| Error Code | Error Description |
| 4001 | Unable to read SMSC from SIM |
| 4002 | Unable to save SMSC |
| 4003 | Unable to set validity period |
| 4004 | Invalid destination number |
| 4005 | Invalid long message action |
| 4006 | Cannot check PDU mode support |
| 4007 | Modem does not support PDU mode |
| 4008 | Cannot connect to modem for sending message |
| 4009 | Send message command error |
| 4010 | Invalid response to send message command |
| 4011 | Submit PDU error |
| 4012 | Invalid response to submit PDU |
| 4013 | Invalid send delay value |
| 4014 | Invalid send retry value |
| 4015 | Invalid character encoding |
| 4016 | Send message error |
| 4017 | Error generating message PDU |
| 4018 | SMSC not specified |
| 4019 | Cannot set communication timeout values |
| 4020 | Unknown error while sending message |