[FIXED] P0335 DTC Causing No Start

Hi,

I am working my mom's 2003 Hyundai Elantra with the above DTC. I am following instructions per Hyundai Service Tech on testing the terminal and connector. The power supply circuit inspection and ground circuit inspection passed successfully. However, I ran into discrepancies while testing the signal circuit inspection.

Check for open in signal harness.
Disconnect PCM connector.
Measure resistance between terminals 2 of sensor harness connector and 29 of the PCM harness connector.
Specification : Approx. 0Ω
Result: I didn't complete this check yet as I couldn't find the PCM.

Check for short to ground in signal harness.
Measure resistance between terminal 2 of sensor harness connector and chassis ground.
Specification : Infinite
Result: 4k Ohms

Check for short to power in signal harness.
Ignition "ON" & Engine "OFF".
Measure voltage between terminal 2 of the sensor harness connector and chassis ground.
Specification : approx. 0V
Result: 4.9 V

I did a test from my Haynes manual also indicating that the sensor is bad. There was something like 6 mega ohms between two terminals where there should have been 500-600 ohms. What do these results mean? How can I repair these mistakes if there is indeed a problem. Thanks.

Steve

Hi,

I am working my mom's 2003 Hyundai Elantra with the above DTC. The car has been cranking for around ten to fifteen seconds before it starts for the last week or so. Finally yesterday morning, it wouldn't start at all. I am following instructions per Hyundai Service Tech on testing the terminal and connector of the CKPS, and the Haynes manual test of the CKPS itself. The power supply circuit inspection and ground circuit inspection passed successfully. However, I ran into discrepancies while testing the signal circuit inspection.

Test 1:
Check for open in signal harness.
Disconnect PCM connector.
Measure resistance between terminals 2 of sensor harness connector and 29 of the PCM harness connector.
Specification : Approx. 0Ω
Result: It was getting late and I have never looked at the PCM on this car, so I skipped the test for now.

Test 2:
Check for short to ground in signal harness.
Measure resistance between terminal 2 of sensor harness connector and chassis ground.
Specification : Infinite
Result: 4k Ohms

Test 3:
Check for short to power in signal harness.
Ignition "ON" & Engine "OFF".
Measure voltage between terminal 2 of the sensor harness connector and chassis ground.
Specification : approx. 0V
Result: 4.9 V

Test 4:
From Haynes manual, test resistance between connectors two and three of the CKPS.
Specification: 500-600 ohms.
Results: 6 M Ohms.

Both tests indicate that I have a problem with both the wiring the of CKPS and the CKPS component itself. I had a few questions. If the signal wire was shorted to either or power or ground, why wouldn't the voltage be positive battery voltage, or a resistance of zero, respectively. If there is a wiring issue, does anyone have reference to a video or other material on how to fix it. Thanks.

Steve

I am movingthread this into the Repair Questions section where it fits better

Hey Steve!
Sorry it's taken so long to get to you on this one. :blush:
I'm thinking that by leaving the PCM connected, you may have inadvertently thrown a wrench into the works regarding the rest of the testing.
You're going to need to disconnect the PCM and the CKP sensor to do any OHMs testing of the circuit for sure.

For anyone else, P0335 is defined as Crankshaft Position Circuit Malfunction
I would check it with everything still connected first. You really only need your meter for this right now. Of course if you have a scope, it may come in useful later on.
With the key in the on position, you should have at least 12v on one pin and ground on one of the others.
The third is the signal, the voltage on this wire will be pulled high then low as the crankshaft turns. So if you can turn the engine real slow with a ratchet clockwise (and maybe with the coil disconnected so it doesn't accidently fire up and dismember you :S ) and your meter back probed into the signal wire, you should be able to see the voltage change from 5v, to 0v and so on depending on the position of the crankshaft reluctor.

Does anyone know if the camshaft and crankshaft position sensors for a 2003 Hyundai Elantra are a pull up or pull down design. I have a P0335 Crankshaft Position Sensor Circuit Malfunction that is causing a no start condition. With the CKP sensor disconnected, I have a reading of 5V on the signal wire. However, according to the Hyundai Service Tech website, the voltage should be 0V. That indicates to me that I have a pull down design(ScannerDanner calls this a pull up design in his videos). I did the same check at the camshaft and observed the exact same thing. The book calls for 0V and I saw 5V. I checked the resistance between the signal wire and ground, and the signal wire and power wire, both were around 3.5-4 kohms. When I unplugged the engine computer, the resistance jumped to infinity, so I blamed the computer for causing the short to both power and ground. I replaced the computer with a salvage yard computer today and still I observer the same behavior. I was wondering if possibly the book is wrong and there should be 5V on the signal wire, maybe the CKP has a pull up(ScannerDanner pull down) design. I am stuck, does anyone know for sure what the design of these hall effect sensors are? Thanks.

