diff --git a/db/brand_sparepart.db.js b/db/brand_sparepart.db.js
index 850879d..3cc37f1 100644
--- a/db/brand_sparepart.db.js
+++ b/db/brand_sparepart.db.js
@@ -1,9 +1,128 @@
 const pool = require("../config");
 
-// Get spareparts by brand_id
-const getSparepartsByBrandIdDb = async (brandId) => {
+// Get spareparts by error_code_id
+const getSparepartsByErrorCodeIdDb = async (errorCodeId) => {
   const queryText = `
     SELECT
+      s.sparepart_id,
+      s.sparepart_name,
+      s.sparepart_code,
+      s.sparepart_description,
+      s.sparepart_model,
+      s.sparepart_foto,
+      s.sparepart_item_type,
+      s.sparepart_qty,
+      s.sparepart_unit,
+      s.sparepart_merk,
+      s.sparepart_stok,
+      bs.created_at,
+      bs.created_by
+    FROM brand_spareparts bs
+    JOIN m_sparepart s ON bs.sparepart_id = s.sparepart_id
+    WHERE bs.error_code_id = $1
+    AND s.deleted_at IS NULL
+    ORDER BY s.sparepart_name
+  `;
+  const result = await pool.query(queryText, [errorCodeId]);
+  return result.recordset;
+};
+
+// Get error codes by sparepart_id
+const getErrorCodesBySparepartIdDb = async (sparepartId) => {
+  const queryText = `
+    SELECT
+      ec.error_code_id,
+      ec.error_code,
+      ec.error_code_name,
+      ec.error_code_description,
+      ec.error_code_color,
+      ec.path_icon,
+      ec.is_active,
+      ec.created_at,
+      ec.updated_at
+    FROM brand_spareparts bs
+    JOIN m_error_codes ec ON bs.error_code_id = ec.error_code_id
+    WHERE bs.sparepart_id = $1
+    AND ec.deleted_at IS NULL
+    ORDER BY ec.error_code
+  `;
+  const result = await pool.query(queryText, [sparepartId]);
+  return result.recordset;
+};
+
+// Insert error_code-spareparts relationship
+const insertErrorCodeSparepartDb = async (errorCodeId, sparepartId, createdBy) => {
+  const queryText = `
+    INSERT INTO brand_spareparts (error_code_id, sparepart_id, created_by, created_at)
+    VALUES ($1, $2, $3, CURRENT_TIMESTAMP)
+  `;
+  const result = await pool.query(queryText, [errorCodeId, sparepartId, createdBy]);
+  return result.recordset;
+};
+
+// Insert multiple error_code-spareparts relationships
+const insertMultipleErrorCodeSparepartsDb = async (errorCodeId, sparepartIds, createdBy) => {
+  if (!sparepartIds || sparepartIds.length === 0) return [];
+
+  const values = sparepartIds.map((_, index) => `($1, $${index + 2}, $${sparepartIds.length + 2}, CURRENT_TIMESTAMP)`).join(', ');
+  const queryText = `
+    INSERT INTO brand_spareparts (error_code_id, sparepart_id, created_by, created_at)
+    VALUES ${values}
+  `;
+  const params = [errorCodeId, ...sparepartIds, createdBy];
+  const result = await pool.query(queryText, params);
+  return result.recordset;
+};
+
+// Delete specific error_code-sparepart relationship
+const deleteErrorCodeSparepartDb = async (errorCodeId, sparepartId) => {
+  const queryText = `
+    DELETE FROM brand_spareparts
+    WHERE error_code_id = $1 AND sparepart_id = $2
+  `;
+  const result = await pool.query(queryText, [errorCodeId, sparepartId]);
+  return result.rowsAffected > 0;
+};
+
+// Delete all spareparts for an error_code
+const deleteAllErrorCodeSparepartsDb = async (errorCodeId) => {
+  const queryText = `
+    DELETE FROM brand_spareparts
+    WHERE error_code_id = $1
+  `;
+  const result = await pool.query(queryText, [errorCodeId]);
+  return result.rowsAffected > 0;
+};
+
+// Update error_code-spareparts (replace all)
+const updateErrorCodeSparepartsDb = async (errorCodeId, sparepartIds, updatedBy) => {
+  // Delete existing relationships
+  await deleteAllErrorCodeSparepartsDb(errorCodeId);
+
+  // Insert new relationships
+  if (sparepartIds && sparepartIds.length > 0) {
+    return await insertMultipleErrorCodeSparepartsDb(errorCodeId, sparepartIds, updatedBy);
+  }
+
+  return true;
+};
+
+// Check if error_code-sparepart relationship exists
+const checkErrorCodeSparepartExistsDb = async (errorCodeId, sparepartId) => {
+  const queryText = `
+    SELECT 1
+    FROM brand_spareparts
+    WHERE error_code_id = $1 AND sparepart_id = $2
+  `;
+  const result = await pool.query(queryText, [errorCodeId, sparepartId]);
+  return result.recordset.length > 0;
+};
+
+// Legacy functions for backward compatibility (deprecated)
+// Get spareparts by brand_id (now using error_code_id mapping via error codes)
+const getSparepartsByBrandIdDb = async (brandId) => {
+  const queryText = `
+    SELECT DISTINCT
       s.sparepart_id,
       s.sparepart_name,
       s.sparepart_code,
@@ -19,18 +138,20 @@ const getSparepartsByBrandIdDb = async (brandId) => {
       s.updated_at
     FROM brand_spareparts bs
     JOIN m_sparepart s ON bs.sparepart_id = s.sparepart_id
-    WHERE bs.brand_id = $1
+    JOIN m_error_codes ec ON bs.error_code_id = ec.error_code_id
+    WHERE ec.brand_id = $1
     AND s.deleted_at IS NULL
+    AND ec.deleted_at IS NULL
     ORDER BY s.sparepart_name
   `;
   const result = await pool.query(queryText, [brandId]);
   return result.recordset;
 };
 
