diff --git a/drivers/isimodem/call-barring.c b/drivers/isimodem/call-barring.c
index 6487ae8b..b8b175dc 100644
--- a/drivers/isimodem/call-barring.c
+++ b/drivers/isimodem/call-barring.c
@@ -48,6 +48,28 @@ struct barr_data {
 	GIsiClient *client;
 };
 
+static int lock_code_to_mmi(char const *lock)
+{
+	if (strcmp(lock, "AO") == 0)
+		return SS_GSM_BARR_ALL_OUT;
+	else if (strcmp(lock, "OI") == 0)
+		return SS_GSM_BARR_OUT_INTER;
+	else if (strcmp(lock, "OX") == 0)
+		return SS_GSM_BARR_OUT_INTER_EXC_HOME;
+	else if (strcmp(lock, "AI") == 0)
+		return SS_GSM_BARR_ALL_IN;
+	else if (strcmp(lock, "IR") == 0)
+		return SS_GSM_BARR_ALL_IN_ROAM;
+	else if (strcmp(lock, "AB") == 0)
+		return SS_GSM_ALL_BARRINGS;
+	else if (strcmp(lock, "AG") == 0)
+		return SS_GSM_OUTGOING_BARR_SERV;
+	else if (strcmp(lock, "AC") == 0)
+		return SS_GSM_INCOMING_BARR_SERV;
+	else
+		return 0;
+}
+
 static bool set_resp_cb(GIsiClient *client, const void *restrict data,
 				size_t len, uint16_t object, void *opaque)
 {
@@ -84,19 +106,19 @@ static void isi_set(struct ofono_call_barring *barr, const char *lock,
 {
 	struct barr_data *bd = ofono_call_barring_get_data(barr);
 	struct isi_cb_data *cbd = isi_cb_data_new(barr, cb, data);
-	int ss_code;
-	char *ucs2 = NULL;
+	int ss_code = lock_code_to_mmi(lock);
 
 	unsigned char msg[] = {
 		SS_SERVICE_REQ,
 		enable ? SS_ACTIVATION : SS_DEACTIVATION,
 		SS_ALL_TELE_AND_BEARER,
-		0, 0,				/* Supplementary services code */
-		SS_SEND_ADDITIONAL_INFO,
+		ss_code >> 8, ss_code & 0xFF,	/* Supplementary services code */
+		SS_SEND_ADDITIONAL_INFO,	/* ? */
 		1,				/* Subblock count */
 		SS_GSM_PASSWORD,
 		28,				/* Subblock length */
-		0, 0, 0, 0, 0, 0, 0, 0,		/* Password */
+		0, passwd[0], 0, passwd[1],	/* Password */
+		0, passwd[2], 0, passwd[3],
 		0, 0, 0, 0, 0, 0, 0, 0,		/* Filler */
 		0, 0, 0, 0, 0, 0, 0, 0,		/* Filler */
 		0, 0				/* Filler */
@@ -105,43 +127,10 @@ static void isi_set(struct ofono_call_barring *barr, const char *lock,
 	DBG("lock code %s enable %d class %d password %s\n",
 		lock, enable, cls, passwd);
 
