Must-Have: OBD2 Diagnostics
Torque Lite / Torque Pro (Android)
Pairs with any ELM327 Bluetooth adapter. Reads and clears OBD2 codes. Torque Lite is free and covers basic code reading. Torque Pro ($5) adds live gauges, battery temp, SOC, and data logging — worth it for ongoing diagnostics.
Dr. Prius App
Prius-specific hybrid battery health check. Shows 14 block voltages (each block = 2 modules) so you can pinpoint which part of the pack is failing. The fastest way to know if your hybrid pack is healthy or dying. Free version is enough to start.
ELM327 Bluetooth Adapter
OBD2 Bluetooth dongle that plugs into the port under the dash (driver's side). Works with Torque Pro and Dr. Prius. Owner-tested pick: Veepeak OBDCheck BLE ↗ — works with both iOS and Android, confirmed compatible with Dr. Prius app.
Techstream (Advanced)
Toyota's official diagnostic software. Reads Prius-specific codes standard OBD2 scanners miss. Requires a mini-VCI cable (~$20 on eBay). Free version available.
Basic Hand Tools (You Probably Own These)
| Tool | Why You Need It | Notes |
|---|---|---|
| 10mm socket & wrench | Almost everything on a Prius is 10mm | Seriously. Buy a magnetic one so you don't lose it in the engine bay. |
| Ratchet set (1/4" and 3/8") | All general repairs | A 72-tooth ratchet is worth it in tight spaces. |
| Torque wrench | Spark plugs, wheel lug nuts | Spark plugs: 13 ft-lbs. Lug nuts: 76 ft-lbs. |
| Trim removal pry tools | Dashboard, door panels, combination meter | Plastic ones only — metal will scratch. $10 set on Amazon. Also pick up a set of retainer clips — the plastic push-pin fasteners snap when you remove panels and you'll want spares. |
| Floor jack + jack stands | Any under-car work | Never use just a floor jack. Always use stands. Prius jack points are marked on the rocker panels. |
| Multimeter | Electrical diagnosis, battery module testing | A $20 digital multimeter is enough for most Prius electrical work. |
Prius-Specific Tools
| Tool | Used For | Where to Get |
|---|---|---|
| HV-safe insulated gloves (1000V rated) | Any work near the hybrid battery | Amazon, electrical supply stores. Non-negotiable for hybrid battery work. |
| Toyota special service tool for HV plug | Disconnecting HV battery service plug | You can DIY with the orange service plug on the battery — no special tool needed if you know the procedure. |
| Soldering iron + capacitors | Combination meter repair | $30 repair kit vs. $500 replacement. See combination meter guide. |
| Coolant hand pump / vacuum bleeder | Inverter coolant flush | Makes coolant flush much cleaner. $20–$40 at AutoZone. |
Where to Buy Parts
RockAuto
Best prices on OEM and aftermarket parts. Filter by Gen 2 year range. Always check the "Economy" vs "OEM Quality" tiers — for critical hybrid parts, go OEM or better.
Toyota OEM (Dealer Parts)
Inverter coolant, HV battery components, and certain sensors are worth buying OEM. Toyota parts desks will sell to the public without service work required.
Florida Junkyards (Pull-A-Part, LKQ)
Excellent source for combination meter clusters, MFD screens, and body parts. Gen 2 (2004–2009) parts are interchangeable across most models. Always verify before pulling.
eBay (Rebuilt Parts)
Good source for rebuilt ABS actuators and reconditioned hybrid batteries. Look for sellers with Prius-specific listings and at least 50 feedback. Ask about warranty before buying.
Fluids (Always Have These)
| Fluid | Spec | Where Used |
|---|---|---|
| Engine oil | 5W-30 full synthetic | Engine. 3.9 quarts with filter change. Gen 2 can consume oil after 100k — check monthly. |
| Toyota Super Long Life Coolant (pink) | Toyota SLLC | Both the engine cooling system and the inverter cooling system use the same SLLC — but they are completely separate circuits that never share fluid. Do NOT mix with green or orange coolant — gelatinous deposits will destroy the inverter pump. Service interval: 100k miles initially, then every 50k miles. |
| DOT 3 brake fluid | DOT 3 | Brake system. Flush every 30k or 2 years — regen braking means pads last forever but fluid still ages. |
Fuse Quick Reference
The Gen 2 Prius has two fuse boxes. Check the diagram printed on each fuse box lid for the complete layout and exact amperage ratings — it's the authoritative reference for your specific car.
- Engine compartment fuse box — under the hood, driver's side near the firewall. Contains the main high-current fuses.
- Interior fuse box — driver's side dash panel, pull the end cap off. Contains accessory and system fuses.
The fuses most relevant to repairs covered on this site:
Replacement fuse assortment (owner-tested):
| Fuse | Box | What It Powers | Repair Connection |
|---|---|---|---|
| DOME | Engine compartment | Interior dome lights and the MFD touchscreen | If the MFD screen goes dark, pull and reseat this fuse first — it's a free 5-minute fix before replacing the screen. → MFD guide |
| AM2 | Engine compartment | Main ECU power feed — retains computer memory when the car is off | Pulling AM2 and reinserting it performs a hard ECU reset, clearing stored adaptations. Used as a troubleshooting step for persistent electrical gremlins that survive a normal 12V disconnect. |
| ABS | Engine compartment | ABS / brake control system main fuse | If the "3 amigos" (ABS + VSC + brake lights) appear immediately after any electrical work, check this fuse before assuming actuator failure. → ABS guide |
| GAUGE | Interior | Instrument cluster (combination meter) | If the entire cluster is completely dead — not just misbehaving gauges — check this fuse before doing a capacitor repair. → Combination meter guide |
| CIG | Interior | 12V accessory outlet (cigarette lighter socket) | If the OBD2 port has no power, this fuse is often the cause — the port shares the same circuit on most Gen 2 trims. → OBD2 guide |