A/C Condenser Fan High Speed Circuit Troubleshooting

NOTE:


1.Check No. 6 (20 A) and No.15 (7.5 A) fuses in the under-hood fuse/relay box.

Are the fuses OK?


YES - Go to 2.


NO - Replace the fuses, and recheck.n


2.Remove the A/C condenser fan relay from the under-hood fuse/relay box, and test it.

Is the relay OK?


YES - Go to 3.


NO - Replace the  A/C condenser fan relay.n


3.Measure the voltage between the A/C condenser fan relay 4P socket terminal No. 1 and body ground.

 

Is there battery voltage?


YES - Go to 4.


NO - Replace the under-hood fuse/relay box.n

4.Connect the A/C condenser fan relay 4P socket terminals No. 1 and No. 2 with a jumper wire.

 

Does the A/C condenser fan run on high?


YES - Go to 5.


NO - Replace the under-hood fuse/relay box.n


5.Disconnect the jumper wire.

6.Turn the ignition switch ON (II).

7.Measure the voltage between the A/C condenser fan relay 4P socket terminal No. 4 and body ground.

 

Is there battery voltage?


YES - Go to 8.


NO - Go to 13.

8.Turn the ignition switch OFF.

9.Reinstall the A/C condenser fan relay.

10.Disconnect ECM/PCM connector A (44P).

11.Connect the ECM/PCM connector A (44P) terminal No. 5 to body ground with a jumper wire.

 

12.Turn the ignition switch ON (II).

Does the A/C condenser fan run on high?


YES - Check for loose wires or poor connections at ECM/PCM connector A (44P) terminal No. 5. If the connections are good, substitute a known-good ECM/PCM, and recheck. If the symptom/indication goes away, replace the original ECM/PCM, then do the ECM/PCM idle learn procedure, except K20Z2 engine, K20Z2 engine.n


NO - Repair open in the wire between the A/C condenser fan relay and the ECM/PCM.n

13.Remove A/C diode B from the under-hood fuse/relay box.

14.Turn the ignition switch ON (II).

15.Measure the voltage between the A/C diode B 2P socket terminal No. 2 and body ground.

 

Is there battery voltage?


YES - Go to 16.


NO - Replace the under-hood fuse/relay box.n


16.Using the diode setting () on a DVOM, check for current flow in both directions between the A/C diode B terminals No. 1 and No. 2.

 

Is there current flow in only one direction?


YES - Replace the under-hood fuse/relay box.n


NO - Replace A/C diode B.n