DTC Troubleshooting: P1549
DTC P1549: Charging System High Voltage
NOTE:
Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information.
If a high voltage battery (24 V, etc.) is connected to the vehicle, this DTC can be stored.

DTC Description
Confirmed DTC
Pending DTC
Freeze Frame
P1549 Charging System High Voltage
      

1.
Problem verification:

Problem verification
?1.
Press the engine start/stop button to select the ON mode.

?2.
Clear the DTC with the HDS.


?3.
Start the engine.

?4.
Check under these conditions:
A/C off
Headlights off
Rear window defogger off

?5.
Hold the engine speed at 3,000 rpm without load (A/T in P or N, M/T in neutral) for 1 minute.

?6.
Check for Pending or Confirmed DTCs with the HDS.
DTC Description
Confirmed DTC
Pending DTC
Freeze Frame
P1549 Charging System High Voltage
      

Is DTC P1549 indicated?

     
YES
     
     
     
The failure is duplicated. Replace the alternator, then do the repair verification.
     
NO
     
     
     
Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the alternator and the under-hood fuse/relay box.?
Repair verification (OBD STATUS check):

?1.
Press the engine start/stop button to select the ON mode.

?2.
Reset the PCM with the HDS.


?3.
Do the PCM idle learn procedure.

?4.
Start the engine.

?5.
Check under these conditions:
A/C off
Headlights off
Rear window defogger off

?6.
Monitor the OBD STATUS for DTC P1549 in the DTCs MENU with the HDS.
DTC Description
OBD Status
P1549 Charging System High Voltage
  


Does the HDS indicate PASSED, FAILED, or NOT COMPLETED?

     
PASSED
     
     
     
Troubleshooting is complete. If any other Pending or Confirmed DTCs were indicated, go to the indicated DTC's troubleshooting.?
     
FAILED
     
     
     
Go to step 1 and recheck.
     
NOT COMPLETED
     
     
     
Meet the test condition, and check the OBD STATUS again.