2003 4.7 P0344...It Haunts Me.

[laramona03]

Hello, Everyone.
Thank you in advance to anyone that responds and has insight on this issue. I also want to mention I've spend the last month researching daily for hours on what could be causing this P0344 code on my 03 Ram 1500 with the 4.7.

Im no mechanic, but I'm broke so I do troubleshooting and work myself. Heres the story...

End of April I get a misfire code in bank 1, so i pull plugs and inspect coils. The coils seem fine visually so I only replace the plugs. Four days later I get the P0344 code after a long day running errands on my way home.
I get home and check the wires, and sure enough right at the pigtail the wires were bare and covered in oil. I cleaned them off, isolated each, replaced the sensor o ring, and tested for ground, and the two 5v with ignition on. Plugged it back in and after a short drive the code came back.
So I decided to replace the sensor with a mopar one. Code came back after a short drive.
I bought the truck from auction and noticed the engine was not the original, so i decide to pull the valve covers and look for chain slack.
The cam, chain, and components all look healthy with the exception of some minor but noticeable chain slack. I decide its enough to warrant a timing job, and i want the truck to last so I bite the bullet.
I replaced all timing components with a Cloyes parts, tripple check timing and torque. While im in there i inspect all the rockers and lifters (prefect condition and the engine is incredibly clean inside absolutely no signs of sludge). New seals go in, i did an oil pan seal as well, and thermostat while Im there.
Truck cranks right up and runs great, but after the short drive the code is back.
So i take a moment to research and think back what happened before the code came up. It was a misfire...maybe the coils were going bad...i connect my old autel scanner and check for coil burn time. It was reading reading bellow the 1.0 millisecond threshold. So i find a video on youtube were a guy find the coil causing feedback interference in the cam reading to the PCM...so I bought new NGK coils to go with the NGK plugs.
Code came back after the same short drive (been taking the same route and it come up at the exact same time/spot).
So i read that it could also be a bad alternator feeding back into the 5v system. I run the truck without the alternator to exclude that and the code came back.
At this point im hours into labor and research and a few hundred in on parts.
I re-check wires at the plug with a multi meter and it all reads fine. I de-pin the wires from the PCM and run some direct to the sensor..code comes back.
I go back to check all the grounds. I clean them all up and slather them in dialectic grease. Confirm the grounds to the heads are set up correctly. Code comes back.
I replaced the PCM and the code came back.

I've runout of ideas...does anyone have any success with this issue on an 03 4.7?

Im starting to think it just not fixable... Thoughts?

 

[alpinegreenneon]

Tone wheel?

 

[laramona03]

Tone wheel?

Thanks for the suggestion! When I replaced all the timing components there was a new tone wheel and sprocket. I made sure it was straight, clean, and matched the one coming off.

 

[Ken226]

It's fixable. It's probably just something, somewhere, that you haven't thought of yet.





Do you have wiring diagrams for the truck?

You've done good work and checked everything that should have been checked. In my opinion, you've picked the low hanging fruit.



At this point, you should look at wiring diagrams to see where else the 5v reference power supply to the cam position sensor is shared with other sensors. Or, if it's solo, not shared with any other sensor.

In many cases like this, a rub through on the 5v power supply somewhere can intermittently short it to ground and kill power on the entire circuit. A clue would be other sensor codes for sensors that share the 5v circuit.

It's usually the case that there are several 5v outputs from the PCM, and each output supplies multiple sensors. You'll need a diagram to see what else shares the cam sensors 5v reference.

It could be that another sensor, non critical, that doesn't even set codes and shares the 5v supply with the cam sensor, is intermittently failing and shorting the circuit to ground within the sensor, pulling all down to 0v and killing power to the critical cam sensor.

It even occurs sometimes that a 5v transistor power supply inside the PCM dies and kills power to a whole branch of sensors. But, you've kinda ruled that out with the PCM replacement.

Any other codes? Do you have wiring diagrams?

If not, AllData DIY will probably have what you need.

 

[laramona03]

Do you have wiring diagrams for the truck?

You've done good work and checked everything that should have been checked. In my opinion, you've picked the low hanging fruit.



