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Welcome to the zmatt.net wiki. This is a space for me to post information about various projects I'm working on, in the hope that this information might be useful to others. It is a continual work in progress so there may be half formed thoughts and broken links.

Public edit access is not currently allowed; if you have feedback you can contact me at contact at zmatt dot net.

Car stuff

I've been doing a fair bit of work on my car (a 2003 Toyota RAV4) recently, as it's getting to the age that various issues start manifesting. While my mother would prefer that I buy a new car, I've been learning a lot in the process of maintaining my 'vintage' RAV. Here's some information as I type it up:

• Inside an automatic transmission: some background on how this typical 4-speed automatic transmission works, including how to calculate the gear ratios from 'first principles'
• Toyota RAV4 2001-2003 harsh transmission shift ECU fix: this model has known issues with harsh shifting and clanging when shifting into reverse, which turns out to be a soldering problem with the engine control unit (ECU)
• Toyota RAV4 torque converter slip: ongoing debugging of an issue I have with torque when accelerating
• Toyota M-OBD protocol and adapters: this model is not OBD-II compliant, but it is possible to connect to it with some off-the-shelf adapters that support custom initialisation sequences; I've also built my own DIY adapter with an Arduino
• Toyota RAV4 alternator repair: replacing alternator bearings was one of the first repair jobs I did on this car, and I learnt a lot in the process about engine compartments and cramped spaces
• Toyota RAV4 A/F sensor and O2 sensor replacement: another tale of engine compartments and cramped spaces, as well as a tale of dodgy replacement parts that aren't quite compatible
• Toyota RAV4 doors lock but do not unlock: a strange issue that I had once