Stupid Check Engine Light

[mightymoose_22]

94 Escort gives code 214- Camshaft Position Sensor Circuit

I had the error once before some years back and it turned out to be that a new camshaft that was installed was missing the magnet that the sensor gets the signal from. That issue was addressed and the CEL went away.

Many months later I have started getting the same code again, but rather than being constant, it is only present while the engine warms up. Once I"m up to temp my CEL goes out, but the 214 code has me a bit confused.

Anyone know something about the cam sensor circuit that would explain why the CEL comes on during warmup? Any other things other than the cam circuit that would cause this?

The car seems to run just fine... just would prefer not to have the CEL issue. Since the light goes out after warmup I'll just assume the wiring is good and the cam sensor is working.

Is the engine temp sensor that feeds the computer connected to the cam circuit?

[Intuit]

Electrical resistance increases with heat. But components expand when heated. Tried checking the connectors for corrossion, cleaning them ? Hopefully not a short anywhere but that's another possibility. Typically see those types of intermittent 'works when heated' shorts in computer electronics vs actualy wires. Would be wishful thinking to hope that it was something as minor/easy as a timing belt slip.

Unfortunately there are a ton of crap, total-junk parts out there for Escorts. They claim "meet or exceed OEM standards" but that's total bull. I've gotten then from AutoZone & Parts+ suppliers. Often way more expensive, but CarQuest has been batting 1000 so far. (only drawback is they operate on banker's hours and have relative few locations) O'Reilley has only been in our area for a short time but so far they've been decent except for their "off the shelf" parts that attendants don't have to fetch. Those do suck.

[mightymoose_22]

I haven't found a short, but that doesn't mean that one isn't there.
What is confusing me is that it is the error code for the camshaft sensor circuit, but is somehow connected to temperature.
If the temp sensor is a factor in the camshaft sensor circuit then that would explain things, but I don't know
It isn't timing... I have quadruple checked it three times :P

[Selectron]

That's the 1.9L eh. I don't have the manual for the '94, but on the '95 it's showing as a standalone circuit - no connection to the ECT sensor nor anything else - just two wires coming off the camshaft position sensor and feeding directly into the PCM.

Because the voltage output generated by the interaction between the magnet and the sensor is at such a low level, the two wires are encased within a grounded screen (protects from RFI), which grounds at the ignition control module, although I highly doubt the screening would be a relevant factor in this.

I'd suspect a failing sensor, or perhaps sensor misalignment. The signal must be present when the engine and sensor are cold because otherwise the engine wouldn't run, but perhaps the amplitude is too low until it heats up. I'd probably remove the sensor, inspect it and reseat it. If that didn't fix it then I'd probably replace it.

Or, another thought, do you know how that magnet is attached? Any chance that it's loose and not being held firmly until the camshaft has heated up?

I'll upload the wiring diagram and sensor removal/installation section later today.

[Selectron]

And these are the diagrams. They show a connector adjacent to the sensor, C1013, then another, C100, between there and the PCM, and so the screen is in two sections to accommodate that connector.

'95 Escort CMP sensor wiring diagram 01
'95 Escort CMP sensor wiring diagram 02
'95 Escort CMP sensor description
'95 Escort CMP sensor removal/installation

[mightymoose_22]

Thanks- I'll get a look at the diagrams over the weekend and see what I can find out.

I don't know how the magnet is mounted on the cam... would be interesting to find out.
This sensor does not come out easily... it requires the intake manifold to be removed, which means the coolant has to be drained... it's a PITA. I wish I knew a way to test the sensor without replacing it

[Selectron]

The output from the sensor could only be meaningfully observed on an oscilloscope, but the problem there is that the factory manual gives no reference waveform to compare it to. The sensor description, above, refers to a single tooth on the camshaft, so the signal frequency would be the camshaft rotational frequency at idle speed, and the waveform is roughly a sine wave, but there's no way of knowing what the amplitude should be, so even if you were to hook a 'scope onto it, you still wouldn't know if you were seeing the correct waveform without a reference waveform or a description indicating the expected amplitude.

A multimeter on its AC voltage range would detect the signal provided it doesn't fall outwith the meter's frequency range, but again you would have no way of knowing if the indicated voltage was within specification. So in a nutshell, I don't think you can do any meaningful testing on it, besides checking that a voltage output does exist, which we already know that it does because otherwise the engine wouldn't fire up.

