[Shbek]

Two years of ownership and 115k on my H6.

Two days ago it started a little rough. I immediately plugged in my OBDLink. The battery voltage was a little low at 13.6, but it was also a bit below freezing. I've had the battery less than 11 months and installed new connectors with the battery. Car ran absolutely fine for 8 miles. Battery was at 14.2, and no pending codes.

Next time I drove the car, it drove fine for about a mile, then when I started to go from a light it nearly died, and the CEL came on. Checked the codes:

p0340 "Camshaft Position Sensor"
With pending p0301 and p0306 which are cylinders 1 and 6 misfiring.

I did the plugs and boots 11 months/6k ago with NGK Laser Iridium plugs and BeckArnley boots.

Could a bad camshaft sensor be causing misfires, or am I having a bigger problem here? Any way I can test the camshaft sensor to make sure that's actually what's wrong? I've been reading up and it seems like p0340 can be a broad problem - wiring, fuel filter, etc.

 

[Evil Soob]

I've had misfires before and the car threw a bunch of codes...mine turned out to be stale gas. With the below freezing weather it could be possible you got an ice crystal or something along that line. If it were me, I'd clear the codes and wait to see what happens next. A can of sea foam in the tank may help if there's any moisture in there.

I believe all the camshaft positioning sensors are the same on the H6 ( I could be wrong) and if you wan to check if one is going bad, just switch the positions and see if the misfire changes to different cylinders.

Are you ready for an oil change? I've seen circumstances where just a little bit of sludge or other impurity will lock up the sliding adjuster in the sensor.

Seems grounding issues are highly suspect in many cases where sensors are involved but with a newer battery I doubt that's your problem.

You can bench test a sensor just by removing it and with a jumper wire apply battery voltage. If it's functioning, you'll see the inside cylinder move when the solenoid activates.

Well, that's all I can offer and I could be wrong on something I've said here........I've been married 39 yrs. and I'm reminded that I'm wrong on a regular basis!

 

[Shbek]

Very helpful! Thank you! I am due for an oil change, but I've been holding off for a warmer day. I went ahead and ordered the sensor, as no parts store nearby has it in stock. :/

Til then, troubleshooting!

 

[Shbek]

Figured I'd update this in case anyone stumbles across it.

My camshaft position sensor arrived *way* faster than expected (19 hours from order to delivery on a Saturday). So I just went ahead and put it in.

Error P0340 referenced in the service manual made me believe it was the passenger side sensor giving the error, so that's the one I replaced. P0345 appears to be the driver side sensor.

I also discovered some corrosion on the wire side of the battery's ground terminal clamp which I cleaned up. Battery voltage shot up to ~14.5-14.7. I also changed the oil since it was due.

Could have just been the terminal clamp, but I don't mind spending the $80 as the (obviously magnetic) sensor had a fair bit of debris on it.

I've done three trips of 5-10 miles and so far, so good.


Sent from my XT1650 using Tapatalk

 

[cricketontherun]

Sensor location?

So I started experiencing the same issue yesterday, and we've had prolonged temps below 16 degrees (more like -8 to 9) for two weeks. I was actually on my way home from getting oil change supplies when the car started shaking like a dog shitting peach pits, the engine seemed to shut down (maybe protect itself) and threw the P0340 code.

I'm trying to locate the sensor itself but have not been able to on my 03 H6. Any suggestions?

 

[1 Lucky Texan]

seems like checking engine and battery grounds and checking battery voltage would be a good place to start.

 

[idosubaru]

get the FSM. they're free all over the internet.

 

[eagleeye]

get the FSM. they're free all over the internet.

here they are in a easily collated collection, I think I would download to a flash drive and scan with multiple antivirus tools etc....

https://sl-i.net/FORUM/showthread.php?18087-Subaru-Factory-Service-Manuals-(FSM)-Every-Model-USDM-EU