Heating/Air Conditioning
DTC 1: A Problem in the Front Blower Motor Circuit1. Check the No. 56 (40 A) fuse in the under-hood fuse/relay box, and the No. 3 (7.5 A) fuse in the driver's under-dash fuse/relay box.
Are the fuses OK?
YES - Go to step 2.
NO - Replace the fuse(s), and recheck.
2. Connect the No. 2 terminal of the front blower motor 2P connector to body ground with a jumper wire.
3. Turn the ignition switch ON (II).
Does the front blower motor run at high speed?
YES - Go to step 4.
NO - Go to step 17.
4. Turn the ignition switch OFF.
5. Disconnect the jumper wire.
6. Disconnect the front power transistor 5P connector.
7. Check for continuity between the No. 5 terminal of the front power transistor 5P connector and body ground.
Is there continuity?
YES - Go to step 8.
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 G401.
8. Connect the No. 4 and No. 5 terminals of the front power transistor 5P connector with a jumper wire.
9. Turn the ignition switch ON (II).
Does the front blower motor run at high speed?
YES - Go to step 10.
NO - Repair open in the wire between the front power transistor and the front blower motor.
10. Turn the ignition switch OFF.
11. Disconnect the jumper wire.
12. Disconnect the heater control panel 30P connector.
13. Check for continuity between the No. 3 and No. 4 terminals of the heater control panel 30P connector and body ground individually.
Is there continuity?
YES - Repair short to body ground in the wire(s) between the heater control panel and the front power transistor.
NO - Go to step 14.
14. Check for continuity between the following terminals of the heater control panel 30P connector and front power transistor 5P connector.
Is there continuity?
YES - Go to step 15.
NO - Repair open in the wire(s) between the heater control panel and the front power transistor.
15. Reconnect the heater control panel 30P connector.
16. Test the front power transistor.
Is the front power transistor OK?
YES - Check for loose wires or poor connections at the heater control panel 30P connector and at the front power transistor 5P 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.
NO - Replace the front power transistor.
17. Measure the voltage between the No. 1 terminal of the front blower motor 2P connector and body ground.
Is there battery voltage?
YES - Replace the front blower motor.
NO - Go to step 18.
18. Turn the ignition switch OFF.
19. Remove the front blower motor relay from the under-hood fuse/relay box, and test it.
Is the relay OK?
YES - Go to step 20.
NO - Replace the front blower motor relay.
20. Measure the voltage between the No. 4 terminal of the front blower motor relay 4P socket and body ground.
Is there battery voltage?
YES - Go to step 21.
NO - Replace the under-hood fuse/relay box.
21. Turn the ignition switch ON (II).
22. Measure the voltage between the No. 1 terminal of the front blower motor relay 4P socket and body ground.
Is there battery voltage?
YES - Go to step 23.
NO - Repair open in the wire between the No. 3 (7.5 A) fuse in the driver's under-dash fuse/relay box and the front blower motor relay.
23. Turn the ignition switch OFF.
24. Check for continuity between the No. 2 terminal of the front blower motor relay 4P socket and body ground.
Is there continuity?
YES - Repair open in the YEL/BLK wire between the front blower motor relay and the front 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 G201.