My 2003 Toyota Matrix has a reverse beep. There, I said it.
It’s pretty silly, and I have a hard time explaining it. Some people ask if the annoying beep is audible outside the car, “you know, like one of those trash trucks!” No, the shrill beep only tortures those in the car, thankfully.
I’m assuming that because the car is a 6-speed manual transmission, and that the reverse gear is right next to first, Toyota felt it an appropriate safety measure to sound an alarm when the driver put the car in reverse. I can’t stand it. So, why not disable it?!
With the help of some great internet sites and email lists (see references below for specifics), I got all the information I needed to proceed.
The first step was to remove the gauges cover. It just pulls right out.
The next step was to get the gauges assembly out. This was sort of tricky, but there are two large white hooks that keep the bottom part of the assembly locked in. There’s one screw on the top side. With enough patience, it can be removed without much trouble.
There’s one big connector that is connected to the gauges assembly. Disconnect that. Now, you’ll have a good view of that harness. Below is a picture of the connector and the wire that sounds the reverse beep. It’s a red with small black stripe. It’s the fifth position from the left on one side.
Now, I didn’t want to simply remove the feature permanently. I wanted the ability to re-enable it in the future, especially if I sold my car. I certainly didn’t want to have to reverse the reverse beep mod! So, a switch was needed to toggle between the mod and the factory setting.
Similar to my Matrix DRL Mod, I chose an AC power cord from a PC for the cable, for its large gauge size and heavy insulating jacket. First, I snipped the red/black wire about 3 inches up from the connector. Second, I spliced the white and black wires from the AC cord to each end of that red/black wire in the harness. The green wire of my AC cord I bolted to the car’s chassis for ground.
Now, where to put this switch? Well, it just so happens that there is one spare button next to the radio. There are a series of three switches, two of which work on all US Toyota Matrix models. The top is the AC switch, the middle is the air recirculate switch, and the last one is unused.
I spoke to Greg at ToyotaPart.com and he sent me the following scan from a maintenance manual:
Those three switches are part of one assembly, so it’s not possible to buy an individual functional switch for that third bay. But I was undeterred.
The panel that covers the switches and radio comes off very easily. Just pull out from the bottom side first and then the top. There are four electrical cable harnesses and one mechanical cable plugged into the combined assembly. Three of them are plugged directly into the reverse side of the panel. One electrical and the mechanical cable are plugged into the switch assembly.
Removing the triple switch assembly was somewhat tricky. It’s got two plastic locks on top and bottom that I pried out with some slotted screwdrivers. Those A/C and recirculate switches have nifty LEDs embedded in them so that they light up when they are switched on. I love that functionality. I wanted to do the same for my switch option on the reverse beep. “On” would be beep disabled and an LED would turn on instead during reversing. “Off” would be beep restored.
As you can see below, there was really no accommodation for a switch travel below the switch cap. It’s really just a false switch cover. According to ToyotaPart.com, the European models use this bay for some option that isn’t available in US markets.
So the trick was to convert that plastic area into a real working switch with travel. I’ve circled that are below in red.
It wouldn’t be an easy task, as there is no clearance below the cap for much travel. In the next couple photos, I’ve circled the usable areas where a switch could be added underneath the plastic cap.
Next, I used a Dremel tool, otherwise known as God’s gift to plastic work, and carved down the cap base. I also had to shave off some plastic ribs that kept the false switch cover from traveling downward. See red circled portion below.
The false switch cover has two latches on each side that keep it in place on top of the plastic base. I next selected a good switch that had a nice toggle detent, and which would fit underneath the switch housing. I found a good double pole, double throw (DPDT).
Underneath the housing, I drilled out a hole for my switch’s actuator, and used the Dremel to square the circle. Now you see the switch placed inside the hole.
On the top side, you can see the actuator protruding into the plastic base section. The actuator isn’t actually long enough to extend past that plastic base, so I needed to use some extra plastic to make contact between the cap and the switch actuator. I just used a cylindrical LED light pipe, cut down to size for this. Also, in the two circled hollow sections below, I placed springs from regular fountain pens to keep the switch cap up during travel.
Next the wiring. I glued my switch into place with an industrial adhesive called E6000. I used a 330 Ohm resistor for my LED current drive (for about 35mA). I soldered both poles of my switch together for added current sharing.
I used heat shrink around the resistor and leads of the switch.
Next was the cap LED. I drilled a hole in my false switch cap (soon to be non-false!).
Here is the LED from the reverse. I used a flat top LED to make it look sleek.
Here is how it looks, nearly flush against the cap. The curvature of the cap prevented it from being perfectly flush.
Here is the switch and its wiring back on the switch assembly.
Next was the wiring of the panel to the new AC cable harness I added. I used wire nuts for the connection to my AC cable.
Finally, here is the reverse LED in action. Toggle the switch, and the LED is inactive and the reverse beep is reactivated!