Circuit Description
The module contains a data storage area which can save pertinent data when the ignition is turned OFF. The keep alive memory (KAM) data is lost if battery power is removed from the module. The KAM area is an integral part of the module and cannot be serviced separately.
DTC Descriptors
This diagnostic procedure supports the following DTC:
DTC B1652 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 B1652 indicates that the keep alive, or long term, memory in the module has been reset. It is a normal occurrence whenever power or ground is removed from the module, such as when the battery is disconnected and reconnected.
Action Taken When the DTC Sets
The module reverts back to the base programmed critical operating data until new data is learned and stored in KAM.
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 |