-	if (!cbd || !passwd || strlen(passwd) > 4 || cls != 7)
-		goto error;
-
-	if (strcmp(lock, "AO") == 0)
-		ss_code = SS_GSM_BARR_ALL_OUT;
-	else if (strcmp(lock, "OI") == 0)
-		ss_code = SS_GSM_BARR_OUT_INTER;
-	else if (strcmp(lock, "OX") == 0)
-		ss_code = SS_GSM_BARR_OUT_INTER_EXC_HOME;
-	else if (strcmp(lock, "AI") == 0)
-		ss_code = SS_GSM_BARR_ALL_IN;
-	else if (strcmp(lock, "IR") == 0)
-		ss_code = SS_GSM_BARR_ALL_IN_ROAM;
-	else if (strcmp(lock, "AB") == 0)
-		ss_code = SS_GSM_ALL_BARRINGS;
-	else if (strcmp(lock, "AG") == 0)
-		ss_code = SS_GSM_BARR_ALL_OUT;
-	else if (strcmp(lock, "AC") == 0)
-		ss_code = SS_GSM_BARR_ALL_IN;
-	else
-		goto error;
-
-	msg[3] = ss_code >> 8;
-	msg[4] = ss_code & 0xFF;
-
-	ucs2 = g_convert(passwd, 4, "UCS-2BE", "UTF-8//TRANSLIT",
-				NULL, NULL, NULL);
-	if (ucs2 == NULL)
-		goto error;
-
-	memcpy((char *)msg + 9, ucs2, 8);
-	g_free(ucs2);
-
-	if (g_isi_request_make(bd->client, msg, sizeof(msg), SS_TIMEOUT,
-				set_resp_cb, cbd))
+	if (cbd && g_isi_request_make(bd->client, msg, sizeof(msg), SS_TIMEOUT,
+					set_resp_cb, cbd))
 		return;
-error:
+
 	CALLBACK_WITH_FAILURE(cb, data);
 	g_free(cbd);
 }
@@ -267,43 +256,23 @@ static void isi_query(struct ofono_call_barring *barr, const char *lock, int cls
 {
 	struct barr_data *bd = ofono_call_barring_get_data(barr);
 	struct isi_cb_data *cbd = isi_cb_data_new(barr, cb, data);
-	int ss_code;
+	int ss_code = lock_code_to_mmi(lock);
 
 	unsigned char msg[] = {
 		SS_SERVICE_REQ,
 		SS_INTERROGATION,
 		SS_ALL_TELE_AND_BEARER,
-		0, 0,				/* Supplementary services code */
-		SS_SEND_ADDITIONAL_INFO,
+		ss_code >> 8, ss_code & 0xFF,	/* Supplementary services code */
+		SS_SEND_ADDITIONAL_INFO,	/* Get BER-encoded result, too */
 		0				/* Subblock count */
 	};
 
-	DBG("barring query lock code %s class %d\n", lock, cls);
+	DBG("barring query lock code %s\n", lock);
 
-	if (!cbd || cls != 7)
-		goto error;
-
-	if (strcmp(lock, "AO") == 0)
-		ss_code = SS_GSM_BARR_ALL_OUT;
-	else if (strcmp(lock, "OI") == 0)
-		ss_code = SS_GSM_BARR_OUT_INTER;
-	else if (strcmp(lock, "OX") == 0)
-		ss_code = SS_GSM_BARR_OUT_INTER_EXC_HOME;
-	else if (strcmp(lock, "AI") == 0)
-		ss_code = SS_GSM_BARR_ALL_IN;
-	else if (strcmp(lock, "IR") == 0)
-		ss_code = SS_GSM_BARR_ALL_IN_ROAM;
-	else
-		goto error;
-
-	msg[3] = ss_code >> 8;
-	msg[4] = ss_code & 0xFF;
-
-	if (g_isi_request_make(bd->client, msg, sizeof(msg), SS_TIMEOUT,
-				query_resp_cb, cbd))
+	if (cbd && g_isi_request_make(bd->client, msg, sizeof(msg), SS_TIMEOUT,
+					query_resp_cb, cbd))
 		return;
 
-error:
 	CALLBACK_WITH_FAILURE(cb, 0, data);
 	g_free(cbd);
 }
@@ -343,60 +312,34 @@ static void isi_set_passwd(struct ofono_call_barring *barr, const char *lock,
 {
 	struct barr_data *bd = ofono_call_barring_get_data(barr);
 	struct isi_cb_data *cbd = isi_cb_data_new(barr, cb, data);
-	int ss_code;
-	char *ucs2 = NULL;
+	int ss_code = lock_code_to_mmi(lock);
 
