2011 GS, A6 - Cooling fan relay location?
03-17-2015, 04:55 PM
#1
2011 GS, A6 - Cooling fan relay location?
I am clueless on this and after having used, "Search" could use some advice. Scenario -
Used A/C for first time this year, works great, get home park car. Restart later and the "Check Engine" is glowing solid. I run scan tool in the OBD and it pulls - P0480 Cooling Fan 1 control circuit malfunction. Car has full power but is running hot, though not hot enough for the DIC to notify me.
The fan does turn on once temperature gets above 215 degrees F. The dreaded connector at the fan is not melted or corroded. I am a former C3 owner X2 and my mind is telling me a relay is not working and the PCM can't ground the circuit.
My questions are - Does this car use relays for cooling fan?
- There are some relays in the fuse box under hood but none are labeled cooling fan (60 Amp fuse is good), I verified. If the fan uses relays could you help me with a location?
- What am I missing in my search to fix fault, and the Code? It is in permanent status currently.
Appreciate any guidance,
Chris
Used A/C for first time this year, works great, get home park car. Restart later and the "Check Engine" is glowing solid. I run scan tool in the OBD and it pulls - P0480 Cooling Fan 1 control circuit malfunction. Car has full power but is running hot, though not hot enough for the DIC to notify me.
The fan does turn on once temperature gets above 215 degrees F. The dreaded connector at the fan is not melted or corroded. I am a former C3 owner X2 and my mind is telling me a relay is not working and the PCM can't ground the circuit.
My questions are - Does this car use relays for cooling fan?
- There are some relays in the fuse box under hood but none are labeled cooling fan (60 Amp fuse is good), I verified. If the fan uses relays could you help me with a location?
- What am I missing in my search to fix fault, and the Code? It is in permanent status currently.
Appreciate any guidance,
Chris
03-17-2015, 10:15 PM
#3
Melting Slicks
The fan circuit does not use any relays. A pwm signal is sent to the fan module from the ECM (this is the small gauge wire at the fan module). Also a fused (60amp) power wire and ground wire attach to the module. Your fan does to operate. The problem then seems to be either that dreaded connector or the module is going bad.
The fan is variable speed. It ramps up slowly. It receives a pulse width modulated signal from the ECM. The PWM signal will change as the coolant temperature changes. The fan module will control the current flow to the fan based on this PWM signal. That's about all there is to it. No external relays are involved. New modules can be purchased for $140 on Ebay. Have one last look at the large connector in question before deciding to purchase a new fan module.
The fan is variable speed. It ramps up slowly. It receives a pulse width modulated signal from the ECM. The PWM signal will change as the coolant temperature changes. The fan module will control the current flow to the fan based on this PWM signal. That's about all there is to it. No external relays are involved. New modules can be purchased for $140 on Ebay. Have one last look at the large connector in question before deciding to purchase a new fan module.
Last edited by KENS80V; 03-17-2015 at 10:33 PM.
03-18-2015, 08:32 PM
#4
Team Owner
The module is solid state...there are transistors in there that are varying the voltage to the fan based on the signal from the computer. It is not a simple on/off situation but an almost continuously variable speed fan controlled by a signal from the computer. I would suggest pulling the connector at the control module and examining the contacts. The current is very high and if the contacts are not connected with plenty of surface area, they can be burned. But also, if the fan is coming on at 215, then all may be working fine. The code is a mystery if the fan is actually coming on.
03-19-2015, 10:01 AM
#5
Where is the module located?
The module is solid state...there are transistors in there that are varying the voltage to the fan based on the signal from the computer. It is not a simple on/off situation but an almost continuously variable speed fan controlled by a signal from the computer. I would suggest pulling the connector at the control module and examining the contacts. The current is very high and if the contacts are not connected with plenty of surface area, they can be burned. But also, if the fan is coming on at 215, then all may be working fine. The code is a mystery if the fan is actually coming on.Where is the module located? I really appreciate the help from you guys
03-19-2015, 02:16 PM
#6
Race Director
Member Since: Sep 2007
Location: Peoria/Phoenix AZ
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C6 of Year Finalist (performance mods) 2019
The fan duty cycle starts at 204* (10%) and increases to full speed (90%) at 235*. It will also start when the AC pressure reaches 160 psi and is full speed at 360 psi. It will turn on at full speed if either engine oil hits 302* or trans oil hits 270*. It'll run at 50% for a max of 2 minutes after key off, if the coolant temps or AC pressures are at or near high limits.
There are several tests to determine causes of improper fan operation, assuming the fan actually runs. Two of the cures require ECM replacement, two more are ground and/or open/high resistance, and the last (when everything else is OK) is to replace the fan module.
I'm in north Peoria, so if you're nearby I'll print out the pages of the manual for you. Otherwise, PM me on the ACE forum and I'll forward my phone # to you.