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. B25 (7.5 A)	Fuse/relay holder A
No. D9 (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) fuse, the No. B25 (7.5 A) fuse, and/or the No. D9 (10 A) fuse circuit(s).?

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 fuse/relay box
Fan control relay	Relay holder F

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
Test condition	Radiator fan relay: disconnected
Test point 1	Radiator fan relay 4P socket (female terminals) No. 1:
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 (30 A) fuse.?

4.

Determine possible failure area (GND line, others):

Determine possible failure area (GND line, others)

?1.

Connect terminals A and B with a jumper wire.

Terminal A	Fan control relay 5P socket (female terminals) No. 1:
Terminal B	Fan control relay 5P socket (female terminals) No. 2:

?2.

Connect terminals A and B with a jumper wire.

Terminal A	Radiator fan relay 4P socket (female terminals) No. 1:
Terminal B	Radiator fan relay 4P socket (female terminals) No. 2:

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

Replace the radiator fan motor.?

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
Test condition	Radiator fan relay: disconnected
	Fan control relay: disconnected
Test point 1	Fan control relay 5P socket (female terminals) No. 2:
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 G351.?

7.

Open wire check (MAIN FAN MOTOR line):

Open wire check (MAIN FAN MOTOR line)

?1.

Disconnect the following connector.

Radiator fan motor 2P connector

?2.

Check for continuity between test points 1 and 2.

Test condition	Vehicle OFF (LOCK) mode
Test condition	Radiator fan relay: disconnected
	Fan control relay: disconnected
	Radiator fan motor 2P connector: disconnected
Test point 1	Radiator fan relay 4P socket (female terminals) No. 2:
Test point 2	Radiator fan motor 2P connector (female terminals) No. 1:

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 (female terminals) No. 1:
Test point 2	Radiator fan motor 2P connector (female terminals) No. 2:

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 5P and the radiator fan motor.?

9.

Open wire check (IG2 A/C line):

Open wire check (IG2 A/C line)

?1.	Turn the vehicle to the ON mode.

?2.

Measure the voltage between test points 1 and 2.

Test condition	Vehicle ON mode
Test condition	Radiator fan relay: disconnected
	Fan control relay: disconnected
Test point 1	Radiator fan relay 4P socket (female terminals) No. 3:
Test point 2	Body ground

Is there battery voltage?


	YES

Go to step 10.


	NO

Repair an open in the IG2 A/C wire between the radiator fan relay and the No. D9 (10 A) fuse.?

10.

Open wire check (IGP2 SUB line):

Open wire check (IGP2 SUB line)

?1.

Measure the voltage between test points 1 and 2.

Test condition	Vehicle ON mode
Test condition	Radiator fan relay: disconnected
	Fan control relay: disconnected
Test point 1	Fan control relay 5P socket (female terminals) No. 3:
Test point 2	Body ground

Is there battery voltage?


	YES

Go to step 11.


	NO

Repair an open in the IGP2 SUB wire between the fan control relay and the No. B25 (7.5 A) fuse.?

11.

Open wire check (FAN LO SIGNAL line):

Open wire check (FAN LO SIGNAL line)

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

?2.	Connect the HDS to the DLC.

?3.	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.

?4.

Disconnect the following connector.

1.5 L engine: PCM connector A (50P)

2.4 L engine: PCM connector A (51P)

?5.

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 or 51P): disconnected
1.5 L engine:
Test point 1	Radiator fan relay 4P socket (female terminals) No. 4:
Test point 2	PCM connector A (50P) No. 17
2.4 L engine:
Test point 1	Radiator fan relay 4P socket (female terminals) No. 4:
Test point 2	PCM connector A (51P) No. 9

Is there continuity?


	YES

Go to step 12.


	NO

Repair an open in the FAN LO SIGNAL wire between the radiator fan relay and the PCM.?

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 or 51P): disconnected
1.5 L engine:
Test point 1	Fan control relay 5P socket (female terminals) No. 5:
Test point 2	PCM connector A (50P) No. 18
2.4 L engine:
Test point 1	Fan control relay 5P socket (female terminals) No. 5:
Test point 2	PCM connector A (51P) No. 10

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.?