With Climate Control
DTC Troubleshooting: B1241 (S)
DTC B1241 or DTC indicator S:
A Problem in the Blower Motor Circuit
1. Clear the DTC with the HDS.
2. Operate the climate control system in several modes.
3. Check for DTCs using the HDS or the self-diagnostic function.
Is DTC B1241 or S indicated?
YES -
Go to step 4.
NO -
Intermittent failure. Check for loose wires or poor connections on the blower motor circuit.�
4. Turn the ignition switch to LOCK (0).
5. Check the No. 21 (40 A) fuse in the under-hood fuse/relay box, and the No. 30 (10 A) fuse in the under-dash fuse/relay box.
Are the fuses OK?
YES -
Go to step 6.
NO -
Check for a short in the No. 21 (40 A) and No. 30 (10 A) fuse circuits.�
6. Turn the ignition switch to ON (II).
7. Measure the voltage between blower motor 2P connector terminal No. 1 and body ground.
Is there battery voltage?
YES -
Go to step 8.
NO -
Go to step 26.
8. Connect the blower motor 2P connector terminal No. 2 to body ground with a jumper wire.
9. Turn the ignition switch to ON (II).
Does the blower motor run?
YES -
Go to step 10.
NO -
Replace the blower motor.�
10. Turn the ignition switch to LOCK (0).
11. Disconnect the jumper wire.
12. Disconnect the power transistor 5P connector.
13. Check for continuity between power transistor 5P connector terminal No. 5 and body ground.
Is there continuity?
YES -
Go to step 14.
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 G402.�
14. Connect the power transistor 5P connector terminals No. 4 and No. 5 with a jumper wire.
15. Turn the ignition switch to ON (II).
Does the blower motor run at high speed?
YES -
Go to step 16.
NO -
Repair an open in the wire between the power transistor and the blower motor.�
16. Turn the ignition switch to LOCK (0).
17. Disconnect the jumper wire.
18. Disconnect the climate control unit 30P connector.
19. Check for continuity between body ground and climate control unit 30P connector terminals No. 11 and No. 12 individually.
Is there continuity?
YES -
Repair a short to body ground in the wire(s) between the climate control unit and the power transistor.�
NO -
Go to step 20.
20. Check for continuity between the following terminals of the climate control unit 30P connector and the power transistor 5P connector.
Is there continuity?
YES -
Go to step 21.
NO -
Repair an open in the wire(s) between the climate control unit and the power transistor.�
21. Turn the ignition switch to ON (II).
22. Measure the voltage between body ground and climate control unit 30P connector terminals No. 11 and No. 12 individually.
Is there voltage?
YES -
Repair a short to power in the wire(s).�
NO -
Go to step 24.
23. Turn the ignition switch to LOCK (0).
24. Reconnect the climate control unit 30P connector.
25. Test the power transistor Blower Power Transistor Test.
Is the power transistor OK?
YES -
Check for loose wires or poor connections at the climate control unit 30P connector and the power transistor 5P connector. If the connections are good, substitute a known-good climate control unit Climate Control Unit Removal/Installation, and recheck. If the symptom/indication goes away, replace the original climate control unit Climate Control Unit Removal/Installation.�
NO -
Replace the power transistor.�
NOTE: If the power transistor is faulty, check the blower motor for damage. If necessary, replace the blower motor before installing a new power transistor Blower Unit Component Replacement.
26. Remove the blower motor relay from the under-hood fuse/relay box, and test it Power Relay Test.
Is the relay OK?
YES -
Go to step 27.
NO -
Replace the blower motor relay.�
27. Measure the voltage between blower motor relay 4P socket terminal No. 2 and body ground.
Is there battery voltage?
YES -
Go to step 28.
NO -
Replace the under-hood fuse/relay box Under-Hood Fuse/Relay Box Removal and Installation.�
28. Turn the ignition switch to ON (II).
29. Measure the voltage between blower motor relay 4P socket terminal No. 4 and body ground.
Is there battery voltage?
YES -
Go to step 30.
NO -
Repair an open in the wire between the No. 30 (10 A) fuse in the under-dash fuse/relay box and the blower motor relay. If the wire is OK, replace the under-hood fuse/relay box Under-Hood Fuse/Relay Box Removal and Installation.�
30. Turn the ignition switch to LOCK (0).
31. Check for continuity between blower motor relay 4P socket terminal No. 3 and body ground.
Is there continuity?
YES -
Repair an open in the wire between the blower motor relay and the blower motor.�
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 G202.