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A/C Condenser Fan High Speed Circuit Troubleshooting




A/C Condenser Fan High Speed Circuit Troubleshooting

NOTE:

- Do not use this troubleshooting procedure if the A/C compressor is inoperative. Refer to the symptom troubleshooting index.
- Before doing any symptom troubleshooting, check for PGM-FI DTCs Initial Inspection and Diagnostic Overview.

1. Connect the HDS to the DLC.

2. Start the engine.

3. Turn on the A/C.

4. Using the HDS, confirm the following values in the PGM-FI Data List at idle.





Are all the values within specifications?

YES -

Go to step 5.

NO -

Troubleshoot the value that is not within the specifications.

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

6. Remove the relay circuit board Under-Hood Fuse/Relay Box Removal and Installation from the under-hood fuse/relay box, and test the fan control relay Testing and Inspection.

Is the relay OK?

YES -

Go to step 7.

NO -

Replace the relay circuit board.

7. Jump the SCS line with the HDS.

NOTE: This step must be done to protect the PCM from damage.

8. Disconnect PCM connector A (49P).

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

10. Measure the voltage between PCM connector A (49P) terminal No. 5 and body ground.





Is there battery voltage?

YES -

Go to step 11.

NO -

Repair an open in the wire between the under-hood fuse/relay box and the PCM. If the wire is OK, replace the under-hood fuse/relay box Under-Hood Fuse/Relay Box Removal and Installation.

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

12. Connect PCM connector A (49P) terminals No. 4, No. 5 and No. 40 to body ground with jumper wires.






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

Do the A/C condenser and radiator fans run on high?

YES -

Check for loose wires or poor connections at PCM connector A (49P). If the connections are good, substitute a known-good PCM, and recheck. If the symptom/indication goes away, replace the original PCM Service and Repair.

NO -

Check for an open in the wire between under-hood fuse/relay box connector C (5P) terminal No. 5 and body ground. If the wire is OK, check for poor ground at G301.