DTC Troubleshooting: B1241 (N and A/C ON)
DTC B1241 or DTC indicator N and A/C ON:
 A Problem in the Blower Motor Circuit
  1. Clear the DTC with the HDS.
  1. Turn the ignition switch to LOCK (0) and then to ON (II).
  1. Check for DTCs.
Is DTC B1241 or N and A/C ON indicated?
YES -
Go to Step 5 .
NO -
Intermittent failure; check for loose wires or poor connections on the blower motor circuit.■
  1. Turn the ignition switch to LOCK (0).
  1. Check the No. 8 (40 A) fuse in the under-hood fuse/relay box, and the No. 16 (7.5 A) fuse in the driver's under-dash fuse/relay box.
Are the fuses OK?
YES -
Go to Step 7 .
NO -
Replace the fuses, and recheck.■
  1. Connect the blower motor 2P connector No. 2 terminal to body ground with a jumper wire.
  1. Turn the ignition switch to ON (II).
Does the blower motor run?
YES -
Go to Step 9 .
NO -
Go to Step 25 .
  1. Turn the ignition switch to LOCK (0).
  1. Disconnect the jumper wire.
  1. Disconnect the power transistor 4P connector.
  1. Check for continuity between the power transistor 4P connector No. 2 terminal and body ground.
Is there continuity?
YES -
Go to Step 13 .
NO -
Check for an open in the BLK wire between the power transistor and body ground. If the wire is OK, check for poor ground at G302.■
  1. Connect the power transistor 4P connector No. 2 and No. 4 terminals with a jumper wire.
  1. Turn the ignition switch to ON (II).
Does the blower motor run at high speed?
YES -
Go to Step 15 .
NO -
Repair open in the GRN wire between the power transistor and the blower motor.■
  1. Turn the ignition switch to LOCK (0).
  1. Disconnect the jumper wire.
  1. Disconnect heater control unit connector B (12P).
  1. Check for continuity between body ground and heater control unit connector B (12P) No. 5 and No. 6 terminals individually.
Is there continuity?
YES -
Repair short to body ground in the wire(s) between the heater control unit and the power transistor.■
NO -
Go to Step 19 .
  1. Check for continuity between the following terminals of heater control unit connector B (12P) and the power transistor 4P connector.
    12P:
    4P:
    No. 5
    No. 1
    No. 6
    No. 3

Is there continuity?
YES -
Go to Step 20 .
NO -
Repair open in the wire(s) between the heater control unit and the power transistor.■
  1. Turn the ignition switch to ON (II).
  1. Measure the voltage between body ground and heater control unit connector B (12P) No. 5 and No. 6 terminals individually.
Is there voltage?
YES -
Repair short to power in the wire(s).■
NO -
Go to Step 22 .
  1. Turn the ignition switch to LOCK (0).
  1. Reconnect heater control unit connector B (12P).
Is the power transistor OK?
YES -
Check for loose wires or poor connections at heater control unit connector B (12P) 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.
  1. Measure the voltage between the blower motor 2P connector No. 1 terminal and body ground.
Is there battery voltage?
YES -
Replace the blower motor.■
NO -
Go to Step 28 .
  1. Turn the ignition switch to LOCK (0).
Is the relay OK?
YES -
Go to Step 30 .
NO -
Replace the blower motor relay .■
  1. Check for continuity between the blower motor relay 4P socket No. 2 terminal and blower motor 2P connector No. 1 terminal.
Is there continuity?
YES -
Go to Step 31 .
NO -
Repair open in the wire between the blower motor relay and blower motor.■
  1. Measure the voltage between the blower motor relay 4P socket No. 1 terminal and body ground.
Is there battery voltage?
YES -
Go to Step 32 .
NO -
  1. Turn the ignition switch to ON (II).
  1. Measure the voltage between blower motor relay 4P socket No. 4 terminal and body ground.
Is there battery voltage?
YES -
Check for an open in the wire between the blower motor relay 4P socket No. 4 terminal and body ground. If the wire is OK, check for poor ground at G301, LHD model, RHD model. ■
NO -
Repair open in the wire between the No. 16 (7.5 A) fuse in the driver's under-dash fuse/relay box and blower motor relay 4P socket.■