diff --git a/tests/codec/codec_ecu_fr_test.ok b/tests/codec/codec_ecu_fr_test.ok
index 30163a9..d925e28 100644
--- a/tests/codec/codec_ecu_fr_test.ok
+++ b/tests/codec/codec_ecu_fr_test.ok
@@ -41,6 +41,49 @@
 conceal: 17, result: d00000000000000000000000000000000000000000000000000000000000000000 XMAXC: [0, 0, 0, 0]
 conceal: 18, result: d00000000000000000000000000000000000000000000000000000000000000000 XMAXC: [0, 0, 0, 0]
 conceal: 19, result: d00000000000000000000000000000000000000000000000000000000000000000 XMAXC: [0, 0, 0, 0]
+=> Testing FR concealment (simple, consecutive bad frames)
+Start with: d9ec9be212901f802335598c501f805bad3d4ba01f809b69df5a501f809cd1b4da, XMAXC: [3f, 3f, 3f, 3f]
+conceal: 00, result: d9ec9be212901f802335598c501f805bad3d4ba01f809b69df5a501f809cd1b4da XMAXC: [3f, 3f, 3f, 3f]
+conceal: 01, result: d9ec9be212901d802335598c501d805bad3d4ba01d809b69df5a501d809cd1b4da XMAXC: [3b, 3b, 3b, 3b]
+conceal: 02, result: d9ec9be212901b802335598c501b805bad3d4ba01b809b69df5a501b809cd1b4da XMAXC: [37, 37, 37, 37]
+conceal: 03, result: d9ec9be2129019802335598c5019805bad3d4ba019809b69df5a5019809cd1b4da XMAXC: [33, 33, 33, 33]
+conceal: 04, result: d9ec9be2129017802335598c5017805bad3d4ba017809b69df5a5017809cd1b4da XMAXC: [2f, 2f, 2f, 2f]
+conceal: 05, result: d9ec9be2129015802335598c5015805bad3d4ba015809b69df5a5015809cd1b4da XMAXC: [2b, 2b, 2b, 2b]
+conceal: 06, result: d9ec9be2129013802335598c5013805bad3d4ba013809b69df5a5013809cd1b4da XMAXC: [27, 27, 27, 27]
+conceal: 07, result: d9ec9be2129011802335598c5011805bad3d4ba011809b69df5a5011809cd1b4da XMAXC: [23, 23, 23, 23]
+conceal: 08, result: d9ec9be212900f802335598c500f805bad3d4ba00f809b69df5a500f809cd1b4da XMAXC: [1f, 1f, 1f, 1f]
+conceal: 09, result: d9ec9be212900d802335598c500d805bad3d4ba00d809b69df5a500d809cd1b4da XMAXC: [1b, 1b, 1b, 1b]
+conceal: 10, result: d9ec9be212900b802335598c500b805bad3d4ba00b809b69df5a500b809cd1b4da XMAXC: [17, 17, 17, 17]
+conceal: 11, result: d9ec9be2129009802335598c5009805bad3d4ba009809b69df5a5009809cd1b4da XMAXC: [13, 13, 13, 13]
+conceal: 12, result: d9ec9be2129007802335598c5007805bad3d4ba007809b69df5a5007809cd1b4da XMAXC: [f, f, f, f]
+conceal: 13, result: d9ec9be2129005802335598c5005805bad3d4ba005809b69df5a5005809cd1b4da XMAXC: [b, b, b, b]
+conceal: 14, result: d9ec9be2129003802335598c5003805bad3d4ba003809b69df5a5003809cd1b4da XMAXC: [7, 7, 7, 7]
+conceal: 15, result: d9ec9be2129001802335598c5001805bad3d4ba001809b69df5a5001809cd1b4da XMAXC: [3, 3, 3, 3]
+conceal: 16, result: d00000000000000000000000000000000000000000000000000000000000000000 XMAXC: [0, 0, 0, 0]
+conceal: 17, result: d00000000000000000000000000000000000000000000000000000000000000000 XMAXC: [0, 0, 0, 0]
