2

I have a Hyundai Sonata EF (2002 - 2005) model that has problems starting.

The service manual says to ( see picture attached).

What is the proper scale on the DMM to use to measure for infinite resistance when no value is stated in the service manual.

CKP Signal Circuit Inspection

ADDITIONAL DETAIL

This question has been answered but I have asked a related question here: Hyundai Sonata EF (2002 - 2005) - P0335 CKPS Malfunction.

I'd appreciate your comments over there as well. Thanks.

Clarified type of crank sensorcrank sensor is hall effect type sensor

2

If the manual says that there should be infinite resistance, then you need to test using the highest range on you DMM. If you have a M ohm range, then use that. Do not rely on the continuity range for detecting high resistances.

I do think that a crankshaft position sensor and associated wiring could have a fault that would not be detected with the lower resistance ranges of a DMM.

Be careful not to touch the DMM probes while testing on the high resistance range, since this could give a false reading.

1

The manual states that the ground must be totally insulated from point 2. The highest range is the correct setting here to begin with. If any resistance (conductance is the better word here) is present, the highest range will give you the best chance to detect it. Additionally, if any resistance is detected at that range, turn the range down to determine the resistance more precisely.

Another useful setting on your DMM is the diode setting, usually located right after the lowest setting (usually 200), either or not incorporated in the 2k setting. I your DMM has it, it's marked with the diode symbol; an arrow with a vertical line next to it. If you use that setting, the number you get represents the resistance, as well as the voltage drop from the positive to the negative probe on your DMM.

Since your crank sensor has labels named supply, ground, and signal, i think your crank position sensor is a semiconductor based one, like many automotive sensors. This means voltage drops are inherent to it's working. Voltage drops tell you more than resistance in the semicondictor world. The highest range may not detect anything that the diode mode does detect. So use them both to get a more complete picture.

  • The crank position sensor is not always a semiconductor. It may well be a hall sensor or an optical sensor, but it could also just be an inductive coil. See en.wikipedia.org/wiki/Crankshaft_position_sensor – HandyHowie Feb 15 '18 at 10:45
  • In this case, it is a hall sensor – ElectronicsNewbie Feb 15 '18 at 11:19
  • @HandyHowie My guess was a hall sensor. The fact that the manual gives the terminals the labels supply, ground, and signal, tells me that there's some additional circuitry in the sensor, consisting of semiconductors. Then it doesn't matter here what kind of crank sensor it is. So that's why I added the diode setting part in my answer. – Bart Feb 15 '18 at 13:31
  • Sorry, I wasn't disagreeing in this case, it was just that you said - 'A crank position sensor is a semiconductor'. Someone else may read the answer with a different car in mind and that car may have an inductive sensor. – HandyHowie Feb 15 '18 at 13:39
  • @HandyHowie That's right, I realise that might not be true for others with this problem. Changed it to OP's specific case. – Bart Feb 15 '18 at 13:43
0

Here "infinite resistance" means no connection so you can start by using the 20ohm range or the 200 ohm range and moving to the higher ranges to make sure or your meter may have a "continuity range" where if there is continuity you get a buzzer sound - very handy as you don't have to look at the meter, this is useful when looking for a fault that is, perhaps, blowing fuses.

In this case if there is a connection it means you have a fault - short or faulty component that has to be corrected.

  • If you are trying to detect a very high resistance, shouldn't you be using the higher end of the DMM resistance ranges, for example k ohms or M ohms? For high resistances, I wouldn't rely on the continuity buzzer. – HandyHowie Feb 15 '18 at 8:26
  • @HandyHowie so if you really want to test what about using an insulation tester... not actually a good idea as it can damage sensitive electronics... – Solar Mike Feb 15 '18 at 8:38
  • Definitely not a good idea. :) I do think that a crankshaft position sensor and associated wiring could have a fault that would not be indicated using the 200 ohm range. – HandyHowie Feb 15 '18 at 8:47
  • I used the 200 ohm and 2k ranges to measure and it reads open or 1. – ElectronicsNewbie Feb 15 '18 at 11:21

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.