P1684-BATTERY WAS DISCONNECTED





For a complete wiring diagram Refer to Section 8W.

Theory of Operation


Note: This is not a fault code. It exists to provide reference information only. A battery backed RAM is used to maintain some learned values. When the battery is disconnected, this memory is lost. When the battery is reconnected, the loss of learned values will be detected by the controller. The code will be set and the learned values will be initialized to known constants and the learning process will continue. Setting the code has no effect except for re-initialization of learned values.


  • When Monitored:

    After a reset (ignition key turned to the RUN position).

  • Set Condition:

    The checksum of the battery backed RAM does not match the stored checksum. Set Time: Less than 7 msec.


Possible Causes
  
BATTERY WAS DISCONNECTED
  
PCM WAS REPLACED OR DISCONNECTED
  
QUICK LEARN WAS PERFORMED
  
(A919) FUSED B+ CIRCUIT TO PCM OPEN
  
(Z908 and Z977) GROUND CIRCUIT OPEN
  

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 21 - TRANSMISSION/TRANSAXLE/AUTOMATIC - 42RLE - DIAGNOSIS AND TESTING).



Diagnostic Test

1.BATTERY WAS DISCONNECTED


Has the battery been disconnected, lost it's charge, or been replaced recently?

Yes
  • Disconnecting or replacing the battery will set this DTC. Erase the DTC.
  • Perform 42RLE TRANSMISSION VERIFICATION TEST - VER 1.


No
  • Go To 2

2.WAS QUICK LEARN PERFORMED


Has a Quick Learn procedure been performed?

Yes
  • Performing Quick Learn will set this DTC. Erase the DTC.
  • Perform 42RLE TRANSMISSION VERIFICATION TEST - VER 1.


No
  • Go To 3

3.PCM REPLACED OR DISCONNECTED


Has the PCM been replaced or disconnected?

Yes
  • Replacing or disconnecting the PCM will set this DTC. Erase the DTC.
  • Perform 42RLE TRANSMISSION VERIFICATION TEST - VER 1.


No
  • Go To 4

4.(A919) FUSED B+ CIRCUIT





NOTE: Check connectors - Clean/repair as necessary.


CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install Miller Special Tool #8815 to perform diagnosis.



NOTE: The test light must illuminate brightly. Compare the brightness to that of a direct connection to the battery.



Does the test light illuminate brightly?

Yes
  • Go To 5


No
  • Repair the Fused B+ circuit for an open. If the fuse is open make sure to check for a short to ground.
  • Perform 42RLE TRANSMISSION VERIFICATION TEST - VER 1.

5.(Z908) AND (Z977) GROUND CIRCUITS





NOTE: Check connectors - Clean/repair as necessary.



NOTE: The test light must illuminate brightly. Compare the brightness to that of a direct connection to the battery.



Does the test light illuminate brightly for all of the ground circuits?

Yes
  • Go To 6


No
  • Repair the Ground circuits for an open.
  • Perform 42RLE TRANSMISSION VERIFICATION TEST - VER 1.

6.INTERMITTENT WIRING AND CONNECTORS






Were there any problems found?

Yes
  • Repair as necessary.
  • Perform 42RLETRANSMISSION VERIFICATION TEST - VER 1.


No
  • Test Complete.