P1684

P1684-BATTERY WAS DISCONNECTED

For a complete wiring diagram Consult Diagrams/Electrical.

Theory of Operation

The PCM uses a battery backed RAM (Random Access Memory) is used to maintain some learned values. When the battery B(+) is disconnected, the memory is lost. When the B(+) is restored, this memory loss is detected by the Transmission Control System. The DTC is set and the learned values are initialized to known constants or previously learned values from EEPROM (Electronic Erasable Programmable Read Only Memory). This results in the reinitialization of some parameters.

- When Monitored:
Whenever the ignition is in the Run/Start position.

- Set Condition:
This DTC will set whenever Powertrain Control Module is disconnected from Fused B(+) or ground. It will also be set using the scan tool to perform a Battery Disconnect and/or Quick Learn procedure.





Always perform the 45RFE/545RFE Pre-Diagnostic Troubleshooting Procedure before proceeding. Testing and Inspection

Diagnostic Test

1. POSSIBLE CAUSES
This DTC is an informational DTC only.
This DTC is set due to a momentary loss of power and/or the ground circuits to the PCM.
Below are a list of possible causes associated with this DTC.
Battery was disconnected.
The Battery Disconnect feature (if equipped) on the scan tool was performed.
The Quick Learn feature on the scan tool was performed.
PCM was replaced or disconnected.
Were any of the above possible causes performed?

Yes

- This is the cause of the DTC. Erase the DTC and return vehicle to customer.
- Perform 45RFE/545RFE TRANSMISSION VERIFICATION TEST. Transmission Verification Test

No

- Go to2

2. CHECK WIRING AND CONNECTORS
The conditions necessary to set this DTC are not present at this time.
Using the schematics as a guide, inspect the wiring and connectors specific to this circuit.

NOTE: Check all power and ground circuits to the PCM for a intermittent or high resistance condition.

Wiggle the wires while checking for shorted and open circuits.
With the scan tool, check the Event Data to help identify the conditions in which the DTC was set.
Where there any problems found?

Yes

- Repair as necessary.
- Perform 45RFE/545RFE TRANSMISSION VERIFICATION TEST. Transmission Verification Test

No

- Test Complete.