At this point, you should look at wiring diagrams to see where else the 5v reference power supply to the cam position sensor is shared with other sensors. Or, if it's solo, not shared with any other sensor.

In many cases like this, a rub through on the 5v power supply somewhere can intermittently short it to ground and kill power on the entire circuit. A clue would be other sensor codes.

It could be that another sensor, non critical, that doesn't even set codes and shares the 5v supply with the cam sensor, is intermittently failing and shorting the circuit to ground within the sensor.

It even occurs sometimes that a 5v transistor power supply inside the PCM dies and kills power to a whole branch of sensors. But, you've kinda ruled that out with the PCM replacement.

Any other codes? Do you have wiring diagrams?

If not, AllData DIY will probably have what you need.

Thanks for the response and suggestions.

This morning i started looking over wiring diagrams. I have this one showing the power and signal are direct but the ground is shared. I have no other codes other than the P0344. I was suggested by a friend to remove the crimps i used for the new pigtail and actually solder the pig tail in and to run additional grounds directly from the pigtail to the frame without removing the one that goes back to the PCM (grounds are your friend).

Ill be trying that today and reporting back how it goes. Ill also check out AllData DIY, never heard of it before today. I usually buy the service manual books off ebay.

 

[Ken226]

You friend had good suggestions.

Unless the crank sensor is dropping out and setting codes too, I'd be looking primarily at the ground K4/20 blk/lt bl from the cam sensor, and where it splices into the shared ground.

Since the crank sensor seems to not be having any trouble, it's probably the section of wire from the cam sensor to the shared ground wire, or at the connector or splice connection.

 

[laramona03]

You friend had good suggestions.

Unless the crank sensor is dropping out and setting codes too, I'd be looking primarily at the ground K4/20 blk/lt bl from the cam sensor, and where it splices into the shared ground.

Since the crank sensor seems to not be having any trouble, it's probably the section of wire from the cam sensor to the shared ground wire, or at the connector or splice connection.

Yeah, I've been pushing off opening up the harness. I've done a few harness things in the past and its always managed to become a larger tedious job than what I was initially going in for. Seems like thats whats next if the changes happening today don't workout.

 

[laramona03]

After soldering the two 5v wires and ground to the pigtail, and running additional grounds from cam and crank sensor pigtails to the frame, the truck idles and runs great until the code comes back up. This makes me think as Ken226 mentioned the issue is probably at the splice of the cam ground into the crank ground.

I think this since the new ground ensure a solid ground, but the PCM still needs reference to that ground and that is the only other possible failure point.

​

 

[Ken226]

After soldering the two 5v wires and ground to the pigtail, and running additional grounds from cam and crank sensor pigtails to the frame, the truck idles and runs great until the code comes back up. This makes me think as Ken226 mentioned the issue is probably at the splice of the cam ground into the crank ground.

I think this since the new ground ensure a solid ground, but the PCM still needs reference to that ground and that is the only other possible failure point.

​

It may be stating the obvious, but check the terminals inside the cam sensor connector. It isn't uncommon for connector terminals to get really loose and cause intermittent signal loss.

 

[jws123]

Are you sure you set the timing dead on? ive rebuilt alot of these engines it can be a bit tricky if you havent done it before. If the cam is 1-2 teeth off it will run fine til it trips the dtc ive done it many times. Also your timing kit 2003 changed from 16-tooth to a 32-tooth timing setup websites often lable it wrong just make sure you have the right kit. I know it match what came out however if someone installed a older engine.. lol Just count the teeth on your timing gear to make sure.

 

[laramona03]

It appears to be fixed.

This afternoon I opened up the harness following the ground from the cam and crank sensor back to the splice. It seemed fine and was soldered together with no signs of damage traced back. to the PCM. I tested for resistance at the PCM connector and at the cam sensor and noticed it was 0 ohms but if the multimeter moved slightly it would read high resistance. I unpinned the ground and made sure it had a solid connection. I put it back together and BLASTED half a can of electrical cleaner and then with an air nozzle made sure it was dry before connecting it again.

That seemed to have been the trick. Either the re-arrangement of the harness, the cleaning of the connection to the PCM, or the combo of the two things fixed it. Since that I've driven it 20 miles around town taking it up to highway speeds with no issues.

