Chevy Trailblazer: Will Not Run A Drive Cycle
video description
what's the difference. The difference is of course. Sad to say, & expired inspection sticker incentive also ignored, few escape the 21. W/ only a see ya next year salutation. Sponsored by the PRNY.
Date: 2023-03-05
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Comments and reviews: 14
T. J.
You need a decade box so you don't have to futz with a pot.
Being a DIY'er from a state without inspections, I was struggling with my mom's car in NJ. Way out of inspection, and I had to replace a dead battery, which reset all the monitors. Got everything to run except evap. As near as I could tell, it wouldn't run because ambient temp never got above freezing for the required length of time even though I drove the crap out of it. Had to go back to Ohio and had an uncle come over a week later to try it again. It passed I guess because there was one day it got warm enough. If that was the reason, how do some of these monitors ever run in the winter?
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You need a decade box so you don't have to futz with a pot.
Being a DIY'er from a state without inspections, I was struggling with my mom's car in NJ. Way out of inspection, and I had to replace a dead battery, which reset all the monitors. Got everything to run except evap. As near as I could tell, it wouldn't run because ambient temp never got above freezing for the required length of time even though I drove the crap out of it. Had to go back to Ohio and had an uncle come over a week later to try it again. It passed I guess because there was one day it got warm enough. If that was the reason, how do some of these monitors ever run in the winter?
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Richard
The Voltmeter has 10, 000, 000 Ohms of input impedance (Resistance) therefore will read 5 Volts no mater what resistance is in the circuit. If looking for accuracy, open circuit voltages are not the way to go. Open circuit current is. 5 micro amps. Do the Ohms Law math and note 5 Volts appears at the meter even if there is 100 ohms in the coolant temperature wiring. Generally speaking, voltages are measured under load (voltmeter in parallel with the load. Open circuit always puts the Voltmeter in series and therefore will always read source voltage.
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The Voltmeter has 10, 000, 000 Ohms of input impedance (Resistance) therefore will read 5 Volts no mater what resistance is in the circuit. If looking for accuracy, open circuit voltages are not the way to go. Open circuit current is. 5 micro amps. Do the Ohms Law math and note 5 Volts appears at the meter even if there is 100 ohms in the coolant temperature wiring. Generally speaking, voltages are measured under load (voltmeter in parallel with the load. Open circuit always puts the Voltmeter in series and therefore will always read source voltage.
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rik999
The change in resistance vs temperature is logarithmic for those thermistors. That chart you showed has enough data points to plot a log curve so you pick off interpolated values of resistance for any temperature. Also you could make a more versatile dummy thermistor test tool by putting a 100 ohm 10 turn pot in series with the one you already use. Might be useful for those picky GM drive cycles. By the way, the multi-turn pot I saw you using should be accurate enough so you don't have to confirm all the time with an ohmmeter (saves time.
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The change in resistance vs temperature is logarithmic for those thermistors. That chart you showed has enough data points to plot a log curve so you pick off interpolated values of resistance for any temperature. Also you could make a more versatile dummy thermistor test tool by putting a 100 ohm 10 turn pot in series with the one you already use. Might be useful for those picky GM drive cycles. By the way, the multi-turn pot I saw you using should be accurate enough so you don't have to confirm all the time with an ohmmeter (saves time.
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Aryon
Hi. It doesn't surprise me that the new sensor you bought, doesn't work. From the perspective of a former QA Inspector, I can tell you that the current testing process is flawed. When factories manufacture large batches of engine parts, only a sample of the whole batch is tested. For example, from a batch of 500 O2 sensors manufactured, only 100 are tested. As a result, the rest are either faulty, or don't work at ball. The whole batch needs to be tested, regardless of its size, to guarantee all parts work.
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Hi. It doesn't surprise me that the new sensor you bought, doesn't work. From the perspective of a former QA Inspector, I can tell you that the current testing process is flawed. When factories manufacture large batches of engine parts, only a sample of the whole batch is tested. For example, from a batch of 500 O2 sensors manufactured, only 100 are tested. As a result, the rest are either faulty, or don't work at ball. The whole batch needs to be tested, regardless of its size, to guarantee all parts work.
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Paddle
I got an 05 Trailblazer. I have a weird stall issue where it will randomly stall, start right up no problem, run fine for days if not weeks, then will stall again. When it does happen it generally is in hot outside temps with the air on, but it will happen in cold, no ac conditions as well, though much rarer. Never throws a code, throttle body clean as a whistle. The only other sympton is that it gets horrible gas mileage 11-12mpg regardless of i drive highway or around town.
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I got an 05 Trailblazer. I have a weird stall issue where it will randomly stall, start right up no problem, run fine for days if not weeks, then will stall again. When it does happen it generally is in hot outside temps with the air on, but it will happen in cold, no ac conditions as well, though much rarer. Never throws a code, throttle body clean as a whistle. The only other sympton is that it gets horrible gas mileage 11-12mpg regardless of i drive highway or around town.
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Allister
Great video Eric, Getting to know the drive cycle monitors takes some time. There is a lot to it. Good electronics diagnosis but checking the sensor characteristic. Hard to believe they actually make them wrong. I have actually designed temperature sensor gauges and had to characterize a thermistor. When at Cosworth they actually built the look up table with the actual sensor they were going to use thereby eliminating possible manufacturing errors.