+conceal: 18, result: d00000000000000000000000000000000000000000000000000000000000000000 XMAXC: [0, 0, 0, 0]
+conceal: 19, result: d00000000000000000000000000000000000000000000000000000000000000000 XMAXC: [0, 0, 0, 0]
+Start with: d9ec9be212901d802335598c5013805bad3d4ba01f809b69df5a5019809cd1b4da, XMAXC: [3b, 27, 3f, 33]
+conceal: 00, result: d9ec9be212901d802335598c5013805bad3d4ba01f809b69df5a5019809cd1b4da XMAXC: [3b, 27, 3f, 33]
+conceal: 01, result: d9ec9be212901b802335598c5011805bad3d4ba01d809b69df5a5017809cd1b4da XMAXC: [37, 23, 3b, 2f]
+conceal: 02, result: d9ec9be2129019802335598c500f805bad3d4ba01b809b69df5a5015809cd1b4da XMAXC: [33, 1f, 37, 2b]
+conceal: 03, result: d9ec9be2129017802335598c500d805bad3d4ba019809b69df5a5013809cd1b4da XMAXC: [2f, 1b, 33, 27]
+conceal: 04, result: d9ec9be2129015802335598c500b805bad3d4ba017809b69df5a5011809cd1b4da XMAXC: [2b, 17, 2f, 23]
+conceal: 05, result: d9ec9be2129013802335598c5009805bad3d4ba015809b69df5a500f809cd1b4da XMAXC: [27, 13, 2b, 1f]
+conceal: 06, result: d9ec9be2129011802335598c5007805bad3d4ba013809b69df5a500d809cd1b4da XMAXC: [23, f, 27, 1b]
+conceal: 07, result: d9ec9be212900f802335598c5005805bad3d4ba011809b69df5a500b809cd1b4da XMAXC: [1f, b, 23, 17]
+conceal: 08, result: d9ec9be212900d802335598c5003805bad3d4ba00f809b69df5a5009809cd1b4da XMAXC: [1b, 7, 1f, 13]
+conceal: 09, result: d9ec9be212900b802335598c5001805bad3d4ba00d809b69df5a5007809cd1b4da XMAXC: [17, 3, 1b, f]
+conceal: 10, result: d9ec9be2129009802335598c5000005bad3d4ba00b809b69df5a5005809cd1b4da XMAXC: [13, 0, 17, b]
+conceal: 11, result: d9ec9be2129007802335598c5000005bad3d4ba009809b69df5a5003809cd1b4da XMAXC: [f, 0, 13, 7]
+conceal: 12, result: d9ec9be2129005802335598c5000005bad3d4ba007809b69df5a5001809cd1b4da XMAXC: [b, 0, f, 3]
+conceal: 13, result: d9ec9be2129003802335598c5000005bad3d4ba005809b69df5a5000009cd1b4da XMAXC: [7, 0, b, 0]
+conceal: 14, result: d9ec9be2129001802335598c5000005bad3d4ba003809b69df5a5000009cd1b4da XMAXC: [3, 0, 7, 0]
+conceal: 15, result: d9ec9be2129000002335598c5000005bad3d4ba001809b69df5a5000009cd1b4da XMAXC: [0, 0, 3, 0]
+conceal: 16, result: d00000000000000000000000000000000000000000000000000000000000000000 XMAXC: [0, 0, 0, 0]
+conceal: 17, result: d00000000000000000000000000000000000000000000000000000000000000000 XMAXC: [0, 0, 0, 0]
+conceal: 18, result: d00000000000000000000000000000000000000000000000000000000000000000 XMAXC: [0, 0, 0, 0]
+conceal: 19, result: d00000000000000000000000000000000000000000000000000000000000000000 XMAXC: [0, 0, 0, 0]
 
 => Testing FR concealment (realistic, various bad frames)
 Frame No. 000: