GF has a 2003 Trailblazer. Her CEL came on this morning. Is this generation able to be interrogated by a key turn sequence or short of terminals at the ALDL?
Second question-I’ve noted that at moderate speeds (~ or below 40 MPH) there is a light cyclic feedback (one cycle/second) through the steering column. I’m thinking something in the front transfer case.
Known problems? Field bulletins?
Thanks
Take it to your local Autozone and they’ll be able to pull the codes for you. From there, they may or may not be able to tell you the problem. The OBD-II codes IME (as a non-mechanic) seem to be rather vague. I think their more designed to point you in the right direction or alert you of a problem you may not even realize exists rather then to diagnose anything for you.
Anyways, I would start at Autozone, let them pull the code, tell them about the steering problem, they tend to know what they’re talking about.
Bump. Night activity kicked it off the front page.
Since the pros haven’t shown up yet, I’ll take a WAG.
I’m inclined not to think it’s the transfer. Whenever I’ve had transfer problems (which admittedly hasn’t been very often) they’ve never resulted in a slow oscillation like that. I’m thinking more along the lines of a power steering problem, possibly as simple as low fluid or maybe a weak pump.
No idea on how to get the code.
To the best of my knowledge (Gary T knows a bunch more about GM than I do) A 2003 is OBDII and cannot be read without a scanner.
As has been mentioned, many auto parts stores will scan your car for free. You will get a generic code like p0102. This page looks like a pretty good secret decoder ring to decode whatever code you come up with.
About your click. Is it road speed dependent, or engine speed dependent? Does it make any difference if the car is in gear or out of gear? Two wheel drive or four? Foot on the gas, or off?
I know that there are some GM FWD transmission that can get a bearing failure and that results in a rhythmic clicking, but I have never heard it described as 1/ second.
Nope. Need a scan tool.
This isn’t clear to me. Does “cyclic” refer to the frequency, once per second? Or to an impression that there’s a rotational component to it? And what exactly does “feedback” mean here? Are you feeling something? Hearing something? Can you describe it more precisely?
It’s not a click. Imagine a man voicing the thought “hmm”. It is road speed dependent, as it exhibits < 40 MPH. I haven’t done anything such as kicking the vehicle out of gear, but should have checked pedal in/out. :smack: My bad. Vehicle has various driving modes, but I’ve only operated it in 2WD.
Sorry for not making it more clear. Cyclic=evenly repetitive, be that 1/sec, 2/sec, etc. I’m feeling and hearing hmm hmm hmm, more pronounced when steering wheel has a slight left turn input.
That suggests a wheel bearing or tire noise. Usually you can hear it come and go if you veer slightly back and forth between left and right.
The CEL and the noise may not even be related. Probably aren’t. If you have a serious wheel bearing issue I think the ABS light would come on, no?(GaryT, Rick?)
Plus you’ll end up with more noise pretty quick.
It may just be that you haven’t rotated the tires or that one or both of the front ones are wearing unevenly. You can tell if the tires are getting choppy (what happens when they aren’t rotated) by running your hand along the tire tread and feeling for unusual high/low spots on the tire.
I’m betting you’ve got a couple of issues here, like bad tires and an O2 sensor acting up.
Could even be a warped brake rotor.
I’m sure that they are not related. If the bearing is bad enough to create a problem in the ABS, it will probably fall off the truck in another 10 feet or so. Bearing can make lots of noise before failure.
That you would feel in the brake pedal.
Dances One trick I have found that works great for isolating this type of noise is find a quiet alley with a large building wall next to it (like the back parking lot of a Walmart) Drive close to the building with the windows on the side of the truck closest to the building open. Listen. Turn around, repeat with the windows on the other side open. You will hear the noise reflected off the building back into the open window.
Almost certainly aren’t. I inferred that he’s heard the noise for a while, and the light just came on. Plus, the things likely to make that type of noise aren’t monitored by the onboard computer.
No. Unless by serious you mean bad enough to make the wheel wobble, which should have been making godawful horrendous noise for some time.
Warning Anecdote;
I just replaced the bearing assembly on my 96 Exploder. The ABS light started flashing about 3 days before the noise* was audible. Then on the 3rd or 4th day the bearing noise became audible and the ABS light stayed on steady. I didn’t put 2 and 2 together until I figured out the bearings were shot by removing the tire.
The ABS sensor is part of the bearing assembly and when the bearing started to break down the sensor picked this up. A couple hundred miles before total breakdown. That’s why I assumed that this might be a normal occurance.
I haven’t run into this myself, and wouldn’t have expected it, but you learn something every day. Thanks for sharing that, I’ll amend my conception of conditions that will trigger the sensor.
Fortunately, in the auto world, a lot is learned by anecdote.
Thanks. I’ll do a tire rotation when GF is up at my house this weekend (compressor and impact gun here) and then reevaluate. A non-doper friend has emailed to advise he has an OBDII scan tool I can borrow, too.
We had to stop for other stuff at Advance Auto, and although the CEL had gone out by then, I asked them to interrogate the ECM and the code stored was for evaporative control emission system leak-minor. Since it hasn’t reoccurred, I’m gonna guess one of us didn’t fully tighten the gas cap. :smack:
Regarding the cyclic feedback, a few weeks passed where plans and weather didn’t permit me to get to it, but last weekend, I did get tires off the ground, and slowly rotated each to feel for CV roughness, rotor/brake drag, wheel weevils, and found nada.
Following an X-rotate, GF said it felt fine, and I drove the vehicle almost 200 miles this weekend and the problem mentioned in the OP is gone.
Thanks to all for your input. 