diff --git a/fs-common-bitproto/can.bitproto b/fs-common-bitproto/can.bitproto
index 422312e..ad5957e 100644
--- a/fs-common-bitproto/can.bitproto
+++ b/fs-common-bitproto/can.bitproto
@@ -42,6 +42,9 @@ message ACCReport {
     bool IMD_UVLO = 12; /* IMD Under Voltage Lock Out, will read 20Hz square wave */
     bool IMD_error = 13; /* 1 if IMD device reports error, this is device error not insulation fault, will read 40Hz square wave */
     bool IMD_earth_connection_fault = 14; /* 1 if IMD detected earth conneciton fault, wil lread 50Hz square wave */
+
+    bool AMS_internal_software_fault = 15; /* 1 if there is a fault in the software at some point */
+
     uint8 IMD_insulation_meas = 17; /* A 0 ~ 100 percentage value that represent the insulation quality measured from IMD. It is measured from IMD_STM_MEAS square_wave's duty cycle in normal_state, the 10Hz square wave */
 }