- The vehicle speed is less than 38 MPH. Alldatadiy.com, on the other hand, uses the factory diagrams. This tutorial will help you to diagnose the Pulse Width Modulated (PWM) fan relay on the 1999-2003 Jeep 4.0L Grand Cherokee SUVs and/or the codes P1491 (Radiator Fan Control Relay Circuit).The dealer, at the time of this writing, will charge you $95 (US) to diagnose it. If it will not spin the fan bearings are shot and the fan is bad. A switched terminal will be hot only when the key is on. If you still need help regarding the P0480 trouble code, please post If your vehicle's check engine light comes on and after pulling the code you find a P0480 displayed, if refers to the engine cooling fan circuit. When the PCM attempts to activate the fan and senses the command and the result do not match, the code is set. Radiator fan relay switch wiring electric override electrical diagrams how to replace a cooling fan relay on most vehicles 2002 dodge caravan cooling fan relay wiring 2016 grand 2006 ford escape fuse diagrams ricks auto repair. A/C selector switch 9. DIAGNOSTIC TROUBLE CODE (DTC) - P0481 HIGH SPEED COOLING FAN RELAY CIRCUIT FAULT (WITHOUT A/C) Details of the Circuit. Check it with the ohmmeter, there should be a big change in resistance, if not the sensor is bad. Probe the sensor terminals. Check all the relays in the same fashion to be sure they are all working. If not, disconnect the fan connection at the fan and using an ohmmeter check the continuity between the fan side of the relay terminal and the connector at the fan, If there is continuity the fan is bad. Mount the fan as high up on the core as possible. Specific repair steps can vary from make/model. Contact Us Open the fuse block and inspect the cooling fan relay fuses. Use a test light to find the hot terminal. Defective faulty fan control relay 1 2. Recently, I was driving my 2015 Jeep Wrangler JK Unlimited through a parking lot on a 95 degree day, and after leaving a stop sign, a check engine light flashed on (later I would learn it was a P0480 Cooling Fan Relay 1 Control Circuit), and shortly thereafter my Jeep overheated. Accuracy isn't necessary since all sensors may be different. The opposite side goes to the fan. Look at the fan and make sure there is no obstruction in front of the radiator blocking airflow. Let the engine cool and put the ohmmeter on the 200,000 scale. When … The cooling fan relay will be commanded ON when the following conditions are met: - The engine coolant temperature reaches 106°C (223°F) or more. Most cooling fans use electric motors that have a moderate to high current draw, and as a result are commonly controlled using relays. Jump the battery plus terminal in the first test with this switched terminal and place an additional jumper from the negative terminal on the relay to ground. cooling fan relay wiring diagram – You will need a comprehensive, expert, and easy to understand Wiring Diagram. Faulty VSS (vehicle speed sensor) It does so by supplying the ground to the relay. Get the BEST auto repair information Alldatadiy.com and Eautorepair.net are professional-grade shop manuals—period. It is a generic code applying to all OBD II (on board diagnostics) vehicles. By using a lower voltage signal to control the relay, there is less stress on the rest of the wiring and charging system. Until such time as you can either complete your checks of the circuits or take the car to a service facility, pull the fuse in the fuse relay … Electric Fan Relay Wiring Diagram– wiring diagram is a simplified tolerable pictorial representation of an electrical circuit.It shows the components of the circuit as simplified shapes, and the capability and signal contacts between the devices. Most late model vehicles use an electric fan to pull air through the radiator. Poor electrical connections in the cooling fan circuit 6. - The A/C clutch requested. When coolant temperature rises above acceptable limits, the computer provides ground to the fan relay. They include wiring diagrams and technical service bulletins. How Dodge Radiator Fan Wiring Diagram is set up. The vehicle computer monitors coolant temperature with a sensor located near the thermostat. Look at the circuit diagram displayed on the side of the relay. The negative terminal in this circuit is the one used when the PCM wishes to active the relay by grounding it. Open or shorted fan control relay harness 2. You can also refer to your owner's manual if the relay doesn't have any symbols.Resistance Test: 1. Open or shorted fan cooling fan harness 5. If not the harness