P0483 fan speed code

[swany]

Towing my 5th wheel from Casa Grande, AZ to St. David today. It is a slight grade all of the way and there was a headwind. About half way here my Banks PDI sounded a warning. No engine light lit on dash. For those who may not be familure with the Banks equipment, it sounds a warning at a lower threshold than the obdll does. So I am assuming that the warning was telling me that something was getting ready to light the engine light. All of my guages read normal, maybe 5 degrees high on water temp is all. After a couple of minutes, the warning light went out and didn't come on again. After I got parked I checked the code and found the P0483 fan speed code.

Re-wind 6 wks or so ago. I was pulling a really steep hill a couple of miles long. As I neared the top my Banks pda gave me a hot trans warning (2nd gear pull). The PDA showed the trans temp at 235. As I understand it the obdll lights the light at 250? I have never seen the trans go to 235 before or since. After this happened I tried to remember if I heard the fan come on while pulling that hill or not and I can't say that I heard it. I have paid attention to it since and I have heard it come on but it doesn't really seem to roar like it has in the past.

Does it have a low and high speed? Could it be that the low works and the high doesn't? Is the fan controled by relays? Are there more than one? Where are they and how do I test them?

This is an '06 Dodge, 5.9 with an re48 automatic trans. Appreciate any help on this, Thanks.

[04cumminsram]

check the plug on the wiring, it may have came unplugged and this would cause the temperature difference on long pulls

happened to me the jesus clip on the connector fell out and it came undone ...

hope it helps

[Cumminalong]

The only thing that gets controlled is the fan clutch engagement and disengagement. The speed is dictated by engine RPM from that point.

On the 06+ trucks, the ECM does see the fan speed, so if the fan clutch is slipping / getting worn out, it may be signalling that it's time for a replacement.

Like Adam said though, check the wiring harness from underneath the truck and make sure the fan wiring hasn't gotten chewed up.

[Parts/Service]

Possible Causes 
OTHER DTC'S
(K161) SIGNAL CIRCUIT SHORT TO (K668) 5-VOLT SUPPLY CIRCUIT
(K161) SIGNAL CIRCUIT OPEN FROM ECM TO FAN CLUTCH ASSEMBLY
(K668) 5-VOLT SUPPLY CKT OPEN FROM ECM HARNESS CONNECTOR TO FAN CLUTCH HARNESS CONNECTOR
INTERMITTENT CONDITION
(K161) SIGNAL CIRCUIT SHORTED TO (690) RETURN IN THE HARNESS
(K161) SIGNAL CIRCUIT SHORTED TO VOLTAGE
(K161) SIGNAL CIRCUIT IN ECM SHORTED TO GROUND INSIDE ECM
(K161) SIGNAL CIRCUIT SHORTED TO VOLTAGE IN THE ECM
(K668) 5-VOLT SUPPLY CIRCUIT IN ECM


1. OTHER DTC'S PRESENT


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1. With the scan tool, read DTCs.


Is DTC P0480 present?

Yes

Repair other DTC's first.

No

Go To 2




2. FAN CLUTCH SHORTED


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1. Disconnect the wiring harness from the fan clutch assembly.


NOTE:  Check connectors - Clean/repair as necessary. 
2. Measure the resistance between the signal circuit in the fan clutch assembly and the return circuit in the fan clutch assembly. 


Is the resistance less than 10 Ohms?

Yes

Replace the fan clutch assembly.


No

Go To 3

3. FAN CLUTCH ASSEMBLEY SHORTED TO GROUND


--------------------------------------------------------------------------------
1. Measure the resistance between the signal circuit in the fan clutch assembly and battery negative.


Is the resistance less than 10 Ohms?

Yes

Replace the fan clutch assembly.


No

Go To 4

4. (K161) SIGNAL CIRCUIT SHORT TO (K668) 5-VOLT SUPPLY CIRCUIT


--------------------------------------------------------------------------------

 
1. Disconnect the Fan clutch connector.


NOTE:  Check connectors - Clean/repair as necessary. 
2. Measure the resistance between the (K161) signal circuit in the fan clutch assembly and the battery (K668) 5-volt supply circuit in the fan clutch assembly.


Is the resistance less than 10 Ohms?

Yes

Replace the Fan clutch assembly.


No

Go To 5

5.  (K161) SIGNAL CIRCUIT OPEN FROM ECM TO FAN CLUTCH ASSEMBLY


--------------------------------------------------------------------------------

 
1. Disconnect the ECM harness connectors.
2. Check connectors - Clean/repair as necessary.
3. Measure the resistance of the (K161) signal circuit between the ECM harness connector and the fan clutch assembly harness connector.


Is the resistance less than 10 Ohms?

Yes

Go To 6

No

Repair the open (K161) circuit from the ECM harness connector to the Fan clutch harness connector.

