Neutral Safety Switch or interlock transmission or rear drum brake gone bad?

toyota
corolla

#1

My wife car is 2002 Corolla. About 3 months ago, the car starts up fine, run find. It’s ok to put on Reverse or Drive on the first time, but if I change gear again, the car sometime shut off. Sometime shut off after 3rd or 4th time that I change the gear. When it shut off, I just put back on Park, and start the car again. When it shut off, I can tell it caused by ahort electrical, not by mechanical.

About a month ago, I looked up on google, and it said could be brake. Ajust it by pulling emergency brake will adjust the brake level. I found that the brake pedal went all the way to the floor. I just had both front and back brake change less than 2 year ago. Front was disk, back was drum brake. The front brake was OK, but the rear drum brake was completed gone. I change the rear drum brake myself. I was suprised to see all the brake shoes turned to dust inside the drum, and the brake was metal to metal. I changed both shoes and rotor. The problem was better for awhile (only shut off once awhile), but now the problem comes back.

Yesterday, I took the car to the shop. The mechanic claims that it Neutral Safety switch went bad and did that. He asked for $500+, and I agree do it, so he is ordering the new switch now. I just not totally convince that it was the switch. I still think there is 50% chance that it is still the brake. Could it be the brake cylinder goes bad, since the brake last only 2 years? Also, my wife told me that she got only 23-25mpg. She should get between 30-35mpg for this car. But I don’t believe her words either. I been asking her reset the trip everytime she filled up, but she never done it. This is my first time to change the brake drum, so I am not cofidence that I fixed the brake problem. Also, did the shop rip me off? I look up the part and it cost about $210, so he gets more than $300 for that job. This looks like half hour job, not like changing the timing belt.


#2

A) If you have brake issues and aren’t confident in your own ability to fix it, then you should have a shop deal with the brakes. At the very least take it to a locally owned shop and ask to have the brakes checked.

B) Nothing about a problem in your rear drum brakes is going to make the car shut off when you change gears. That is bizarre, and I have no idea what kind of theory would even support that.

C) The neutral safety switch will keep the car from starting - and that is all. A bad neutral safety switch will not make the car stall. They are wired through the circuit for the starter to disable the starter if the car isn’t in Park or Neutral. Once the car is running, it is out of the picture. On that point, I will leave myself open for correction just in case there’s something weird I’ve never heard of or something weird I don’t know about Corollas. But I’m leaving that chance at very small.

As for what makes the car stall, is your check engine light on? Does the car idle smoothly other than when it stalls?


#3

On my early 90’s Corolla at least, a faulty neutral safety switch will not cause the engine to stall. If it fails, it won’t crank is the symptom.

OP: Stalling is one thing, definitely an inconvenience. But braking is another, a safety issue. If your brakes are not performing well, it is critical you address this as first priority. Consider to ask friends, relatives, co-workers for a recommendation of inde shops in your area that preferably specialize in Toyotas or Asian cars.


#4

Gotta agree. I suspect the rear brake are dragging which would also cause the quick wear and the lowered gas mileage. Why they are dragging could be not properly adjusted, bad brake hoses restricting the flow of brake fluid, or something else in the master cylinder. Stalling would be a separate issue.


#5

Update: Neutral safety switch was the problem. $529 to fix the problem. It was expensive, but he fixed the problem.
About the brake, I had it done 2 year ago by a mechanic. And they were bunch of dump mechanics at that location. I don’t work on the car often, but I am better than them. That is why I did the brake myself. Only thing is they had tools and equipment that I don’t have. There is a long story about how they F-up my disk brake on my car. The new brakes was froze up and my tire almost caught on fire. I bought back, they laughed at me. I end up redo the job myself. I can’t find a good mechanic with a good price around here. As you can see above, this mechanic is quite good, but his service is quite expensive. Anyway, my wife car’s brake is working fine like a new car. No noise or anything. I just need to confirm the mpg.


#6

B) Nothing about a problem in your rear drum brakes is going to make the car shut off when you change gears. That is bizarre, and I have no idea what kind of theory would even support that.

When you change gear, you need to step on the brake. All cars have this safety build in. When your brake too low, it touches the floor instead turn off the safty switch cause the car shut off. Most car have automatic ajuster to level off the brake padel. Rear drum brake adjust by pulling emergency hand brake. The problem is my wife never use her emergency brake. And her brake touching the floor.


#7

"When you change gear, you need to step on the brake. All cars have this safety build in. When your brake too low, it touches the floor instead turn off the safty switch cause the car shut off.