 	unsigned char msg[] = {
 		SS_SERVICE_REQ,
 		SS_GSM_PASSWORD_REGISTRATION,
 		SS_ALL_TELE_AND_BEARER,
-		0, 0,				/* Supplementary services code */
+		ss_code >> 8, ss_code & 0xFF,	/* Supplementary services code */
 		SS_SEND_ADDITIONAL_INFO,
 		1,				/* Subblock count */
 		SS_GSM_PASSWORD,
 		28,				/* Subblock length */
-		0, 0, 0, 0, 0, 0, 0, 0,		/* Old password */
-		0, 0, 0, 0, 0, 0, 0, 0,		/* New password */
-		0, 0, 0, 0, 0, 0, 0, 0,		/* New password */
+		0, old_passwd[0], 0, old_passwd[1],
+		0, old_passwd[2], 0, old_passwd[3],
+		0, new_passwd[0], 0, new_passwd[1],
+		0, new_passwd[2], 0, new_passwd[3],
+		0, new_passwd[0], 0, new_passwd[1],
+		0, new_passwd[2], 0, new_passwd[3],
 		0, 0				/* Filler */
 	};
 
-	if (!cbd || strlen(old_passwd) > 4 || strlen(new_passwd) > 4)
-		goto error;
+	DBG("lock code %s (%u) old password %s new password %s\n",
+		lock, ss_code, old_passwd, new_passwd);
 
-	DBG("lock code %s old password %s new password %s\n",
-		lock, old_passwd, new_passwd);
-
-	if (strcmp(lock, "AB") == 0)
-		ss_code = SS_GSM_ALL_BARRINGS;
-	else
-		goto error;
-
-	msg[3] = ss_code >> 8;
-	msg[4] = ss_code & 0xFF;
-
-	ucs2 = g_convert(old_passwd, 4, "UCS-2BE", "UTF-8//TRANSLIT",
-				NULL, NULL, NULL);
-	if (ucs2 == NULL)
-		goto error;
-
-	memcpy((char *)msg + 9, ucs2, 8);
-	g_free(ucs2);
-
-	ucs2 = g_convert(new_passwd, 4, "UCS-2BE", "UTF-8//TRANSLIT",
-				NULL, NULL, NULL);
-	if (ucs2 == NULL)
-		goto error;
-
-	memcpy((char *)msg + 17, ucs2, 8);
-	memcpy((char *)msg + 25, ucs2, 8);
-	g_free(ucs2);
-
-	if (g_isi_request_make(bd->client, msg, sizeof(msg), SS_TIMEOUT,
+	if (cbd &&
+		g_isi_request_make(bd->client, msg, sizeof(msg), SS_TIMEOUT,
 				set_passwd_resp_cb, cbd))
 		return;
 
-error:
 	CALLBACK_WITH_FAILURE(cb, data);
 	g_free(cbd);
 }
diff --git a/drivers/isimodem/ss.h b/drivers/isimodem/ss.h
index 7c20bcce..93554db0 100644
--- a/drivers/isimodem/ss.h
+++ b/drivers/isimodem/ss.h
@@ -24,102 +24,104 @@
 #ifndef __ISIMODEM_SS_H
 #define __ISIMODEM_SS_H
 
-#define PN_SS			0x06
-#define SS_TIMEOUT		15
-#define SS_MAX_USSD_LENGTH	160
+#define PN_SS				0x06
+#define SS_TIMEOUT			15
+#define SS_MAX_USSD_LENGTH		160
 
 enum ss_message_id {
-	SS_SERVICE_REQ = 0x00,
-	SS_SERVICE_COMPLETED_RESP = 0x01,
-	SS_SERVICE_FAILED_RESP = 0x02,
-	SS_GSM_USSD_SEND_REQ = 0x04,
-	SS_GSM_USSD_SEND_RESP = 0x05,
-	SS_GSM_USSD_RECEIVE_IND = 0x06,
-	SS_STATUS_IND = 0x09,
-	SS_COMMON_MESSAGE = 0xF0
+	SS_SERVICE_REQ = 			0x00,
+	SS_SERVICE_COMPLETED_RESP =		0x01,
+	SS_SERVICE_FAILED_RESP =		0x02,
+	SS_GSM_USSD_SEND_REQ =			0x04,
+	SS_GSM_USSD_SEND_RESP =			0x05,
+	SS_GSM_USSD_RECEIVE_IND =		0x06,
+	SS_STATUS_IND =				0x09,
+	SS_COMMON_MESSAGE =			0xF0
 };
 