-// Get brands by sparepart_id
+// Get brands by sparepart_id (now using error_code_id mapping)
 const getBrandsBySparepartIdDb = async (sparepartId) => {
   const queryText = `
-    SELECT
+    SELECT DISTINCT
       b.brand_id,
       b.brand_name,
       b.brand_type,
@@ -41,8 +162,12 @@ const getBrandsBySparepartIdDb = async (sparepartId) => {
       b.created_at,
       b.updated_at
     FROM brand_spareparts bs
-    JOIN m_brands b ON bs.brand_id = b.brand_id
+    JOIN m_sparepart s ON bs.sparepart_id = s.sparepart_id
+    JOIN m_error_codes ec ON bs.error_code_id = ec.error_code_id
+    JOIN m_brands b ON ec.brand_id = b.brand_id
     WHERE bs.sparepart_id = $1
+    AND s.deleted_at IS NULL
+    AND ec.deleted_at IS NULL
     AND b.deleted_at IS NULL
     ORDER BY b.brand_name
   `;
@@ -50,81 +175,16 @@ const getBrandsBySparepartIdDb = async (sparepartId) => {
   return result.recordset;
 };
 
-// Insert brand-spareparts relationship
-const insertBrandSparepartDb = async (brandId, sparepartId, createdBy) => {
-  const queryText = `
-    INSERT INTO brand_spareparts (brand_id, sparepart_id, created_by, created_at)
-    VALUES ($1, $2, $3, CURRENT_TIMESTAMP)
-  `;
-  const result = await pool.query(queryText, [brandId, sparepartId, createdBy]);
-  return result.recordset;
-};
-
-// Insert multiple brand-spareparts relationships
-const insertMultipleBrandSparepartsDb = async (brandId, sparepartIds, createdBy) => {
-  if (!sparepartIds || sparepartIds.length === 0) return [];
-
-  const values = sparepartIds.map((_, index) => `($1, $${index + 2}, $${sparepartIds.length + 2}, CURRENT_TIMESTAMP)`).join(', ');
-  const queryText = `
-    INSERT INTO brand_spareparts (brand_id, sparepart_id, created_by, created_at)
-    VALUES ${values}
-  `;
-  const params = [brandId, ...sparepartIds, createdBy];
-  const result = await pool.query(queryText, params);
-  return result.recordset;
-};
-
-// Delete specific brand-sparepart relationship
-const deleteBrandSparepartDb = async (brandId, sparepartId) => {
-  const queryText = `
-    DELETE FROM brand_spareparts
-    WHERE brand_id = $1 AND sparepart_id = $2
-  `;
-  const result = await pool.query(queryText, [brandId, sparepartId]);
-  return result.rowsAffected > 0;
-};
-
-// Delete all spareparts for a brand
-const deleteAllBrandSparepartsDb = async (brandId) => {
-  const queryText = `
-    DELETE FROM brand_spareparts
-    WHERE brand_id = $1
-  `;
-  const result = await pool.query(queryText, [brandId]);
-  return result.rowsAffected > 0;
-};
-
-// Update brand-spareparts (replace all)
-const updateBrandSparepartsDb = async (brandId, sparepartIds, updatedBy) => {
-  // Delete existing relationships
-  await deleteAllBrandSparepartsDb(brandId);
-
-  // Insert new relationships
-  if (sparepartIds && sparepartIds.length > 0) {
-    return await insertMultipleBrandSparepartsDb(brandId, sparepartIds, updatedBy);
-  }
-
-  return true;
-};
-
-// Check if brand-sparepart relationship exists
-const checkBrandSparepartExistsDb = async (brandId, sparepartId) => {
-  const queryText = `
-    SELECT 1
-    FROM brand_spareparts
-    WHERE brand_id = $1 AND sparepart_id = $2
-  `;
-  const result = await pool.query(queryText, [brandId, sparepartId]);
-  return result.recordset.length > 0;
-};
+// Deprecated functions removed - table structure changed to use error_code_id instead of brand_id
 
