I have a 2002 camaro SS with the LS1. Im getting code P0481. I have the shop manuals and they are overwhelming to me. I have been looking at the chart in Volume 2 page 6-788. I have checked my fuses and they are good. Is there a comman failure issue here? Or am I going to have to go thru this chart?

My scanner is an Xray 5000 and I cant control the 2 and 3 fans with it.

Can anyone point me in there right direction here?

Also, is it going to harm my car driving it with this code happening?

Thank you for your replies.

 

1) The Xray 5000 is not a bidirectional scanner and cannot send control signals. You could try clearing the code and see if it comes back, if the lamp stays off, just keep an eye on it.
2) The code says that the control circuit for fan #2 is not working properly, this can cause the engine to overheat, and the AC to stop working if the refrigerant pressure goes too high due to overheating.
3) The ECM sends a ground to the control relay circuit for fan #2, the ECM sees improper voltage to the control circuit for the relay.
4) You can try this procedure but you will need Voltmeter and a wiring diagram
Check for the following conditions:

• A faulty connection at the PCM – inspect the harness connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, and faulty terminal to wire connections.
• Inspect the wiring harness for damage.
• If the harness appears to be okay, disconnect the PCM, turn the ignition ON and observe a voltmeter connected between the fan 2 relay driver circuit and ground at the PCM harness connector while moving connectors and wiring harnesses related to the fan 2 relay. A change in voltage will indicate the location of the fault.
• With the ignition off, disconnect the relay. Turn ignition ON (DO NOT START). Probe the coil feed circuit of the relay with a test lamp connected to ground.
  • Does the test lamp illuminate?
    • NO - Check the fuse. If blow check each branch of the circuit for a short and repair. If problem found and repaired, clear DTC.
    • YES – A scan tool will be needed to check the command ON and OFF with the control circuit.
• Also test the control circuits of the rely for a short to voltage or an open. If problem found, repair.

 

i would suspect a failing relay, maybe change 1 and 2 fan relays and see if the code follows

 

to clear codes unhook battery and reconnect. to reset any computer based sensors uhook both battery cables and when they are both off touch them together for 20 seconds or so, then clean and reconnect. this also clears codes

 

The pcm is setting the code because it does not see the positive voltage at the pcm pin C2-33. Since the power for the relays feeds all three relays and only relay 2 and 3 are failing, the power to the relays is not the problem. And since this circuit uses two relays (2 and 3) in parallel, it is unlikely a problem with just one relay (one would still provide a circuit). Most likely cause is a bad or broken connection at C100 in the engine compartment. C100 is the farthest forward of the three larger connectors atop the passenger side wheel well. The wires to check are the dark blue ones on each half of this connector. Check for 12v at these wires. It is there at all times. If there is 12v at the dark blue wire going to the pcm, the pcm or the pcm connector are suspect. If there is no 12v at either dark blue wire, there is an open circuit between there and the relay box.

 

Thank you GaryDoug for this info. I am going to check this out next.

 

Thank you GaryDoug for this info. I took the un hooked the terminal ends and no power on any of the legs.

 

Remove relays 2 and 3. Measure all terminals at the top of each socket. On each relay socket, there should be two terminals with 12v at all times. If not, there is a problem from there to the fuses. If they are both live, the problem is with the relays or the wiring to C100.

 

Thank you GaryDoug for your help. I checked the fuse and relay box. Fan 2 has 2 hot wires. They are orange. Fan 3 has 1 terminal hot orange where fan 3 relay plugs in on the top. But on the bottom side of the box/socket I have 2 hot orange wires for fan 3 relay. Could this be my issue? Not getting the power all the way up to the relay?

Thank you

 

NO, fan 3 should have 5 terminals on the top of the relay socket. One is an orange wire. The others are white, gray, black, and dark blue. Sorry, I misinformed you about relay 3