Ummmm…no.


#8

“her brake touching the floor.”

I REALLY hope that you have good insurance coverage for the accident that is sure to take place in the very near future.

Even though your rear drum brakes have nothing to do with the engine stalling, a brake pedal that touches the floor is a sign of the need for immediate attention to the brake hydraulic system. This could be simply the result of a low level of fluid in the brake master cylinder, or it could be the result of a worn-out master cylinder, but either way, your wife will soon be unable to stop the car.


#9

Update: the shut off while changing gear was coming back yesterday. Bought it back to the mechanic. Just wasted $529. I was skeptical that wasn’t the problem, but I just didn’t have any other options. I got ripped off and he didn’t fix the problem.
Anyway, I already changed the rear drum brake, and it is working fine. It is not the problem right now. The problem right now is shut off when changing gear. Please give any advices why the car shut off. Please leave the brake problem alone unless it is relative to the shut off.


#10

I still need to know if your check engine light is on. You never answered.

Short of having any codes to work with. Have your idle air control valve cleaned and checked - including a check of the wiring. While someone is at it, cleaning the throttle body and MAF sensor would be a good idea. It’s all in the same line of stuff, and just cleaning it all up does not cost a lot of money. Also take a good look at the vacuum line for the brake booster.


#11

yes, the engine light is on, but it was after market catalytic converter. It was on about 3 years right after I changed the cat. The mechanic also said the same. Cost about $1200 for EOM cat.


#12

Also, there is no other problems beside the shut off when changing gear. The car idle an run like a new car.


#13

“yes, the engine light is on, but it was after market catalytic converter. It was on about 3 years right after I changed the cat”

In the 3 years since that light first lit up, the car’s OBD system could have stored any number of diagnostic codes in addition to the one relating to the catalytic converter. You need to take the car to a COMPETENT mechanic who can read all of the trouble codes as a starting point before any more repair attempts are done.


#14

Of course, the mechanic read the code before he did any works. He said the engine light from after market cat. I did not tell him that, he found out by reading code. This is not the same cheap mechanic that I used before. This is an expensive mechanic been fixing car for over 25 years.


#15

"This is an expensive mechanic been fixing car for over 25 years

Then your worries are over, as expensive mechanics are always the best ones.
;-))

Please report back to us when he figures out what the problem is.


#16

Find out what the exact code is and report it. (format: P0123) There are no codes that can tell you that an catalytic converter is bad, and certainly not any that can tell you the problem is from an aftermarket cat. There are errors related to oxygen sensor readings where the “official” indication is that the cat is not working efficiently. But in the end - it’s just a report from an oxygen sensor and oxygen sensors are crucial to how the computer does the fuel/air mix - which is then crucial to how the car runs. I’ll guess off-hand that you actually have a “P0420” code, and if that is true then it is unlikely related to stalling. However, without the actual code all anyone can do is guess about that.

So aside from that - let me give a note about the idle air control valve - when your foot is not on the throttle, the IACV is what controls the air going into the engine. If it is gunked up and sticky, or failing electrically, or getting an unreliable electrical power supply - it can easily stall the car. The car will not idle properly with an IACV problem.


#17

I didn’t looking for expensive mechanic. I need a good mechanic that can fix the problem. It just happenned that he is expensive.
Doesn’t matter if he is the best mechnic. He is by himself. And we are here as a group. That is the advantage of online. I also aware of the problem is complicated, so I don’t want to be blam for using cheap mechanic that can’t fix the problem. So I went for the mechanic with best rating.


#18

“The car will not idle properly with an IACV problem.”

The car doesn’t have any problems with idle, starting, or tunning. Can this rule out IACV problem?


#19

“The car doesn’t have any problems with idle”

I’d call stalling a pretty darned big idle problem. Look - when you’re doing stuff in the car - like stopping and shifting and steering etc. the load on the engine changes all of the time. The computer reads that and adjusts fuel/air and stuff to deal with the load. Without your foot on the throttle the IACV is key in those adjustments. If it is wonky for some reason it can cause stalling - which in this situation is THE FAILURE TO IDLE.

I cannot diagnose your car by internet. I have no idea if you have an IACV problem. But checking and cleaning an IACV is a very easy, routine and cheap thing to do. I’m not telling you to have the engine rebuilt.


#20

OK. I will ask him for the code and cleanning IACV. Hope this will work. And I don’t have to spend another $500 for something else that is not broken. Thanks.