Checklist v4: step 31, each wheel by hand on stands; DECODE-3: 449 bytes 0, 1, 3 as climate-control sensor candidates

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01DDwfd6Ki8UfG4hK6W5YpJz

docs/impl/plans/Z27AG-CAPTURES.md

@@ -1,7 +1,7 @@
 ---
 type: plan
 status: ready
-updated: 2026-10-14
+updated: 2026-10-15
 ---
 # Z27AG decoding captures: what to do in the car
 
@@ -59,7 +59,9 @@ recorder refuses marks with "no session" otherwise); engine off, doors shut.
 - **On jack stands** (23–26, since v2): front wheels up, rears chocked, handbrake
   off. Unpowered steering; speedometer readings held in 2nd and 3rd (fronts turn,
   rears stay still, which tells the wheels apart); braking from speed with vacuum
-  assist; reverse. Stands replace the driving speeds where a drive is not practical.
+  assist; reverse. Stands replace the driving speeds where a drive is not practical. Step 31
+  (since v4, kept in this section, numbered after the IMU steps so earlier numbers stay): each
+  wheel spun by hand, the other front held still; the rears only if they are raised too.
 - **IMU calibration** (27–30, since v3): once the IMU is fixed in its final place. Level
   twice on the same spot, facing one way and then turned round (a rough 180° is fine:
   the ground's slope reverses and cancels, the mounting's tilt does not); then three
@@ -67,7 +69,7 @@ recorder refuses marks with "no session" otherwise); engine off, doors shut.
   which kind of stretch it is). Any session holds raw IMU samples (`imu.bin`), so
   these can go in their own short session or with anything else.
 
-Version 3 (2026-10-14) adds the IMU calibration section. Version 2 (2026-10-13) adds the stands section and writes down the conditions the
+Version 4 (2026-10-15) adds step 31, one wheel at a time by hand. Version 3 (2026-10-14) adds the IMU calibration section. Version 2 (2026-10-13) adds the stands section and writes down the conditions the
 first run showed matter: engine off and handbrake on for 1–13, foot brake held for
 the handbrake step, neutral with the clutch up for the revs.