diff --git a/libraries/AP_InertialSensor/AP_InertialSensor.cpp b/libraries/AP_InertialSensor/AP_InertialSensor.cpp
index b9d2aa0b67..e788475693 100644
--- a/libraries/AP_InertialSensor/AP_InertialSensor.cpp
+++ b/libraries/AP_InertialSensor/AP_InertialSensor.cpp
@@ -743,8 +743,8 @@ AP_InertialSensor::detect_backends(void)
         ADD_BACKEND(AP_InertialSensor_Invensense::probe(*this, hal.spi->get_device(HAL_INS_MPU9250_NAME), ROTATION_YAW_270));
         // new cubes have ICM20602, ICM20648, ICM20649
         ADD_BACKEND(AP_InertialSensor_Invensense::probe(*this, hal.spi->get_device("icm20602_ext"), ROTATION_ROLL_180_YAW_270));
-        ADD_BACKEND(AP_InertialSensor_Invensensev2::probe(*this, hal.spi->get_device("icm20948_ext"), ROTATION_ROLL_180_YAW_270));
-        ADD_BACKEND(AP_InertialSensor_Invensensev2::probe(*this, hal.spi->get_device("icm20948"), ROTATION_NONE));
+        ADD_BACKEND(AP_InertialSensor_Invensensev2::probe(*this, hal.spi->get_device("icm20948_ext"), ROTATION_PITCH_180));
+        ADD_BACKEND(AP_InertialSensor_Invensensev2::probe(*this, hal.spi->get_device("icm20948"), ROTATION_YAW_270));
         break;
 
     case AP_BoardConfig::PX4_BOARD_FMUV5:
diff --git a/libraries/AP_InertialSensor/AP_InertialSensor_Invensensev2.cpp b/libraries/AP_InertialSensor/AP_InertialSensor_Invensensev2.cpp
index aeb429c057..cb954e69cc 100644
--- a/libraries/AP_InertialSensor/AP_InertialSensor_Invensensev2.cpp
+++ b/libraries/AP_InertialSensor/AP_InertialSensor_Invensensev2.cpp
@@ -172,24 +172,24 @@ void AP_InertialSensor_Invensensev2::start()
     // grab the used instances
     enum DevTypes gdev, adev;
     switch (_inv2_type) {
-    case Invensensev2_ICM20948:
-        gdev = DEVTYPE_INS_ICM20948;
-        adev = DEVTYPE_INS_ICM20948;
-        _accel_scale = (GRAVITY_MSS / 2048.f);
-        break;
     case Invensensev2_ICM20648:
         gdev = DEVTYPE_INS_ICM20648;
         adev = DEVTYPE_INS_ICM20648;
-        _accel_scale = (GRAVITY_MSS / 2048.f);
+        // using 16g full range, 2048 LSB/g
+        _accel_scale = (GRAVITY_MSS / 2048);
         break;
     case Invensensev2_ICM20649:
+        // 20649 is setup for 30g full scale, 1024 LSB/g
         gdev = DEVTYPE_INS_ICM20649;
         adev = DEVTYPE_INS_ICM20649;
-        _accel_scale = (GRAVITY_MSS / 1024.f);
+        _accel_scale = (GRAVITY_MSS / 1024);
         break;
+    case Invensensev2_ICM20948:
     default:
         gdev = DEVTYPE_INS_ICM20948;
         adev = DEVTYPE_INS_ICM20948;
+        // using 16g full range, 2048 LSB/g
+        _accel_scale = (GRAVITY_MSS / 2048);
         break;
     }
 
@@ -563,8 +563,8 @@ void AP_InertialSensor_Invensensev2::_select_bank(uint8_t bank)
  */
 void AP_InertialSensor_Invensensev2::_set_filter_and_scaling(void)
 {
-    uint8_t gyro_config = BITS_GYRO_FS_2000DPS;
-    uint8_t accel_config = BITS_ACCEL_FS_16G;
+    uint8_t gyro_config = (_inv2_type == Invensensev2_ICM20649)?BITS_GYRO_FS_2000DPS_20649 : BITS_GYRO_FS_2000DPS;
+    uint8_t accel_config = (_inv2_type == Invensensev2_ICM20649)?BITS_ACCEL_FS_30G_20649:BITS_ACCEL_FS_16G;
 
     // assume 1.125kHz sampling to start
     _fifo_downsample_rate = 1;
diff --git a/libraries/AP_InertialSensor/AP_InertialSensor_Invensensev2_registers.h b/libraries/AP_InertialSensor/AP_InertialSensor_Invensensev2_registers.h
index 560c3471f6..06fe0b95bf 100644
--- a/libraries/AP_InertialSensor/AP_InertialSensor_Invensensev2_registers.h
+++ b/libraries/AP_InertialSensor/AP_InertialSensor_Invensensev2_registers.h
@@ -138,6 +138,7 @@
 #       define BITS_GYRO_FS_500DPS                  0x02
 #       define BITS_GYRO_FS_1000DPS                 0x04
 #       define BITS_GYRO_FS_2000DPS                 0x06
+#       define BITS_GYRO_FS_2000DPS_20649           0x04
 #       define BITS_GYRO_FS_MASK                    0x06 // only bits 1 and 2 are used for gyro full scale so use this to mask off other bits
 #define INV2REG_GYRO_CONFIG_2          INV2REG(REG_BANK2,0x02U)
 #define INV2REG_XG_OFFS_USRH           INV2REG(REG_BANK2,0x03U)
@@ -166,6 +167,7 @@
 #       define BITS_ACCEL_FS_4G                      0x02
 #       define BITS_ACCEL_FS_8G                      0x04
 #       define BITS_ACCEL_FS_16G                     0x06
+#       define BITS_ACCEL_FS_30G_20649               0x06
 #       define BITS_ACCEL_FS_MASK                    0x06 // only bits 1 and 2 are used for gyro full scale so use this to mask off other bits
 #define INV2REG_FSYNC_CONFIG           INV2REG(REG_BANK2,0x52U)
 #       define FSYNC_CONFIG_EXT_SYNC_TEMP          0x01