This is how I test these Chevy Vortec V8 engine knock sensors! Multimeter: amzn.to/3UvL8KY Knock Sensors: amzn.to/3JjToZu Intake Gaskets: amzn.to/2XLjTz6 Wiring Harness: amzn.to/3oMVzJ2 As an Amazon Associate I earn from qualifying purchases.
If the knock sensor isn't putting out a normal engine noise waveform as the engine is running the PCM sets those codes on that model. Knock sensors generate AC voltage depending on how much noise they pick up. Testing a knock sensor output with an ohm meter is inconclusive at times. You really should use a lab scope to not only see if it generates a signal, but also if the signal's amplitude is high enough. I've run into new OEM and aftermarket sensors that are defects that don't put out enough amplitude. If you're a DIY it probably doesn't matter much, but as a tech you want to fix it right the first time.
Knock sensors contain a pure quartz crystal that produces a voltage. Clean, use dielectric grease and seal the harness plug with high temp red RTV. Any expansion or contraction of the small void will pass thru the cover at the wire. (Best read on A/C scale) but this is the same as submarine sonar. The crystal shape is different, but put an electric signal to the quartz and it vibrates) ASE Master Tech - 78 Retired.
I'm impressed you know your stuff! Yea, it's just got a little Quartz crystal in there that vibrates when it knocks. That's what I've been told before, which makes sense.
@@MattsShop OBD-2 made engines tighter and sensors better. There is between 9-12mb of code stored for logic, testing and key cycle counts, warmup cycles counts, 60 mph counters for PO894 internal slip on auto trans (input to output shaft) allowance! I was shocked how many tech still didn’t understand OBD-2 after 20 years of use. Start the engine and for 2-5 minutes the PCM runs test from resistance, voltage drops, switches, relays, O2’s, crank, cam, VSS, cam phase solenoids while EVAP and others are on a clock. I was joking since 2004, that we drive computers on four wheels with room for a few friends and some of their crap! I also put photos on screen of Palm Springs gas station with $4.89 per gallon gas. After 243 days per year in a hotel, I was getting burn out with 4 major jobs. Tore a rotator cuff, had surgery 2 weeks later, then got a call. No more job, sent equipment back. One handed. Once Dr approved any activity, then they could come a get it. 6 months laters, I shipped the tools in two large crates. OBD-2 tracks misfire and isolates the cylinder. Chrysler even shut it off by killing the injector. Fun trick to play on tech who left for the bathroom, come back and had constant misfire. EEPROM, enhanced N-Channel Metal Oxide Field Effect Transistor changed a lot. Shunted Hall-Effect are great, no more quad-drivers, edge board connectors, etc. low emissions, ultra low emissions, zero emissions classes. EV1 is now 36 years old. I drove a hydrogen fuel cell van after spending the entire day at 1 of 4 GM Labs. They had Hughes Aircraft Engineers with a few NASA engineers blending 180Vdc into 3-ph A/C using photo receptors and high voltage electronic transistors with magnets to help control low speed arching. Cool stuff. ES-10 blew me away. They had a video racing a fast-back Mustang and the pickup beat it at 9.04 seconds. They leased 1,500 electric S10 trucks to Con-Ed to read meters on East coast.
A lot of people keep having this problem. I haven't had it happen, but you gotta use Delphi sensors. Some people complain of counterfeit sensors. Maybe broken wires behind the sensor harness.
Further to that, do you usually disconnect the battery when doing this job? I was curious is having the PCM reset itself would cause it to relearn all the values of all the sensors, and that's why you've never had any knock sensor codes come up on the allegedly not genuine ACDelco sensors.
I commented your other video about my CEL goes on and off with knock sensor codes.. I did the multimeter test to wire harness and both sensors read great. So you’re saying they can still read good but actually be bad? Installed them Oct. 2023
I'm having the same exact problem with my 04 6.0. I just bought the relocation brackets and the valley pan cover. I don't know what else to do other than that. My 01 5.3 I changed them in 2020 and everything has been fine since. 🤔
i just got the check engine light on today with code p0332 got the same code back in june i just clear the code to turn off check engine light seems to run fine when the engine light comes on u think i should get them changed 2003 5.3 vortec 1500 152000 miles
Hello all. I have some questions. I have a 2004 avalanche 1500 4wd. Recently I start driving and after 5 minutes the security light turns on. Voltage drops completely and ac stops blowing cold. Also my key fob stops working. Then after awhile all the gauges drop to zero then some work and voltage goes up then down. This happens sometimes sometimes while just turning it on. And for the life of me I cannot find that little ground wire behind motor. Can you help please a s
![ประสบการณ์ จ้าง Developer ที่ผมจะไม่มีวันลืม [ภาค2]](http://i.ytimg.com/vi/pZbsSDRrmXA/mqdefault.jpg)
This is how I test these Chevy Vortec V8 engine knock sensors!
Multimeter: amzn.to/3UvL8KY
Knock Sensors: amzn.to/3JjToZu
Intake Gaskets: amzn.to/2XLjTz6
Wiring Harness: amzn.to/3oMVzJ2
As an Amazon Associate I earn from qualifying purchases.
If the knock sensor isn't putting out a normal engine noise waveform as the engine is running the PCM sets those codes on that model. Knock sensors generate AC voltage depending on how much noise they pick up. Testing a knock sensor output with an ohm meter is inconclusive at times. You really should use a lab scope to not only see if it generates a signal, but also if the signal's amplitude is high enough. I've run into new OEM and aftermarket sensors that are defects that don't put out enough amplitude. If you're a DIY it probably doesn't matter much, but as a tech you want to fix it right the first time.
