Rear A/C-Heater Control Module Rear Blower Control Inoperative In One Or More Speeds
Possible Causes:
- Rear Blower Speed circuit(s) open.
- Rear Blower Control Feed circuit open.
- Rear A/C-Heater Control Module.
CAUTION:
Always turn ignition off before disconnecting or connecting any control module connector. Failure to do so could result in damage to control module.
NOTE:
Ensure vehicle being tested has a fully charged battery. If it does not, false symptoms may occur.
NOTE:
For component location, see appropriate illustration under COMPONENT LOCATIONS
. For terminal identification, see appropriate illustration under CONNECTOR IDENTIFICATION
. For circuit and wire color identification, see WIRING DIAGRAMS
. For component removal and installation procedures, see appropriate component under REMOVAL & INSTALLATION
.
Testing:
- Turn ignition off. Turn off Rear Blower Control on the A/C-Heater Control Module. Disconnect Rear A/C-Heater Control Module harness connector. Turn ignition on. Measure voltage on Rear A/C-Heater Control Module harness connector terminals 2, 3 and 5. Is voltage more than 10 volts on each circuit? If yes, go to next step. If no, repair open in Rear Blower Speed circuit(s). Perform BODY VERIFICATION TEST under VERIFICATION TESTS.
- Turn ignition off. Reconnect Rear A/C-Heater Control Module harness connector. Using a jumper wire connected to ground, backprobe Rear A/C-Heater Control Module harness connector terminal No. 4. Turn ignition on. Turn Rear Blower Switch on the Rear A/C-Heater Control Module to each speed position. Does the Rear Blower operate in all speeds? If yes, go to next step. If no, replace Rear A/C-Heater Control Module. Perform BODY VERIFICATION TEST under VERIFICATION TESTS.
- Turn ignition off. Disconnect A/C-Heater Control Module C4 harness connector. Disconnect Rear A/C-Heater Control Module harness connector. Measure resistance between A/C-Heater Control Module harness connector terminal No. 8 and Rear A/C-Heater Control Module harness connector terminal No. 4. Is resistance less than 5 ohms? If yes, replace A/C-Heater Control Module. Perform BODY VERIFICATION TEST under VERIFICATION TESTS. If no, repair open in Rear Blower Control Feed circuit. Perform BODY VERIFICATION TEST under VERIFICATION TESTS.