How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask -Brad- Your Own Question
-Brad-, Dodge Dealership Tech
Category: Dodge
Satisfied Customers: 7828
Experience:  16 Yrs Chrysler/Dodge Technician. ASE Master Certified(L-1)
Type Your Dodge Question Here...
-Brad- is online now
A new question is answered every 9 seconds

I have a 2013 dodge dart limited 2.0l that does not have and

Customer Question

hello I have a 2013 dodge dart limited 2.0l that does not have and codes and no low fan speed operation . I have let ran with a/c off until it gets up to 230 degrees and the high fan speed will come on and gradually slow down to 183 degrees and cut itself off and does not come back on til 230 degrees again and do the same thing and with a/c on my fans still do not come on until about the same temperature on high only and gradually cuts off completely at about 183 degrees . I have checked the 60 amp fuse and the 5 amp fuse and they are good and I have just replaced the fan assembly with fan control module and no change and I was checking to see was the fan control relay labeled as T03 in the under hood fuse box or as another or what else to diagnose to make sure that I have a computer problem and or how to check for a bad relay and where is or bad computer or what .
Submitted: 6 months ago.
Category: Dodge
Customer: replied 6 months ago.
Also I have power all the time to my fan control module wire violet/brown and I only get power to my blue/gray wire until my temperature get up to 230 degrees and I have power to my big red wire also .
Expert:  -Brad- replied 6 months ago.

Good afternoon and welcome to JustAnswer!!

My name is ***** ***** I have worked for a Chrysler-Dodge-Jeep dealership for 19 years and I will do my best to help.

Can I get your VIN number to grab a wiring diagram?

Talk soon,


Customer: replied 6 months ago.
Expert:  -Brad- replied 6 months ago.

Thanks for the VIN!!

The Radiator Fan Module is a smart device which controls the Pulse-Width Modulated (PWM) Radiator Fan speed. The Radiator Fan Module receives a continuous wake-up signal from the Radiator Fan Relay output. The Powertrain Control Module (PCM) uses a Low Side Driver (LSD) to control the Radiator Fan Relay to close the relay and turn on the wake-up signal. The PCM communicates with the Radiator Fan Module through a PWM signal. The PCM communicates the desired fan speed to the Radiator Fan Module using the PWM circuit. If a fault is detected in the voltage supply, ground or internal fan circuitry, the Radiator Fan Module sends a fault message to the PCM using the same PWM circuit. During normal operation, the Radiator Fan can be operated between 10% duty cycle (Low speed) and 92% duty cycle (High speed).

NOTE:If the wake-up signal between the Radiator Fan Relay and the Radiator Fan Module is lost, no fault is set but the Radiator Fan defaults to low speed operation.

Typical Low Side Driver Operation and Fault Detection: This type of driver circuit is generally used for relay control, controlling a solenoid or a similar type of driver device. The PCM provides a ground to operate the device when switched on. The PCM also provides fault detection for the device, wiring and internal driver. For diagnostic purposes the PCM uses an internal pull down diagnostic resistor connected in series and a voltage reference (V-Ref) comparator for fault detection.

Since you have replaced the fan and module it's possibly a bad PCM but in order to confirm this you will need a scantool to actuate the low speed and high speed fan to see if the drivers in the PCM are bad. I have attached the wiring diagram to help..

If you need anymore assistance feel free to shoot me a reply and don't forget to RATE 5 Stars before leaving the site so I get credit for helping you today..

Have a great day,


Customer: replied 6 months ago.
Ok the wiring diagram and the information you sent me I have already reviewed and I already tried with my scan tool which is a snap-on modis ultra and I could not get a low fan speed des state , but I get a high fan speed des state every time . Now on the radiator fan relay location according to my prodemand I think it is the relay in my under fuse box and its listed as T02 is there a diagram or diagnostic check to check this radiator fan relay or do u think that I'm looking at a computer problem . I really need to get this vechicle fixed a.s.a.p. because I couldn't find a component test on the radiator fan relay do you have anything on these .
Customer: replied 6 months ago.
Ha Brad are you working on me a answer for my problem here.