Hi,ihave a volvo fh12 420 with no 5v signal on most of the sensor wiring.Truck cranks but will not start.Thanks in advance for your assistance.Roop

will need to check if fuel or electricial problem ---fuel pump working getting fuel to engine --- getting spark --

Are we talking about no cranking at all or cranks but won't start?

Hi Ionut, I think it would be a good idea to look at the throttle pedal operation, which what I'm reading as the fault on your vehcle. Regards John

P0340 Camshaft position sensor circuit malfunction
Check the wires for the sensor. There may be frayed or burn spots that are affecting the signal.

Crankshaft Position (CKP) Sensors and Camshaft Positions (CMP) Sensors used on cars and trucks today come in all sorts of different shapes, sizes and configurations. All this variety might make you think that testing them is difficult and/or impossible. Well, nothing could be further from the truth since they can be easily tested with simple tools and testing techniques.
Photo 2 of 3This one belongs to a 94 Chevy Astro mini-van. This
Crank Sensor is a Pick Up Coil type that produces an Analog Signal.

This article is a primer that will help you to learn and understand the essentials of testing the Crankshaft Position Sensor (Camshaft Position Sensors too). You'll learn basic working theory, do's and don'ts, what tools to use and how to test them, and a lot of other good stuff.
How to Tell Them Apart

Another thing that can make testing the CKP and CMP Sensors seem intimidating is the fact that every make and model rolling around on pavement uses a different type of Position Sensor. For example, the Ford truck your neighbor might be driving will have a Position Sensor(s) that is (are) completely different in appearance than your GM (or Chrysler, or Honda, or Nissan or Suzuki, etc.) vehicle.

Not only that, but these sensors are called by so many different names like: Hall Effect Sensor, CKP Sensor, CMP Sensor, Pickup Coil, Magnetic Pulse Generator, Variable Reluctor, and the list goes on with a few more names. This may make it seem like every single one is tested in a different way. Well, the good news is that although they all differ from one another physically and are called so many god-knows-what names, they can usually be generalized into two basic categories: 2 wire type and 3 wire type. And this means that you only have to learn two specific testing methods.

So, before we dive into the rest of the article, I want to emphasize that the key to successfully testing and diagnosing all of the different Crank Sensors (and Cam Sensors) out there, is to know if they are either a two or three wire type! Now in case you're wondering what I mean by two and three wire types... I'm referring to the amount of wires in their connector (of course there's always an exception to every rule, but more about this later). Alright, let's jump into the next subheading and let's start learning more about this.
What does a Crankshaft (Camshaft) Position Sensor Do?

I'll start by explaining the specific role that the Crank (and Cam) Sensor play in the Electronic Ignition System of your car or truck. This info applies to whatever make and model you may be driving, so whether it's a Ford, a Chevy, a Chrysler/Dodge/Jeep, a Nissan, a Honda, a Toyota, or whatever, this primer will help.

In a nutshell, the Crankshaft Position Sensor's job is to help: 1) the Ignition System produce Spark and 2) the Fuel System to start injecting gasoline into the cylinders. All this so that the vehicle's engine will start and stay running. More specifically, the CKP Sensor produces a signal that tells the Fuel Injection Computer or the Ignition Control Module the exact position of the cylinder pistons as they come up or go down in the compression cycle. With this information the Fuel Injection Computer or the Ignition Control Module knows the exact time it has to make the Ignition Coil or Ignition Coils spark (not to mention when to start injecting fuel into the cylinders). Lastly, this signal can be either an Analog Voltage Signal of a Digital DC Voltage Signal.

if the engine light is not on then it may have been bypassed, they did it a lot over the years, it could be the crank sensor, if the crank sensor is not making the right signal it will cut the fuel, as ecu thinks there is no movement. usually its the sensor its self as the reader is not reading correctly. could even be the wiring to the plug so would check that. there are meany things that can stop the engine running as well this can be the throttle sensor not reading, if it does not give the correct signal it can jump the throttle this can lead to stalling, these can be cleaned, but also a blocked egr can do the same diesels are common for clogging up, i would check these few things.

you will have to check the crank sensor see if fuel pump is on when cranking engine if it is check the ignighter by checking if coils are getting signal if there is no signal check fuses and cam crank sensors

Check your crank sensor. The symptoms you describe indicate a timing error. When you push hard the ECU tries to advance the ignition according to the signals it receives from the the crank position sensor CPS. These signals are either being interrupted or corrupted. Make sure the cps connection is dry, free of dirt and corrosion and that there is continuity in the wires with no obvious breaks or insulation removed. Remove the CPS and check that it is clean and free of body cracks. If problems persist swap the crank sensor out for a new one. These sensors are prone to heat and age.

Hi


Thanks for using FixYa. P1345 code is Camshaft to crankshaft correlation fault. I believe the mechanic is saying right. Also you’ll need to check the CMP Sensor, as if that is loose it might cause a variation in the sensor signal. Also it could be due to the Distributor, so you’ll need to check the distributor rotor. Please do accept the solution if the issue is resolved or else revert for further assistance.


Thanks
Rylee

The same thing happened to my 94 volvo 960 the engine belt was having the same problem, i changed it the belt, it was fine for a few miles after that it just died, does not fire, not sure if it is getting fuel, but the mechanic says the timing belt went off. you may have to check the crank sensor on yours.

enrixba