between the fuse block and the fan is faulty. The activated relay completes a circuit, allowing an electric current to flow through it and reach the cooling fans. There are multiple factors that can lead to this error code. C5 corvette electric fan relay wiring to wire an electric fan with a relay arduino controls fan tutorial trinary switch infinitybox 12v toggle switch wiring… Best Fan In Thestylishnomad.Com 13560+ Best Fan Thestylishnomad.Com 2019 (Please call for fan shroud suggestions). Disconnecting the PCM could cause loss of programming and the vehicle may not start unless towed to the dealer for reprogramming. Most modern vehicles use electric cooling fans to help pull air through the radiator so that it can keep the engine cool. If the above procedure could not find a failure, the probability is that a poor connection to the PCM or the PCM itself is at fault. If the fan operated, check the relays. The PCM controls the cooling fan by grounding the cooling fan control circuit which turns ON the cooling fan relay. Any one know where the thermostat or temp switch for the control circuit is? Additionally, many vehicles have multi-speed fans requiring as many as three fan speed relays for low, medium and high. If you have a P1491 Radiator Fan Control Relay Circuit trouble code, this post will help you understand what it is and how to fix it. Repair if necessary and use dielectric grease on the terminals. Open or shorted fan control relay harness 4. The fans that are used to cool the engines radiator are run by electric motors. Electric fan is responsible for causing air movement around the engine coolant radiator. P1491 Radiator Fan Control Relay Circuit P1491 Radiator Fan Control Relay Circuit. Related. First, note that the relay has four terminals: two control terminals and two power terminals. A duty cycle is determined based on these input parameters. Use an ohmmeter to test that the constant battery terminal and the fan harness terminal have continuity meaning the circuit has closed. What does that mean? The cooling fan relay coil receives the Ignition Voltage directly. Open the hood and do a visual inspection. The reading will be about 2.5. With this sort of an illustrative manual, you’ll have the ability to troubleshoot, avoid, and complete your assignments without difficulty. See the schematic printed on the relay itself or consult the schematic in your vehicle repair manual, if necessary. IAT (intake air temperature) failure 8. Pricing: ---Eautorepair.net--- 1 month subscription $19.95 per vehicle 1-year subscription $29.95 per vehicle 4-year subscription $44.95 per vehicle ---Alldatadiy.com--- 1-year $29.95 subscription: additional vehicles $19/95 each 5-year $49.95 subscription: additional vehicles $34.95 each Which one should YOU choose? Poor electrical connections in the cooling fan circuit 6. Most late model vehicles use an electric fan to pull air through the radiator. Open or shorted fan cooling fan harness 3. The cooling fan relay is the relay that controls the engine’s cooling fans. Look at the side of the relay for the switched power terminal or just turn the key on. The amount of air movement caused by the fan is controlled based on the Vehicle Speed, coolant temperature, A/C pressure status, A/C switch request status, and A/C clutch state. Set the … Search using your favorite search engine "technical service bulletins for ....." Look up the code and the type of manufacturer recommended repair. If swapping relays still doesn't operate your cooling fan, make sure the relay is receiving power from the computer. If there was no switched power at the relay, the ignition switch is suspect. NOTE: P0480 speaks of the basic circuit, however codes P0481, and P0482 relate to the same problem with the only difference is they relate to the different fan speed relays. The cooling fan relay takes the low voltage signal and internally switches the relay “on” to allow battery voltage to be supplied to the radiator cooling fan. In most cases, their diagrams are right from the factory manuals. NOTE: This information is presented for information purposes only. Faulty cooling fan 1 3. The fan that is not in front of the air conditioning condenser is the main cooling fan and the one to concentrate on initially. IAT (intake air temperature) failure 8. A/C refrigerant pressure sensor 10. If you’re tracking down a wiring issue, Eautorepair.net is the better choice. When the temperature reaches about 223-degrees F (value depends on make/model/engine), the PCM will command the cooling fan relay to turn on the