 module.exports = {
-  getSparepartsByBrandIdDb,
-  getBrandsBySparepartIdDb,
-  insertBrandSparepartDb,
-  insertMultipleBrandSparepartsDb,
-  deleteBrandSparepartDb,
-  deleteAllBrandSparepartsDb,
-  updateBrandSparepartsDb,
-  checkBrandSparepartExistsDb,
+  // New functions using error_code_id
+  getSparepartsByErrorCodeIdDb,
+  getErrorCodesBySparepartIdDb,
+  insertErrorCodeSparepartDb,
+  insertMultipleErrorCodeSparepartsDb,
+  deleteErrorCodeSparepartDb,
+  deleteAllErrorCodeSparepartsDb,
+  updateErrorCodeSparepartsDb,
+  checkErrorCodeSparepartExistsDb,
 };
\ No newline at end of file
diff --git a/services/brand.service.js b/services/brand.service.js
index 84c498d..867f55a 100644
--- a/services/brand.service.js
+++ b/services/brand.service.js
@@ -9,9 +9,9 @@ const {
 } = require("../db/brand.db");
 
 const {
-  insertMultipleBrandSparepartsDb,
-  updateBrandSparepartsDb,
-  getSparepartsByBrandIdDb,
+  insertMultipleErrorCodeSparepartsDb,
+  updateErrorCodeSparepartsDb,
+  getSparepartsByErrorCodeIdDb,
 } = require("../db/brand_sparepart.db");
 
 // Error code operations
@@ -41,20 +41,10 @@ class BrandService {
     try {
       const results = await getAllBrandsDb(param);
 
-      // Add spareparts data for each brand
-      const brandsWithSpareparts = await Promise.all(
-        results.data.map(async (brand) => {
-          const spareparts = await getSparepartsByBrandIdDb(brand.brand_id);
-          return {
-            ...brand,
-            spareparts: spareparts
-          };
-        })
-      );
-
+      // Return brands data - spareparts are now associated with error codes, not brands
       return {
         ...results,
-        data: brandsWithSpareparts
+        data: results.data
       };
     } catch (error) {
       throw new ErrorHandler(error.statusCode, error.message);
@@ -67,17 +57,17 @@ class BrandService {
       const brand = await getBrandByIdDb(id);
       if (!brand) throw new ErrorHandler(404, "Brand not found");
 
-      // Get spareparts for this brand
-      const spareparts = await getSparepartsByBrandIdDb(brand.brand_id);
-
       const errorCodes = await getErrorCodesByBrandIdDb(brand.brand_id);
 
-      const errorCodesWithSolutions = await Promise.all(
+      const errorCodesWithSolutionsAndSpareparts = await Promise.all(
         errorCodes.map(async (errorCode) => {
           const solutions = await getSolutionsByErrorCodeIdDb(
             errorCode.error_code_id
           );
 
+          // Get spareparts for this error code
+          const errorCodeSpareparts = await getSparepartsByErrorCodeIdDb(errorCode.error_code_id);
+
           const solutionsWithFiles = await Promise.all(
             solutions.map(async (solution) => {
               let fileData = null;
@@ -112,14 +102,14 @@ class BrandService {
           return {
             ...errorCode,
             solution: solutionsWithFiles,
+            spareparts: errorCodeSpareparts,
           };
         })
       );
 
       return {
         ...brand,
-        spareparts: spareparts,
-        error_code: errorCodesWithSolutions,
+        error_code: errorCodesWithSolutionsAndSpareparts,
       };
     } catch (error) {
       throw new ErrorHandler(error.statusCode, error.message);
@@ -179,10 +169,6 @@ class BrandService {
 
       const brandId = createdBrand.brand_id;
 
-      if (data.spareparts && Array.isArray(data.spareparts) && data.spareparts.length > 0) {
-        await insertMultipleBrandSparepartsDb(brandId, data.spareparts, data.created_by);
-      }
-
       for (const errorCodeData of data.error_code) {
         const errorId = await createErrorCodeDb(brandId, {
           error_code: errorCodeData.error_code,
@@ -198,6 +184,11 @@ class BrandService {
           throw new Error("Failed to create error code");
         }
 
