Electronic Climate Control
DTC B1241 or DTC indicator C: A Problem in the Blower Motor Circuit1. Clear the DTC by turning the ignition switch OFF, and then ON (II).
2. Operate the climate control system in several modes.
3. Check for DTCs using the HDS or self-diagnostic
Is DTC B1241 or C 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 OFF.
5. Check the No 21 (40 A) fuse in the under-hood fuse/relay box, and the No 30 (10 A) fuse in the driver's under dash fuse/relay box.
Are the fuses OK?
YES - Go to step 6.
NO - Replace the fuse(s), and recheck.
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 step 8.
NO - Go to step 23.
8. Turn the ignition switch OFF.
9. Disconnect the jumper wire.
10. Disconnect the power transistor 4Pconnectoi
11. Check for continuity between the No 2 terminal of the power transistor 4P connector and body ground.
Is there continuity?
YES - Go to step 12.
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 G504.
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 step 14.
NO - Repair open in the BLU/BLK wire between the power transistor and the blower motor.
14. Turn the ignition switch OFF.
15. Disconnect the jumper wire.
16. Disconnect the climate control unit 30P connector.
17. Check for continuity between the No. 27 and No. 28 terminals of the climate control unit 3OP connector 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.
NO - Go to step 18.
18. Check for continuity between the following terminals of the climate control unit 3OP connector and power transistor 4P connector.
Is there continuity?
YES - Go to step 19.
NO - Repair any open in the wire(s) between the climate control unit and the power transistor.
19. Start the engine.
20. Check for voltage between the No. 27 and No. 28 terminals of the climate control unit 30P connector and body ground individually.
Is there 1 V or more?
YES - Repair short to power in the wires.
NO - Go to step 21.
21. Reconnect the climate control unit 30P connector.
22. Test the power transistor.
Is the power transistor OK?
YES - Check for loose wire or poor connections at the climate control unit 30P connector and at the power transistor 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.
NO - Replace the power transistor.
23. Disconnect the jumper wire.
24. Disconnect the blower motor 2P connector.
25. 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.
NO - Go to step 26.
26. Turn the ignition switch OFF.
27. Remove the blower motor relay from the under-hood fuse/relay box, and test it.
Is the relay OK?
YES - Go to step 28.
NO - Replace the blower motor relay.
28. 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 step 29.
NO - Replace the under-hood fuse/relay box.
29. Turn the ignition switch ON (II).
30. 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 step 31.
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.
31. Turn the ignition switch OFF.
32. Check for continuity between the No. 3 terminal of the blower motor relay 4P socket and body ground.
Is there continuity?
YES - Repair open in the WHT/BLU 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.