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Discussion Starter · #1 ·
The CE light is on + code P0480 appears--> Fan Controller 1 Relay.

The fuses are fine and I swapped the FC 1 and 2 relays and the code didn't change, so this rules out relay malfunction.

Would a malfunctioning Driver's fan cause the code? In slow traffic temps reach ~250, leading me to believe that the fans are not running in low speed mode, and the serial circuit means fan #2 cannot run either if #1 burned out.

Under what condition would Fan 1 engage so I can check if it's really broken? Full a/c? Thanks much.
 

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Yes both fans run in series in low speed mode, but they run in parallel in high speed mode. So if the coolfan 1 relay was shot, niether fan would run until the engine got hot enough and then the right fan would kick on to high speed and would be the only one running.

Coolfan 2 relay is for high speed operation for the right fan. Coolfan 3 relay energizes for high speed operation for the left fan. Coolfan 1 relay is always energized to provide power to the left and right fan in series during low speed operation, and provides power to the left fan during high speed operation.

And what do you mean when you said you swapped the relays and the code didnt change? Does that mean you cleared it and it came back or it just didnt go off by itself? Both fans come on when the A/C is turned on and I believe both fans go to highspeed. Another way to test the fans themselves is to just disconnect the connector at the fan and put 12volts directly to the fan motor and see if it comes on. You could also yank the coolfan1 relay and jumper the correct slots, which would supply 12 volts to both fans and they should both turn on in low speed.
 

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P0480
DTC P0480
Circuit Description
Battery positive voltage is supplied to the cool fen 1 relay from the cooling fan 1 fuse. The Powertrain Control Module (PCM) controls the cooling fan 1 relay by grounding the low speed cooling fan relay control circuit via an internal solid state device called a driver. The primary function of the driver is to supply the ground for the component being controlled. Each driver has a fault line, which is monitored by the PCM. When the PCM is commanding a component on, the voltage potential of the control circuit should be low (near 0 volts). When the PCM is commanding the control circuit to a component off, the voltage potential of the circuit should be high (near battery voltage). If the fault detection circuit senses a voltage other than what is expected, the DTC will set. The PCM will monitor the control circuit for the following:

- A short to ground
- A short to voltage
- An open circuit
- An open relay coil
- An internally shorted or excessively low resistance relay coil.

When the PCM detects any of the above conditions, the DTC will set and the affected driver will be disabled, Conditions for Running the DTC

- The ignition voltage is between 6 and 18 volts.
- The engine speed is greater than 400 RPM.
Conditions for Setting the DTC
- An improper voltage level has been detected on the low speed cooling fan relay control circuit
- The above conditions are present for at least 5 seconds.
Action Taken When the DTC Sets
- The PCM will illuminate the Malfunction Indicator Lamp (MIL) during the second consecutive trip in which the diagnostic test has been run and failed .
- The PCM will store conditions, which were present when the DTC set as Freeze Frame and Failure Records data.

Conditions for Clearing the MIL/DTC
- The PCM will turn OFF the MIL during the third consecutive trip in which the diagnostic has been run and passed.
- The History DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction.
- The DTC can be cleared by using the scan tool.

Diagnostic Aids

Check for the following conditions:

- A faulty connection at the PCM, inspect the harness connectors for the following conditions.
-- Backed out terminals
-- Improper mating
-- Broken locks
-- Improperly formed or damaged terminals
-- Faulty terminal to wire connections
-- Inspect the wiring harness for damage.
- If the harness appears to be OK, disconnect the PCM, turn the ignition ON and observe a Digital Multimeter (DMM) connected between the low speed cooling fan relay control circuit of the cooling fan 1 relay and ground at the PCM harness connector. While moving connectors and the wiring harness related to the cooling fan 1 relay, a change in voltage will indicate the location of the fault.
Review the Freeze/Failure Records vehicle mileage since the diagnostic test last failed. This may help determine how often the condition that caused the DTC to be set occurs.

Test Description

1. Listen for an audible click when the cooling fan 1 relay operates. Command both the ON and OFF states. Repeat the commands as necessary.
2. Tests for voltage at the coil side of the cooling fan 1 relay. The cooling fan 1 fuse supplies battery positive voltage to the coil side of the cooling fan 1 relay.
3. Verifies that the PCM is providing ground to the cooling fan 1 relay.4.
4. Tests if ground is constantly being applied to the cooling fan I relay.
 

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Discussion Starter · #5 ·
Last Question!

Thanks everyone!

Can a broken FAN MOTOR alone set the P480 code? Or can only a circuit failure set the code?

I've confirmed both relays work.

Thx much.
 

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bierry said:
Thanks everyone!

Can a broken FAN MOTOR alone set the P480 code? Or can only a circuit failure set the code?

I've confirmed both relays work.

Thx much.
A bad fan motor can set the code.
 

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Discussion Starter · #7 ·
Speedrachet,

Really appreciate your detailed assistance. I'm suspecting the fan motor because a plastic bag jammed it once before. It was removed but the motor's prob gone. Thanks again.
 

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Discussion Starter · #9 ·
Problem fixed - bad motor!

Thanks everyone for pitching in. I installed a new fan motor and all is well.

Contrary to what I've been told though, I was unable to slide the fan assembly from undercarriage - the roll bar is in the way. Had to remove the upper rad hose and wiggle the assembly out from above.

And do shop around! Cheapest online was $52, dealer wanted $81, Pep+autozone charged $71, then a last call to Advanced Auto Parts came in at $29.99. Ordered 3PM Sat and arrived before noon Sunday.
 
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