Circuit Description
The module performs internal tests on the EEPROM. Each time the module performs a write function to the EEPROM, the module reads back the data that has been written and makes a comparison. If the data does not match after 3 consecutive write and verify attempts, the module will set B1556 as current.
Conditions for Setting the DTC
| • | The data read back after a write does not match the data being written after 3 consecutive attempts. |
| • | The condition must occur when data is being written. |
Action Taken When the DTC Sets
| • | A DTC B1556 is stored in the BCM memory. |
| • | The BCM stores the value being written in another memory address in the EEPROM. |
Conditions for Clearing the DTC
| • | A current DTC clears when the malfunction is no longer present. |
| • | A history DTC clears when the module ignition cycle counter reaches the reset threshold, without a repeat of the malfunction. |
Diagnostic Aids
| • | 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 a Current DTC, replace the module. |
Step | Action | Yes | No |
|---|---|---|---|
1 | Did you perform the Diagnostic System Check for the system exhibiting the symptom? | Go to Step 2 | Go to Control Module References for the applicable Diagnostic System Check |
2 |
Is the DTC retrieved as a current DTC? | Go to Step 3 | Go to Diagnostic Aids |
3 |
Important: Perform the programming or setup procedure for the module if required. Replace the control module setting the DTC as current. Refer to Control Module References . Did you complete the replacement? | Go to Step 4 | -- |
4 |
Does the DTC reset? | Go to Step 2 | System OK |
