Persistent Code 0340

randii · Post by **randii** » Wed May 06, 2009 1:31 am

I swapped in a long block... no significant other changes but now I can't seem to shake this P0340 camshaft position sensor code. The motor starts and runs (kinda rough), and throws no other codes.

I've run the trouble-tree and swapped in a known-good computer... and even rewired the whole darn shielded circuit (three hours of my life I won't get back) and lo and behold, I get the same thing! Any suggestions as to how to clear this code, which says camshaft position sensor (CPS) malfunction error, but not CPS out of range...

I'm thinking about pulling the timing belt and reinstalling after checking alignment... I don't think I could be off, but at this point, I am suspecting my own sanity.

Randii

Post by **Legacy777** » Wed May 06, 2009 3:10 am

Can you please provide some additional details. What year Subaru, what model, what model/year did the donor long block come from, etc.

randii · Post by **randii** » Wed May 06, 2009 6:54 am

The car is a 1999 Wagon with manual tranny, and the donor was a 1996 Wagon with an auto. The price was right, and I never could find a reasonable 2.2 Phase II donor.

I milled up some simple spacer plates to allow me to bolt the 1999 intake onto the Phase I heads on the '96 long block. I'm using the 1999 body harness, 1999 engine harness, and 1999 sensors. I swapped the 1999 crank pulley and camshaft pulley across, since the pips on the backside of the pulley sweep differently on autos and manuals.

Randii

Post by **Legacy777** » Wed May 06, 2009 4:54 pm

Hmmm.

Were they both legacies?

Besides the code, how does the engine run? Any other symptoms of things not being correct?

log1call · Post by **log1call** » Thu May 07, 2009 1:52 am

If you just plugged engine loom connector to body loom connector then that will probably be your trouble I would think. They might look the same but the internal connections hardly ever are between models or markets.

Skruyd · Post by **Skruyd** » Thu May 07, 2009 6:24 am

Possible it's the Camshaft position sensor? You said you only messed with the wiring and the computer, but never checked the sensor. If you can get your hands on a scope. It will really help out diagnosing the sensor.

randii · Post by **randii** » Thu May 07, 2009 10:40 am

Both are Legacy wagons.

The 1996 engine harness and 1999 engine harness have different connectors where they plug into their respective body harnesses... so I transferred the 1999 engine harness to the 1996 donor motor when I moved the 1999 intake manifold across to the 1996 donor motor.

The engine runs roughly, but steadily at idle. It revs OK, but not powerfully.

I have swapped the Camshaft position sensors between the 1996 and 1999... both test correctly (and similarly) for resistance, but I suppose might be wrong. I probably should whip out the oscilloscope and check signal...

Randii

log1call · Post by **log1call** » Thu May 07, 2009 10:54 pm

Are you sure the body harness is feeding into the ecu on the correct pins for the ecu?

Did you alter the wiring routing when you swapped it and the manifold? Some wires, despite their shielding, pick up interferance. The routing of the wiring can be critical.

greg donovan · Post by **greg donovan** » Thu May 07, 2009 11:21 pm

i know the coolant temp sensor needs to be cleared by a subaru scantool. perhaps this thing is the same way?

Post by **Legacy777** » Fri May 08, 2009 6:32 pm

Just curious.....have you checked for vacuum leaks? Spraying starting fluid around the intake manifold would help you try and find any possible leaks.

randii · Post by **randii** » Sun May 10, 2009 1:26 am

I am sure the body harness is feeding into the ECU on the correct pins for the ECU -- I'm using the whole 1999 engine harness and the whole 1999 body harness... nothing has changed other than the long block underneath, not the wiring routing, not anything electronically.

The scan tool I have has the capability to clear codes, and I have done this between testing cycles.

There are no vacuum leaks... my adapter plates are quite nicely air-tight.

Randii

Post by **Legacy777** » Sun May 10, 2009 6:25 am

Wasn't necessarily saying around the plates, just in general...

log1call · Post by **log1call** » Sun May 10, 2009 6:57 am

Have you checked the cam pulley isn't defective? That the cam sensor isn't loose?

randii · Post by **randii** » Sun May 10, 2009 10:16 pm

log1call wrote:Have you checked the cam pulley isn't defective? That the cam sensor isn't loose?

I have swapped in camshaft pulley sensors, same problem.

I am swapping another camshaft pulley on today. I've checked the electronics every way I can, and swapped different sensors (my wife was LESS than amused when I swapped a couple of old sensors into her 2007 to verify that they were OK on her ride!

oh well!), so by my thinking, maybe the camshaft pulley has a problem? I can't imagine what could go wrong with the hardware, but when all reasonable possibilities are included, ya gotta look at the unreasonable ones...

Randii

log1call · Post by **log1call** » Mon May 11, 2009 7:10 am

A wrong model pulley perhaps or just the belt timing out? If you look here.. http://cid-4ca3c3459aaa7f7f.skydrive.li ... a=90828925 and download "04_DTC Criteria" and have a look at the criteria for that code, you will see a diagram where they explain that the code is set if there are not three signals per two turns of the crank. If you look at the crank sensor code you will see that the crank sensor is an irregular signal, and that there are only thirty signals sent when you are measuring the correct portion of your crank rotation. If the cam doesn't start being counted at the correct point on the crank, the cam will set the code.
Goes with the rough idle too really.

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Persistent Code 0340

Persistent Code 0340