And why cascading failures in modern cars are a pain in the ass.

So the 2016 MDX TECH is a pretty fun car, but despite the fact that it boasts a 10-speaker system on a 510-watt amplifier. The placement and direction of the speakers are amazing, and it sounds fantastic. BUT THAT ISNT GOOD ENOUGH.

Some of us like it loud. Like can’t hear yourself talking loud. Like the car next to you on the highway can tell what song is playing even though you both have your windows up loud. Now, I could go all out and replace all 10 speakers in the car, add a couple of amplifiers, upgrade the factory sub, and so on. That will cost thousands and give a great result. But I’m pressed for time and can’t be without my car for a few days while I scratch my head over the pile of parts that used to be my car. The existing speakers (and especially tweeters) fill out the high end quite well, I’m just lacking in the low end. The factory subwoofer does a good job of filling in the low end, but it has no more thump than the door speakers do.

Simply replacing the door speakers with better ones won’t do, because ELS uses 2-ohm speakers all over, and virtually every speaker you can get now is 4-ohm, meaning unless I bite the bullet and replace the amp too, I’m looking at a drastic reduction in volume. So forget that. I settled on replacing the 8-inch (ugh) factory subwoofer with a dual-12 sealed box and appropriate amp/cap combo.

Step one, disassemble half the damn interior just to get to the factory subwoofer. You’d think it would be just a panel. MAYBE two. You’d be wrong. All I really need for this project is a beefy power wire from the battery, a beefy ground to the chassis, an ACC signal, and the high level output at the factory subwoofer.

Step two, run a 4-gauge wire from the battery to roughly the third row (which has never not been folded away. RDX? fuck that). I put the wire through the passenger-side firewall gromet. Tons of space. Hard to reach. Also ran a shorter 4-gauge wire to the chassis, at the same ground point the radio and xm modules use.

Step three, cut the 4-wire plug at the subwoofer and extend the wires to the high-level input at my new subwoofer.

Step four, extend a single wire from behind the rear accessory plug to the remote input of the new subwoofer.

Step five, test. It sounds great. I’m tired. Gimme a beer. Put the whole car back together.

Step six, what the hell are all these errors and warnings in the dash?

THE FOLLOWING THINGS IN YOUR CAR NO LONGER WORK: ADAPTIVE CRUISE CONTROL, EMISSIONS, BRAKES, TRANSMISSION, POWER STEERING, VEHICLE STABILITY, TRAILER STABILITY, LANE DEPARTURE WARNING, HILL START ASSIST

Fuck it. Going home. I’ll fix it tomorrow.

Okay maybe the battery got too low and freaked everything out. Nope, car starts just fine. Wont shift out of park though, not even neutral. Keeps saying ‘release the accelerator to shift’. Accelerator isn’t being pressed! Press the gas. Engine revs. So that works. WTF. The problem could literally be anywhere, these computers have a knack for cascading failures, but the 3rd gen MDX has it particularly bad. Any one sensor goes haywire and the whole car shuts down.

Connect it to my OBD reader and only one code comes up: Throttle position sensor signal high. That means I must have fucked the ground wire somewhere between the ECU and the TPS, and every system that relies on that data is now shut down, because computers. I could run a new wire from the TPS ground pin to another sensor ground, or to the ECU itself, but like a dumbass I thought repairing the wire would just be easier.

Lesson learned: Never use a sharp knife to poke a hole in the firewall gromet. Holding a broken wire 1/4″ out of the firewall gromet and fitting a soldering kit around all the pipes and hoses in the way is a literal nightmare. It’s never taken me 1.5 hours to solder a single tiny wire before.

BUT THE CAR SOUNDS GREAT NOW