Radiator and A/C Condenser Fan Low 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 symptom troubleshooting, check for powertrain DTCs (see GENERAL TROUBLESHOOTING INFORMATION ).

Check the No. B10 (7.5 A) and the No. B30 (30 A) fuse in the under-dash fuse/relay box.
Are the fuses OK?

YES -Go to step 2.

NO -Replace the fuse, and recheck. If the fuse blow again, check for a short in the No.B10 (7.5 A) fuse and the No. B30 (30 A) fuse circuits.
Remove the radiator fan relay from auxiliary under-hood relay box B, and test it (see POWER RELAY TEST ).
Is the relay OK?

YES -Go to step 3.

NO -Replace the radiator fan relay.
Connect the HDS to the DLC.
Turn the ignition switch to ON (II).
Turn on the A/C.
Check the FAN LOW CTRL in the PGM-FI Data List with the HDS.
Is the FAN LOW CTRL on?

YES -Go to step 8.

NO -Substitute a known-good ECM/PCM (see SUBSTITUTING THE ECM/PCM ), and recheck. If the symptom/indication goes away with a known-good ECM/PCM, replace the original ECM/PCM (see ECM/PCM REPLACEMENT ).
Turn the A/C switch and the fan control switch OFF, then turn the ignition switch to LOCK (0).
Measure the voltage between radiator fan relay 4P socket terminal No. 1 and body ground.

Fig 1: Measuring Voltage Between Radiator Fan Relay 4P Socket Terminal No. 1 And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there battery voltage?

YES -Go to step 9.

NO -Replace the under-dash fuse/relay box.
- USA models (see REMOVAL AND INSTALLATION )
- Canada models (see CANADA MODELS )
Connect radiator fan relay 4P socket terminals No. 1 and No. 2 with a jumper wire.

Fig 2: Connecting Radiator Fan Relay 4P Socket Terminals No. 1 And No. 2 With Jumper Wire
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Do the radiator and A/C condenser fans run?

YES -Go to step 10.

NO -Go to step 19.
Disconnect the jumper wire.
Turn the ignition switch to ON (II).
Measure the voltage between radiator fan relay 4P socket terminal No. 7 and body ground.

Fig 3: Measuring Voltage Between Radiator Fan Relay 4P Socket Terminal No. 7 And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there battery voltage?

YES -Go to step 13.

NO -Repair an open in the wire between the No. B10 (7.5 A) fuse in the under-dash fuse/relay box, A/C diode B and the radiator fan relay.
Turn the ignition switch to LOCK (0).
Reinstall the radiator fan relay.
Jump the SCS line with the HDS.
NOTE: This step must be done to protect the ECM/PCM from damage.
Disconnect ECM/PCM connector A (44P).
Connect ECM/PCM connector A (44P) terminal No. 4 to body ground with a jumper wire.

Fig 4: Connecting ECM/PCM Connector A (44P) Terminal No. 4 To Body Ground With Jumper Wire
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Turn the ignition switch to ON (II).
Do the radiator and A/C condenser fans run on LO?

YES -Check for loose wires or poor connection at ECM/PCM connector A (44P). If the connection is good, substitute a known-good ECM/PCM (see SUBSTITUTING THE ECM/PCM ), and recheck. If the symptom/indication goes away, replace the original ECM/PCM (see ECM/PCM REPLACEMENT ), then do the ECM/PCM idle learn procedure (see ECM/PCM IDLE LEARN PROCEDURE ).

NO -Repair an open in the wire between the radiator fan relay and the ECM/PCM.
Disconnect the jumper wire.
Reinstall the radiator fan relay.
Disconnect the radiator fan 2P connector.
Turn the ignition switch to ON (II), then turn the A/C switch and the fan control switch ON.
Measure the voltage between radiator fan 2P connector terminal No. 1 and body ground.

Fig 5: Measuring Voltage Between Radiator Fan 2P Connector Terminal No. 1 And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there battery voltage?

YES -Go to step 24.

NO -Repair an open in the wire between the radiator fan relay and the radiator fan.
Turn the A/C switch and the fan control switch OFF, then turn the ignition switch to LOCK (0).
Remove the fan control relay from auxiliary under-hood relay box A, and test it (see POWER RELAY TEST ).
Is the relay OK?

YES -Go to step 26.

NO -Replace the fan control relay.
Check for continuity between radiator fan 2P connector terminal No. 2 and fan control relay 5P socket terminal No. 6.

Fig 6: Checking Continuity Between Radiator Fan 2P Connector Terminal No. 2 And Fan Control Relay 5P Socket Terminal No. 6
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

YES -Go to step 27.

NO -Repair an open in the wire between the radiator fan and the fan control relay.
Remove the radiator fan relay.
Connect radiator fan relay 4P socket terminal No. 1 and No. 2 with a jumper wire.

Fig 7: Connecting Radiator Fan Relay 4P Socket Terminal No. 1 And No. 2 With Jumper Wire
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Connect fan control relay 5P socket terminal No. 6 to body ground with a jumper wire.

Fig 8: Connecting Fan Control Relay 5P Socket Terminal No. 6 To Body Ground With Jumper Wire
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Does the radiator fan run on high?

YES -Go to step 30.

NO -Replace the radiator fan motor (see FAN, FAN MOTOR, AND SHROUD REMOVAL AND INSTALLATION ).
Disconnect the jumper wires.
Disconnect the A/C condenser fan 2P connector.
Check for continuity between fan control relay 5P socket terminal No. 14 and A/C condenser fan 2P connector terminal No. 1.

Fig 9: Checking Continuity Between Fan Control Relay 5P Socket Terminal No. 14 And A/C Condenser Fan 2P Connector Terminal No. 1
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

YES -Go to step 33.

NO -Repair an open in the wire between the fan control relay and the A/C condenser fan.
Check for continuity between A/C condenser fan 2P connector terminal No. 2 and body ground.

Fig 10: Checking Continuity Between A/C Condenser Fan 2P Connector Terminal No. 2 And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

YES -Replace the A/C condenser fan motor (see FAN, FAN MOTOR, AND SHROUD REMOVAL AND INSTALLATION ).

NO -Check for an open in the wire between the A/C condenser fan and body ground. If the wire is OK, check for poor ground at G401 (see LEFT ENGINE COMPARTMENT WIRE HARNESS (BF) ).