In this video, we're going to be going over
the top five problems on the second-generation GMC Yukon. Now, these problems are going to be the same
as on a Chevy Tahoe, Chevy Suburban, even a first-generation Cadillac Escalade. It's also going to be on the pickup trucks,
the Chevy Silverado, GMC Sierra, and even the Avalanche. Why these vehicles are all the same, they're
all based on the same platform. They all have the same drivetrain, so the
problems are going to be the same. Now, there's nothing wrong with these vehicles,
all vehicles have problems, these are just the top five that we have found with this
platform. Number one, O2 sensors. Underneath here on the driver's side, the
O2 sensor located right here, this O2 sensor is Bank 1 Sensor 1. So that's the driver's side. That's one, three, five, seven as far as the
cylinders go.
This is the one that's going to change the
air-fuel ratio on the driver's side. Now, if we move over to the passenger side,
this is Bank 2 Sensor 1. Now, this is going to change the air-fuel
ratio on the passenger side, two, four, six, eight, those cylinders. This O2 sensor right here, this is going to
monitor the cat converter. This is the Bank 1 Sensor 2, and then over
here is the Bank 2 Sensor 2. That's going to do the same. It's going to monitor the cat converter on
this side. These O2 sensors in the back are going to
be the downstream O2 sensors, and the ones in the front are going to be the upstream
O2 sensors. The O2 sensors in the back should never give
you a drivability issue. It shouldn't change the air-fuel ratio or
anything. Those are just monitoring the cat converters. So, you may get a code for those O2 sensors
or a cat code, and it's going to be caused by those. But they shouldn't change the way the engine
runs.
If the front O2 sensors are bad, you may end
up with a drivability condition. The engine may run really rough. One side of the cylinders may all be misfiring
and you get a check engine light. You may even get a flashing check engine light
with a code P300, P0300, which is a misfire code. Now, they may not send in O2 sensor code,
but if it's all one side, it's probably the O2 sensor. So if the engine's running rough and you can
determine which side the misfires are coming from, if it's Bank 2, you can come over here,
disconnect the O2 sensor right here with the engine off, and restart the vehicle, see if
your drivability went away.
The computer should compensate with that disconnected
and put it in a baseline. And if it runs good, it's probably the O2
sensor. Now, these O2 sensors in the front are the
same. So, what you could also do is disconnect the
O2 sensors, they're really not that hard, and swap the two front ones. If your code switches or if the engine runs
different on the other side, it's probably the O2 sensor as well. You always want to check the wires on the
O2 sensor. This one has actually rubbed on the frame
and caused a hole. If you look at the actual wires, it doesn't
look like it's gotten through any of the insulation on the wires. That's just the outer protector, which is
fine. But a lot of times if you see any copper in
there, then the O2 sensor is going to have to be replaced. You can't repair these wires. Also, the connector, disconnect the connector
and just look at the connector. Make sure there's no green or corrosion in
there. Number two, ABS activation at slow speeds. So when you're driving the vehicle and you
come to a stop in around three or four miles per hour, you may see that your brake pedal
may be pulsating.
It may even be hard to stop. You might not get ABS light on at all. What happens is the ABS module is going to
monitor the two front wheel speeds. And if it sees a difference in the wheel speeds,
it's going to think one of the wheels is slipping. So what happens is the sensor itself actually
gets pulled away from the hub and the tone ring or the reluctor wheel, and that's caused
by a little bit of rust buildup underneath.
So what you need to do is take the breaks
off and get to the sensor itself. You can pull the sensor out and clean off
that rust debris, coat it with a little bit of Primer or some type of paint, put the sensor
back in, and you should be good to go. Number three, knock sensors. Now, the knock sensors on this vehicle are
located underneath the intake. You're going to have to disable the fuel system,
disconnect the fuel line, pull the intake up, pull all this snorkel off, and get that
out of the way.
And then there's two knock sensors, one in
the front and one in the back, and there's a wiring harness there as well. Whenever you're replacing the knock sensors,
it's a good idea to replace that harness as well because a lot of times you could have
a connector issue and you can't see it. So, it's fairly inexpensive, just replace
the knock sensors and the harness together. Now, when you have a knock sensor problem,
most likely you're just going to get a check engine light and a code for the knock sensor.
You're probably not going to get a drivability
issue, it's rare that you do. But most likely, it's just the check engine
light. Knock sensors are actually extremely sensitive. You don't want to drop the new sensor or it's
going to be junk. And when you put them in, you want to make
sure you torque them to the proper spec. Number four, oil pressure. A lot of times you'll be driving, and you'll
notice on your oil pressure gauge that the oil pressure is zero.
What there is is an oil pressure sensor on
the back of the engine, back here behind the intake. It is possible to get to it without taking
the intake off, although it makes it a lot easier to just pull the intake off. If you find the oil pressure is pegged at
like 80 Psi or kPa, then you disconnect the connector while the engine's not running. And if it drops to zero, then the connector
is shorted, the actual oil pressure sensor is shorted, and that's got to be replaced. You can always hook up an oil pressure gauge
to the oil pressure where the sender is and check the oil pressure there. They also make an adapter you can put where
the oil filter is. You're going to have to take the oil filter
down, put the adapter there, and then put your oil pressure sensor or gauge on that
and then try it. Make sure they match. If they don't match, then obviously there's
something electrical going on.
You could always have a PCM problem or a wiring
problem, or you could always have a cluster problem if this gauge, sometimes they stick. As you can see, the battery gauge on this,
that is not correct. That's not the right reading. So, that's pretty common as well. Number five, steering intermediate shaft. You may be driving along, and when you have
the steering wheel a quarter turn and you go over some bumps, it may sound like the
whole front of the vehicle is falling apart. Well, it's probably not. It's probably just this steering intermediate
shaft. The steering intermediate shaft is located
right here. What it's going to do is it's going to connect
the steering box to another shaft, and then it goes to the intermediate shaft, which is
going to connect to the base of the steering column.
Now, the intermediate shaft telescopes in
and out. And with the column attached to the body and
the steering box connected to the frame, there's going to be a little flex. And what you're hearing is that flex. One way to fix that is to take the intermediate
shaft out, grease it, and put it back in. But it's probably only going to last you 5,000
miles, best thing to do is just replace it.
We have a bonus one for you. If you have a weird electrical problem and
you can't figure it out, just nothing's adding up, here's a couple tips. Always check this ground strap, see how green
it is? This actually needs to be replaced. A lot of times you can grab these ground straps
and just rip them and they're just not good. And that's going to cause you a lot of weird
electrical issues, so make sure you fix that. This one goes to the hood. It's not quite as important. It would be a good idea to fix this, but that
shouldn't give you too many electrical issues. So make sure you check all your grounds, but
especially this one that can cause some problems. If you pull the fuse box cover off under the
hood and you see any evidence like this, you know you have a rodent problem. Something has definitely gotten in there,
and we're going to go one step further and check it out. All right this whole piece slides up.
It's a good idea to disconnect the battery
before you go any further. And then there's a latch right here, just
slide that out. And then you can tip this up and just look
underneath here. And you can see there's acorns and other evidence. Look, a mouse chewed that right there, so
that's going to need to be repaired. So you may want to check all these wires and
see what you find. A lot of times you could have an O2 sensor
problem or a four-wheel-drive issue, and you just can't figure out what's going on. Definitely check under here, and make sure
there's no damage. So like I said earlier, there's nothing wrong
with these vehicles. These are just the top five problems that
we have found.
If you've had similar problems, leave us a
comment below or if you have any questions. If you enjoyed this video, make sure you subscribe
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