Suzuki Swift AT/Won't shift from Park unless AC is OFF

[ninjababez]

Car: Suzuki Swift 1.2L AT 2015
Problem:
Unable to press the shifter button to change gear, unless AC is OFF

Brief history:

issue started after non casa body repair was done (rear collision)
apparently, the shop was not able to seal the 3rd brake light properly, hence shorting occured.
after replacing the fuse, shifter worked fine for a day. but since it the replacements were popping as soon as it was installed (next day), i decided on installing a higher rated fuse temporarily (10A to 20A)*i know, wrong move*; just up until the next day where i have a time to have it fixed.

after electrician (non-casa) replaced the brake switch, and rewired the 3rd brake light (grounded due to water intrusion);
brake switch is OK (but was still replaced)
everything works normally, except that i have to make sure AC is OFF; if AC is ON, there's no way for me to shift from PARK (button is hard to press).
NOW even if the AC is OFF, unless i UNLOCK the Shift LOCK; there is no way for me to move it from PARK

I still have the original, working brake switch; should i return it?
car is with my other boss, and downtime (leaving in casa for diagnostic, is not an optio)
no CEL btw

[dr. d]

sounds like the problem is "cross-wire syndrome", probably at the fusebox area...
try this... remove one fuse at a time, and see if the problem "improves" each time one is removed.
i know... non-logical.. but the procedure is free.

[ninjababez]

sounds like the problem is "cross-wire syndrome", probably at the fusebox area...
try this... remove one fuse at a time, and see if the problem "improves" each time one is removed.
i know... non-logical.. but the procedure is free.

youre correct bro, pero ginawa na yan nung electician with me. doubtful ako nun tinutulungan ko sya, pero um oo ako, kasi gusto nga daw nya ma isolate.

[mina_nuka]

Check for power at the O/B orange/black wire at the brake light switch. If there is power, check if power goes through G/B green black wire at the brake switch with the brake pedal pressed. This is done with the transaxle shifter is in the P position. Then check for power at the shift interlock solenoid.

[dr. d]

Check for power at the O/B orange/black wire at the brake light switch. If there is power, check if power goes through G/B green black wire at the brake switch with the brake pedal pressed. This is done with the transaxle shifter is in the P position. Then check for power at the shift interlock solenoid.

i like this guy!
...knows his stuff.

[ninjababez]

Check for power at the O/B orange/black wire at the brake light switch. If there is power, check if power goes through G/B green black wire at the brake switch with the brake pedal pressed. This is done with the transaxle shifter is in the P position. Then check for power at the shift interlock solenoid.

Salamat mina
Pag pinabasa ko ba ito sa reys electrical na tech, ma gets kaya nila ito agad?

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[oj88]

Check for power at the O/B orange/black wire at the brake light switch. If there is power, check if power goes through G/B green black wire at the brake switch with the brake pedal pressed. This is done with the transaxle shifter is in the P position. Then check for power at the shift interlock solenoid.

You can skip the first test. Just check that the brake lights are working when you step on the brakes. That will confirm that the brake light circuit is energized and the brake switch is working.

[mina_nuka]

You can skip the first test. Just check that the brake lights are working when you step on the brakes. That will confirm that the brake light circuit is energized and the brake switch is working.

There are two brake switches.




One

For the brake lights


Another for the shift lock release on this car.




Some cars have two,
one for the brake lights

The other
for PCM input to cancel the torque converter clutch.

[oj88]

There are two brake switches.




One

For the brake lights


Another for the shift lock release on this car.




Some cars have two,
one for the brake lights

The other
for PCM input to cancel the torque converter clutch.

I beg to differ. This is based on our 2013 Swift A/T 1.4. It only has one (1) brake pedal switch with two wires (white part near the center of the pic below).

The brake pedal position switch typically goes to the Swift's body control module (BCM). The controller then provides the logic and drive to operate the brake lights and the A/T inter-lock solenoid. The switch does not directly drive the brake lights nor the solenoid, the controller does.

If the brake switch is not working or if that part of the circuit is dead, it won't be able to trigger both the brake lamps and A/T interlock.

Further, the fact that the A/C has to be off to be able to shift, also seems to suggest that the BCM was damaged. And as it turns out, among other things, the BCM also controls the A/C.

Where I'm getting to is that, by shorting the 3rd brake lamp, the mechanic could've damaged the controller. And with the TS using a 20A fuse (in a 10A circuit), I think it made matters worse. I am hoping that I'm wrong because I was originally going to say that since this was a body work, the mechanic could've just left out a ground anchor point near where the damage was.



NOTE: Edited for additional information and grammar correction.

[ninjababez]

Mga bros salamat sa reply
Ito pala yun orig brake switch (hope this helps you guys help me identify my trouble)
Do you think permanent unlock nalang sa shift lock ang solution? Una kasi as long as AC is off, ok lang eh
Ngayon maski off ang AC, ayaw talaga

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