The memory seat module (MSM) calibrations are stored in the electrically erasable programmable read only memory (EEPROM). When the ignition is first turned ON, the MSM completes the following actions:
• | Performs internal tests on the EEPROM |
• | Determines the integrity of the non-volatile memory |
The MSM compares the previously stored checksum with the checksum calculated when the ignition is first turned ON. If the 2 checksums do not match, the MSM indicates a calibration malfunction (checksum error) is current.
• | The stored checksum does not match the calculated checksum. |
• | The MSM detects an internal memory malfunction (checksum error). |
• | The condition must occur when the ignition is first turned ON. |
• | Stores a DTC B1658 in the MSM memory. |
• | No driver warning message displays for this DTC. |
• | The MSM uses default values for any memory address in the EEPROM that is corrupt. |
• | This DTC requires an ignition cycle in order to change from current to history. |
• | The MSM no longer detects an internal memory malfunction (checksum error). |
• | A history DTC clears after 50 consecutive ignition cycles if the condition for the malfunction is no longer present. |
• | Use a scan tool. |
You may need to replace the MSM because of the following factors:
• | You cannot remove the EEPROM from the MSM. |
• | DTC B1658 is an internal MSM malfunction. |
The number(s) below refer to the step number(s) on the diagnostic table.
Perform the entire power seat systems diagnostic system check before you continue with the diagnosis of this diagnostic trouble code (DTC).
Clear all of the DTCs. Cycle the ignition in order to ensure that the DTC did not falsely set.
Clear all of the DTCs after you complete the repair procedure.
Step | Action | Value(s) | Yes | No |
---|---|---|---|---|
Did you perform the Power Seat Systems Diagnostic System Check? | -- | Go to Step 2 | ||
Is the DTC still present? | -- | Go to Step 3 | ||
3 | Replace the memory seat module (MSM). Refer to Memory Seat Control Module Replacement . Is the MSM replacement complete? | -- | Go to Step 4 | -- |
Are all of the DTCs cleared? | -- | -- |