DTC Troubleshooting: 12
| DTC 12: | A Problem in the Blower Motor Circuit |
| 1. | Check the No. 11 (40 A) fuse in the under-hood fuse/relay box, and the No. 14 (10 A) fuse in the under-dash fuse/relay box. Are the fuses OK? YES - Go to 2. NO - Replace the fuse(s), and recheck.n |
| 2. | Connect the No. 2 terminal of the blower motor 2P connector to body ground with a jumper wire.
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| 3. | Turn the ignition switch ON (II). Does the blower motor run? YES - Go to 4. NO - Go to 17. |
| 4. | Turn the ignition switch OFF. |
| 5. | Disconnect the jumper wire. |
| 6. | Disconnect the power transistor 4P connector. |
| 7. | Check for continuity between the No. 2 terminal of the power transistor 4P connector and body ground.
Is there continuity? YES - Go to 8. 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 G501.n |
| 8. | Connect the No. 2 and No. 4 terminals of the power transistor 4P connector with a jumper wire.
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| 9. | Turn the ignition switch ON (II). Does the blower motor run at high speed? YES - Go to 10. NO - Repair open in the wire between the power transistor and the blower motor.n |
| 10. | Turn the ignition switch OFF. |
| 11. | Disconnect the jumper wire. |
| 12. | Disconnect the heater control panel 36P connector. |
| 13. | Check for continuity between the No. 20 and No. 21 terminals of the heater control panel 36P connector and body ground individually.
Is there continuity? YES - Repair any short to body ground in the wire(s) between the heater control panel and the power transistor.n NO - Go to 14. |
| 14. | Check the continuity between the following terminals of the heater control panel 36P connector and the power transistor 4P connector.
Is there continuity? YES - Go to 15. NO - Repair any open in the wire(s) between the heater control panel and the power transistor.n |
| 15. | Reconnect the heater control panel 36P connector. |
| 16. | Test the power transistor. Is the power transistor OK? YES - Check for loose wires or poor connections at the heater control panel 36P connector and at the power transistor 4P connector. If the connections are good, substitute a known-good heater control panel, and recheck. If the symptom/indication goes away, replace the original heater control panel.n NO - Replace the power transistor.n |
| 17. | Disconnect the jumper wire. |
| 18. | Disconnect the blower motor 2P connector. |
| 19. | 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 20. |
| 20. | Turn the ignition switch OFF. |
| 21. | Remove the blower motor relay from the under-hood fuse/relay box, and test it. Is the relay OK? YES - Go to 22. NO - Replace the blower motor relay.n |
| 22. | Measure the voltage between the No. 1 terminal of the blower motor relay 4P socket and body ground.
Is there battery voltage? YES - Go to 23. NO - Replace the under-hood fuse/relay box.n |
| 23. | Turn the ignition switch ON (II). |
| 24. | 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 25. NO - Repair open in the wire between the No. 14 fuse in the under-dash fuse/relay box and the blower motor relay.n |
| 25. | Turn the ignition switch OFF. |
| 26. | 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 BLU/WHT 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 G201.n |