Radiator and A/C Condenser Fan High Speed Circuit Troubleshooting
Radiator and A/C Condenser Fan High Speed Circuit TroubleshootingNOTE:
- Do not use this troubleshooting procedure if only one fan is inoperative, or if the A/C compressor is inoperative. Refer to the symptom troubleshooting index. Heating/Air Conditioning
- Before performing symptom troubleshooting, check for powertrain DTCs.
- The normal operating A/C pressure for the radiator and A/C condenser fans to run at high speed when the A/C is ON or the ECT is above 206 °F with A/C OFF.
1. Check the No. 57 (30 A) fuse and No. 58 (30 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. Using the HDS, confirm the following values in the Data List at idle.
Are all the values OK?
YES - Go to step 3.
NO - NO - Troubleshoot the value that is not within the specifications.
3. Turn the ignition switch OFF.
4. Disconnect the A/C pressure switch 2P connector.
5. Turn the ignition switch ON (II).
6. Measure the voltage between the No. 2 terminal of the A/C pressure switch 2P connector and body ground.
Is there about 5 V?
YES - Go to step 7.
NO - Go to step 15.
7. Turn the ignition switch OFF.
8. Check for continuity between the No. 1 and No. 2 terminals of the A/C pressure switch.
Is there continuity?
YES - Go to step 9.
NO - Go to step 19.
9. Reconnect the A/C pressure switch 2P connector.
10. Disconnect the heater control panel 30P connector.
11. Turn the ignition switch ON (II).
12. Measure the voltage between the No. 23 terminal of the heater control panel 30P connector and body ground.
Is there about 5 V?
YES - Go to step 13.
NO - Repair open in the wire between the heater control panel and the A/C pressure switch.
13. Turn the ignition switch OFF.
14. Measure the resistance between the No. 19 and No. 27 terminals of the heater control panel 30P connector.
Is the resistance less than 24 kohms?
YES - Check for loose wires or poor connections at the heater control panel 30P connector and at the A/C pressure switch 2P 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 - Test the evaporator temperature sensor.
15. Turn the ignition switch OFF.
16. Jump the SCS line with the HDS.
NOTE: This step must be done to protect the powertrain control module (PCM) from damage.
17. Disconnect the PCM connector A (44P).
18. Check for continuity between the No. 41 terminal of PCM connector A (44P) and No. 2 terminal of the A/C pressure switch 2P connector.
Is there continuity?
YES - Check for loose wires or poor connections at the PCM connector A (44P). If the connections are good, substitute a known-good PCM, and recheck. If the symptom/indication goes away, replace the original PCM.
NO - Repair open in the wire between the PCM and the A/C pressure switch.
19. Check for proper A/C system pressure.
Is the pressure within specifications?
YES - Replace the A/C pressure switch.
NO - Repair the A/C pressure problem.