Ohms reading When checking for resistance at sensor fryer probes, at 350* if the readings on the meter rise forever, is that infinite resistance?

I quote some details from BMW's owners...
Symptoms: Dreaded yellow triangle, ABS light, and CEL on. All other functions (speedo, tach, cruise control, trip computer, etc) working.

Procedure: Pull the ABS controller out and disconnect it from the wiring harness. Mine is under a panel to the left of the glove compartment. Remove the wiring backshell so you can get at the wiring connections on the back side of the connecting plug (you need to be able to see the colors of the wires and get a Ohm meter probe on them).

Using a Bentleys Electrical Manual find the connection diagram for the wheel sensors to the ABS Controller. The pin designators will most likely be wrong (they were for mine) BUT the color designators for each of the wires is correct.

Example: Right Rear sensor is connected by two wires, one blue and one blue green.

Connect Ohm meter across these two pins. NOTE: I wound paper clips around the probes to make a very small probe tip which helps. Write down the resistance reading. Mine was 3.08k ohms.

Work through the other 3 wheels and write down the resistance readings. If any of the pairs is open (i.e. infinite resistance) you have a bad connection between the ABS Controller and the wheel sensor. You can then remove the affected wheel, unplug the sensor, short out the pins on the plug (not the wheel sensor part but the chassis wiring part) and if the ohm meter is still reading open you have a broken cable between the wheel sensor and the ABS controller. If the cable is good connect the ohm meter across the wheel sensor itself and if the cable still reads open you have a bad wheel sensor, replace and retest.

Here is what I found. All wheels read 3.08k ohms except the right rear which read 4.4M ohms. This sensor was replaced during my rebuild exercise and it looks like they provided the wrong part. I replaced the part with a dealer item and retested. 3.08k ohms was read with the new part. Reconnected everything and the ABS light went out, the yellow triangle light went out. I used my OBDII computer interface to clear the CEL light and all is well again.

Total testing/repair time: 2hrs and 35 minutes!

Here is my theory. The "older" ABS Controllers (like mine) use sensors with the lower reisitance (3.08k ohm) while the newer Controllers use the higher resistance sensors (4.4M ohm). The part I bought was from a 02 E39! I can return it but I think I will use it to test my 00 528 problems first.

Additionally, I suggest check charging system (alternator/power module/battery) has a defect that a professional BMW technician should look at, Most probably the alternator is toast.

Hope this helps; also keep in mind that your feedback is important and I'll appreciate your time and consideration if you leave some testimonial comment about this answer.

Thank you for using Fixya, and have a nice day.

Hi there.
You can check the heater using an ohm meter. Connect the test leads across the heater terminal, you should get a reading if the heater is good, if it is bad, zero (0) or infinite reading will appear on you tester.
For a switch, put one test lead on one terminal and the other test lead on opposite terminal. When switch is "OFF" you should read zero (0) resistance, when the switch is "ON", you should read infinite resistance.
There may be a shorted wiring that tripped your fuse box.
For wiring diagram and other troubleshooting reference, you can download Owner's Manual at http://www.grindmaster.com
Regards.

Computerboard will display "PROB" error when it could not sense resistance reading from the temperature probe sensor (temperature probe sensor is either open circuit or short circuited). Check first the temperature probe connectors, tighten loosely fitted connectors on wiring harness and computer board, then check if the wires are not damaged. Disconnect the temperature probe and check the resistance using an ohm meter. If the reading is either zero or infinite, you have to replace the temp probe.

P3 refers to one of the dishwasher's three temperature sensors: sump temperature, booster heater temperature, or rinse water temperature. The dishwashers control circuitry has determined one of them is open or shorted, or at least out of range.

Judging from the symptom you mentioned, that you see rapid temperature reading changes before it finishes filling, I'd say it's probably the sump probe (because that's the temperature displayed during the fill cycle), located under the large removeable screen inside the dishwasher.

To test or replace, remove the small access panel at the lower front of the dishwasher (2 screws).
After the dishwasher has reached a good normal operating temperature, unplug the sump probe connector (white plastic connector with two small black wires going to it and coming from the area mentioned above where the temp. probe is. Using a multimeter, test the resistance of the probe. If the water in the dishwasher is hot (150 deg. F or more), you should read somewhere in the area of 5,000 to 10,000 ohms. If your measurement varies significantly from this range, replace the probe- most likely you'll see a reading near zero ohms or a very high reading, possibly an open-circuit probe (infinite resistance i.e. "OL" indicated on most multimeters).

It's possible I'm wrong about which temp. probe P3 refers to. There is also a temp. probe on the booster heater and one on the rinse piping on the rear of the dishwasher. Test procedure is the same for all of them, although the probe on the rinse piping is not constantly subjected to hot water so testing at room temperature would result in higher resistance value (lower temperature means higher resistance for these temperature probes).

Try reading the resistance on the coil itself. If your coil is damaged and has a high resistance the voltage will still read 120 volts, becuase there is no current. The voltage drop across the coil is equal to the resistance of the coil times the current. V = I * R. "I" being current. If the resistance of the coil is high because it is broken then the voltage will still read 120V. Another way is to read the current through the coil.

If it is a 1500W fryer then the current through the coil is about 12 amps. 1500/120= 12.5. To calculate the resistance of the coil you would you take the voltage divided by the current. 120/12.5 = 9.6 ohms.

Therefore the resistance of the coil should be very low. It will actually be lower when it is not hot. So your ohmeter should read somewhere between 5 and 15 ohms.

Bob Janelli

I’m happy to help further over the phone at https://www.6ya.com/expert/bob_62dfa2f81bb55288

Hello. Usually the problem lies in the wiring to/from the probe, the connection points, or the interface board, and I have even seen the harness between the computer and interface board have a problem. The probe has a specific resistance at a specific temperature, so cause resistance anywhere in the circuit, and you now have a different reading on the computer, or so it thinks. I hope you used a pin pusher, and didn't cut/wire nut the probe wires, because you just added a lot of resistance to the circuit. The probe should read 1654 ohms at 350 deg., but your only getting 280 deg. so, the probe would be 1514 ohms.
I have no way of knowing at this point if you have the old interface board, or the new, so I will give you the pin test points for the new one, disconnect your computer, and on the relay board, there will be 12 points with a label for J2, pins 11 & 12 should be for the probe, from the back to there. If the readings are not correct to that point, then you have wiring, or problem with the interface board, if they are, then the interface cable to computer, or the computer.
You can go to www.frymaster.com, download a service manual, and do some snooping, but they don't tell you everything, like those resistances.

Hope that helped, and thank you.
If you need further help, "ask me"

I believe at 350 the probe should read 942 ohms with a variation of 2%. Hope this helps.

The element will show infinite resistence if defective. Overload switch.....Do you mean High Limit T/Stat? Use your ohm meter across terminals- should read closed circuit...0 ohms. If not, push red reset button...if clicks once, is now reset and contactors will close and unit will heat. If always clicks, replace limit t/stat Like wise, check themostat--should click once for heat demand and check cicuit same as limit t/stat. May have wire burned off terminal connector at element.

When high is displayed it means that the probe and controller is reading that your oil temp is 30 degrees over your set temp. Use an external probe, locate it about one inch above your probe in the tank check actual temp and compare to your set temp. If you find that it is not 30 degrees over than there may be a problem with your probe, wiring or the digital controller. With a multi meter you can check your probe resitance it should be at 942 ohms at 350 degrees.