The internal fault detection is handled inside the control module. No external circuits are involved.
The control module runs a program to detect an internal fault when power up is commanded. The only requirements are voltage and ground.
| • | The control module detects an internal write error. | 
| • | The control module detects an internal checksum error. | 
The microprocessor refuses all additional inputs.
| • | The current DTC B1000 will clear when the microprocessor makes a successful write to the EEPROM and checksum maneuver. | 
| • | A history DTC B1000 will clear after 100 consecutive ignition switch ON/OFF cycles if the condition for the malfunction is no longer present. | 
| • | This DTC may be stored as a history DTC with out affecting the operation of the module. If stored only as a history DTC and not retrieved as a current DTC, do not replace the module. | 
| • | If this DTC is retrieved as both a Current and History DTC, replace the module. | 
Step  | Action  | Yes  | No  | 
|---|---|---|---|
1  | Preform the Diagnostic System Check for the system exhibiting symptoms. Refer to Control Module References . Did you perform the Diagnostic System Check?  | Go to Step 2  | |
2  | Is the DTC received as a current DTC?  | Go to Step 3  | Go to Diagnostic Aids  | 
3  | 
 Important: Perform the control module programming/configuration procedure if required. Replace the control module. Refer to Control Module References . Did you complete the replacement?  | System OK  | --  |