What Is the U0140 Code?
Symptoms
Causes
Seriousness
Can I Still Drive?
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Error code U0140 is a specific extension of OBD-II DTC U0. All U codes indicate a malfunction regarding a vehicle’s user network (Wiring Bus/UART). The number 0 indicates that this code is generic, and applies to all makes and models. The third numeral in the code sequence (1) always indicates where the vehicle has encountered an error. In this case, the number 1 signifies an issue regarding a vehicle’s fuel and air metering, which in most cases can mean a variety of things. So, let’s dive a little deeper.
More About Error Code U0140
Error code U0140 is associated with the Body Control Module (BCM) or the wires from the Engine Control Module (ECM) to the BCM. The BCM is part of your car’s electrical system. It controls various functions, including the tire pressure monitor, door locks, keyless entry and anti-theft systems. DTC U0140 could imply that the BCM is faulty and it’s not receiving or sending signals properly. The BCM could also be experiencing a short, causing it to no longer communicate adequately with the ECM..
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What Are the Symptoms of a U0140 Code?
The main, and most common symptom of a U0140 error code is the illumination of your car’s check engine light. You might also notice that certain body control functions no longer work as they’re supposed to. In more dangerous circumstances, your vehicle could misfire at high speeds while driving, imposing danger to you and other drivers. Your car might also start shaking as you increase speed. You might also experience poor acceleration, blown fuses, or your car may not start at all.
What Are Some Causes of a U0140 Code?
Several things could lead to the malfunction of your vehicle’s BCM or the wiring associated with it, which often triggers error code U0140. Sometimes, during accidents, the BCM may be shocked or jarred due to impact, which could cause the module to stop working altogether. Other times, the wiring harness may be loose, exposed or cut. If a wire becomes exposed and comes in contact with another wire or piece of metal, this will cause a short to occur.
Another common cause of error code U0140 is excessive vibration. Ongoing vibration can cause wear and tear to your car’s BCM. This vibration can often occur due to unbalanced tires or other malfunctioning parts. Over time, general wear and tear can also cause the BCM to fail as well.
How Serious Is the U0140 Code?
The level of severity associated with a U0140 error code often depends on which part of your car is malfunctioning. This code can cause your vehicle to shake when accelerating. Error code U0140 could also cause your vehicle’s anti-theft locks or key locks to fail. Overall, this code should be taken very seriously.
Can I Still Drive with a U0140 Code?
Drivers experiencing a U0140 DTC should have their vehicle scanned and repaired ASAP. Driving is not advisable if the code is affecting driveability and causing misfires. This will put other drivers, as well as yourself, at serious risk of injury. If a misfire occurs, driving for extended periods of time could cause your engine to overheat and ultimately fail.
How Easy Is It to Diagnose a U0140 Code?
Before a mechanic attempts to diagnose this DTC, they willcheck all technical service bulletins for the vehicle’s make and model. If it’s a known issue that is currently covered under warranty, you could save yourself some time and money.
A qualified mechanic will first check system voltage or battery voltage in order to determine if the system has the correct voltage for your vehicle. A very low or dead battery could have a major impact on the serial data as it is voltage-sensitive.
Next, they will check all fuses and relays to ensure that the problem doesn’t relate to a worn fuse. If the mechanic thinksthe wiring is the issue, they will double-check by inspecting the connections. A mechanic will make sure the connections are not loose by wiggling them , and will also check for corrosion by removing the connector and checking on both sides. Additionally, your mechanic should check to make sure no individual pins are loose.
If your connector doesn’t show any signs of problems, your mechanic will check the terminal power using a diagnostic code reader. Doing so will help determine which pins have a problem. If any terminals aren’t receiving power, the problem likely lies with the wiring harness. But if the terminals are receiving power, the problem is with the BCM. It should be noted that checking terminal power at the connector pins is a more advanced operation. Not all of the pins are used simply as power. Only certain scanners incorporating a digital multimeter or a scope can test each pin at the connector. This practice is best left to qualified mechanics.
How Difficult Is It to Inspect a U0140 Code?
A professional mechanic should handle all repairs to ensure both the safety of your car and expedited repairs.
A qualified mechanic will typically repair a U0140 by replacing your car’s BCM. Keep in mind that if the connections to your BCM are burned, the mechanic will check for any issues with the wiring to the BCM. If the wiring also smells burned or has any other strange odors, the problem is likely caused by a faulty BCM.
Additionally, if you’re no longer getting power to your BCM, your mechanic will check for any openings in the wiring, and also look for damaged or melted wiring insulation.
Need Additional Help with Your U0140 Code?
If you need assistance with your vehicle relating to a U0140 DTC, check out the extensive list of service centers in your area on KBB.com. Be sure to visit KBB.com to locate a local service center near you.
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