Pontiac Grand Prix - Meaning, Causes & Diagnosis

OBDII code P0480 is quite common.  It indicates that your Pontiac Grand Prix’s “cooling fan 1 control circuit” is malfunctioning.  It’s a generic code, so it has the same meaning for any vehicle made for the 1996 model year and up.

P0480 Definition:  Cooling Fan 1 – Control Circuit Malfunction

This is the definition and breakdown of P0480 as it relates to the Pontiac Grand Prix. 

Cooling Fan 1.

Electric cooling fans are now standard equipment in modern vehicles.  The PCM (powertrain controller module) activates them whenever the Grand Prix is at a specific temperature.  They will turn on either one or both when your air conditioner runs.

Control Circuit Malfunction

If the PCM has commanded cooling fan 1 to turn on, but there is an error, P0480 will be stored in the PCM’s memory.  This occurs if either the fan doesn’t respond or the PCM detects a serious fault in the control circuit.

P0480 Symptoms Pontiac Grand Prix

Your Grand Prix will not be any different with P0480.  The engine will run normally without fan, unless it is heated too much.  The engine might start to knock, misfire, or smoke if you heat it too much.

As stated above, driving your Grand Prix without a functioning fan can cause it to overheat, particularly if you are driving on a hot day or you’re in heavy traffic.  This can cause your air conditioner not to work properly.

You’ll want to keep an eye on the temperature gauge and fix P0480 as soon as possible.  If you overheat, you might blow the head gasket which can lead to more costly repairs.

Pontiac Grand Prix - Causes + Diagnosis

Below are possible causes of P0480.  This code can have many causes.  These are listed in an order that allows you to verify their authenticity.  

1. Look for other codes

It is possible to cross-reference other codes and gain useful insight.  If you receive a code relating to engine coolant temperature sensor then repairing it could clear P0480 from your Grand Prix.

2. Check Cooling Fan 1

Unplug the battery.  You don’t want the fan spinning up (which could happen if you try and spin it and the vehicle is hot).

Two Pontiac Grand Prix fans can be found if your Pontiac Grand Prix is in the same city. DON'T put your hand in front the air conditioner Is almost always fan 1.

You’re going to spin the fan to see if it’s locked up or otherwise bad.  Before spinning the fan, make sure the engine and battery are cold.  When the engine heats up, fans can switch on by themselves.

If the fan requires effort to spin, then it’s bad.  You can fix your Grand Prix by replacing it.  You can clear the codes to check if it is back.

3. The Wiring Harness is located at the Fan.

Check the wire harness connecting to the fan to make sure it is turning ok.  Debris from roads can damage fan wiring.  If you live in an area that is chipmunk friendly, don’t be surprised if they chewed the wiring.  I’ve seen this a few times.

You must ensure that your terminals are securely connected to the fan.  Check that all pins have been checked for corrosion.

4. Examine the Fuses and Fan Relay

Now that we have verified that nothing obvious is causing P0480, it’s time to take a look under your Grand Prix’s hood at the fan relay.  Before you do, inspect the fan relay fuses to make sure that they haven’t been blown.  Visually, you can check this.  You can verify that the fan relay is powered on.

Now it’s time to take a look at fan relay 1 itself.  Check out the video below, it’ll show you how to test the fan relay with a multimeter.  If there’s no power going to the relay, you’ll need to find where the short is.

5. Additional P0480-related Causes

Here are some other common causes of P0480, although they aren’t as common as the ones listed above:

• VSS = Vehicle Speed Sensor
• Refuse to Intake Air Temp Sensor
• The A/C Pressure Switch

Conclusion

A bad fan, or relay of a fan can cause P0480.  We wish you all the best with your Pontiac Grand Prix repair!