Circuit Description
DTC B1657 indicates that the option bit portion of the instrument panel cluster (IPC) electrically erasable programmable read only memory (EEPROM) has an unrecoverable error. The option bit portion of the instrument cluster EEPROM stores the manufacturing information.
DTC Descriptors
This diagnostic procedure supports the following DTC:
DTC B1657 Electronic Control Unit (ECU) Performance
Conditions for Running the DTC
The module runs the program to detect an internal fault when power up is commanded. The only requirements are voltage and ground. This program runs even if the voltage is out of the valid operating range.
Conditions for Setting the DTC
DTC B1657 sets when the IPC detects an error in the option bit portion of the EEPROM during a diagnostic system self-test.
Action Taken When the DTC Sets
When DTC B1657 sets, the following actions may occur:
| • | The IPC display does not operate. |
| • | The IPC illuminates the malfunction indicator lamp (MIL). |
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 without 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 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | Go to Diagnostic System Check - Vehicle in Vehicle DTC Information |
2 |
Is DTC retrieved as a current DTC? | Go to Step 3 | Go to Diagnostic Aids |
3 | Replace the module setting the DTC as current. Refer to Control Module References for replacement, setup and programming. Did you complete the replacement? | Go to Step 4 | -- |
4 |
Does the DTC reset? | Go to Step 2 | System OK |
