DTC Troubleshooting: B1241 (N)
  1. Measure the voltage between body ground and the heater control unit 32P connector terminals No. 10 and No. 11 individually.
Is there voltage?
YES -
Repair short to power in the wire(s).■
NO -
Go to Step 22 .
  1. Reconnect the heater control unit 32P connector.
  1. Test the power transistor.
Is the power transistor OK?
YES -
Check for loose wires or poor connections at the heater control unit 32P connector and at the power transistor 4P connector. If the connections are good, substitute a known-good heater control unit, and recheck. If the symptom/indication goes away, replace the original heater control unit .■
NO -
Replace the power transistor. ■
  1. Disconnect the jumper wire.
  1. Disconnect the blower motor 2P connector.