engine wont restart when hot, no spark P0340 has 12v on both connectors, freq from 5-11hz when cranking
1999 pathfinder 130000 miles starts fine when its cooled down, can drive for hours with no problem as long as it not turned off. When trying to restart when hot, it cranks,but has no spark. If I keep cranking I get error P0340 and knock sensor. Knock is from un burned gas from trying to start when hot. I Have 12 volts on 2 wire connector and 12v on 6 wire connector to distributor. On circuit 1 signal from pcm it varies from 5hz to 11hz, 2nd wire from left has good ground as is the other ground, The distributor has been replaced because the original had rusted, at first thought it was bad new d
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Since the crank position sensor gets its timing signal off the damper, I would first replace the damper to be sure timing was correct. The fact that this failure occurs after a "heat soak" cycle, and the P0340 code is a cam position sensor error, I would be suspicious of both the crank and cam position sensors. If the crank position sensor is dead, and the ECM is defaulting to the cam position sensor, problems with incorrect timing will be more acute. I would recommend having a car is not starting service completed by a mobile, professional mechanic, such as one from YourMechanic, to diagnose this problem, get an accurate assessment of damage and cost estimate for repairs.
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When the signal to and from the camshaft position sensor and the PCM is broken, the ignition spark and fuel injector timing will fail and the PCM will store the P0340 OBD-II trouble code. This will trigger the illumination of the Check Engine Light and most likely be the source of your no starting issue.
Error code P0340 indicates a malfunction with the camshaft position sensor A circuit. This type of malfunction can cause serious issues that require immediate repair because the underlying cause of the code could damage your vehicle`s engine if you continue to drive it.
What Does Code P0340 Mean? The OBD-II diagnostic trouble code P0340 indicates a “Camshaft Position Sensor “A” Circuit Malfunction.” It covers the entire circuit attached to the aforementioned sensor, such as the electric wiring and the powertrain control module (PCM).
Car Will Not Start: Over time, as the camshaft position sensor fails, the signal it sends to the engine control module weakens. When the engine no longer receives the signal, you will not be able to start your car. Engine Misfires: A failing camshaft position sensor can cause your engine to misfire.
Bad Sensors
One common culprit for this problem is the crankshaft position sensor, which measures the position and speed of the crankshaft. The computer uses the information from this sensor to know when to fire the spark plugs. If the sensor isn`t working, the spark plugs won`t fire, keeping the engine from starting.
This is the most common mistake when diagnosing the P0340 trouble code. Another mistake that is made during the diagnostic procedure is neglecting to consider a misfiring problem or a crankshaft sensor problem as possible sources of the P0340 trouble code.
A P0340 error code indicates a problem with the Camshaft Position Sensor A circuit. It`s possible that the wires leading to the camshaft position sensor are faulty, or that the sensor itself has failed.
Engine code P0340 could be caused by a number of things, including a bad sensor, damaged wiring, or a faulty ECM.
Another cause for the P0340 fault code could be a weak battery. Batteries are often overlooked when it comes to regular maintenance and even though your car starts and drives normally, the battery can lose its capacity and cause a number of issues with the car.
The camshaft sensor works according to the Hall principle. It scans a ring gear on the camshaft. The rotation of the ring gear changes the Hall voltage of the Hall IC in the sensor head. This change in voltage is transmitted to the control unit and evaluated there in order to establish the required data.
P0335 is a diagnostic trouble code (DTC) for “Crankshaft Position Sensor “A” Circuit Malfunction”. This can happen for multiple reasons and a mechanic needs to diagnose the specific cause for this code to be triggered in your situation.
The O2 sensor will not cause the no start. The no start can be caused by the fuel pump or the ignition system. You should check the engine for spark and fuel pressure, when it is not turning on to help narrow the problem down.
Battery Current Sensor Problems
Dirt and Debris: Dirt, debris, or corrosion on car batteries can penetrate into the sensor causing malfunctioning. This failure can lead to a number of electrical problems including no-start.
In fact, most sensors are responsible for actually making the changes to critical systems such as ignition and fuel systems. Since any engine requires the correct air to fuel ratio and ignition timing to start, having a faulty sensor that can`t adjust these symptoms on the fly can cause the engine to not start.
A failing camshaft position sensor begins losing its ability to quickly transfer data. Mismatched fuel delivery and ignition timing, even if off by a few milliseconds, will cause your vehicle to sputter, accelerate poorly, lack power, stall or even shut off.
Engine Misfires or Vibrates
A failing crankshaft position sensor cannot provide the right information about piston positioning in the engine, causing a cylinder to misfire. This could also occur from faulty spark plug timing, but if the spark plug checks out, then the crankshaft sensor is likely the source.
Since any engine requires the correct air to fuel ratio and ignition timing to start, having a faulty sensor that can`t adjust these symptoms on the fly can cause the engine to not start.
