diff --git a/docs/impl/plans/CAN-BITRATE.md b/docs/impl/plans/CAN-BITRATE.md
index 8745eeb..9c35a17 100644
--- a/docs/impl/plans/CAN-BITRATE.md
+++ b/docs/impl/plans/CAN-BITRATE.md
@@ -26,6 +26,9 @@ Persisted (boot and hot-plug):
 (svc-core), the single writer: the adapter now acknowledges frames like any scan tool. To go back, set
 `CAN_OPTS="listen-only on restart-ms 100"` there and replug the PEAK (or restart `can-up@can_pcan`).
 
+obd-poller is **disabled since 2026-10-13**: the Z27AG's ECU never answered OBD-II on CAN (most likely K-line, pin 7,
+not wired). The adapter was left acknowledging anyway, as harmless at the measured bitrate.
+
 ## Goal
 
 Find the bitrate of the bus reachable at the OBD port of the Mitsubishi Colt (Z27AG), then make `can_pcan` come up with it automatically.