DTC Troubleshooting: B1241 (N)

DTC indicator N or DTC B1241:  A Problem in the Blower Motor Circuit


1.Clear the DTC.

2.Turn the ignition switch OFF, and then ON.

3.Operate the climate control system is several modes.

4.Check the DTCs.

Is DTC N or B1241 indicated?


YES - Go to 5.


NO - Intermittent failure, check for loose wires or poor connections on the blower motor circuit.n


5.Check the No. 21 (40A) fuse in the under-hood
fuse/relay box, and the No. 30 (7.5A) fuse in the driver's under-dash fuse/relay box.

Are the fuses OK?


YES - Go to 6.


NO - Replace the fuse(s), and recheck.n


6.Connect the No. 2 terminal of the blower motor 2P connector to body ground with a jumper wire.

7.Turn the ignition switch ON (II).

Does the blower motor run?


YES - Go to 8.


NO - Go to 22.

8.Turn the ignition switch OFF.

9.Disconnect the jumper wire.

10.Disconnect the power transistor 4P connector.

11.Check for continuity between the No. 2 terminal of the power transistor 4P connector and body ground.

Is there continuity?


YES - Go to 12.


NO - Check for an open in the wire between the power transistor and body ground. If the wire is OK, check for poor ground at G503.n


12.Connect the No. 2 and No. 4 terminals of the power transistor 4P connector with a jumper wire.

13.Turn the ignition switch ON (II).

Does the blower motor run at high speed?


YES - Go to 14.


NO - Repair open in the wire between the power transistor and the blower motor.n

14.Turn the ignition switch OFF.

15.Disconnect the jumper wire.

16.Disconnect climate control unit connector B (16P).

17.Check for continuity between the No. 1 and No. 2 terminals of climate control unit connector B (16P) and body ground individually.

Is there continuity?


YES - Repair any short to body ground in the wire(s) between the climate control unit and the power transistor.n


NO - Go to 18.

18.Check for continuity between the following terminals of climate control unit connector B (16P) and power transistor 4P connector.

16P: 4P: 
No. 1 No. 1 
No. 2 No. 3 

Is there continuity?


YES - Go to 19.


NO - Repair any open in the wire(s) between the climate control unit and the power transistor.n

19.Reconnect climate control unit connector B (16P).

20.Test the power transistor.

Is the power transistor OK?


YES - Go to 21.


NO - Replace the power transistor.n


21.Perform the A/C communication in the Self-Diagnostic Function to obtain the IS-BUS communication varification status

Is the communication OK?


YES - Check for loose wire or poor connections at climate control unit connector B (16P) and at the Power transistor 4P connector. If the connections are good, substitute a known-good climate control unit and printed circuit board, and recheck. If the symptom/indication goes away, replace the original climate control unit and printed circuit board.n


NO - Check for loose wire or poor connections at climate control unit connector B (16P) and at the power traisistor 4P connector. If the connections are good, substitute a known-good climate control unit, and recheck. If the symptom/indication goes away, replace the original climate control unit.n

22.Disconnect the jumper wire.

23.Disconnect the blower motor 2P connector.

24.Measure the voltage between the No. 1 terminal of the blower motor 2P connector and body ground.

Is there battery voltage?


YES - Replace the blower motor.n


NO - Go to 25.


25.Turn the ignition switch OFF.

26.Remove the blower motor relay from the under-hood fuse/relay box, and test it.

Is there relay OK?


YES - Go to 27.


NO - Replace the blower motor relay.n

27.Measure the voltage between the No. 2 terminal of the blower motor relay 4P socket and body ground.

Is there battery voltage?


YES - Go to 28.


NO - Replace the under-hood fuse/relay box.n


28.Turn the ignition switch ON (II).

29.Measure the voltage between the No. 4 terminal of the blower motor relay 4P socket and body ground.

Is there battery voltage?


YES - Go to 30.


NO - Repair open in the wire between the No. 30 fuse in the driver's under-dash fuse/relay box and the blower motor relay.n

30.Turn the ignition switch OFF.

31.Check for continuity between the No. 3 terminal of the blower motor relay 4P socket and body ground.

Is there contnuity?


YES - Repair open in the WHT/BLU wire between the blower motor relay and the blower motor.n


NO - Check for an open in the wire between the blower motor relay and body ground. If the wire is OK, check for poor ground at G302.n