diff --git a/automotive/remoteaccess/hal/default/src/RemoteAccessService.cpp b/automotive/remoteaccess/hal/default/src/RemoteAccessService.cpp
index 2a7f209..1b42a1f 100644
--- a/automotive/remoteaccess/hal/default/src/RemoteAccessService.cpp
+++ b/automotive/remoteaccess/hal/default/src/RemoteAccessService.cpp
@@ -331,6 +331,24 @@
     ClientContext context;
     ScheduleTaskRequest request = {};
     ScheduleTaskResponse response = {};
+
+    if (scheduleInfo.count < 0) {
+        return ScopedAStatus::fromExceptionCodeWithMessage(EX_ILLEGAL_ARGUMENT,
+                                                           "count must be >= 0");
+    }
+    if (scheduleInfo.startTimeInEpochSeconds < 0) {
+        return ScopedAStatus::fromExceptionCodeWithMessage(EX_ILLEGAL_ARGUMENT,
+                                                           "startTimeInEpochSeconds must be >= 0");
+    }
+    if (scheduleInfo.periodicInSeconds < 0) {
+        return ScopedAStatus::fromExceptionCodeWithMessage(EX_ILLEGAL_ARGUMENT,
+                                                           "periodicInSeconds must be >= 0");
+    }
+    if (scheduleInfo.taskData.size() > scheduleInfo.MAX_TASK_DATA_SIZE_IN_BYTES) {
+        return ScopedAStatus::fromExceptionCodeWithMessage(EX_ILLEGAL_ARGUMENT,
+                                                           "task data too big");
+    }
+
     request.mutable_scheduleinfo()->set_clientid(scheduleInfo.clientId);
     request.mutable_scheduleinfo()->set_scheduleid(scheduleInfo.scheduleId);
     request.mutable_scheduleinfo()->set_data(scheduleInfo.taskData.data(),
@@ -348,7 +366,8 @@
         case ErrorCode::OK:
             return ScopedAStatus::ok();
         case ErrorCode::INVALID_ARG:
-            return ScopedAStatus::fromExceptionCode(EX_ILLEGAL_ARGUMENT);
+            return ScopedAStatus::fromExceptionCodeWithMessage(
+                    EX_ILLEGAL_ARGUMENT, "received invalid_arg from grpc server");
         default:
             // Should not happen.
             return ScopedAStatus::fromServiceSpecificErrorWithMessage(
diff --git a/automotive/remoteaccess/hal/default/test/RemoteAccessServiceUnitTest.cpp b/automotive/remoteaccess/hal/default/test/RemoteAccessServiceUnitTest.cpp
index a46a983..7992a50 100644
--- a/automotive/remoteaccess/hal/default/test/RemoteAccessServiceUnitTest.cpp
+++ b/automotive/remoteaccess/hal/default/test/RemoteAccessServiceUnitTest.cpp
@@ -473,7 +473,71 @@
     EXPECT_EQ(grpcRequest.scheduleinfo().periodicinseconds(), kTestPeriodicInSeconds);
 }
 
-TEST_F(RemoteAccessServiceUnitTest, TestScheduleTask_InvalidArg) {
+TEST_F(RemoteAccessServiceUnitTest, TestScheduleTask_InvalidCount) {
+    ScheduleInfo scheduleInfo = {
+            .clientId = kTestClientId,
+            .scheduleId = kTestScheduleId,
+            .taskData = kTestData,
+            .count = -1,
+            .startTimeInEpochSeconds = kTestStartTimeInEpochSeconds,
+            .periodicInSeconds = kTestPeriodicInSeconds,
+    };
+
+    ScopedAStatus status = getService()->scheduleTask(scheduleInfo);
+
+    ASSERT_FALSE(status.isOk());
+    ASSERT_EQ(status.getExceptionCode(), EX_ILLEGAL_ARGUMENT);
+}
+
+TEST_F(RemoteAccessServiceUnitTest, TestScheduleTask_InvalidStartTimeInEpochSeconds) {
+    ScheduleInfo scheduleInfo = {
+            .clientId = kTestClientId,
+            .scheduleId = kTestScheduleId,
+            .taskData = kTestData,
+            .count = kTestCount,
+            .startTimeInEpochSeconds = -1,
+            .periodicInSeconds = kTestPeriodicInSeconds,
+    };
+
+    ScopedAStatus status = getService()->scheduleTask(scheduleInfo);
+
+    ASSERT_FALSE(status.isOk());
+    ASSERT_EQ(status.getExceptionCode(), EX_ILLEGAL_ARGUMENT);
+}
+
+TEST_F(RemoteAccessServiceUnitTest, TestScheduleTask_InvalidPeriodicInSeconds) {
+    ScheduleInfo scheduleInfo = {
+            .clientId = kTestClientId,
+            .scheduleId = kTestScheduleId,
+            .taskData = kTestData,
+            .count = kTestCount,
+            .startTimeInEpochSeconds = kTestStartTimeInEpochSeconds,
+            .periodicInSeconds = -1,
+    };
+
+    ScopedAStatus status = getService()->scheduleTask(scheduleInfo);
+
+    ASSERT_FALSE(status.isOk());
+    ASSERT_EQ(status.getExceptionCode(), EX_ILLEGAL_ARGUMENT);
+}
+
+TEST_F(RemoteAccessServiceUnitTest, TestScheduleTask_TaskDataTooLarge) {
+    ScheduleInfo scheduleInfo = {
+            .clientId = kTestClientId,
+            .scheduleId = kTestScheduleId,
+            .taskData = std::vector<uint8_t>(ScheduleInfo::MAX_TASK_DATA_SIZE_IN_BYTES + 1),
+            .count = kTestCount,
+            .startTimeInEpochSeconds = kTestStartTimeInEpochSeconds,
+            .periodicInSeconds = kTestPeriodicInSeconds,
+    };
+
+    ScopedAStatus status = getService()->scheduleTask(scheduleInfo);
+
+    ASSERT_FALSE(status.isOk());
+    ASSERT_EQ(status.getExceptionCode(), EX_ILLEGAL_ARGUMENT);
+}
+
+TEST_F(RemoteAccessServiceUnitTest, TestScheduleTask_InvalidArgFromGrpcServer) {
     EXPECT_CALL(*getGrpcWakeupClientStub(), ScheduleTask)
             .WillOnce([]([[maybe_unused]] ClientContext* context,
                          [[maybe_unused]] const ScheduleTaskRequest& request,