P1345 – Crankshaft Position – Camshaft Position Correlation (Buick, Cadillac, Chevrolet, GM, Isuzu, Pontiac, Saturn)

By Randy Worner (Contact Me)
Last Updated 2016-11-14
ASE/ACA World Class Technician

Manufacturer Specific Definitions for P1345

Table of Contents

1. What Does Code P1345 Mean?
2. What are the common causes of code P1345?
3. What are the symptoms of code P1345?
4. How do you troubleshoot code P1345?
5. Codes Related to P1345
6. Get Help with P1345

What Does Code P1345 Mean?

The camshaft position sensor (CMP) provides the Powertrain Control Module or PCM with the exact location of the camshaft or camshaft timing. The Crankshaft Position Sensor (CKP) provides crankshaft position or crankshaft timing to the PCM. This information is typically used for engine rpm. The CMP and CKP must be synchronized or timed together in order to insure proper firing of the spark plugs and to insure enough fuel gets to the cylinder at the right time.

Code P1345 is a manufacturer’s specific code and as such lets you know that diagnosing this condition may be different between manufacturer’s vehicles. In these instances, P1345 will set when the voltage signal being returned by the CMP sensor is not within a predetermined number of degrees of the CKP sensor signal.

What are the common causes of code P1345?

• Engine mechanical issues – valve timing most likely
• Failed Camshaft Position Sensor – possible
• Failed Crankshaft Position Sensor – possible
• Cam / Crank sensor relearn not performed – possible
• Failed PCM – unlikely

What are the symptoms of code P1345?

• Malfunction Indicator Light “ON”
• Engine cranks but won’t start
• Hard to start – hot or cold
• Engine stalls while driving

How do you troubleshoot code P1345?

First, take a look and see if there are any technical service bulletins (TSB) for your particular vehicle. There may be an update, or known fix put out by the manufacturer that can save you from wasting time and money. This is especially true of the P1345 code.

Next, see if there are any other diagnostic fault codes. Diagnose current faults first, in the order in which they are stored. Misdiagnosis occurs when this code is diagnosed when it is a stored code, especially while other codes are active. If these codes are present, diagnose them before attempting to diagnose the P1345.

If the P1345 is the only active fault code present, and there are no updates/TSBs for your particular vehicle, then the next step is to locate both Camshaft and Crankshaft Position Sensors on your particular vehicle. Once located, visually inspect the connectors and wiring. Look for chafing, rubbing, bare wires, burn spots or melted plastic. Pull the connectors apart and carefully inspect the terminals (the metal parts) inside the connectors. See if they look corroded, burnt or possibly green in color versus the normal metal color you are probably used to seeing. You can get some electrical contact cleaner and a plastic bristle brush at any parts store if cleaning of the terminals is needed. Afterwards let them air dry, then get some dielectric silicone grease (same stuff they use for light bulb sockets) and put some where the terminals come into contact.

If you have a scan tool, clear the diagnostic trouble codes from memory, and see if the P1345 code returns. If it does not, then the connections were most likely your problem.

Connections are the most common problems seen, followed closely by cam/crank relearn procedures with worn out timing components right behind.

If the P1345 code does return, we will need to test the sensor and its associated circuits.  First, see if you can monitor Cam/Crank Sync status with your scan tool. If so, start the engine /attempt to start the engine and see if these 2 sensors are in sync. If the scan tool indicates that these two sensors are in sync, further diagnosis by the manufacturer’s flow charts will be in order. If not, you will need to verify that the sensors are operating correctly.

In order to verify that the sensors are operating correctly you will need to determine which type of sensor you have: Hall Effect or Magnetic Pick up. You can typically tell which one you have by 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 style sensor.

If it is a Hall Effect sensor, disconnect the harness going to the Camshaft and the Crankshaft Position Sensors. With a Digital Volt Ohm Meter (DVOM), test the 5V power supply circuit going to each sensor to insure it is being powered up (Red lead to the 5V power supply circuit, black lead to a good ground). If there is no 5 volts to the sensor, repair the wiring from the PCM to the sensor, or possible a bad PCM.

If that’s OK, with a DVOM, check to make sure you have 5V on each signal circuit going to each sensor to insure it has a signal circuit (Red lead to the sensor signal circuit, black lead to a good ground). If there is no 5 volts to the sensor, repair the wiring from the PCM to the sensor, or possible a bad PCM.

If that’s OK, check to make sure you have a good ground at each sensor. Connect a test light to 12V and touch the other end of the test light to the ground circuit going to each sensor. If the test light does not light up, this would indicate the problem circuit. If it does light up, wiggle the wiring harness going to each sensor to see if the test light flickers, indicating an intermittent connection.

If it is a Magnetic Pickup style sensor, we can check the sensor itself to see if it is working properly. 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. Check the resistance and compare it to specifications for your vehicle: typically, 750 – 2000 ohms. While still on ohms, disconnect 1 lead of your ohmmeter from the sensor and connect it to a good ground on the vehicle. If you get any 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 may 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 over, read the a/c voltage output on your DVOM. Compare to manufacturers specifications for your vehicle. A good rule of thumb is generally .5V AC.

If you replaced the sensor and have a scan tool, clear the diagnostic trouble codes from memory, and see if this code returns. If the P1345 does not return, then the connections/wiring issues were most likely your problem.

If the P1345 code does return, monitor the Camshaft and Crankshaft Position Sensor signals with a dual trace lab scope to see if they are out of sync. It may also be necessary to perform a Cam / Crank Relearn Procedure if the vehicle manufacturer calls for this. Check the service manual for more information. If unsure, seek assistance from a trained automotive diagnostician. And remember, if a PCM is diagnosed as the cause, it must be programmed, or calibrated to the vehicle in order to be installed correctly.

Codes Related to P1345

P0335 – Crankshaft Position Sensor malfunction-  generic code for CKP sensor.

P0340 – Camshaft Position Sensor malfunction –  generic code for CMP sensor.

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