You may notice poor engine performance including irregular acceleration, misfiring, hard starting, or surging. On some car models, a failed CMP sensor will prevent the ignition from making a spark, so that the engine won`t start at all.
Another cause for the P0340 fault code could be a weak battery. Batteries are often overlooked when it comes to regular maintenance and even though your car starts and drives normally, the battery can lose its capacity and cause a number of issues with the car.
Relevant Questions and Answers :
the most relevant questions and answers related to your specific issue
engine wont restart when hot, no spark P0340 has 12v on both connectors, freq from 5-11hz when cranking
ANSWER : Since the crank position sensor gets its timing signal off the damper, I would first replace the damper to be sure timing was correct. The fact that this failure occurs after a "heat soak" cycle, and the P0340 code is a cam position sensor error, I would be suspicious of both the crank and cam position sensors. If the crank position sensor is dead, and the ECM is defaulting to the cam position sensor, problems with incorrect timing will be more acute. I would recommend having a car is not starting service completed by a mobile, professional mechanic, such as one from YourMechanic, to diagnose this problem, get an accurate assessment of damage and cost estimate for repairs.
Engine will not stay started. I have replaced idle control valve map sensor spark plugs spark plug wires no check engine light is
ANSWER : You have a problem with the distributor assembly. I recommend replacing the distributor assembly. This will replace all the possible sensors and coil for the ignition and fix the problem you have.
Car cranks but won’t start – 2007 Mercedez-Benz E350
ANSWER : Hello. There are quite a few things that can cause this. It appears that you have already changed quite a few parts trying to overcome this problem. From what you are explaining, this is almost always fuel related. I have had a lot of these vehicles act up like this and the problem is usually with the fuel pump relay or with the relay connections in the fuse box. The only way to find the problem is to see if the engine is lacking fuel or spark when the problem occurs.
Most of the time it will be because the fuel pump is not coming on. At that time, the circuit can be tested. The excessive heat typically causes a bad connection. If you are thinking of having this starting issue checked, consider having a certified mechanic, such as one from YourMechanic, who can come to your home or office to diagnose why it will not start.
Engine gets hot and shuts down but has spark – 1989 Mercedes-Benz 300CE
ANSWER : Hi there, thanks for writing in. The fuel pumps in the fuel tank may have been damaged from debris in the fuel tank damaging the motors. Remove the fuel tank pumps and look inside the tanks to see if there is debris at the bottom of the tank. The pumps will suck in the debris and damage the pumps. If you need help having this checked, a certified professional from YourMechanic can come to your location to test the vehicle and diagnose the stalling issue.
engine cranks over but won’t start
ANSWER : Hello. Thank you for writing in. The fuel smell you are having is from the engine throwing fuel into the cylinders that is not being burned. The spark system will is likely the cause of your no start. If none of the coils are receiving power, then the issue is likely the powe’re source to the coils. Check for voltage there. If they are reciting voltage but not producing spark, then all of the coils need to be replaced. You should replace them all at the same time anyway. This keeps the wear on the vehicle even. Replace the plugs at the same time.
Truck cranks but won’t start. Has good fuel pressure and spark. Engine will crank and run if you pour gas in the throttle body.
ANSWER : Hi there. Check the injectors harness with the key on and the engine off without trying to crank. There should be a voltage on one side of the harness supplying fuel to the injectors. Then crank the engine and back probe the wires to see if there is power on the other terminal on the harness. If there is no power, then the injectors are not compressing down and causing the system to not complete the circuit. If there is a voltage, then the injectors may be plugged up not allowing the fuel to spray out. I recommend replacing the injectors if you are unable to clean them out with injection cleaner. If you need further assistance with you engine not starting, then seek out a professional, such as one from Your Mechanic, to help you.
Engine crank, no coil spark, fuel pump does not kick in.
ANSWER : Hi there. There could be multiple issues causing your lack of spark problem, ranging from a minor electrical short in the main relay to an issue with your ECU. In order to know for sure, you should have a professional mobile mechanic complete an electrical problems inspection.
Engine not sparking; van cranks but won’t turn over
ANSWER : If you are sure the fuel system is working correctly via pressure and injector firing, then the ignition would be logical to look at. Whether you have a 6-cylinder or 8-cylinder engine the ignition system is similar. The ignition has 5 main components that supply ignition system voltage to the spark plugs. The ignition coil supplies the necessary voltage. It is triggered by a camshaft sensor in the distributor and ignition voltage is routed to the correct spark plug vis the distributor rotor, cap and wires. No spark to any of the spark plugs indicates a failure of either the coil, sensor, distributor, or rotor. You may want to enlist the help of a mechanic, such as one from YourMechanic, who will have tools and training to diagnose your no-start issue.