 enum ss_ussd_type {
-	SS_GSM_USSD_MT_REPLY = 0x01,
-	SS_GSM_USSD_COMMAND = 0x02,
-	SS_GSM_USSD_REQUEST = 0x03,
-	SS_GSM_USSD_NOTIFY = 0x04,
-	SS_GSM_USSD_END = 0x05
+	SS_GSM_USSD_MT_REPLY =			0x01,
+	SS_GSM_USSD_COMMAND =			0x02,
+	SS_GSM_USSD_REQUEST =			0x03,
+	SS_GSM_USSD_NOTIFY =			0x04,
+	SS_GSM_USSD_END =			0x05
 };
 
 enum ss_ussd_status {
-	SS_GSM_STATUS_REQUEST_USSD_START = 0x02,
-	SS_GSM_STATUS_REQUEST_USSD_STOP = 0x03,
-	SS_GSM_STATUS_REQUEST_USSD_FAILED = 0x04
+	SS_GSM_STATUS_REQUEST_USSD_START =	0x02,
+	SS_GSM_STATUS_REQUEST_USSD_STOP =	0x03,
+	SS_GSM_STATUS_REQUEST_USSD_FAILED =	0x04
 };
 
 enum ss_operations {
-	SS_ACTIVATION = 0x01,
-	SS_DEACTIVATION = 0x02,
-	SS_REGISTRATION = 0x03,
-	SS_ERASURE = 0x04,
-	SS_INTERROGATION = 0x05,
-	SS_GSM_PASSWORD_REGISTRATION = 0x06
+	SS_ACTIVATION =				0x01,
+	SS_DEACTIVATION =			0x02,
+	SS_REGISTRATION =			0x03,
+	SS_ERASURE =				0x04,
+	SS_INTERROGATION =			0x05,
+	SS_GSM_PASSWORD_REGISTRATION =		0x06
 };
 
 enum ss_basic_service_codes {
-	SS_ALL_TELE_AND_BEARER = 0x00,
-	SS_GSM_ALL_TELE = 0x0A,
-	SS_GSM_TELEPHONY = 0x0B,
-	SS_GSM_ALL_DATA_TELE = 0x0C,
-	SS_GSM_FACSIMILE = 0x0D,
-	SS_GSM_SMS = 0x10,
-	SS_GSM_VOICE_GROUP = 0x11,
-	SS_GSM_ALL_TELE_EXC_SMS = 0x13,
-	SS_GSM_ALL_BEARER = 0x14,
-	SS_GSM_ALL_ASYNC = 0x15,
-	SS_GSM_ALL_SYNC = 0x16,
-	SS_GSM_ALL_DATA_CIRCUIT_SYNC = 0x18,
-	SS_GSM_ALL_DATA_CIRCUIT_ASYNC = 0x19,
-	SS_GSM_ALL_DATA_PACKET_SYNC = 0x1A,
-	SS_GSM_ALL_PAD_ACCESS = 0x1B
+	SS_ALL_TELE_AND_BEARER =		0,
+	SS_GSM_ALL_TELE =			10,
+	SS_GSM_TELEPHONY =			11,
+	SS_GSM_ALL_DATA_TELE =			12,
+	SS_GSM_FACSIMILE =			13,
+	SS_GSM_SMS =				16,
+	SS_GSM_VOICE_GROUP =			17,
+	SS_GSM_ALL_TELE_EXC_SMS =		19,
+	SS_GSM_ALL_BEARER =			20,
+	SS_GSM_ALL_ASYNC =			21,
+	SS_GSM_ALL_SYNC =			22,
+	SS_GSM_ALL_DATA_CIRCUIT_SYNC =		24,
+	SS_GSM_ALL_DATA_CIRCUIT_ASYNC =		25,
+	SS_GSM_ALL_DATA_PACKET_SYNC =		26,
+	SS_GSM_ALL_PAD_ACCESS =			27
 };
 
