Faulty Brake Light Switch Has Transmission Shifting In and Out of Gear While Stopped

Faulty Brake Light Switch Has Transmission Shifting In and Out of Gear While Stopped
engineering is a double-edged sword : On one hand, nowadays ’ randomness engineering has helped create cars that are more dependable, more effective, and precisely plain drive better than anything that ’ randomness come before them. These days we get more power and performance out of a bantam 4-cylinder engine than we could once have hoped for from an engine half again as adult .
At the same time, though, today ’ sulfur engineering can cause some actual difficulties when the cars aren ’ triiodothyronine working right. back in the day, a transmittance that dropped into neutral on its own credibly had a transmission problem. today ? It could be anywhere in the car… even in the brake lights .
here ’ s a trouble that had the technician scratching his head, largely because he didn ’ t understand how the system worked .

Neutrals at a Stop

A 2012 Chevy Cruze with a 6T40 came in with a eldritch discipline : It was dropping in and out of gear at a stop. The cable car only had 42,000 miles on it, the ATF was clean, and there were no other problems apparent.

The technician checked the computer system and there were no codes in memory. So he decided to pull the transmittance out and tear it down. A exhaustive inspection revealed nothing incorrectly inside .
But, since it was already apart, he rebuilt the infection. He installed a new TECHM and put it back in the car. And it did the like thing it was doing before : It dropped in and out of gear at a intercept .
Since rebuilding the infection didn ’ triiodothyronine work, the technician bought a low-mileage, used unit and installed that in the car. And it continued to drop in and out of gear .
finally person suggested that the technician connect a scan tool to the car and look for something that corresponded with the transmission dropping in and out of gear .
It didn ’ t take long to find it : The brake ignite switch was cycling on and off at a break, correctly in time with the transmission dropping in and out of gear. Replacing the switch eliminated the problem .

Working the Way It’s Supposed To

Okay, let ’ s forget about the technician project parts at the car ; obviously a bad choice under any circumstances. Why would a faulty brake light switch affect the transmission like this ? Turns out, the calculator was doing precisely what it was supposed to do, based on the information it was receiving .
That ’ sulfur because this infection is supposed to shift into impersonal at a diaphragm, if you have your foot on the brake. Dropping into neutral reduces the load on the locomotive, which allows it to use less gas while stopped at a light .
GM first started adding this neutral-idle strategy to a few vehicles equipped with the 6T40 in 2012, and continued adding it to the rest of their vehicles through 2014. The earlier system is called Gen 1 ; the late with the raw command arrangement is called Gen 2. Both generations had some form of neutral-idle organization.

sol, if the system international relations and security network ’ metric ton universal after a specific class, how can you tell whether you ’ re working on a Gen 1 or Gen 2 ? Check the TECHM ( calculator ). Gen 1 systems have a 1, 2, or 3 on the identifier ; Gen 2 systems use a B, C, or D .
In addition, Gen 2 vehicles don ’ t have pressure switches, so the filters for the atmospheric pressure switches aren ’ t there, either .

The Neutral-Idle Operating Strategy

One of the big changes to these systems is the neutral-idle operate strategy. here ’ s how it works :
For the computer to turn the neutral-idle system on, the infection has to be in drive, first gear engine brake. The transmittance has to be at normal operating temperature, and the accelerator position detector and the vehicle speed have to indicate the car is at a diaphragm. ultimately, the transmittance computer has to see that you have the brakes applied .
When all these conditions are met, the calculator reduces atmospheric pressure to the 1234 personal computer solenoid 5, which reduces pressure to the 1-2-3-4 clutch bag. This lets the cling to case, which reduces the remainder in travel rapidly between the torsion converter stimulation, and the torsion converter turbine or the TCC case focal ratio .
The decrease in the travel rapidly dispute between these components reduces the engine load while the vehicle is stopped. This, in turn, reduces the amount of gas the locomotive uses .
Sounds bare, right ? indeed why did this arrangement cause a problem for the technician ? Because the brake ignite interchange began cycling on and off randomly, even though no one was applying the brake pedal. The computer saw this signal going on and off and started applying and releasing the 1-2-3-4 clutch.

Replacing the brake light interchange corrected the problem. Had the technician been mindful of the neutral-idle organization, he might have been more probably to look for a trouble in the system before considering a infection trouble. In the end, the solution was childlike : replace the brake light switch .
today ’ south engineering is indeed a double-edged sword. And, if you don ’ thyroxine understand how that technology is designed to work, you can be sure that sword will cut you to the cram. But if you take the prison term to learn how the system is supposed to operate, you can feel comfortable no matter what type of car you ’ rhenium working on .
Thank you to Bill Anthony of Total Driveline Experts in Wood Dale, Illinois, for information provided for this article.

source : https://tonupboys.com
Category : Car Brakes