Changing front brake pads on 08 Malibu. Is it necessary to bleed the brakes? If so do I just do the front or all four?

No.. its not required when replacing pads on anything I know of. Only when you disconect any of the brake lines for any reason.

It's best to change the brake fluid every 2 years, in order to prolong the life of the ABS system, brake calipers, master cylinder, and wheel cylinders. Also, this helps to tremendously improve brake performance, by eliminating air and moisture from the system. Ensure you only use an ABS approved brake fluid, such as Valvoline.

When you replace the front pads, be sure to remove and clean the caliper pins; then, relubricate the pins with silicone grease. This is a very important step. I recommend that you use premium ceramic pads, such a Wagner ThermoQuiet.

Regularly changing the brake fluid, lubricating the caliper pins with silicone grease, and using quality ceramic pads are key to trouble-free braking.

Took the car in the speaker place to get the speakers repaired. Speaker guy noted that the ignition harness is missing.
What in the world would have happened to it?
Who and why would it be missing?
There are some current problems with the car...
Mainly the fuel and computer.
The computer will say "needs oil change" and it doesn't
It will say "low air in tires" and it isn't.
It will say "low fuel" when there is no low fuel.
The problem with the fuel is, the indicator is at empty when it's really not empty, and EVERY ONCE IN A WHILE, it will pop back up to what the actual fuel level really is. But most of the time we're driving around not knowing exactly how much fuel. This is my college son's car so, with those issues, what are my priorities and please tell me more about the ignition harness issue.
I'm am not even close to a mechanic, but I am just looking for as much information as I can possibly get to help me understand everything I can.
Thanks in advance for any help given.

Thank you for your answers.

Ignition harness can't be missing, car would not run. Pieces of it may have been cut and patched for a radio connection or bypassed for other reasons.

I'd find another mechanic... this ones playing you for a fool.

If the ignition harness was "Missing" the car wouldn't even start much less run.

OK thank you.. this guy is not a mechanic.. far from it. He only works on speakers. I was having a problem with the battery connection and mentioned it to him and he said he noticed the ignition harness was missing and that might have been my problem with the car starting.. but in actuality it was simply the battery connections weren't on there good.

2008 Chevy Malibu~~~~
So bummed.. got new tires, repaired the brakes, took car in for inspection and... FAILED.
I got the codes, went to auto zone and supposedly got more details on the codes.
Here are the codes:

p0717~~vehicle speed sensor input over 6mph-ECM detected the ISS signal less than 50 RPM (probable cause-failed input sensor/open or short circuit condition/corroded or moisture in connector)

p0700~~The TCM has detected an emission related fault (probable cause-check other service codes first)

p0650~~ECM has detected an improper voltage level on the circuit with the light command on (Probable cause-open or circuit condition/failed driver circuit in the ECM)

p0463~~Poor electrical connection at the fuel level sending unit (Probable cause-failed fuel level sending unit

The car seems to run just fine. We do have a notification on the dash/computerized/where the radio is that says we need gas when we do not/says needs air when we do not/and says we need oil change when we do not.

I would like to point out that there is a speaker system in the car and it is not working--have been back three times for them to "repair" it.

I would also like to point out that the speaker guy mentioned that the ignition harness is missing/but people I have talked to say that is NOT POSSIBLE.

PLEASE OH PLEASE help me with this.
Could some of these codes be related to ONE OR TWO problems?
Is there anything that I can check myself (not being a huge mechanic type person that I am)?
My son is in college and I need to save all the money I can possible save!

I don't know why this question is on here.. this was supposed to be a new question...

They moved it... same car... basically the same topic... thus same thread. (no I'm not a moderator... just a member here).

Opinion here... you are really deep in this car and you need someone with a lot more experience than you have to sort this out... you've got multiple issues... you need to have your own code scanners when you are working through them to know what's cleared... and you are going to need a really good service manual.

Electrical problems can be rough for people who understand electronics to sort through... they are bewildering to people who don't.

