DTC B1861: Battery Fail: Diagnosis

STEP 1. Using scan tool (M.U.T.-IIISE), check whether DTC B1860 is set.
CAUTION: To prevent damage to scan tool (M.U.T.-IIISE), always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool (M.U.T.-IIISE).
1. Connect scan tool (M.U.T.-IIISE). Refer to "HOW TO CONNECT THE SCAN TOOL (M.U.T.-IIISE) ."
2. Turn the ignition switch to the "ON" position.
3. Check whether TCU DTC B1860 is set.
  Q: Is DTC B1860 set?
  
  YES: Troubleshoot DTC B1860 (Refer to DTC B1860: BATTERY CONNECTION ).
  
  NO: Replace the TCU battery (Refer to TCU BATTERY REPLACEMENT ). Then go to Step 2.
STEP 2. Using scan tool (M.U.T.-IIISE), check whether the DTC is set again.
Check again if the DTC is set in the TCU.
1. Erase the DTC.
2. Turn the ignition switch from "LOCK" (OFF) position to "ON" position.
3. Check the DTC.
  Q: Is the DTC set?
  
  YES: Replace the TCU (Refer to TCU ).
  
  NO: The trouble can be an intermittent malfunction (Refer to How to use Troubleshooting/inspection Service Points - HOW TO COPE WITH INTERMITTENT MALFUNCTION ).