Defective or faulty fan control relay 3 4. Open or shorted fan cooling fan harness 5. Get the BEST auto repair information Alldatadiy.com and Eautorepair.net are professional-grade shop manuals—period. When … The vehicle computer monitors coolant temperature with a sensor located near the thermostat. IAT (intake air temperature) failure 8. Most late model vehicles use an electric fan to pull air through the radiator. 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 Poor electrical connections in the cooling fan circuit 6. Published by Saum Hadi. The ground completes the circuit to the relay and switches power to the fan. Repair if necessary and use dielectric grease on the terminals. Check all the relays in the same fashion to be sure they are all working. Most cooling fans use electric motors that have a moderate to high current draw, and as a result are commonly controlled using relays. A code P1492 indicates a problem with the relay circuit. While you are driving, air in sufficient quantity is passing through the radiator effectively cooling the engine. Alldatadiy.com, on the other hand, uses the factory diagrams. Defective coolant temperature sensor 7. If they are good pull the cooling fan relays out. When you bring the car to a stop no air is passing through the radiator and the engine begins to increase in temperature. The vehicle's PCM's function is to act as a ground to operate components, not to supply power. Set the … 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 PCM controls the cooling fan by grounding the cooling fan control circuit which turns ON the cooling fan relay. 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. 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. A malfunctioning cooling fan relay can … 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". Additionally, many vehicles have multi-speed fans requiring as many as three fan speed relays for low, medium and high. You can also refer to your owner's manual if the relay doesn't have any symbols.Resistance Test: 1. However, specific troubleshooting steps will vary depending on the vehicle. Electric fan is responsible for causing air movement around the engine coolant radiator. This is a generic powertrain diagnostic trouble code (DTC), which means it covers all makes/models, 1996-newer. A/C refrigerant pressure sensor 10. Video on how to diagnose dtc p1491, radiator fan control relay circuit malfunction on a 2003 jeep liberty sport. Refer to the top or side of the relay to locate these terminals. If you still need help regarding the P0480 trouble code, please post A duty cycle is determined based on these input parameters. For precise readings consult a service manual. If not the harness between the fuse block and the fan is faulty. DIAGNOSTIC TROUBLE CODE (DTC) - P0481 HIGH SPEED COOLING FAN RELAY CIRCUIT FAULT (WITHOUT A/C) Details of the Circuit. If swapping relays still doesn't operate your cooling fan, make sure the relay is receiving power from the computer. - The A/C clutch requested. 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. When coolant temperature rises above acceptable limits, the computer provides ground to the fan relay. See the schematic printed on the relay itself or consult the schematic in your vehicle repair manual, if necessary. 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. 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. 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. A switched terminal will be hot only when the key is on. 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. 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. - The vehicle speed is less than 38 MPH. The PCM controls the cooling fan by grounding the cooling fan control circuit which turns ON the cooling fan relay. Search using your favorite search engine "technical service bulletins for ....." Look up the code and the type of manufacturer recommended repair. It is not intended as repair advice and we are not responsible for any actions All information on this site is copyright protected. Pull the connector apart and look for corrosion or bent pins. Open or shorted fan control relay harness 4. Use a test light to find the hot terminal. 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 … 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. Accuracy isn't necessary since all sensors may be different. Probe the sensor terminals. 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. Use an ohmmeter to test that the constant battery terminal and the fan harness terminal have continuity meaning the circuit has closed. By using a lower voltage signal to control the relay, there is less stress on the rest of the wiring and charging system. Cooling Fan 3 Relay Control Circuit High. Look at the circuit diagram displayed on the side of the relay. The cooling fan relay is an electromagnetic switch that controls the power supply to the engine’s cooling fans. 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. Mount the fan as high up on the core as possible. 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. Some Dodge vehicles have a solid state radiator fan controller that varies the fan speeds by pulsing the ground to the radiator fan motor. (adsbygoogle = window.adsbygoogle || []).push({}); While you are driving, air in sufficient quantity is passing through the radiator effectively cooling the engine. With this sort of an illustrative manual, you’ll have the ability to troubleshoot, avoid, and complete your assignments without difficulty. Open or shorted fan cooling fan harness 3. Shut the engine down and pull the CTS plug again. This will allow mounting of the fan(s) without compromising the core of the radiator. The cooling fan relay is the relay that controls the engine’s cooling fans. 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. 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. Check the electrical connection at the fan. If the fan operated, check the relays. Look at the fan and make sure there is no obstruction in front of the radiator blocking airflow. This is a generic powertrain diagnostic trouble code (DTC), which means it covers all makes/models, 1996-newer. If you’re tracking down a wiring issue, Eautorepair.net is the better choice. The cooling fan relay coil receives the Ignition Voltage directly. 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. The fan as well as other apparatus draws too much amperage to be safe in the cockpit, so it's kept under the hood. Do not go any farther without consulting your service manual. Some of the most common possible causes are: 1. This is a generic powertrain diagnostic trouble code (DTC) applicable to most 1996-newer vehicles. However, specific troubleshooting steps will vary depending on the vehicle. - The A/C clutch requested. That saves a lot of time because you don’t have to refer back to the component locator or circuit locations. Check the terminals for an additional power terminal and look where it would be on the relay. However, Alldatadiy.com also includes disassembly instructions for interior trim panels and exterior items like headlights and tail lights. P1491 Radiator Fan Control Relay Circuit P1491 Radiator Fan Control Relay Circuit. + + this will be your new ground switched output. 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