For 1990-2009 cars only
Circuit Description
The SBM calibrations are stored in EEPROM (Electronically Erasable Programmable Read Only Memory).
When you turn ON the ignition, the SBM performs internal tests on the EEPROM. The tests may determine the integrity of the non-volatile memory. The SBM attempts to write to the non-volatile memory when the ignition turns ON. After 3 unsuccessful attempts at writing to the non-volatile memory, the SBM will indicate that a calibration malfunction (error) is current.
Conditions for Setting the DTC
| • | The SBM has 3 consecutive unsuccessful attempts at writing to the non-volatile memory. |
| • | The SBM detects an internal memory malfunction (write error). |
| • | The condition occurs when the ignition is first turned ON. |
Action Taken When the DTC Sets
| • | DTC B1656 stores in the SBM memory. |
| • | No driver warning message will display for this DTC. |
Conditions for Clearing the DTC
| • | Under all fault conditions the ignition must be cycled before this DTC will change to history. |
| • | The SBM no longer detects an internal memory malfunction condition (write error). |
| • | A history DTC will clear after 50 consecutive ignition cycles if the condition for the malfunction is no longer present. |
Diagnostic Aids
| • | The EEPROM is not removable from the SBM. |
| • | A DTC B1656 is an internal malfunction to the SBM. |
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 | Did you perform the Body Control Module Diagnostic System Check? | -- | Go to Step 2 | |
2 |
Is the repair complete? | -- | Go to Step 3 | -- |
3 |
Is the repair complete? | -- | -- |