You are right. Most people don't have an oscilloscpe to check the waveform. If they are reading really low or high ohms generally there is a problem.
Great video. How can I test the wire that runs to the pcm I have a hunch it’s the pcm or wire I already changed twice thank you
Greatest youtube mechanic, deserves 1000 wives
Thank you!!
Knock sensors contain a pure quartz crystal that produces a voltage. Clean, use dielectric grease and seal the harness plug with high temp red RTV. Any expansion or contraction of the small void will pass thru the cover at the wire.
(Best read on A/C scale) but this is the same as submarine sonar. The crystal shape is different, but put an electric signal to the quartz and it vibrates)
ASE Master Tech - 78
Retired.
I'm impressed you know your stuff! Yea, it's just got a little Quartz crystal in there that vibrates when it knocks. That's what I've been told before, which makes sense.
@@MattsShop OBD-2 made engines tighter and sensors better. There is between 9-12mb of code stored for logic, testing and key cycle counts, warmup cycles counts, 60 mph counters for PO894 internal slip on auto trans (input to output shaft) allowance! I was shocked how many tech still didn’t understand OBD-2 after 20 years of use. Start the engine and for 2-5 minutes the PCM runs test from resistance, voltage drops, switches, relays, O2’s, crank, cam, VSS, cam phase solenoids while EVAP and others are on a clock. I was joking since 2004, that we drive computers on four wheels with room for a few friends and some of their crap! I also put photos on screen of Palm Springs gas station with $4.89 per gallon gas. After 243 days per year in a hotel, I was getting burn out with 4 major jobs. Tore a rotator cuff, had surgery 2 weeks later, then got a call. No more job, sent equipment back. One handed. Once Dr approved any activity, then they could come a get it. 6 months laters, I shipped the tools in two large crates. OBD-2 tracks misfire and isolates the cylinder. Chrysler even shut it off by killing the injector. Fun trick to play on tech who left for the bathroom, come back and had constant misfire. EEPROM, enhanced N-Channel Metal Oxide Field Effect Transistor changed a lot. Shunted Hall-Effect are great, no more quad-drivers, edge board connectors, etc. low emissions, ultra low emissions, zero emissions classes. EV1 is now 36 years old. I drove a hydrogen fuel cell van after spending the entire day at 1 of 4 GM Labs. They had Hughes Aircraft Engineers with a few NASA engineers blending 180Vdc into 3-ph A/C using photo receptors and high voltage electronic transistors with magnets to help control low speed arching. Cool stuff. ES-10 blew me away. They had a video racing a fast-back Mustang and the pickup beat it at 9.04 seconds. They leased 1,500 electric S10 trucks to Con-Ed to read meters on East coast.
What if the sensor and the harness are new but you still have the code, how do you test the harness going to the computer?
Yes, and did you use the DELPHI sensors?
Ditto
Just did this test on my 01 sierra 4.8 that had a p0332 code.
Both knock sensors measured 101k ohms but barely any ac volts.
Where do i go from here?
Have you ever had any issues with the codes coming back even though the knock sensors are new OEM and the harness was replaced along with them?
A lot of people keep having this problem. I haven't had it happen, but you gotta use Delphi sensors. Some people complain of counterfeit sensors. Maybe broken wires behind the sensor harness.
Further to that, do you usually disconnect the battery when doing this job? I was curious is having the PCM reset itself would cause it to relearn all the values of all the sensors, and that's why you've never had any knock sensor codes come up on the allegedly not genuine ACDelco sensors.
At 1:47 when you are testing the new knock sensor out of the truck, what do you have the other (positive lead) connected to? Thanks!
Positive goes in the center of the knock sensor. Negative goes to the body of the knock sensor or a ground.
@@MattsShop thanks for the quick Reply!
I commented your other video about my CEL goes on and off with knock sensor codes.. I did the multimeter test to wire harness and both sensors read great. So you’re saying they can still read good but actually be bad? Installed them Oct. 2023
The only true way to see if they are bad or not is to replace them and test them, but they can read good and still be intermittent.
cmon matt i need them avalanche videos i truly find the useful to fix up my own z71 05 avalanche
P0327 keeps coming back. Everything checks out. Delphi sensors, new harness, clean connection to ecm and ecm connection as well. Help?
I'm having the same exact problem with my 04 6.0. I just bought the relocation brackets and the valley pan cover. I don't know what else to do other than that. My 01 5.3 I changed them in 2020 and everything has been fine since. 🤔
i just got the check engine light on today with code p0332 got the same code back in june i just clear the code to turn off check engine light seems to run fine when the engine light comes on u think i should get them changed 2003 5.3 vortec 1500 152000 miles
Hello all. I have some questions. I have a 2004 avalanche 1500 4wd. Recently I start driving and after 5 minutes the security light turns on. Voltage drops completely and ac stops blowing cold. Also my key fob stops working. Then after awhile all the gauges drop to zero then some work and voltage goes up then down. This happens sometimes sometimes while just turning it on. And for the life of me I cannot find that little ground wire behind motor. Can you help please a s
Bro I got this code P0332 from a lifter tick. I fixed the lifter tick but the code is still there. What you think! P0332 only. Not P0327.
See ya on the next one man I m follow ING man
Laterrrrrr!
@@MattsShopwhat about the voltage the ecm puts out how do I test that?
Checking it out man
It seems the question is avoided how to test the power from pigtail to the pcm low input voltage nobody answers that question
Mannn
Learn how to speak English.