P0340 on Hyundai Santa Fe

May want to check crank signal too. Those can throw a p0340 with a bad crank.

I did. It has good signal at ecm

Check ECM connector condition and drag test relevant pins. Maybe signal is making it to the connector but getting disrupted on its way into the ECM?

already did that

Is it repeatable & are you scoping both cam & crank at time of failure?

yes. no lose of signal

Hi Randy what happens to the cam and crank signal at the exact point it stalls do they diminish slowly or is it an abrupt loss of signal this should be a clue also would moniture an ignition feed with cam and crank to see if your lossing ignition feed

diminish slowly

Then you know now it is not cam and crank will have moniture all other vital outputs and compare to crank to see what what goes down first make sure you zoom as to not miss a glitch especially on cam and crank which would look like it diminished slowly after the glitch if not zoomed in all the way

Car runs for about 5 seconds then ecm turns injectors off . Still have spark when this happens

That screams of a security issue when it is so duplicative maybe time to talk to customers to see if any one replaced with used modules

Car has no security system. And this original ecm

If it will stay running with cam sensor discounted time to do cam crank correlation and compare with known good to see why ecm does not like cam signal ps always use oem for cam and crank sesors

Factory cam sensor or aftermarket? If aftermarket, try a factory sensor. We've seen it quite a few times here. They do not like aftermarket cam sensors.

I'm with Jake needs to be OEM sensor

Are you sure the balance shaft is timed properly​.​Never know who or what was done to something that old​.​The timing belt would have to have been changed in 18 years.

Timing marks are all dead on . Belt was replaced about 4 years ago

Will it run if you unplug the Cam sensor?

yes

So with the cam sensor unplugged it continues to run and does not stall??

yes does the same thing

Can you share the scope file?

I will try to save one tomorrow

Hi ben here is the capture

Looking at the waveform you attached it appears to me the cam sensor is no good. It is hanging up at towards the end of the file. Have you inspected whatever it uses for a tone ring? It seems even when it starts the cam sensor is to wide. I would definitely install a new sensor.

At the end is when car shuts off

Pulled ton ring yesterday . And it was fine. And already putt a oe sensor in it. Butt thanks for input

Hey Randy, I just had an 02 with a 2.4 & a dead crank sensor. Here is my capture of cam & crank. The plateaus of the cam sensor waveform look different more noisy on yours. Not sure if that means anything. please let me know what you find or if this helps

Did you capture a good one after repair

I did not the client towed it away

thanks anyway

This sounds far fetched but I was in a class last night & the instructor shared a story of a 05 ish Kia that had similar issues to what you are explaining & he said it ended up being bad fuel. Sounds like it would be worth checking fuel quality maybe look into TSB's related to fuel & no start.

I looked at your waveform again & I am still thinking the tops look weird. Is it possible something is back feeding into it that circuit. like maybe a ignition or injectors. Check harness. just babbling ideas I hope I'm not just repeating what you have already done. Good luck

Here's the typical correlation that Hyundai provides, it doesn't seem to match up with what you're getting. Edit: Cam sprocket pin sheared like James mentioned maybe?

Looks to me his cam signal is up side down, Invert A and it matches you picture

I have seen those connectors get banged up and cause intermittent stalling issues. Maybe have a helper crank the engine while you push on the connector and see if you can get it to run longer. I think the location of the sensor is right in front of the engine, facing you. If this is the engine setup I am thinking of.

Already pack probed all three wires and scoped it . It is all good

Randy, I have seen 2 possibilities for this DTC when timing mark's are ok. 1. Check crank sprocket bolt. The orig torque was updated. Should be 116-123 ft/lbs. Trigger wheel behind sprocket walks on key 2. Another possibility is the cam sprocket may have moved on alignment pin. Sprocket hole will elongate, eventually pin will shear.

