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P0340 code on Ford 2.0L DOHC

Getting a P0340 (Camshaft Position Sensor signal) code on a 1999 Ford Escort ZX2 (2.0L DOHC). The sensor was cheap so that's the first thing I changed out - no change. Did all the point-to-point resistance tests in the Ford procedures - all in-spec. Found that the timing belt had some stripped-out teeth and that the cams didn't look quite aligned - Replaced the timing belt and set the crank-to-cam and cam-to-cam alignment. I'm sure it's correct, but still have the code. I even changed out the spark plug wires because I've heard bad ones could cause interference, and they probably had 100K miles on them anyway. Stil have the code.

When I unplug the sensor, the engine runs pretty well. When I plug it in, the engine runs ok at idle but sputters if I rev it up and dies when I let off.

That tells me the PCM is seeing the signal from the sensor, and substituting defaults when it's unplugged.

The "tone ring" on the cam has all its teeth and is aligned matching the diagram.

I'm about to try an oscilloscope on the sensor lines and see if there's noise, but I doubt I'll find anything.

Can a bad VCT unit cause this code? I'm not seeing the VCT-specific codes about too much or too little advance.

Thoughts anybody?

Reply to
Paul Barrett
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Did you use the alignment tools when you did the belt? The OTC set is pretty cheap for this application.

Reply to
Steve Austin

I used an equivalent tool to lock in the cams. I set the crank to TDC by checking the piston position, and also double-checking that the keyway on the crank pulley was at 12 o'clock. (Never did find where the crank alignment pin would go - is it under the exhaust manifold?) If this was set wrong, would it cause a P0340, but run ok with the sensor unplugged?

Reply to
Paul Barrett

Sounds about right. You let the exhaust cam sprocket float and then locked it down, right? One thing to try is to disconnect your alternator.

Paul Barrett wrote:

Reply to
Steve Austin

I moved the exhaust cam back and forth a bit with a wrench to make sure the VCT was at the neutral point before I installed the alignment tool, but I didn't actually loosen the sprocket bolt. Should I have?

Disconnect the alternator? Sure why not - otherwise I'm down to replacing the computer but I'm betting that's a waste of money.

Reply to
Paul Barrett

I always loosen both sprockets. The procedure calls for it and the job seems to go faster. The crank stop hole is on the front of the engine towards the bell housing. Access is a little tight on some of them.

Reply to
Steve Austin

Just an FYI for anybody else who gets this code (and a thanks for the help).

I had to order the dang E20 torx socket - nobody around here stocks them.

But once I had that, I just floated both sprockets as suggested, re-aligned everything, torqued it all back down, and voila - no more P0340. In fact it now idles smoother than it has since we bought it (used).

The only thing that bugs me is that this code is supposed to mean a fault in the cam sensor circuit. I had expected if it was just the timing it'd be some other code. Oh well, live and learn.

Reply to
Paul Barrett

Can u please tell me where that crankshaft sensor is located i also have a 99 escort zx2

Reply to
damcadams38

Don't know but I found this, first link in a search

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Reply to
AMuzi

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