PTC Heater Circuit Troubleshooting
  1. Check for continuity between body ground and the PTC heater core 7P connector terminals No. 4, 5, 6, and 7 individually.
Is there continuity?
YES -
Go to Step 7 .
NO -
Check for open in the wires between the PTC heater core and body ground at G401. ■
  1. Turn the ignition switch ON (II).