HI Randy. Is it possible that the wrong trigger or tone wheel for the cam sensor has been installed. We had a 2001 Mitsubishi that fooled us for a while. THere was a cam signal but it was not what the ECM wanted to see. The installed one on the car had a different length window on the trigger wheel. We had to get the correct factory part to fix the P0340 code. I also agree with the possibility…

Nothing has been done to this car for a long time . With cam or crank

I second what James said. Make sure the dowel pin or keyway, whatever it has isn't damaged on the cam gear.

This thing is out of time to me. As everyone mentioned inspect the sprockets/reluctor a for wear.

As long as your crank signal is not inverted this thing is out of time. If it is inverted then I still feel the cam or crank signal is shifted ever so slightly. (Meaning the key way may be worn).

Eyeballing the cam signal in the good example it does look different than the cam in the one Randy provided. Something whacky going on.

Notice the wide tooth of the cam should always be centered with the crankshaft reluctor tooth.

Yeah, it's low when it should be high in Randy's capture. Either out of time or something happened with that cam would be my guess. The cam reluctor seems odd too, but it may just be me going crosseyed.

Agreeing with JJ and Ben. also....I see what looks like a current ramp on every single CMP and CKP signal. I wonder whether the ECM is actually seeing that or if it's just the PICO leads seeing it.

I worked on this car about five years ago with a no power complaint and setting no codes ended up being the crank reluctor and spun 25 degrees retarded but never set a code . I agree with you on cam and crank correlation may be of . Butt this would not shut the injectors off after three seconds of running .

Have you brain deaded or touched the battery cables together? To clear memory.

yep.

The CMP signal controls the injector timing on this vehicles. If the signal is not right the ECM does not know what to do with it. I ran into a similar situation a while back on a Dodge Avenger that had a used engine installed. Everything looked perfect on the scope. However, FCA decided to go from a raised tooth on the crankshaft TDC to a missing tooth TDC. The used engine had a raised tooth…

talked to a engineer at Hyundai yesterday and he said this generation of the car would not set a cam and crank correlation code. so if you have inputs to ecm that is all it needs to run . remember early obd11. so what would cause injectors to just shut off

Hi Randy: That only leaves RFI/EMI and/or bad ground (alternator?). The patterns are bothering me. The anomalies lessen/go away as RPM is fading. I wonder what they look like A/C Coupled. I'd be curious about what default strategy is when the CMP signal is lost. If it's "Tag, you're it", that explains it running when the CMP is disconnected. Guido

I saw the same thing bought new leds same pattern I think it may be the way I have my leads running . Will change on monday and recheck . I think it is were my pico scope is mounted to close to my laptop . Will post on monday

Hi Randy: One of the folks here had an issue with skewed patterns. If memory serves, it was the laptop power supply. Guido

Yes I think that is it also .

Do they lose power or does the ECM just stop controlling them? Just wondering if the relay turns off or if the ECM gets fed up and just stops pulsing the injectors.

Computer is turning of injector pules

Here is a capture with injector being turned off

It's odd, and maybe I'm just reading too far into it, but those "ramps" also show up in the injector trace and they seem to coincide with the injectors firing. The thing is is they show up as a voltage decrease as opposed to an increase like in the cam and crank traces. Also they continue on after the ECM stops pulsing the injectors. It feels a bit like I'm grasping at this point, but I just…

You need to look at the forest amongs the trees

Butt if you unplug cam sensor it should still run and not turn injectors off . So what is turning injectors off . Throttle is closed rpm is under 1200 rpm its not fuel cut . Service info says cam sensor is to sync fuel injection for better control . Loss of injector comes from were ????

Hi Randy: I can't speak for anyone else. I think the underlying question is not the what but the why. At least, that's what I'm trying to wrap my head around. Scott, if you're monitoring this thread, do you know which post Randy was replying to? (Hint, Hint.) Guido

I looked but maybe i missed it. Did you say if these were OEM sensors?

yes oem

I am no expert but I will make a few comments of what I see. The engine seems to be in time from what I can tell. But I think something is going on with the camshaft reluctor. The big tooth on the camshaft reluctor is twice as big as it should be. Also the rising edge of the small tooth is suppose to start around 88 degrees yours starts at about 130 degrees. I made a little drawling and hope it…

I would agree with you but look at the second capture I sent . Why is injector turning off.

