Impreza WRX
- Years
- 2002-2005
- Chassis
- GD / GG (bugeye, blobeye)
- Markets
- USDM, JDM, EDM, ADM, SADM
The flagship, with definition-backed editing and live tuning on qualified calibrations.
Flagship platform / 2001-2006
Classic Subaru. Modern workspace.
Bring ROM editing, logging, diagnostics, and guarded flashing together for the 16-bit classics. A Customer license adds qualified Live Tuning, with feature availability checked against your exact calibration.
WRX · STi · Forester Turbo · Legacy B4 · Outback H6
Explore PulseWidth Classic
Explore the full sample workspace below. All activity is simulated.
PULSEWIDTH CLASSIC
INTERACTIVE PREVIEW
A4TC400L2003 USDM Subaru Impreza WRX (MT)WRX preview.pwt
Colormap: ClassicDemo ECU disconnected
Base Timing
No changesFine:0.5
Swipe to scroll. Select range to edit.
Sample trace paused
Ignition Timing (°)
1 cell selected · 2400 RPM · 1 g/rev23.9
Drag a rectangle · Shift-click a range · Ctrl/⌘-click to toggle cells. Headers select rows or columns. Edits apply to the whole selection.
Full table surface1 selected
Gold area = selected cells · Gold marker = sample lookup
Demo project ready. Drag a range, Shift-click, or Ctrl-click to select cells.
ILLUSTRATIVE PREVIEWInspired by PulseWidth Classic, not an exact clone. Sample table lookups—not a vehicle or engine-response model. No real ECU connection or writes.
LIVE DATA / LOG REVIEW3:00 sample · 3 acceleration segments
Engine Speed3775RPM
Manifold Relative Pressure15.00psi
Throttle Opening Angle94.2%
0:24
FULL LOG TIMELINEViewing 0:15–0:40 of 3:00
Drag to reveal earlier/later data
Move over the graph to follow a datapoint. Pan the timeline below to explore the rest of the log. Synthetic data; not a vehicle measurement.
Total code scans performed: —
Ready to scan
Run a fictional scan, or select an example from shared history.
This preview never reads, clears or changes real codes. No names, VINs, uploaded logs or account identities are stored in demo history. Real vehicle diagnostics remain separate.
FLASH WORKSPACE
Read. Review. Write.
Selected ROMTest rom
- 1Connect
- 2Read
- 3Review
- 4Write
- 5Verify
- 6Reconnect
Try a complete read-to-write session. You control the confirmations; the demo handles the progress and log.
Read Test rom first to create a fictional recovery point.FLASH LOGDemo time · 00:00
Demo ready. Selected ROM: Test rom. No vehicle connected.
Illustrative events only · no device commands
Try the Classic editor: select a table, edit a cell, or enable simulated Live Tuning.Inspired by PulseWidth Classic, not an exact clone. All activity is simulated. Layout and features vary by ROM and license.
Vehicle-specific
Definition matching
PulseWidth checks the vehicle and ECU identity before a supported calibration is opened.
5
Model families
WRX, STi, Forester Turbo, Legacy/Liberty B4, and Outback H6.
0
Soldering irons
Read, flash, log, and diagnose through the factory OBD-II port. No chip pulls, no daughterboards.
Live
Calibration workflow
Qualified tables can be adjusted with immediate ECU feedback while the engine runs.
Compatibility
Find your car.
These are the Subarus that shipped with the 16-bit HC16 ECU. Coverage below comes straight from our definition set, one mapped calibration at a time.
Impreza WRX STi
- Years
- 2001-2006
- Chassis
- GDB
- Markets
- JDM, EDM, ADM
Includes AVCS-equipped models. The USDM 2004+ STi uses a newer 32-bit ECU outside this platform (dedicated edition planned).
Forester Turbo
- Years
- 2001-2003
- Chassis
- SF5 / SG5 (S/tb, early XT)
- Markets
- JDM, EDM, ADM, SADM
The USDM 2004+ Forester XT uses a newer 32-bit ECU outside this platform.
Legacy / Liberty B4
- Years
- 2002-2003
- Chassis
- BE / BH (twin turbo)
- Markets
- JDM, ADM
Includes BH wagons and the 3.0 DOHC six.