+        // Create sparepart relationships for this error code
+        if (errorCodeData.spareparts && Array.isArray(errorCodeData.spareparts)) {
+          await insertMultipleErrorCodeSparepartsDb(errorId, errorCodeData.spareparts, data.created_by);
+        }
+
         // Create solutions for this error code
         if (errorCodeData.solution && Array.isArray(errorCodeData.solution)) {
           for (const solutionData of errorCodeData.solution) {
@@ -237,33 +228,14 @@ class BrandService {
     }
   }
 
-  // Validate sparepart id
-  static async validateSparepartIds(sparepartIds) {
-    if (!sparepartIds || !Array.isArray(sparepartIds) || sparepartIds.length === 0) {
-      return [];
-    }
-
-    const existingSpareparts = await getSparepartsByIdsDb(sparepartIds);
-
-    if (existingSpareparts.length !== sparepartIds.length) {
-      const existingIds = existingSpareparts.map(sp => sp.sparepart_id);
-      const invalidIds = sparepartIds.filter(id => !existingIds.includes(id));
-      throw new ErrorHandler(400, `Invalid sparepart IDs: ${invalidIds.join(', ')}`);
-    }
-
-    return existingSpareparts;
-  }
-
+  
   // Update brand
   static async updateBrandWithFullData(id, data) {
     try {
       const existingBrand = await getBrandByIdDb(id);
       if (!existingBrand) throw new ErrorHandler(404, "Brand not found");
 
-      if (data.spareparts) {
-        await this.validateSparepartIds(data.spareparts);
-      }
-
+  
       if (data.brand_name && data.brand_name !== existingBrand.brand_name) {
         const brandExists = await checkBrandNameExistsDb(data.brand_name, id);
         if (brandExists) {
@@ -282,10 +254,6 @@ class BrandService {
 
       await updateBrandDb(existingBrand.brand_name, brandData);
 
-      if (data.spareparts !== undefined) {
-        await updateBrandSparepartsDb(existingBrand.brand_id, data.spareparts || [], data.updated_by);
-      }
-
       if (data.error_code && Array.isArray(data.error_code)) {
         const existingErrorCodes = await getErrorCodesByBrandIdDb(id);
         const incomingErrorCodes = data.error_code.map((ec) => ec.error_code);
@@ -312,6 +280,10 @@ class BrandService {
               }
             );
 
+            if (errorCodeData.spareparts && Array.isArray(errorCodeData.spareparts)) {
+              await updateErrorCodeSparepartsDb(existingEC.error_code_id, errorCodeData.spareparts, data.updated_by);
+            }
+
             if (
               errorCodeData.solution &&
               Array.isArray(errorCodeData.solution)
@@ -380,6 +352,10 @@ class BrandService {
               created_by: data.updated_by,
             });
 
+            if (errorCodeData.spareparts && Array.isArray(errorCodeData.spareparts)) {
+              await insertMultipleErrorCodeSparepartsDb(errorId, errorCodeData.spareparts, data.updated_by);
+            }
+
             if (
               errorCodeData.solution &&
               Array.isArray(errorCodeData.solution)
diff --git a/validate/brand.schema.js b/validate/brand.schema.js
index 5d9d30f..57fe595 100644
--- a/validate/brand.schema.js
+++ b/validate/brand.schema.js
@@ -10,7 +10,6 @@ const insertBrandSchema = Joi.object({
   brand_model: Joi.string().max(100).optional().allow(""),
   is_active: Joi.boolean().required(),
   description: Joi.string().max(255).optional().allow(""),
-  spareparts: Joi.array().items(Joi.number().integer()).optional(), // Array of sparepart_id
   error_code: Joi.array()
     .items(
       Joi.object({
@@ -21,6 +20,7 @@ const insertBrandSchema = Joi.object({
         path_icon: Joi.string().optional().allow(""),
         is_active: Joi.boolean().required(),
         what_action_to_take: Joi.string().optional().allow(""),
+        spareparts: Joi.array().items(Joi.number().integer()).optional(),
         solution: Joi.array()
           .items(
             Joi.object({
@@ -57,7 +57,6 @@ const updateBrandSchema = Joi.object({
   brand_model: Joi.string().max(100).optional().allow(""),
   is_active: Joi.boolean().required(),
   description: Joi.string().max(255).optional().allow(""),
-  spareparts: Joi.array().items(Joi.number().integer()).optional(), // Array of sparepart_id
   error_code: Joi.array()
     .items(
       Joi.object({
@@ -68,6 +67,7 @@ const updateBrandSchema = Joi.object({
         path_icon: Joi.string().optional().allow(""),
         is_active: Joi.boolean().required(),
         what_action_to_take: Joi.string().optional().allow(""),
+        spareparts: Joi.array().items(Joi.number().integer()).optional(), 
         solution: Joi.array()
           .items(
             Joi.object({