Nissans do the exact same thing. The ECM does not know how to interpret the signal so it kills the injectors. Basically, it just throws it‘s hands up and says “I don’t know what to do with this.” and shuts the injectors down.

This car should still run fine with cam sensor unplugged. And it does not . and setting a p0340 . circuit code. computer is seeing the signal . what is left

Here is another known good... Your signals should match these and they don't. I haven't wrapped my head around what could be wrong yet though.

What is code description. Do not over think early obd11

Now the question is why?

Yea that gap should be more than double what it is now

Answer I will show pics tomorrow . Fed and calif

If The Cam sensor signal could be flipped over it would be right. Due the signal it almost looks the same whether or not it is inverted (kind of like an optical illusion). Has the wiring been altered?

Yeah, it almost looks inverted.

Some one swapped the power and ground wires maybe. But then why would this all of a sudden happen. I did a math channel and inverted it and it much closer but still off to the known good i have

This was my personnel car up to 3 months ago . Never any problems . I sold to customer and now this

I would have to say the ecm is shutting it down because it does not like the cam pattern. Per what I read from Hyundai the injectors fire off the cam signal. So if you clearly have a Cam signal issue you need to figure that out first and fix that issue.

New oem cam sensor and reluctor wheel . Now what . What is code description po340

Not likely but possibly a bad new cam sensor? If you replaced the reluctor wheel were you able to tell if it was the exact same? Maybe the marks are in different spots. Did this car just come in out of the blue with this issue and code?

No customer drove to work no problems . Came out to go to lunch and has this problem . Now what ???. Can some body answer my question?? What is the definition of this code

Camshaft position sensor A circuit malf

So if you have signal at ecm what could be the problem

Power or ground to the ECM or the ECM itself?

So were would you go with that code ??? Ecm is seeing this I should in the capture . Early obd11 dumn ecm

Every time your cam signal happens it pulls your crank sensor pattern away from ground. something is wrong with the ground for the crank sensor either the wire or internally to the crank sensor. Please voltage drop the ground wire for the crank sensor or load test it. if it is fine then something is wrong with the crank sensor.

Thanks . Already ran separate ground and same thing . new oem crank sensor

Was that capture before or after? You have a bad ground to that sensor in that capture. So you may very well have multiple issues. I would also be concerned with AC ripple. also to clarify what did you run a separate ground for? The cam or crank sensor?

Cam sensor to battery

It is not the cam sensor that has the problem. The crank sensor or crank sensor circuit is where the ground problem is.

I will recheck today . Thanks

Post with fix it was ecm will post caps tomorrow . thanks to all you of for input

Can you post a new cam crank after fix please

first capture bad . second capture good . notice the cam and crank correlation between the two. ....And how the signal in capture two is cleaner. only ecm replaced. explain this ..this is weird. outer limits weird

Coming in a little late here, but did you open the old ECM to see if there's anything obvious? Water intrusion or a burst cap or something?

No to busy this week will take home and inspect this weekend . Butt this is just to weird

Hi Jj Here is what i found . Over heated connector

Hi Randy: Now we know the why. BTW, where did the moisture come from? Guido

Its not moisture I think . Looks like it just overheated that terminal . This is on the bottom side of ecm . Inside ecm cover has no signs of moisture .

Hi Randy: I was looking at the first picture. Guido

Good stuff. Crazy that it was messing with the cam signal the way it was. I wish there was a resource for PCB schematics, I'd love to be able to dig even deeper and see what board level components were being messed with.

For a week now that is all I can think about . What would cause this . When car comes in next time for service im going to play around and see .

I agree with what Guido said, that first picture looks like moisture intrusion which in turn could have lead to the heating.