fan. The cooling fan relay will be commanded ON when the following conditions are met: - The engine coolant temperature reaches 106°C (223°F) or more. For precise readings consult a service manual. Refer to the top or side of the relay to locate these terminals. Reconnect it and warm the engine. This is a generic powertrain diagnostic trouble code (DTC) applicable to most 1996-newer vehicles. Defective coolant temperature sensor 7. Multiple factors can lead to this error code, some of the most common possible causes are: 1. Pull the connector off. + + this will be your new ground switched output. The relay is regulated by grounding the control circuit via the driver or the internal switch, a process which is entirely controlled by the ECM. The schematic will help you also when checking the fan cooling circuit. But other Chrysler and Dodge vehicles use a more traditional radiator fan relay. Cool Automotive Products and Tool Recommendations, Read AUTO REPAIR ARTICLES sorted by topic, Generic non-manufacturer-specific P code definitions, Honda alternator and charging systems explained, Harsh shift, rough idle, GM service bulletin #PIP5446A, Custom Wordpress Website created by Wizzy Wig Web Design, Minneapolis MN. While you are driving, air in sufficient quantity is passing through the radiator effectively cooling the engine. Faulty cooling fan 3 5. Spin the fan with your finger (make sure the vehicle and key is off). your question in our FREE car repair forums, Check engine light (malfunction indicator lamp) illumination and code P0480 set, Engine temperature will rise when the vehicle stops and idles, Fan control relay harness is open or shorted, Fan cooling fan harness is open or shorted, Cooling fan circuit poor electrical connection. Some Dodge vehicles have a solid state radiator fan controller that varies the fan speeds by pulsing the ground to the radiator fan motor. Check the terminals for an additional power terminal and look where it would be on the relay. Look at the markings on top or side of the relay case and locate the two control circuit terminals, which connect to the relay's coil, and the two power circuit terminals, which let electrical current pass to the fan. adjustable fan switch/thermostat with built-in relay and radiator probe (12v switching, non-variable speed only) 86 30 87 85 5 amp fuse signal circuit 12v switched (ignition or fuse panel) power “on” when key is in the “run” position. If the circuit has not closed or the relay has not clicked, the relay is bad. your question in our FREE car repair forums. A malfunctioning cooling fan relay can … So you have to refer to the factory legends to learn the identification symbols and then refer back to circuit diagrams to find the splice and ground locations. - The A/C clutch requested. This one turns on the fan when the circuit is closed. The switch will click on. It is a generic code applying to all OBD II (on board diagnostics) vehicles. A code P1492 indicates a problem with the relay circuit. The cooling fan relay is an electromagnetic switch that controls the power supply to the engine’s cooling fans. The cooling fan relay will be commanded ON when the following conditions are met: - The engine coolant temperature reaches 106°C (223°F) or more. When you bring the car to a stop no air is passing through the radiator and the engine begins to increase in temperature. Faulty VSS (vehicle speed sensor) However, specific troubleshooting steps will vary depending on the vehicle. Step 1 - A relay is used to control (switch) a high amperage electrical circuit with a low amperage one, for example a radiator fan can pull up to 25 amps when in use, which would burn the computer circuit that controls it, a relay is used to bridge this circuit to prevent electrical damage. This is a generic powertrain diagnostic trouble code (DTC), which means it covers all makes/models, 1996-newer. That saves a lot of time because you don’t have to refer back to the component locator or circuit locations. The ground completes the circuit to the relay and switches power to the fan. In the Painless Performance electric fan relay kit we got from Speedway Motors, a circuit breaker is supplied if you wanted to safely get power directly from the battery. The operating components in the cooling fan circuit include the cooling fan fuse, relay, coolant temperature sensor and the computer. This is a generic powertrain diagnostic trouble code (DTC), which means it covers all makes/models, 1996-newer. Look for the simple open and shut circuit. A/C refrigerant pressure sensor 