Steve

Does anyone know if the camshaft and crankshaft position sensors for a 2003 Hyundai Elantra are a pull up or pull down design. I have a P0335 Crankshaft Position Sensor Circuit Malfunction that is causing a no start condition. With the CKP sensor disconnected, I have a reading of 5V on the signal wire. However, according to the Hyundai Service Tech website, the voltage should be 0V. That indicates to me that I have a pull down design(ScannerDanner calls this a pull up design in his videos). I did the same check at the camshaft and observed the exact same thing. The book calls for 0V and I saw 5V. I checked the resistance between the signal wire and ground, and the signal wire and power wire, both were around 3.5-4 kohms. When I unplugged the engine computer, the resistance jumped to infinity, so I blamed the computer for causing the short to both power and ground. I replaced the computer with a salvage yard computer today and still I observer the same behavior. I was wondering if possibly the book is wrong and there should be 5V on the signal wire, maybe the CKP has a pull up(ScannerDanner pull down) design. I am wondering since both the CMP and CKP circuits differ from what the book calls for that maybe the book is wrong, or perhaps there is an issue causing both to be wrong. Does anyone know for sure what the design of these hall effect sensors are? Thanks.

Steve

take a test light to battery ground and tap it repeatedly on the signal wire listen for the injectors to fire and fuel pump to run

I also wanted to note I was able to get a reading of 183 rpm from my scan tool while it was cranking. Does anyone know if that seems to slow, or does it crank that slowly while the engine is starting? Does the rpm come from the crank or cam position sensors.

Steve

Hey Cheryl, thanks for the quick response. Whenever I tap the signal wire to ground, all I hear is a relay clicking in the fuse box.

Steve

The relay clicks on and off about once a second.

I can't speak to this YMM specifically, but every other Hyundai cam/crank sensor I've seen have been pull down designs. I'm inclined to believe that the measurements you saw are correct, and that the service info is wrong.

Is it possible for you to backprobe the signal wire with the sensor plugged in, and watch the voltage on your meter during cranking? Given that it's a 0-5V square wave, it should pull the displayed voltage down to something lower. Two or three volts would be my guess. OR, you can turn the key on and manually turn the crank by hand. You should see 0-5V transitions. Either one would tell you if the crank sensor is active or not.

183 RPM sounds reasonable, depending on battery condition. Maybe a bit slow, but not slow enough to cause your no start problem.The RPM PID itself can come from the crank sensor, cam sensor, or a combination of the two. It's tough to generalize, since there's so many different variations out there. :blink:

For our info, are you missing spark, injection pulse?

Hi there Steve, just a heads up, I've merged your threads. If you can keep all your questions regarding the same problem in one thread, it will not only yield the most relevant, helpful information, but it will also help anyone researching the same problem in the future

Thanks Tyler,

There really is no way for me to back probe at the connector, it and the wires heading into are covered by some sort of sheathing. Is it okay to cut away at the sheathing?

As far as spark and fuel injector pulse I honestly haven't even looked, I just saw the P0335 DTC and assumed it had to do with the CKPS or related circuits. I'll test fuel and spark and get back to you.

Steve

If it's the style in the latest Scanner Danner Premium video, you can snap the shielding right off.

Around 11 minutes in.

Got it, thanks Noah!

Tyler, I back probed the signal wire at the connector, and to a known good ground. I turn the key on and turned the engine at the crank pully. I did indeed see the meter from around 0.027V up to 4.99V. I don't know exactly how often I should see the switching occur. I took a video of my DVOM while I was turning the crank pulley, which I uploaded to YouTube here, . In short, I would see it switch maybe five or six times over 60 degrees of engine rotation, so the CKPS seems to be working fine to me. Any ideas? I'll test spark and injector pulse tomorrow and let you know. Thanks for all the help.

Steve

I also just wanted note that my power wire heading to the sensor is 12V. Have you ever seen the power at 12V while the signal is at 5V?

I think perhaps you are confusing yourself, my rule is not to depend too much on manufacturers tests and flow charts.

Just start with the simplest possible test with everything connected and using the original PCM test back pin each sensor in turn and measure the voltage between the signal and ground. Cranking the engine the signal from both Hall Effect sensors should be a 5v square wave with probably somewhere between a 40% and 60% duty cycle so with a decent voltmeter it will fluctuate but expect the meter to read somewhere between 2 and 3 volts.
If you don't see this on the crank sensor signal I would strongly suspect the crank sensor but would double check the 5v reference supply and and ground when cranking the engine. As you don't have a scope and as you have already checked the wiring there isn't much else you can do other than swap in a new sensor.

Hi Andy, this thread should actually be merged with P0335 DTC Causing No Start, as this thread was created accidentally. As I mention in the other thread, I did back probe at the CKPS connector and turned the engine over using the crank bolt. In short, I saw it switch from 0.027V to 4.99V maybe five or six times every 60 or so of engine rotation. Is there any need to do the test with the engine cranking, or can I safely eliminate the sensor as the problem. Thanks.

Watch my Kia video I just uploaded, same design as Hyundai I believe. And yes, it is a 5v pull down design, so your computer and wiring are fine.
And that you are seeing it switch means everything is working as designed.
Next step for me would be to verify the cam signal is present, then check for a jumped timing belt next.