be a coil/pickup sensor inside the distributor; it might even be a wire from the coil going to the PCM to check the ignition system’s firing. Once located, visually inspect the connectors and wiring. Look for scrapes, rubbing, bare wires, burns, or melted plastic. Disconnect the connectors and carefully inspect the terminals (the metal parts) inside the connectors. See if they look burnt or have a greenish tint indicating corrosion. Use electrical contact cleaner and a plastic bristle brush if cleaning the terminals is necessary. Let it dry and apply electrical grease where the terminals make contact.
Depending on the vehicle, the most likely cause for P0323 to set is poor connections/updated ignition parts. This is why researching TSBs for your vehicle cannot be emphasized enough.
If you have a scan tool, clear the diagnostic codes from the memory and see if P0323 returns. If it does not, the connections were likely your problem.
If the P0323 code returns, we will need to test the sensor and its associated circuits. The next steps will be determined by the type of sensor you have: Hall effect or magnetic sensor. You can usually tell which one you have based on the number of wires coming from the sensor. If there are 3 wires from the sensor, it is a Hall effect sensor. If it has 2 wires, it will be a Magnetic Pick-up type sensor.
If it is a Hall effect sensor, disconnect the harness going to the camshaft and crankshaft position sensors. With a Digital Volt Ohm Meter (DVOM), test the 5V power supply circuit going to each sensor to ensure it is powered (red wire to the 5V power circuit, black wire to a good ground). If there is no 5 volts at the sensor, repair the wiring from the PCM to the sensor, or possibly a faulty PCM.
If that’s okay, with a DVOM, check that you have 5V on each signal circuit going to each sensor to ensure it has a signal circuit (red wire to the sensor signal circuit, black wire to a good ground). If there is no 5 volts at the sensor, repair the wiring from the PCM to the sensor, or possibly a faulty PCM.
If that is okay, check that you have a good ground at each sensor. Connect a 12V test light and touch the other end of the test light to the ground circuit going to each sensor. If the test light does not illuminate, that would indicate the circuit problem. If it lights up, wiggle the wire harness going to each sensor to see if the test light flickers, indicating an intermittent connection.
If it is a Magnetic Pick-up type sensor, we can check the sensor itself to see if it is functioning correctly. We will test it for: 1) Resistance 2) A/C Voltage Output 3) Short to Ground
With the sensor disconnected, connect the two leads of your ohmmeter to the 2 terminals of the camshaft/crankshaft position sensor. Read the ohms resistance and compare it to your vehicle’s specifications: typically 750 – 2000 ohms. While still on ohms, disconnect 1 lead of your ohmmeter from the sensor and connect it to a good vehicle ground. If you get an ohms reading other than infinite or OL, the sensor has an internal short to ground. Remember not to touch the metal part of the leads with your fingers, as this could affect your readings.
Reconnect the two leads of your DVOM to the 2 terminals of the camshaft/crankshaft position sensor. Set your meter to read A/C voltage. While cranking the engine, read the a/c voltage output on your DVOM. Compare to the manufacturer’s specifications for your vehicle. A good rule of thumb is typically 0.5 V AC.
If all tests have passed so far and you continue to get a P0323 code, this would most likely indicate a faulty ignition/distributor/engine sensor, although a faulty PCM cannot be ruled out until the sensor has been replaced. In some cases, once the sensor is replaced, it will need to be calibrated to the PCM to function correctly.
If in doubt, seek assistance from a qualified automotive diagnostician. PCMs often need to be programmed or calibrated to the vehicle to be installed correctly.