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. 30 (30 A) and the No. 10 (7.5 A) fuses in the under-dash fuse/relay box.
Are the fuses OK?

YES -Go to step 2.

NO -Replace the fuse(s), and recheck. If the fuse(s) blow again, check for a short in the No. 30 (30 A) and No. 10 (7.5 A) fuses circuit.
Remove the radiator fan relay from the auxiliary under-hood relay box, 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 the A/C and FAN to ON on the climate control unit.
Check the FAN LOW CTRL in the PGM-FI Data List with the HDS.
Is the FAN LOW CTRL on?

YES -Go to step 7.

NO -Substitute a known-good PCM (see SUBSTITUTING THE PCM ), and retest. If the symptom/indication goes away with a known-good PCM, replace the original PCM (see 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 -Repair an open in the wire between the No. 30 (30 A) fuse in the under-dash fuse/relay box and the radiator fan relay.
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 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. 4 and body ground.

Fig 3: Measuring Voltage Between Radiator Fan Relay 4P Socket Terminal No. 4 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. 10 (7.5 A) fuse in the under-dash fuse/relay box, A/C diode A 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 powertrain control module (PCM) from damage.
Disconnect PCM connector A (49P).
Connect PCM connector A (49P) terminal No. 44 to body ground with a jumper wire.

Fig 4: Connecting PCM Connector A (49P) Terminal No. 44 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 low?

YES -Check for loose wires or poor connections at PCM connector A (49P). If the connections are good, substitute a known-good PCM (see SUBSTITUTING THE PCM ), and recheck. If the symptom/indication goes away, replace the original PCM (see PCM REPLACEMENT ), then do the PCM idle learn procedure (see PCM IDLE LEARN PROCEDURE ).

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

Fig 5: Measuring Voltage Between Radiator Fan Motor 2P Connector Terminal No. 2 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 motor.
Turn the A/C switch and fan control switch OFF, then turn the ignition switch to LOCK (0).
Test the radiator fan motor (see FAN MOTOR TEST ).
Is the motor OK?

YES -Go to step 26.

NO -Replace the radiator fan motor (see FAN, FAN MOTOR, AND SHROUD REMOVAL AND INSTALLATION ).
Remove the fan control relay from the auxiliary under-hood fuse/relay box, and test it (see POWER RELAY TEST ).
Is the relay OK?

YES -Go to step 27.

NO -Replace the fan control relay.
Turn the ignition switch ON (II), then turn the A/C switch and fan control switch ON.
Measure the voltage between fan control relay 5P socket terminal No. 1 and body ground.

Fig 6: Measuring Voltage Between Fan Control Relay 5P Socket Terminal No. 1 And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there battery voltage?

YES -Go to step 29.

NO -Repair an open in the wire between the radiator fan motor and the fan control relay.
Turn the A/C switch and fan control switch OFF, then turn the ignition switch to LOCK (0).
Disconnect the A/C condenser fan motor 2P connector.
Check for continuity between fan control relay 5P socket terminal No. 4 and A/C condenser fan motor 2P connector terminal No. 2.

Fig 7: Checking Continuity Between Fan Control Relay 5P Socket Terminal No. 4 And A/C Condenser Fan Motor 2P Connector Terminal No. 2
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

YES -Go to step 32.

NO -Repair an open in the wire between the fan control relay and the A/C condenser motor fan.
Check for continuity between A/C condenser fan motor 2P connector terminal No. 1 and body ground.

Fig 8: Checking Continuity Between A/C Condenser Fan Motor 2P Connector Terminal No. 1 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 CONNECTOR TO FUSE/RELAY BOX INDEX ).