Hello all! I am new to the forum so what better way to introduce myself than to ask a question . I just dropped a remac engine into my 2003 Discovery 2. Aside from the engine, most everything else is new. New coils, new MAF, new O2 sensors, new crankshaft sensor, etc. The camshaft position sensor is from the old engine. Initial startup was fine. After I shut it down and restarted, it ran for about 15 seconds before pulling a P0340 Camshaft Position Sensor Circuit Malfunction. Even after the service engine soon light comes on the vehicle runs fine. If I clear it out and let the car cool, it does not come back...it's only appearing after hot starts. It happens evertime I restart hot and it only pulls the P0340 code, no others. Has anyone had any experience with this? I don't want to assume the CMP sensor is bad just because the 'service engine soon' light is telling me so...I didn't think these sensors were prone to failure. I have only put about 6 miles on the new engine...I'm hoping to solve this issue before I keep driving it.

 

With a high end scanner you can test the cam sensor to verify if it is failing, if it is failing, this is rare for a Rover

 

Do you mean that the CMP can be tested by diagnostic through the ECU or are you referring to testing the sensor directly with an oscilliscope? The problem is getting weirder...I started it up tonight to move it out of the garage and turned it off to hose the dust off of it. After about 15 minutes, I re-started it and the P0340 came back...the truck was still cold so there goes my hot start theory. The Rover is not running funny or anything so I took it out, drove about 15 miles. Shut it off, cleared the code and restarted, no P0340! I immediately drove the car about 35 miles with no check engine light. Shut it off when I got home, restarted...P0340 again. Cleared it, started one more time, no code. It's only happening at start up, does not affect engine performance and only happens every couple of starts. I'm really scratching my head on this one.

 

Is it properly connected and is the wiring connector in good shape. I have seen the issue also be caused by a faulty crankshaft position sensor cause it looks at the same one.

 

The wiring and connector look good. I replaced the CKP sensor for good measure so that component is brand new. I'd just hate to assume it's the CMP sensor itself since they don't often go bad, especially given how expensinve they are. I'm trying to wrap my head around what would make this problem only occur at hot or warm engine restarts and not every time.

 

Jim,
Are you still having an issue with the P0340? As said before cam sensors by nature rarely fail. Did you check your connector for oil ingress, due to it's location? As rovin4life said a bad crank sensor can trigger cam sensor faults, but I never saw a P0340 from a bad crank sensor. Also are you monitoring the fault code all the time or just when the check engine light comes on? The PCM has to see most faults for two consecutive drive cycles before it turns your light on, so the code may be there even though the light is not on. Finally you can't always assume that because a part is new, that it is good. ibis1

 

I am still having the issue. I haven't done anything about it yet since I'm still trying to break in the new engine and have only put limited miles on it. That and the fact that the MIL coming on has absolutely no effect on the engine performance, I haven't freaked too much when it comes on. I did check the connector again and it is clean, no oil or grease. The code is limited to appearing at engine start up only. I've checked for pending codes and found nothing. I have also reviewed freeze-frame data on my scan tool and have seen nothing out of the ordinary. What I can't figure is why it only happens in the first 30 seconds after starting the Rover, I can shut it off and clear the code, immediately restart the car; no code. It's more of a nuissance than anything else at this point but I don't want to carry my OBDII scanner everywhere I go and always have to start the car twice :-). Not sure if I should break down and buy a new CMP sensor for about $300 or take to to the local LR dealer and pay them $170 to tell me I have a bad CMP sensor so I know for certain.

 

Jim,
Before I would lay out any more money, I would reinstall the old crank sensor. (if you have it) I just don't see camshaft sensors failing, even with very high mileage. I don't suppose you have access to a scope do you? ibis1

 

I'm also having the same issue. I have a 99 disco II and my scan tool always shows pending P0340 right after I start. I cleaned the connector, at least I think it was the connector. The harness branches off to two connectors, one is just above the oil filter and the other is further which I can't seem to see or feel. I'll try again, also I have had something blowing the ecu fuse for the last year intermittent, I'm wondering if their is a short also with the cam sensor? I can't seem to find the problem, but luckily it hasn't blown the fuse for a month or so and I'm over due for inspection. So I'm also hoping the P0340 won't fail me at the inspection in NJ too. Anyhow any advice may help, thanks.

EDIT: FOUND AN INTERMITTENT SHORT ON THE WIRE HARNESS FOR THE CAM POS SENSOR, IT WAS HITTING THE EXHAUST MANIFOLD. I REPAIRED THE WIRE AND THE CODE IS GONE...HOPEFULLY THE INTERMITTENT SHORT FOR THE COMPUTER FUSE IS GONE TOO.

 

New engine right? Maybe it has the wrong cam gear. Disco 1's and 2's don't use the same gear, and this is where the cam sensor reads from. An oscilloscope can show the waveform from the sensor, you can look through the CMP mounting hole with a boroscope to see the gear or you can remove the front cover. The older gears have 4 narrow "spokes", the newer ones are machined with a couple of "d" shaped holes. I have actually seen this issue before, don't overlook it if you haven't resolved your problem yet.