C

DTC Troubleshooting: B1241 or Indicator C

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

1. Clear the DTC with the HDS.

2. Turn the ignition switch to LOCK (0), and then to ON (II).

3. Do the self-diagnostic function with the HDS Initial Inspection and Diagnostic Overview or climate control unit. Initial Inspection and Diagnostic Overview

4. Check for DTCs.

Is DTC B1241 or C indicated?
YES - Go to step 5.

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


5. Turn the ignition switch to LOCK (0).

6. Check the No. 12 (40 A) fuse in the relay block, and the No. 30 (10 A) fuse in the under-dash fuse/relay box.

Are the fuses OK?
YES - Go to step 7.

NO - Replace the fuse(s), and recheck. If fuse(s) blow again, check for a short in the No. 12 (40 A) and No. 30 (10 A) fuse(s) circuit.


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

8. Turn the ignition switch to ON (II).

Does the front blower motor run at high speed?
YES - Go to step 9.

NO - Go to step 24.






9. Turn the ignition switch to LOCK (0).

10. Disconnect the jumper wire.

11. Disconnect the front power transistor 4P connector.

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

Is there continuity?
YES - Go to step 13.

NO - Check for an open in the wire between the front power transistor and body ground. If the wire is OK, check for poor ground at G507.






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

14. Turn the ignition switch to ON (II).

Does the front blower motor run at high speed?
YES - Go to step 15.

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






15. Turn the ignition switch to LOCK (0).

16. Disconnect the jumper wire.

17. Disconnect climate control unit connector A (40P).

18. Check for continuity between body ground and climate control unit connector A (40P) terminals No. 9 and No. 10 individually.

Is there continuity?
YES - Repair short to body ground in the wire(s) between the climate control unit and the front power transistor.

NO - Go to step 19.






19. Check for continuity between the following terminals of climate control unit connector A (40P) and the front power transistor 4P connector.





Is there continuity?
YES - Go to step 20.

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






20. Turn the ignition switch to ON (II).

21. Measure the voltage between body ground and climate control unit connector A (40P) terminals No. 9 and No. 10 individually.

Is there any voltage?
YES - Repair short to power in the wire(s).

NO - Go to step 22.






22. Reconnect climate control unit connector A (40P).

23. Test the front power transistor. Front Blower Power Transistor Test

Is the front power transistor OK?
YES - Check for loose wires or poor connections at climate control unit connector A (40P) and at the front 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 front power transistor. Front Blower Power Transistor Test


24. Disconnect the jumper wire.

25. Disconnect the front blower motor 2P connector.

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

Is there battery voltage?
YES - Replace the front blower motor. Blower Unit Component Replacement

NO - Go to step 27.






27. Turn the ignition switch to LOCK (0).

28. Remove the front blower motor relay from the relay block, and test it. Power Relay Test

Is the relay OK?
YES - Go to step 29.

NO - Replace the front blower motor relay.


29. Measure the voltage between the front blower motor relay 4P socket terminal No. 1 and body ground.

Is there battery voltage?
YES - Go to step 30.

NO - Replace the under-hood fuse/relay box. Under-Hood Fuse/Relay Box Removal and Installation






30. Turn the ignition switch to ON (II).

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

Is there battery voltage?
YES - Go to step 32.

NO - Repair open in the wire between the No. 30 (10 A) fuse in the under-dash fuse/relay box and the front blower motor relay.






32. Turn the ignition switch to LOCK (0).

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

Is there continuity?
YES - Repair open in the WHT wire between the front blower motor relay and the blower motor.

NO - Check for an open in the wire between the front blower motor relay and body ground. If the wire is OK, check for poor ground at G202.