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Great video Eric, Getting to know the drive cycle monitors takes some time. There is a lot to it. Good electronics diagnosis but checking the sensor characteristic. Hard to believe they actually make them wrong. I have actually designed temperature sensor gauges and had to characterize a thermistor. When at Cosworth they actually built the look up table with the actual sensor they were going to use thereby eliminating possible manufacturing errors.
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buffy
When I m bored and want entertainment I watch other mechanics you tube videos, when I want education, I watch you videos. Not knocking other mechanics content but being a mechanic over 45 years but now retired I find I ve been there done that. Some of the tougher jobs I catch myself saying stuff like, wish I had that tool or that looks easier from when I did that. Your videos seem to be the jobs no one wants or gets in their shops.
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When I m bored and want entertainment I watch other mechanics you tube videos, when I want education, I watch you videos. Not knocking other mechanics content but being a mechanic over 45 years but now retired I find I ve been there done that. Some of the tougher jobs I catch myself saying stuff like, wish I had that tool or that looks easier from when I did that. Your videos seem to be the jobs no one wants or gets in their shops.
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Gunga
Eric, the temperature probe you are using isn't a contact probe, but a submersion probe. There should be a line on the side of the probe, which determines whether it's a partial (typically an inch of two) or full submersion probe (requires 6-8 submerged depth.
Fluke makes a surface probe (Fluke 80PK-3A Surface Probe) which has a ceramic tip with the thermistor wires/ribbon in the tip.
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Eric, the temperature probe you are using isn't a contact probe, but a submersion probe. There should be a line on the side of the probe, which determines whether it's a partial (typically an inch of two) or full submersion probe (requires 6-8 submerged depth.
Fluke makes a surface probe (Fluke 80PK-3A Surface Probe) which has a ceramic tip with the thermistor wires/ribbon in the tip.
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Chris
Looking into upgrading to a better scan tool and watching you use that one Autel scanner and seeing everything you have been able to do with it has now led me into wanting to ask you the question of what model Autel you are using. Thanks for the great video(s. You, sir, are a very thorough technician. Let Ms. O know it's about time for her to make you some more muffins, lol
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Looking into upgrading to a better scan tool and watching you use that one Autel scanner and seeing everything you have been able to do with it has now led me into wanting to ask you the question of what model Autel you are using. Thanks for the great video(s. You, sir, are a very thorough technician. Let Ms. O know it's about time for her to make you some more muffins, lol
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ToughAncientSpark
When troubleshooting customers RV appliances, the first question I would ask is What is it doing or not doing? .
Always got a thoughtful concise and informative answer from the customer.
They are your best source of info and always know simple facts like When I turn on the thermostat, nothing happens, even though they don't know the technology behind it.
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When troubleshooting customers RV appliances, the first question I would ask is What is it doing or not doing? .
Always got a thoughtful concise and informative answer from the customer.
They are your best source of info and always know simple facts like When I turn on the thermostat, nothing happens, even though they don't know the technology behind it.
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KC
I ran into a similar issue with my Holly sniper.
The temperature reading was off with the sensor that came with the unit.
I ended up purchasing a Delphi temperature sensor and that cured my problems.
Just to let you know, there are calculators on the web that will give you the exact ohms reading to temperature.
Great job and always great videos!
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I ran into a similar issue with my Holly sniper.
The temperature reading was off with the sensor that came with the unit.
I ended up purchasing a Delphi temperature sensor and that cured my problems.
Just to let you know, there are calculators on the web that will give you the exact ohms reading to temperature.
Great job and always great videos!
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Chris
It's almost funny how many months I go with an expired NYS inspection. My theory is most agencies don't even have inspection data available in their computer/db. I have been pulled over with an expired inspection multiple times and they say nothing. Maybe NYSP are starting to enforce it more lately. Never been pulled over by them with an expired inspection.
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It's almost funny how many months I go with an expired NYS inspection. My theory is most agencies don't even have inspection data available in their computer/db. I have been pulled over with an expired inspection multiple times and they say nothing. Maybe NYSP are starting to enforce it more lately. Never been pulled over by them with an expired inspection.
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kain0m
17: 00 About how the PCM measures the Temperature: the Sensor line is connected internally to +5V through a Pull-Up resistor (typically something like 2kOhm. The sensor completes the circuit to ground, forming a potential divider. The PCM then senses the voltage at this connection, which is then translated to a temperature via a lookup table.
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17: 00 About how the PCM measures the Temperature: the Sensor line is connected internally to +5V through a Pull-Up resistor (typically something like 2kOhm. The sensor completes the circuit to ground, forming a potential divider. The PCM then senses the voltage at this connection, which is then translated to a temperature via a lookup table.
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The
My 2001 Dodge Dakota will NOT do a drive cycle if the fuel is above about 1/3 tank. I am one of those people who always tries to keep my tank at least
1/2 full. Learned the hard way to let to run down if I want it to run the purge cycle. let it run down to about 1/4 tank and magic happens. Drive cycle complete.
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My 2001 Dodge Dakota will NOT do a drive cycle if the fuel is above about 1/3 tank. I am one of those people who always tries to keep my tank at least
1/2 full. Learned the hard way to let to run down if I want it to run the purge cycle. let it run down to about 1/4 tank and magic happens. Drive cycle complete.
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