 enum ss_codes {
-	SS_GSM_ALL_FORWARDINGS = 0x02,
-	SS_GSM_ALL_COND_FORWARDINGS = 0x04,
-	SS_GSM_FORW_UNCONDITIONAL = 0x15,
-	SS_GSM_BARR_ALL_OUT = 0x21,
-	SS_GSM_BARR_ALL_IN = 0x23,
-	SS_GSM_CALL_WAITING = 0x2B,
-	SS_GSM_FORW_NO_REPLY = 0x3D,
-	SS_GSM_FORW_NO_REACH = 0x3E,
-	SS_GSM_FORW_BUSY = 0x43,
-	SS_GSM_ALL_BARRINGS = 0x014A,
-	SS_GSM_BARR_OUT_INTER = 0x014B,
-	SS_GSM_BARR_OUT_INTER_EXC_HOME = 0x014C,
-	SS_GSM_BARR_ALL_IN_ROAM = 0x015F
+	SS_GSM_ALL_FORWARDINGS =		002,
+	SS_GSM_ALL_COND_FORWARDINGS =		004,
+	SS_GSM_FORW_UNCONDITIONAL =		21,
+	SS_GSM_BARR_ALL_OUT =			33,
+	SS_GSM_OUTGOING_BARR_SERV =		333,
+	SS_GSM_INCOMING_BARR_SERV =		353,
+	SS_GSM_BARR_ALL_IN =			35,
+	SS_GSM_CALL_WAITING =			43,
+	SS_GSM_FORW_NO_REPLY =			61,
+	SS_GSM_FORW_NO_REACH =			62,
+	SS_GSM_FORW_BUSY =			67,
+	SS_GSM_ALL_BARRINGS =			330,
+	SS_GSM_BARR_OUT_INTER =			331,
+	SS_GSM_BARR_OUT_INTER_EXC_HOME =	332,
+	SS_GSM_BARR_ALL_IN_ROAM =		351,
 };
 
 enum ss_response_data {
-	SS_SEND_ADDITIONAL_INFO = 0x01
+	SS_SEND_ADDITIONAL_INFO =		0x01
 };
 
 enum ss_subblock {
-	SS_FORWARDING = 0x00,
-	SS_STATUS_RESULT = 0x01,
-	SS_GSM_PASSWORD = 0x03,
-	SS_GSM_FORWARDING_INFO = 0x04,
-	SS_GSM_FORWARDING_FEATURE = 0x05,
-	SS_GSM_DATA = 0x08,
-	SS_GSM_BSC_INFO = 0x09,
-	SS_GSM_PASSWORD_INFO = 0x0B,
-	SS_GSM_INDICATE_PASSWORD_ERROR = 0x0D,
-	SS_GSM_INDICATE_ERROR = 0x0E,
-	SS_GSM_ADDITIONAL_INFO = 0x2F,
-	SS_GSM_USSD_STRING = 0x32
+	SS_FORWARDING =				0x00,
+	SS_STATUS_RESULT =			0x01,
+	SS_GSM_PASSWORD =			0x03,
+	SS_GSM_FORWARDING_INFO =		0x04,
+	SS_GSM_FORWARDING_FEATURE =		0x05,
+	SS_GSM_DATA =				0x08,
+	SS_GSM_BSC_INFO =			0x09,
+	SS_GSM_PASSWORD_INFO =			0x0B,
+	SS_GSM_INDICATE_PASSWORD_ERROR =	0x0D,
+	SS_GSM_INDICATE_ERROR =			0x0E,
+	SS_GSM_ADDITIONAL_INFO =		0x2F,
+	SS_GSM_USSD_STRING =			0x32
 };
 
 enum ss_isi_cause {
-	SS_GSM_ACTIVE = 0x01,
-	SS_GSM_REGISTERED = 0x02,
-	SS_GSM_PROVISIONED = 0x04,
-	SS_GSM_QUIESCENT = 0x08
+	SS_GSM_ACTIVE =				0x01,
+	SS_GSM_REGISTERED =			0x02,
+	SS_GSM_PROVISIONED =			0x04,
+	SS_GSM_QUIESCENT =			0x08
 };
 
 #endif /* __ISIMODEM_SS_H */