6. (K668) 5-VOLT SUPPLY CIRCUIT OPEN FROM ECM HARNESS CONNECTOR TO FAN CLUTCH HARNESS


--------------------------------------------------------------------------------

 
1. Measure the resistance of the (K668) 5-volt supply circuit between the ECM harness connector and the fan clutch assembly harness connector.


Is the resistance less than 10 Ohms?

Yes

Go To 7

No

Repair the open (K668) circuit from ECM harness connector to Fan clutch connector.

7. (K161) SIGNAL CIRCUIT SHORTED TO RETURN IN THE HARNESS


--------------------------------------------------------------------------------

 
1. Measure the resistance between the (K161) signal circuit in the fan clutch assembly harness connector and the return circuit in the fan clutch assembly harness connector.


Is the resistance less than 10 Ohms?

Yes

Repair the shorted (K161) circuit.
 

No

Go To 8

8. (K161) SIGNAL CIRCUIT SHORTED TO VOLTAGE


--------------------------------------------------------------------------------

 
1. Measure the voltage between the (K161) signal circuit in the fan clutch assembly harness connector and battery negative.


Is the voltage greater than 1 volt?

Yes

Repair the (K161) signal circuit shorted to voltage.


No

Go To 9

9. (K161) SIGNAL CIRCUIT IN ECM SHORTED TO GROUND INSIDE ECM


--------------------------------------------------------------------------------

 
1. Reconnect the ECM harness connectors.
2. Measure the resistance between the (K161) signal circuit in the fan clutch assembly harness connector and battery negative.


Is the resistance less than 10 Ohms?

Yes

Replace the ECM.

No

Go To 10

10. (K161) SIGNAL CIRCUIT SHORTED TO VOLTAGE IN THE ECM


--------------------------------------------------------------------------------

 
1. Reconnect the fan harness connector.
2. Turn the ignition on.
3. While back probing the fan connector measure the voltage between the fan speed (K161) signal circuit in the fan clutch assembly harness connector and battery negative while manually rotating the fan blade.


Did voltage go from less than 0.7 volts to 4.5 to 5.5 volts?

Yes

Repair the Fan Speed (K161) Signal circuit in the engine harness.
 

No

Go To 11

11. (K668) 5-VOLT SUPPLY CIRCUIT IN ECM


--------------------------------------------------------------------------------

 
1. Turn the ignition on.
2. Measure the voltage between the (K668) 5-volt supply circuit in the fan clutch assembly harness connector and battery negative.


Is the voltage between 4.5 and 5.5 volts?

Yes

Refer to the INTERMITTENT CONDITION Symptom (Diagnostic Procedure).

No

Replace the ECM.

[swany]

OK, thanks and Wow! I will do some poking around under the truck for the obvious first. Thanks again.

[tobinj]

Just replace the ffan clutch, shortly the truck will start billowing white smoke at start up and acting funny at idle, and probaly be hard to start.  Mine was doing all this and only throwing the fan clutch code all the while I was chasing what was thought to be a leaky injector and wasn't.  Replaced the fan clutch on the advice of a mechanic who just did a ram with the same issues and took him a week to figure out cause he too was chasing an injector.  In short if you got the code then the fan clutch is shorting somewhere somehow and for some reason this can really trick up the ECM.

Tobin

[Cumminalong]

The problem isn't necessarily the fan clutch.

The wiring that controls the fan is in the same circuit as the crank and cam position sensor, along with the AC, the alternator and a few other things.

What usually shorts and causes that problem is the wiring harness over by the alternator. It tends to rub through and causes that short.

[tobinj]

Your correct I should of rephrased and said mine just happened to be the fan clutch wiring which requires you to replace the clutch itself, it definately reeks havoc on the ECM at least with mine it did.

[Old timer]

Hello Parts/Service,

This is my first time on her and I was wondering what "Refer to the INTERMITTENT CONDITION Symptom (Diagnostic Procedure)"  means and how I can reference it.

I don't have a code but my fan works intermittently and have done all of these test only to come to the last one Refer to the INTERMITTENT CONDITION Symptom (Diagnostic Procedure). and I don't know where to go from here.  Will you help?

Thanks!

[lilfroger]

The "Refer to the INTERMITTENT CONDITION Symptom (Diagnostic Procedure)" is going to be a 'standard' Dodge troubleshooting step.  We of course as owners don't get access to all the spectacular flow charts / training material / documents that the service techs have in their wonderful computers tough

Why don't you go start a new thread with all the specifics for your vehicle ~ issue ~ steps tried & lets turn it over to the masses & see who can see something different.

Welcome btw

[Old timer]

Thanks, sounds like a good idea.  I will start a new thread and see what becomes of it.

Thanks again