From 29cb892e1a0afb2ad1e647f100bf9f789291dad8 Mon Sep 17 00:00:00 2001
From: firestar5683 <168790843+firestar5683@users.noreply.github.com>
Date: Sat, 18 Jul 2026 19:17:25 -0500
Subject: [PATCH] Toyota

---
 opendbc_repo/opendbc/car/toyota/interface.py  |  7 ++++++-
 .../opendbc/car/toyota/tests/test_toyota.py   | 20 +++++++++++++++++++
 2 files changed, 26 insertions(+), 1 deletion(-)

diff --git a/opendbc_repo/opendbc/car/toyota/interface.py b/opendbc_repo/opendbc/car/toyota/interface.py
index 29cb7fd77..2278606d9 100644
--- a/opendbc_repo/opendbc/car/toyota/interface.py
+++ b/opendbc_repo/opendbc/car/toyota/interface.py
@@ -62,8 +62,13 @@ class CarInterface(CarInterfaceBase):
 
     # A DSU bypass adapter reroutes the stock DSU messages to the camera bus.
     # These messages are normally absent there on pre-TSS2 platforms.
+    # Require the native-bus message to be absent so startup relay mirroring is not mistaken for an adapter.
+    pt_fingerprint = fingerprint.get(0, {})
+    radar_fingerprint = fingerprint.get(1, {})
     camera_fingerprint = fingerprint.get(2, {})
-    if not use_sdsu and candidate not in TSS2_CAR and (0x343 in camera_fingerprint or 0x4CB in camera_fingerprint):
+    has_dsu_bypass = ((0x343 in camera_fingerprint and 0x343 not in radar_fingerprint) or
+                      (0x4CB in camera_fingerprint and 0x4CB not in pt_fingerprint))
+    if not use_sdsu and candidate not in TSS2_CAR and has_dsu_bypass:
       ret.flags |= ToyotaFlags.DSU_BYPASS.value
 
     # In TSS2 cars, the camera does long control
diff --git a/opendbc_repo/opendbc/car/toyota/tests/test_toyota.py b/opendbc_repo/opendbc/car/toyota/tests/test_toyota.py
index 535b46994..8fe72e05e 100644
--- a/opendbc_repo/opendbc/car/toyota/tests/test_toyota.py
+++ b/opendbc_repo/opendbc/car/toyota/tests/test_toyota.py
@@ -113,6 +113,26 @@ class TestToyotaInterfaces:
       assert message not in can_parsers[Bus.pt].vl
       assert message in can_parsers[Bus.cam].vl
 
+  @pytest.mark.parametrize(("native_bus", "message"), [(1, 0x343), (0, 0x4CB)])
+  def test_dsu_bypass_ignores_startup_bus_mirror(self, native_bus, message):
+    fingerprint = {bus: {} for bus in range(8)}
+    fingerprint[native_bus][message] = 8
+    fingerprint[2][message] = 8
+
+    car_params = CarInterface.get_params(
+      CAR.LEXUS_IS,
+      fingerprint,
+      [],
+      alpha_long=False,
+      is_release=False,
+      docs=False,
+      starpilot_toggles=SimpleNamespace(),
+    )
+
+    assert not car_params.flags & ToyotaFlags.DSU_BYPASS.value
+    assert not car_params.openpilotLongitudinalControl
+    assert car_params.safetyConfigs[0].safetyParam & ToyotaSafetyFlags.STOCK_LONGITUDINAL.value
+
   def test_dsu_bypass_does_not_change_tss2_or_smart_dsu(self):
     fingerprint = {bus: {} for bus in range(8)}
     fingerprint[0][0x2FF] = 8