Actually there is one thing you could do, which would be to access the sensor's signal wires at connector C100 (backprobe so that the circuit remains intact, and don't measure with respect to ground, but instead place both probes on the signal wires - doesn't matter which way around they go), measure the AC voltage and see if it's roughly constant from cold engine to hot, or if the amplitude changes markedly with temperature. For what it's worth, I would expect it to be fairly constant at a steady idle.

Reading your opening post again, two things are bothering me. Firstly, I'm not convinced that there will be a rotating magnet - it might work but would probably give a lumpy waveform, so I think a rotating ferrous tab is more likely, and if it's just a projecting ferrous tab (and the description does refer to a 'tooth located on the camshaft') then I would expect it to be part of the camshaft casting or machining, in which case, how could it have been missing. And then secondly, regardless of whether it's a magnet or a ferrous tab or a piece of blue tack, if it was missing then the engine never would have been able to fire up without it because it wouldn't have been able to initiate the fuel injector sequence (sensor description, above, also mentioned on wiring diagram 01).

So I suspect that you weren't told the real story on what went wrong first time around, which doesn't help because the same issue may have raised its head again but you don't know for sure what it is.

As you said, it requires removing the intake manifold just to remove and inspect the sensor so it would probably make sense to try to locate the connectors for the signal wires and the two sections of RFI shielding and check those first.

According to the factory manual, C1013 (shown on wiring diagram 01) connects to the CMP sensor itself, and this is the location for C100:

'95 Escort CMP sensor - connector C100 location

Wiring diagram 02 in the earlier post, above, shows the two sections of shielding as entering connector C100 on a single black wire, leaving it on a red/dark blue wire which finally grounds at the ignition module, and the two signal wires from the sensor pass through the same connector, which if the C100 location diagram is accurate looks like it might be easily accessible. This is from the '95 manual though, so the '94 connector location and wire colours might have been different.

[mightymoose_22]

Originally Posted by Selectron

So in a nutshell, I don't think you can do any meaningful testing on it, besides checking that a voltage output does exist, which we already know that it does because otherwise the engine wouldn't fire up.

Actually the engine does run with a bad cam sensor circuit. The engine will default to "batch mode" meaning that the injectors fire into all cylinders rather than sequentially, which significantly kills mileage. I can even unplug the sensor and let the engine run, but then the light won't go out.
The engine won't start if the CRANK sensor is bad though.

Actually there is one thing you could do, which would be to access the sensor's signal wires at connector C100 (backprobe so that the circuit remains intact, and don't measure with respect to ground, but instead place both probes on the signal wires - doesn't matter which way around they go), measure the AC voltage and see if it's roughly constant from cold engine to hot, or if the amplitude changes markedly with temperature. For what it's worth, I would expect it to be fairly constant at a steady idle.

I'll give that a try, but I do strongly suspect I'm gonna have to just take the intake off and swap the part. Experience tells me that my light is 99% likely to still be on if I do that though :P

Reading your opening post again, two things are bothering me. Firstly, I'm not convinced that there will be a rotating magnet - it might work but would probably give a lumpy waveform, so I think a rotating ferrous tab is more likely, and if it's just a projecting ferrous tab (and the description does refer to a 'tooth located on the camshaft') then I would expect it to be part of the camshaft casting or machining, in which case, how could it have been missing.

I shouldn't have said "magnet". I have never actually removed the cam... I always take the head in to a shop for that kind of service. What I should have said is that whatever piece is on the cam that the sensor reads the signal from was not present on the cam. This occurred when I put in a new engine. The new cam was missing something that the original had, so the part had to be installed, or the entire cam was switched (I don't know which since the shop does the head work for me). The correct cam and parts are on the car now, and appear to work just fine once up to temp.


I appreciate the input. I will dig in to this over the weekend and get back with some info next weekend most likely

[zzyzzx2]

Have you tried unplugging it then plugging it back in? I once disloged mine a little when I was replacing the fuel filter.

[denisond3]

Personally I thought the magnet was inside the sensor, and what was on the end of the cam was just a physical 'lobe' so the magnet & solenoid would see a magnetic variation.

But what may be worth saying; I have seen a couple of the cam position sensors that had cracks in the plastic housing, up near the end that goes inside the hole in the head. I wondered if I should have gotten a new sensor, but the old one has been working okay.

You have to unbolt the int. manifold to get that sensor out dont you? And what would be the result of a dirty/corroded connector?