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As a man of science, I set out today to explore Toyota's Proximity Alert System which in my 2020 RAV4 Hybrid will emit a sound alerting nearby pedestrians that the vehicle is in a drive gear and may begin to move. I now share my findings so that they may be properly peer reviewed and evaluated, and the experiment tested by other people of science to verify its validity.
Items needed to perform this experiment:
1 flathead screwdriver
1 10mm socket (this may disqualify some of you from participating)
Wire cutters
1 knife / wire strippers
1 small sized paperclip (preferably with rubber coating)
30 minutes
The scientific process:
Using the flathead screwdriver, five retention clips can be disengaged and removed from the fan shroud.
Using the 10mm socket, two bolts can be removed from the front side of the fan shroud, freeing it from two clear mounting brackets.
Using the 10mm socket, three bolts can be removed from the hood latch. One must take care not to drop these bolts down into the engine.
The fan shroud can easily be flexed and removed from the vehicle.
It is at this point one will notice a speaker device attached to the vehicle near the center line of the vehicle. It is important to distinguish this speaker device from the two horn units that may look similar. Once located, the plug that leads into the speaker device from the left side may be unclipped, and one may find that if the vehicle is put into drive or reverse that it will move without emitting the high-pitched tone that some may find unpleasant to hear when the vehicle is in battery-only drive. Interesting.
But...an error message? Unacceptable. On the electronic dash display pops up, "Proximity Alert System malfunction: Visit your dealer." I think not.
In my highly scientific research I jammed a single strand of copper wire between the contacts within the cord which was unplugged from the speaker device and turned the ignition on again. I was once more presented with the error message. I theorized that there wasn't enough voltage passing between the contacts to complete the circuit. I attempted the same procedure with three strands of copper twisted tightly together using a high precision cordless drill, which seemed to pass enough power such that when the vehicle was turned on I could drive forward and backward without sound, and without error message.
But this bridge was not entirely faithful, as the ends had already begun to come undone upon insertion. Close observation revealed that my three strand prototype was roughly the same diameter as a small paperclip's metal core. Ever mindful of circuit shorts, I set out to find a plastic coated paperclip, which about one inch of could be used to make Bridge 2: Electric Boogaloo. A quick trip on the freshly calibrated blade of my pocketknife revealed roughly 1/4" of bare metal on each end, which slotted nicely into the plug's contacts and didn't leave live circuitry exposed for all the radiator to see. Driving results remained the same as with the copper, huzzah!
Conclusion:
Another ignition and drive test with our scientific paperclip installed revealed no tone emission or error appearance, so I securely covered the now-exposed plug ends and replaced the fan shroud to its original position. I suspect that this experiment could be repeated on other vehicles of similar build with similar results.
Additional information:
NHTSA mandates that any hybrid/electric vehicle built during or after September of 2020 be fitted with a device to emit sound when under non-gas engine drive to alert pedestrians of the vehicle's ability to move. I am a man of science, not of law, and I cannot encourage anyone else which way to interpret this ruling. All I know is that my vehicle was built well before this time, and that if I hear about Tesla retrofitting their older EVs with a PAS I will follow their lead. Conduct this experiment fully informed if you wish, and happy quiet driving.
Items needed to perform this experiment:
1 flathead screwdriver
1 10mm socket (this may disqualify some of you from participating)
Wire cutters
1 knife / wire strippers
1 small sized paperclip (preferably with rubber coating)
30 minutes
The scientific process:
Using the flathead screwdriver, five retention clips can be disengaged and removed from the fan shroud.
Using the 10mm socket, two bolts can be removed from the front side of the fan shroud, freeing it from two clear mounting brackets.
Using the 10mm socket, three bolts can be removed from the hood latch. One must take care not to drop these bolts down into the engine.
The fan shroud can easily be flexed and removed from the vehicle.
It is at this point one will notice a speaker device attached to the vehicle near the center line of the vehicle. It is important to distinguish this speaker device from the two horn units that may look similar. Once located, the plug that leads into the speaker device from the left side may be unclipped, and one may find that if the vehicle is put into drive or reverse that it will move without emitting the high-pitched tone that some may find unpleasant to hear when the vehicle is in battery-only drive. Interesting.
But...an error message? Unacceptable. On the electronic dash display pops up, "Proximity Alert System malfunction: Visit your dealer." I think not.
In my highly scientific research I jammed a single strand of copper wire between the contacts within the cord which was unplugged from the speaker device and turned the ignition on again. I was once more presented with the error message. I theorized that there wasn't enough voltage passing between the contacts to complete the circuit. I attempted the same procedure with three strands of copper twisted tightly together using a high precision cordless drill, which seemed to pass enough power such that when the vehicle was turned on I could drive forward and backward without sound, and without error message.
But this bridge was not entirely faithful, as the ends had already begun to come undone upon insertion. Close observation revealed that my three strand prototype was roughly the same diameter as a small paperclip's metal core. Ever mindful of circuit shorts, I set out to find a plastic coated paperclip, which about one inch of could be used to make Bridge 2: Electric Boogaloo. A quick trip on the freshly calibrated blade of my pocketknife revealed roughly 1/4" of bare metal on each end, which slotted nicely into the plug's contacts and didn't leave live circuitry exposed for all the radiator to see. Driving results remained the same as with the copper, huzzah!
Conclusion:
Another ignition and drive test with our scientific paperclip installed revealed no tone emission or error appearance, so I securely covered the now-exposed plug ends and replaced the fan shroud to its original position. I suspect that this experiment could be repeated on other vehicles of similar build with similar results.
Additional information:
NHTSA mandates that any hybrid/electric vehicle built during or after September of 2020 be fitted with a device to emit sound when under non-gas engine drive to alert pedestrians of the vehicle's ability to move. I am a man of science, not of law, and I cannot encourage anyone else which way to interpret this ruling. All I know is that my vehicle was built well before this time, and that if I hear about Tesla retrofitting their older EVs with a PAS I will follow their lead. Conduct this experiment fully informed if you wish, and happy quiet driving.