Radiator Fan High Speed Circuit Troubleshooting
Radiator Fan High Speed Circuit Troubleshooting
1.
Fuse check:

Fuse check
?1.
Check the following fuses.
Fuse
Location
No. A1-3 (30 A)
Under-hood fuse/relay box
No. A11 (5 A)
No. B9 (10 A)
Under-dash fuse/relay box

Are the fuses OK?

     
YES
     
     
     
Reinstall the fuses, then go to step 2.
     
NO
     
     
     
Replace the fuse(s), and recheck. If the fuse(s) blows again, repair the short to ground on the No. A1-3 (30 A), the No. A11 (5 A), and/or the No. B9 (10 A) fuse circuit.?
2.
Radiator fan and fan control relays check:

Radiator fan and fan control relays check
?1.
Check the following relays.
Relay
Location
Radiator fan relay
Under-hood relay holder C
Fan control relay
Under-hood relay holder B

Are the relays OK?

     
YES
     
     
     
Go to step 3.
     
NO
     
     
     
Replace the relay(s).?
3.
Open wire check (+B MAIN FAN line):

Open wire check (+B MAIN FAN line)
?1.
Measure the voltage between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
Radiator fan relay: disconnected
Test point 1
Radiator fan relay 4P socket No. 3 (female terminals):
Test point 2
Body ground


Is there battery voltage?

     
YES
     
     
     
Go to step 4.
     
NO
     
     
     
Repair an open in the +B MAIN FAN wire between the radiator fan relay and the No. A1-3 (30A) fuse.?
4.
Determine possible failure area (GND line, others):

Determine possible failure area (GND line, others)
?1.
Remove the fan control relay.

?2.
Connect terminals A and B with a jumper wire.
Terminal A
Fan control relay 5P socket No. 1 (female terminals):
Terminal B
Fan control relay 5P socket No. 2 (female terminals):


?3.
Connect terminals A and B with a jumper wire.
Terminal A
Radiator fan relay 4P socket No. 3 (female terminals):
Terminal B
Radiator fan relay 4P socket No. 4 (female terminals):


Does the radiator fan run at high speed?

     
YES
     
     
     
Remove the jumper wires, then go to step 9.
     
NO
     
     
     
Remove the jumper wires, then go to step 5.
5.
Radiator fan motor operation check:

Radiator fan motor operation check
?1.
Test the radiator fan motor.

Is the motor OK?

     
YES
     
     
     
Go to step 6.
     
NO
     
     
     
6.
Open wire check (GND line):

Open wire check (GND line)
?1.
Check for continuity between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
Radiator fan relay: disconnected
 
Fan control relay: disconnected
Test point 1
Fan control relay 5P socket No. 2 (female terminals):
Test point 2
Body ground


Is there continuity?

     
YES
     
     
     
Go to step 7.
     
NO
     
     
     
Repair an open in the GND wire between the fan control relay and ground G305.?
7.
Open wire check (MAIN FAN MOTOR line):

Open wire check (MAIN FAN MOTOR line)
?1.
Disconnect the flowing connector.
Radiator fan motor 2P connector

?2.
Check for continuity between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
Radiator fan relay: disconnected
 
Fan control relay: disconnected
 
Radiator fan motor 2P connector: disconnected
Test point 1
Radiator fan relay 4P socket No. 4 (female terminals):
Test point 2
Radiator fan motor 2P connector No. 1 (female terminals):


Is there continuity?

     
YES
     
     
     
Go to step 8.
     
NO
     
     
     
Repair an open in the MAIN FAN MOTOR wire between the radiator fan relay and the radiator fan motor.?
8.
Open wire check (FAN HI/LO RLY COM line):

Open wire check (FAN HI/LO RLY COM line)
?1.
Check for continuity between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
Radiator fan relay: disconnected
Fan control relay: disconnected
 
Radiator fan motor 2P connector: disconnected
Test point 1
Fan control relay 5P socket No. 1 (female terminals):
Test point 2
Radiator fan motor 2P connector No. 2 (female terminals):


Is there continuity?

     
YES
     
     
     
Check for poor connections or loose terminals at the under-hood fuse/relay box and the radiator fan motor.?
     
NO
     
     
     
Repair an open in the FAN HI/LO RLY COM wire between the fan control relay and the radiator fan motor.?
9.
Open wire check (IG2 OPTION line):

Open wire check (IG2 OPTION line)
?1.
Turn the vehicle to the ON mode.

?2.
Measure the voltage between test points 1 and 2.
Test condition
Vehicle ON mode
Radiator fan relay: disconnected
 
Fan control relay: disconnected
Test point 1
Radiator fan relay 4P socket No. 7 (female terminals):
Test point 2
Body ground


Is there battery voltage?

     
YES
     
     
     
Go to step 10.
     
NO
     
     
     
Repair an open in the IG2 OPTION wire between the radiator fan relay and the No. B9 (10 A) fuse.?
10.
Open wire check (RFC RLY CL- line):

Open wire check (RFC RLY CL- line)
?1.
Turn the vehicle to the OFF (LOCK) mode.

?2.
Connect the HDS to the DLC.

?3.
Turn the vehicle to the OFF (LOCK) mode.

?4.
Jump the SCS line with the HDS, and wait more than 1 minute.
NOTE: This step must be done to protect the PCM from damage.


?5.
Disconnect the following connector.
PCM connector No.2 (58P)

?6.
Check for continuity between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
Radiator fan relay: disconnected
Fan control relay: disconnected
 
PCM connector No.2 (58P): disconnected
Test point 1
Radiator fan relay 4P socket No. 8 (female terminals):
Test point 2
PCM connector No.2 (58P) No. 12


Is there continuity?

     
YES
     
     
     
Go to step 11.
     
NO
     
     
     
Repair an open in the RFC RLY CL- wire between the radiator fan relay and the PCM.?
11.
Open wire check (IGPS (LAF) line):

Open wire check (IGPS (LAF) line)
?1.
Turn the vehicle to the ON mode.

?2.
Measure the voltage between test points 1 and 2.
Test condition
Vehicle ON mode
Radiator fan relay: disconnected
 
Fan control relay: disconnected
Test point 1
Fan control relay 5P socket No. 5 (female terminals):
Test point 2
Body ground


Is there battery voltage?

     
YES
     
     
     
Go to step 12.
     
NO
     
     
     
Repair an open in the IGPS (LAF) wire between the fan control relay and the No. A11 (5 A) fuse.?
12.
Open wire check (FAN HI SIGNAL line):

Open wire check (FAN HI SIGNAL line)
?1.
Check for continuity between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
Radiator fan relay: disconnected
Fan control relay: disconnected
 
PCM connector A (50P): disconnected
Test point 1
Fan control relay 5P socket No. 7 (female terminals):
Test point 2
PCM connector No. 2 (58P) No. 36


Is there continuity?

     
YES
     
     
     
Check for any authorized service information related to the DTCs or symptoms you are troubleshooting, or substitute a known-good PCM, then recheck. If the PCM was substituted, and the symptom/indication goes away, replace the original PCM.?
     
NO
     
     
     
Repair an open in the FAN HI SIGNAL wire between the fan control relay and the PCM.?