10. Verify the battery positive terminal in the relay block with constant power. - The vehicle speed is less than 38 MPH. Shut the engine down and pull the CTS plug again. Published by Saum Hadi. A/C selector switch 9. If they are good pull the cooling fan relays out. This is also a good idea before buying a vehicle. Cooling Fan 3 Relay Control Circuit High. you take on any vehicle. Attach the fan to the small area around the core Of the radiator where there is a metal lip that is approximately 1/4" to 3/8". If you have a P1491 Radiator Fan Control Relay Circuit trouble code, this post will help you understand what it is and how to fix it. - The A/C clutch requested. Check the electrical connection at the fan. Pull the connector apart and look for corrosion or bent pins. It is always a wise idea to look up the technical service bulletins (TSB) on your particular vehicle to see what type complaints have been coming in to the dealer service department related to this code. Jump the battery terminal to the fan harness terminal and the fan will operate. Defective or faulty fan control relay 3 4. Do not go any farther without consulting your service manual. Defective coolant temperature sensor 7. Some of the most common possible causes are: 1. Dodge Radiator Fan Wiring Diagram. All information on this site is copyright protected. If your vehicle's check engine light comes on and after pulling the code you find a P0480 displayed, if refers to the engine cooling fan circuit. However, Alldatadiy.com also includes disassembly instructions for interior trim panels and exterior items like headlights and tail lights. The PCM controls the cooling fan by grounding the cooling fan control circuit which turns ON the cooling fan relay. A constant power supply from the battery is present on a terminal in each of the relays. There is a problem within this circuit causing the fan to fail to operate allowing the engine to overheat while sitting still or driving at a slow speed. The PCM controls the cooling fan by grounding the cooling fan control circuit which turns ON the cooling fan relay. ground switched device using a simple spst relay. The bottom of the fuse block lid will usually indicate placement, but if not, look in the owner's manual. The radiator fan switch relay may not be supplying power to the fan. (adsbygoogle = window.adsbygoogle || []).push({}); While you are driving, air in sufficient quantity is passing through the radiator effectively cooling the engine. The first part of the installation is to install the electric fan to your radiator, and remove the mechanical fan. However, specific troubleshooting steps will vary depending on the vehicle. There must be a relay that the control circuit closes, this relay may be welded closed or the control circuit is telling the cooling fan to run. If necessary, a replacement relay costs around $20.There are three ways to check for a bad terminal. The PCM (powertrain control module) senses the increase in engine temperature through the CTS (coolant temperature sensor) located near the thermostat. It is not intended as repair advice and we are not responsible for any actions You just want to know if it's working. Eautorepair.net redraws factory wiring diagrams in color and includes the component, splice and ground locations right in their diagrams. If they prove to be good, check the CTS with an ohmmeter. Video on how to diagnose dtc p1491, radiator fan control relay circuit malfunction on a 2003 jeep liberty sport. - The vehicle speed is less than 38 MPH. A relay kit, our part number CCFKRL, will include everything you need to properly wire up your electric cooling fans, with the exception of additional wiring needed to complete all of the circuits. This will allow mounting of the fan(s) without compromising the core of the radiator. Many vehicles will have two engine fans, one for engine cooling and the second for cooling the air conditioning condenser, and additional cooling for the engine. If you need to dig into your doors, dash or console, Alldatadiy.com is the better choice because Eautorepair.net doesn’t any interior or exterior trim or body part removal. All content © 2004-2021 OBD-Codes.com, Cooling fan 2005 Chevy Tahoe 5.3L p0480 [Solved], 2000 Olds Silhouette p0131, p0137, p0480, p0742 + more, 2005 Chevy Trailblazer Ext P0480 wont start, post The fan relays are nothing but a remote light switch. The fan as well as other apparatus draws too much amperage to be safe in the cockpit, so it's kept under the hood. 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