Can someone please enlighten me on how to use a multi meter to test sensors on my 04 f150 such as transmission sensors, rear center and sensor, front wheel wheel speed sensors, ect. If someone would like to post here or call me and give me a quick run down including what to set my multimeter at I would greatly appreciate it. I'm chasing gremlins in my truck and been researching for a week online and on YouTube but found very little on testing thesesensors. Also I would like to learn how to check continunuity in wires. I'll be more than happy to compensate you for your time . I'm darn good at repairing our trucks, but when it comes to electrical stuff I'm stumped. I would take a class on auto electronics but I don't have the time right now and want to fix things myself instead of taking it to a mechanic or the dealer. Again post here or shoot me a pm and we can talk. Might take about 10 or 15 min max. Thanks so much!!

 

I bet "Google" can help with that

 

Trust me I've googled so much I got the message you have reached the end of the internet.

 

YouTube

 

alastropine - My UEI has a continuity position. It beeps when there is continuity.
As far as resistance goes, the wheel sensors are normally just coils of wire and so should have little resistance. There should be a spec maximum resistance in the shop manual somewhere. I looked at the manual forthe 2011 and found this:

"These DTCs set in continuous memory if the ABS module detects an open, short to ground or voltage or a damaged wheel speed sensor input circuit, the appropriate DTC sets when the vehicle speed exceeds 6 km/h (4 mph). DTCs set in the ignition cycle can only be cleared by cycling the ignition off and on once the fault has been corrected. DTCs C1165 and C1175 also set on-demand."

So the computer can set a code for various faults. You can check to see if the sensor is open (infinite resistance) or shorted to ground (no resistance to ground when disconnected.

 

I'll see if I can get you some specs tomorrow. As feathermerchant stated, you'll usually use continuity to check sensors. Please be very careful using continuity with a sensor plugged in though as you are technically powering/joining a circuit. If you're not careful you can create larger issues for yourself... Typically when you test sensors you unplug them (it's pretty hard to get the probes into some of the connectors without disconnecting anyways). Some sensors also send pulses... for example, your speedometer sensor is usually a 5+-0V pulse so you need to measure frequency. Don't go crazy on checking continuity on wires though in your truck.


You definitely need to know what specifications you're looking for when testing the sensors though otherwise the numbers will be meaningless (other than a short or open circuit).


I'll see what I can pull for you in the morning

 

Basics on multi meter use is pretty straight forward. One thing is to never test continuity is an energized circuit. Meaning vehicle off and battery disconnected Switch head lights on to drain truck to voltage zero. The second thing that people screw up is when checking current often the meter has two current ranges 2 amp and 10 amp. Make sure to use the right range as using the lower 2 amp setting often results in blowing the internal fuse. I am a electronic Tech and have done this often myself. Gremlins can most often be the result of poor ground connections. Check those carefully first!!

 

Thanks guys. I'll do myself a favor a disconnect the battery and hit the headlights to drain any remaining power