I'm an electronic Engineer... my hobby is mechanical stuff on vehicls and motorcycles, I've done engine swaps... grafted wiring harneses into cars the engine was never intended for... I've rebuilt engines... transmissions and almost everything else over the last 30+ years, and what I see even with my experience in that car is a rats nest of problems. And more electrical problems in one vehicle than I have ever dealt with.

You really need a mechanic that knows this car... and automotice electrical systems.

Out of curiousity... this isn't an retired cab... is it?

Oh OK oops.. I asked it again! Hope I don't get in trouble for that! I didn't know it was moved. Ok thanks for your answer.. this sucks.
And I was just noticed as I drove down the street that it does not "shift" smoothly... and when I was driving down the road the speed needle would sort of jerk up.
What is weird is I never noticed these two things before I took it in to get inspected.
And when I drove off after the failed inspection, as I was driving away the guy kept eyeballing me to the point where I was uncomfortable... I don't know what that was about.

Have you ever run a carfax on this vehicle? I'm curious about its history... like previous accidents or flood damage?

2008 makes it a front wheel drive vehicle... and the transmission is electrically controlled. How many miles is on it?

It's not really the same topic though...

No I sure have not.

It is my son's car. His dad went with him to purchase it and honestly I had a bad feeling about it as soon as I saw it. And those messages popped up maybe a month or two months after he bought it. Makes me mad because my son put 4000 of his own money into it. Got the car for about 7500 I think.

It looks nice and it ran smooth, but just had bad feeling. And I noticed that one of the headlights was new and the other one was older (not as clean).

91k

I just noticed/realized what carfax is. I will try to run it now. Thanks for that..

My son is 18 and doesn't know anything about cars.. that's why it makes me mad he put so much of his money into it and it's just awful apparently..

OK I just looked at carfax. Didn't know there was a fee for that. I'm not sure if it's worth it. Every penny counts for me right now. It says there are 12 records. Not sure if that is true or not.

Your call there... there were a LOT of flooded cars from Hurricane Sandy that got cleaned up and resold... some of them flagged by insurance... some of them not.

Without even seeing the car... I'm wondering if this isn't one of them... how long has he had this so far?

I have no idea if it is a retired cab or not. You mean cab as in Taxi cab? I don't think so. How can I tell? I must say I can smell things others can't and it just smelled funny to me. Kind of like a hotel. I didn't like it. Nobody else noticed.

He got this car I believe it was February 2012? Got it in Houston. Let me go look to see exactly when he got it. My memory isn't that good right now... got a lot going on.

The inside looks great...

September 2012! Not February!

Sorry I hope I'm not being annoying. I wanted to point out that they had an alarm put on the car as well as the speakers... I'm just wondering if when they installed those, if they messed up the electrical somewhere else. To me this all seems to be an electrical/computer problem.

I saw that before when you mentioned it... the speakers... not a chance... alarm? A lot depends on exactly which one it is and how it ties into the system.

OK thanks for your answers!

If a person "just works on speakers", I would not let him work on anything of mine. In modern vehicles, the wiring is critical and if anything is disconnected that should not be, it could render the vehicle undriveable. If this person has np certifications for working on cars or trucks, he should be reported to the |Department of Motor Vehicles for operating a repair business without a license. One wrong wire cut and it could mean someone's life .

I absolutely agree with you handyman. We did not let this person work on the car. The speakers were not working properly... took the car to fix the speakers, I mentioned about the car not starting sometimes and the cables being loose, he took a look at it, and the reason the cables were loose was because plastic covering was preventing the cable from getting a good connection (the speaker things are connected as well), so he sliced the bottom of that plastic thing which was totally fine with me, and tightened it and wah lah.. no more battery issues. So after that... and after he finished fixing the speakers, he said... "you know another problem you might be having with your car not starting is the ignition harness is missing"... he said "I DO NOT DO REPAIR WORK ON CARS"... So that is what brought me to that question. He did not work on the car other than the speaker issue. Sorry if I confused anyone there... And you know what... the car has been working great since he tightened/sliced battery cable...
NOW, just got to get it in and get the rest of the work done... ugh!