I feel like an idiot, but thinking back i never cleaned the connector to the PCM just the PCM pins. So if anyone else runs into this issue please do yourself a favor and clean the PCM pins AND harness connectors to the PCM before recreating my experience the last few weeks.

The silver lining in all of this...a ton of maintenance got done and she runs great!

Thank you to everyone that helped me think of other things to try. It was exactly what i needed to get my head out of my A$$.

 

[Ken226]

It appears to be fixed.

This afternoon I opened up the harness following the ground from the cam and crank sensor back to the splice. It seemed fine and was soldered together with no signs of damage traced back. to the PCM. I tested for resistance at the PCM connector and at the cam sensor and noticed it was 0 ohms but if the multimeter moved slightly it would read high resistance. I unpinned the ground and made sure it had a solid connection. I put it back together and BLASTED half a can of electrical cleaner and then with an air nozzle made sure it was dry before connecting it again.

That seemed to have been the trick. Either the re-arrangement of the harness, the cleaning of the connection to the PCM, or the combo of the two things fixed it. Since that I've driven it 20 miles around town taking it up to highway speeds with no issues.

I feel like an idiot, but thinking back i never cleaned the connector to the PCM just the PCM pins. So if anyone else runs into this issue please do yourself a favor and clean the PCM pins AND harness connectors to the PCM before recreating my experience the last few weeks.

The silver lining in all of this...a ton of maintenance got done and she runs great!

Thank you to everyone that helped me think of other things to try. It was exactly what i needed to get my head out of my A$$.

Good work. These kinda problems are difficult to track down.

 

[BigTerry66]

Hello, Everyone.
Thank you in advance to anyone that responds and has insight on this issue. I also want to mention I've spend the last month researching daily for hours on what could be causing this P0344 code on my 03 Ram 1500 with the 4.7.

Im no mechanic, but I'm broke so I do troubleshooting and work myself. Heres the story...

End of April I get a misfire code in bank 1, so i pull plugs and inspect coils. The coils seem fine visually so I only replace the plugs. Four days later I get the P0344 code after a long day running errands on my way home.
I get home and check the wires, and sure enough right at the pigtail the wires were bare and covered in oil. I cleaned them off, isolated each, replaced the sensor o ring, and tested for ground, and the two 5v with ignition on. Plugged it back in and after a short drive the code came back.
So I decided to replace the sensor with a mopar one. Code came back after a short drive.
I bought the truck from auction and noticed the engine was not the original, so i decide to pull the valve covers and look for chain slack.
The cam, chain, and components all look healthy with the exception of some minor but noticeable chain slack. I decide its enough to warrant a timing job, and i want the truck to last so I bite the bullet.
I replaced all timing components with a Cloyes parts, tripple check timing and torque. While im in there i inspect all the rockers and lifters (prefect condition and the engine is incredibly clean inside absolutely no signs of sludge). New seals go in, i did an oil pan seal as well, and thermostat while Im there.
Truck cranks right up and runs great, but after the short drive the code is back.
So i take a moment to research and think back what happened before the code came up. It was a misfire...maybe the coils were going bad...i connect my old autel scanner and check for coil burn time. It was reading reading bellow the 1.0 millisecond threshold. So i find a video on youtube were a guy find the coil causing feedback interference in the cam reading to the PCM...so I bought new NGK coils to go with the NGK plugs.
Code came back after the same short drive (been taking the same route and it come up at the exact same time/spot).
So i read that it could also be a bad alternator feeding back into the 5v system. I run the truck without the alternator to exclude that and the code came back.
At this point im hours into labor and research and a few hundred in on parts.
I re-check wires at the plug with a multi meter and it all reads fine. I de-pin the wires from the PCM and run some direct to the sensor..code comes back.
I go back to check all the grounds. I clean them all up and slather them in dialectic grease. Confirm the grounds to the heads are set up correctly. Code comes back.
I replaced the PCM and the code came back.

I've runout of ideas...does anyone have any success with this issue on an 03 4.7?

Im starting to think it just not fixable... Thoughts?

I would either check the amount sensor or replace it..