Answers
Sep 19, 2023 - 06:44 PM
Hello Marlo.
The P0642 fault code on a 2009 Ford F150 Lariat 5.4 Supercrew indicates an abnormally low voltage reading within the "A" circuit. This can be caused by various factors, including a faulty engine control module, bad sensor, blown fuses, defective system power relays, open circuits, or damaged components. This voltage is critical for the proper operation of various sensors and components in the engine and other systems. Here are some steps to help diagnose and potentially fix the issue:
1) Check for damaged components. Visually inspect the related wiring harness and connectors, looking for any broken, bent, or corroded pins or wires. Repair or replace any damaged components as necessary.
2) Inspect fuses and fusible links. Check for any blown fuses or fusible links in the circuit. Replace any defective fuses or fusible links.
3) Test the system power relay. If the system power relay is faulty, it can cause a low voltage reading. Use a multimeter to test the relay for proper operation. Replace the relay if necessary.
4) Perform a voltage drop test. A voltage drop test can help identify any open circuits or high resistance in the circuit. Follow a detailed guide or consult a professional for the specific steps to perform this test.
5) Check the engine control module. If all other components and connections are in good condition, the issue may be with the engine control module itself. Consult a professional or the vehicle's service manual for guidance on testing and potentially replacing the engine control module.
If you are not comfortable performing these steps yourself, it is recommended to consult a professional mechanic or take your vehicle to a trusted repair shop for further diagnosis and repair. They will have the necessary tools and expertise to accurately diagnose and fix the P0642.
You may need some parts in the process, click this link to be directed to our website where your vehicle information has already been entered. Simply enter the part's name into the search field to get started.
We hope this helps. Have a nice day.
The P0642 fault code on a 2009 Ford F150 Lariat 5.4 Supercrew indicates an abnormally low voltage reading within the "A" circuit. This can be caused by various factors, including a faulty engine control module, bad sensor, blown fuses, defective system power relays, open circuits, or damaged components. This voltage is critical for the proper operation of various sensors and components in the engine and other systems. Here are some steps to help diagnose and potentially fix the issue:
1) Check for damaged components. Visually inspect the related wiring harness and connectors, looking for any broken, bent, or corroded pins or wires. Repair or replace any damaged components as necessary.
2) Inspect fuses and fusible links. Check for any blown fuses or fusible links in the circuit. Replace any defective fuses or fusible links.
3) Test the system power relay. If the system power relay is faulty, it can cause a low voltage reading. Use a multimeter to test the relay for proper operation. Replace the relay if necessary.
4) Perform a voltage drop test. A voltage drop test can help identify any open circuits or high resistance in the circuit. Follow a detailed guide or consult a professional for the specific steps to perform this test.
5) Check the engine control module. If all other components and connections are in good condition, the issue may be with the engine control module itself. Consult a professional or the vehicle's service manual for guidance on testing and potentially replacing the engine control module.
If you are not comfortable performing these steps yourself, it is recommended to consult a professional mechanic or take your vehicle to a trusted repair shop for further diagnosis and repair. They will have the necessary tools and expertise to accurately diagnose and fix the P0642.
You may need some parts in the process, click this link to be directed to our website where your vehicle information has already been entered. Simply enter the part's name into the search field to get started.
We hope this helps. Have a nice day.
Oct 03, 2023 - 01:13 AM
It's a faulty ecm.also could be a bad ground
Oct 20, 2023 - 09:10 PM
Check all grounds make sure they have good contact and there's no corrosion on them a bad ground can cause more problems then you think
Add New Comment