PUMP GP-AUXILIARY SEA WATER 5243159 - Caterpillar

Which Generate This Code:This diagnostic code is recorded when the voltage of the backup battery is between 1.5 DCV and 1.7 DCV. This diagnostic code may result in the following conditions:
The loss of stored data
The loss of the real time clockTest Step 1. VERIFY THE DIAGNOSTIC CODE.
Turn the disconnect switch to the ON position.
Connect the ET to the ECM and clear the fault codes.
Determine if CID 0817 FMI 12 is present.Expected Result:CID 0817 FMI 12 is present.Results:
YES - The diagnostic code is present. The internal battery for the MSS ECM has a low voltage.Repair: The battery in the MSS ECM cannot be replaced. The entire ECM must be replaced. Refer to Testing and Adjusting Section, "Electronic Control Module (ECM) - Replace". Stop.
NO - The code is no longer present. The internal battery in the MSS ECM is no longer below voltage. Stop.