Camshaft Sensor Circuit codes

Knightspirit

Well-known member
Sep 22, 2019
214
64
Mount Shasta, CA
So I am having an intermittent power loss issue over the last couple of weeks. Every once in a while - I would suddenly lose power - and while I could still drive - I could not go over 1500 RPM's and no power at all. Giving it gas has no effect. So I was able to limp it home both times this happened. Then it happened again the other day - and this time I got an engine light with it - so I was able to get the codes.

PO340 - Camshaft Position sensor A, bank-1 circuit malfunction
PO300 Random cylinder misfire detected.

Anyone else ever gotten these codes? While it could be the position sensor itself - it might also be anything in the circuit. I actually have another sensor from a donor motor I am working on - so I was thinking I would just replace the sensor and see what happens - but to get to it I would need to remove the water pump pulley and it's a much bigger process than I thought - so I figured I would chime in here before running off on some tangent that might not even need to be done! I recently replaced all of the spark plugs and the wires - so that part should be OK.

Would a bad sensor be intermittent like that - or would it just fail?

Thanks
 

discostew

Well-known member
Sep 14, 2010
6,738
636
Northern Illinois
It's probably a wire or connector issue. Some of the wire is part of the sensor. though. Take a good look at the pigtail coming out of the cam sensor.
 

Knightspirit

Well-known member
Sep 22, 2019
214
64
Mount Shasta, CA
It's probably a wire or connector issue. Some of the wire is part of the sensor. though. Take a good look at the pigtail coming out of the cam sensor.
OK-so I am having trouble getting to this sensor. I did find this in the manual:

CAMSHAFT POSITION SENSOR (CMP SENSOR) Servicerepairno-19.22.07
Remove
  1. Disconnectbatterynegativelead.
  2. Raisevehicleonaramp.
  3. Releasesensormutiplugfromcliplocatedon front cover.
  4. Disconnectmultiplug.
  5. Removeboltsecuringsensor.
  6. Removesensorfromfrontcover.
  7. Remove ’O’ ring from sensor and discard.
Refit
8. Cleansensorandmatingfaceonfrontcover.
9. LubricateNEW’O’ringandfittosensor.
10. EngageCMPsensorinfrontcoverlocation.
Secure with bolt. Tighten to 8 Nm.
11. Connectsensormultiplugandsecuretobracket. 12. Lowerramp.
13. Reconnectbatterynegativelead.
page284image89716064 page284image1773376



It looks like I can get to it if I can remove the fan. I rented a fan wrench - and I read in the manual that it is a left hand thread - so clockwise loosens it. With the belt on - I can't get it loose due to slippage - and even when using a long screw driver to brace the pulley - it's not budging. What's your trick for getting the fan off?

Tips? Thanks in advance!
 
Last edited:

discostew

Well-known member
Sep 14, 2010
6,738
636
Northern Illinois
I think if you can find a local shop that's willing to work on it you should be able to get that replaced for about 1 hour of labor. My fan tools probably cost about 180 bucks. The math is easy on this one. Buy yourself a genuine Rover sensor and find a mechanic to install it.
 

Knightspirit

Well-known member
Sep 22, 2019
214
64
Mount Shasta, CA
Here's an update on this thread:

I was able to replace the cam shaft position sensor - without removing the belt or water pump pulley. I removed the oil filter - which gives access to the plug for the sensor - and then if you get directly under the sensor on the drivers side - you can get a little 1/4 drive socket in there to remove the bolt holding the sensor in. Not an easy task - but doable.

After doing that - I drove for a couple of days with no issue - and thought that I had fixed the problem. However - it came back again the other day, again just a couple of blocks from home. Apparently - it kicks in once the engine reaches operating temperature - doesn't happen cold. It doesn't feel like the engine is missing or running rough - it just won't accelerate past about 1200 rpms. Each time it happened I was able to limp home at 10 MPH. Pushing on the gas has no effect. This last time it happened - I did not get a check engine light - no codes.

So if anyone has any ideas as to where I should go form here - I'm listening! I did read also that if the cam sensor is bad - the computer automatically sets the timing at top dead center - and the manual says you would probably not even notice that the sensor was bad. So in retrospect - this is probably not related to the sensor at all...
 

Knightspirit

Well-known member
Sep 22, 2019
214
64
Mount Shasta, CA
Found it! Thanks Roverover for directing me to the crank sensor. I discovered that the two wires that come out of the plug there had no insulation on them - just bare wires - so I was able to pull the whole thing up into the engine bay where I could work on it - and shrink-wrapped the wires and wrapped with tape. I ordered a new crank sensor form AB and went ahead and replaced it since I was in there - and now she purrs like a kitten.

I ended up replacing both the cam sensor and the crank sensor - both extremely difficult to get to! Now I know how, though. As for mileage - I am just over 170K with head gaskets replaced.