Outback H6 3.0
- Years
- 2001-2004
- Chassis
- BH / BP (incl. VDC, L.L.Bean)
- Markets
- USDM, AUDM, JDM
Naturally aspirated six: diagnostics, logging, and calibration access.
| Model | Chassis | Years | Markets | Notes |
|---|---|---|---|---|
| Impreza WRX | GD / GG (bugeye, blobeye) | 2002-2005 | USDM, JDM, EDM, ADM, SADM | The flagship, with definition-backed editing and live tuning on qualified calibrations. |
| Impreza WRX STi | GDB | 2001-2006 | JDM, EDM, ADM | Includes AVCS-equipped models. The USDM 2004+ STi uses a newer 32-bit ECU outside this platform (dedicated edition planned). |
| Forester Turbo | SF5 / SG5 (S/tb, early XT) | 2001-2003 | JDM, EDM, ADM, SADM | The USDM 2004+ Forester XT uses a newer 32-bit ECU outside this platform. |
| Legacy / Liberty B4 | BE / BH (twin turbo) | 2002-2003 | JDM, ADM | Includes BH wagons and the 3.0 DOHC six. |
| Outback H6 3.0 | BH / BP (incl. VDC, L.L.Bean) | 2001-2004 | USDM, AUDM, JDM | Naturally aspirated six: diagnostics, logging, and calibration access. |
Not sure which ECU your car has? Plug in and PulseWidth identifies it automatically. The app reads the calibration ID from the ECU and tells you exactly what is supported before anything is written.
What you get
Modern tooling for a 16-bit ECU.
See the calibration, not just the numbers
Explore definition-backed tables for boost, fueling, ignition, and compensations. Heat maps, chart views, comparison tools, and map tracing help you understand each change in context. ROM-level diagnostic controls remain subject to account compliance requirements.
Flash through the factory port
Reflash your ECU through the stock OBD-II connector with a standard J2534 cable (Tactrix OpenPort 2.0 works out of the box). Before a single byte is written, PulseWidth runs a pre-flight checklist: ROM size and processor match, checksum validation, battery voltage, and a prompt to back up your stock ROM. Dry-run test writes, CRC compare, and read-back verify are built into the flash screen.
Live tuning: change maps while the engine runs
With a paid Customer license, PulseWidth Classic 1.0.2 applies qualified calibration changes in real time on supported release calibrations. Each calibration has its own approved live-table list, and the app verifies the exact ROM before enabling writes. When you're happy, commit the result to a permanent flash.
Launch Control, only where the exact ROM qualifies
Classic 1.0.2 includes Launch Control for exact A4TC400L after the app confirms the ROM identity and manual-transmission vehicle context. Other calibrations keep the feature hidden and blocked in this release instead of presenting an unqualified control.
Profile-matched live data and recording
Stream the channels these ECUs actually expose (RPM, load, timing, knock feedback, boost, temperatures), record them continuously, and keep the result tied to the vehicle and exact tune revision. Reusable logging profiles make it easier to capture the channels relevant to your next tuning step.
Diagnostics without the dealer
Read and clear trouble codes, check readiness, and watch sensors live: the same K-line session the factory tools used, minus the factory tools. DTC descriptions are built in, per calibration.
Your garage, organized
Every car, calibration, ROM revision, and tune session lives in one garage view. Vehicle identity and calibration matching help you keep the correct project in focus.
Straight answers
Questions we actually get.
Is my car supported?
If it's a 2002-2005 WRX (any market), a 2001-2006 JDM/EDM/ADM STi, a 2001-2003 Forester Turbo, a 2002-2003 Legacy/Liberty B4 twin turbo, or a 2001-2004 Outback H6, it almost certainly runs the 16-bit HC16 ECU this platform targets. The fastest way to know for sure: connect with a supported interface such as the Tactrix OpenPort 2.0 and PulseWidth will read your ECU's calibration ID and tell you exactly what's supported.
What hardware do I need?
A Windows PC and a J2534 pass-through cable. The Tactrix OpenPort 2.0 is the reference cable and works out of the box. No ECU removal, no soldering, no eBay adapter roulette.
What is live tuning and does my car get it?
Live tuning lets PulseWidth change qualified calibration values while the engine is running. A paid Customer license enables it for supported HC16 calibrations in Classic 1.0.2; the available tables vary by calibration and are listed in the ROM capability selector. Launch Control is currently limited to exact A4TC400L after the app confirms the ROM and manual-transmission context.
How safe is flashing a 20-year-old ECU?
Safer with guardrails than without. PulseWidth validates ROM size, processor type, and checksums before writing, checks battery voltage, prompts you to save a stock backup, and offers dry-run test writes and read-back verification. No tool can make flashing risk-free, but ours refuses to do the obviously dangerous thing.
My 2004-2005 USDM STi isn't listed. Why?
The USDM 2004+ STi shipped with a newer 32-bit ECU, which sits outside the classic HC16 platform. Same story for the USDM 2004+ Forester XT. Newer generations will get their own dedicated editions later; create a free account and you'll see the announcement when that happens.
Is this legal for my street car?
PulseWidth is advanced calibration and diagnostic tooling for trained users and professionals working toward lawful emissions-compliant calibrations. Account training is required before ROM-level DTC access, but training is not a legal safe harbor and PulseWidth does not certify a vehicle or calibration. Review the emissions policy and obtain qualified advice and testing for your specific use.
Your car has been waiting twenty years for this.
Create a free account to read, edit, flash, log, and diagnose a supported HC16 Subaru. Add a one-time vehicle license when you want live tuning, encrypted PWT projects, and selectable PulseWidth ECU features.