U140A — Implausible Right Front Wheel Speed Signal Received #

The description of this Diagnostic Trouble Code (DTC) may vary depending on the vehicle manufacturer. Always refer to the specific service literature for your make and model.

Known description variations:

• U140A — Implausible Right Front Wheel Speed Signal (Jeep)
• U140A — Invalid Data Received From Right Front Wheel Speed Sensor (Chrysler)
• U140A — Right Front Wheel Speed Signal Unreliable (Dodge)

Code summary for U140A #

U140A is a manufacturer-specific communication code that indicates the Anti-lock Braking System (ABS) module has received an implausible signal from the Right Front Wheel Speed Sensor. This sensor is critical for functions like ABS, traction control, and stability control. When the module detects a signal that does not make sense based on vehicle dynamics or compared to the other wheel speed sensors, it sets this code. This issue can compromise your vehicle’s safety systems and may trigger warning lights on your dashboard. Addressing the root cause quickly is important to maintain safe vehicle operation.

Frequent symptoms for fault code U140A #

The symptoms associated with code U140A often relate to the performance of electronic safety systems. If this code is present, you may notice one or several of the following symptoms:

• ABS warning light illuminated on the dash
• Traction control or ESC (Electronic Stability Control) light on
• Loss of ABS or traction/stability control function
• Possible speedometer irregularities
• Pulsating brake pedal in some situations
• Unusual behavior from automatic braking or stability assistance features

Likely causes for U140A (in order of frequency) #

There are several possible causes for the U140A code, with some being more common than others. Understanding the most typical sources can help streamline your diagnosis:

1. Faulty right front wheel speed sensor (sensor itself defective or dirty)
2. Damaged or corroded sensor wiring/connectors (open, short, or poor connection)
3. Broken or dirty sensor tone ring (the toothed ring the sensor reads from)
4. ABS module communication fault (rare, but possible)
5. Aftermarket wheels or improper tire size (causing mismatched wheel speed readings)

Step-by-step diagnosis for U140A #

Diagnosing U140A should follow a logical path, starting from the simplest checks to more in-depth testing. Here’s a proven approach:

1. Interview the driver—note recent ABS or traction issues, road conditions, or recent repairs.
2. Perform a visual inspection—look for damaged wires or connectors at the right front wheel speed sensor.
3. Check for debris or buildup—examine the sensor and tone ring for dirt, rust, or debris.
4. Read live data from all wheel speed sensors using a scan tool. Compare the right front reading with the other wheels while spinning by hand.
5. Test the sensor’s resistance—using a multimeter, check it matches OEM specs (see service manual).
6. Check continuity of the wiring from the sensor to the ABS module. Repair if open or shorted.
7. Inspect the tone ring (if visible)—look for missing teeth, cracks, or excessive rust.
8. Clear codes and road test—if repairs are made, clear the DTC and confirm operation under various driving conditions.

Possible repairs for U140A #

Once you have identified the root cause, several repair solutions may be necessary to resolve U140A and restore normal system function:

• Replace the right front wheel speed sensor if it’s faulty or contaminated
• Repair or replace damaged sensor wiring/connectors
• Clean or replace the sensor tone ring if it’s dirty, cracked, or broken
• Reprogram or replace the ABS module (rare, if proven faulty)
• Install proper OEM wheels/tires if aftermarket fitment is causing sensor discrepancies

Can you drive with code U140A? #

Driving is NOT recommended when code U140A is present. While your vehicle may still operate, critical safety systems like ABS and traction control could be compromised—or completely disabled. This means your vehicle may not respond as expected during emergency braking or slippery road conditions. Prompt diagnosis and repair are strongly advised to ensure your safety and that of others on the road.

Vehicles most commonly affected by U140A #

U140A is most frequently seen in certain Jeep, Dodge, and Chrysler models equipped with ABS and advanced traction systems. The following vehicles are known to report this code more often:

• Jeep Grand Cherokee (various model years)
• Jeep Cherokee
• Jeep Wrangler
• Dodge Durango
• Chrysler 300
• Dodge Charger

Common mistakes & best practices for U140A #

There are a few pitfalls and recommended practices when dealing with U140A. Avoiding these errors will save time and prevent unnecessary repairs:

• Replacing the wheel speed sensor without checking wiring or the tone ring
• Overlooking corrosion at connectors, especially in winter climates
• Failing to use OEM replacement parts, leading to repeat failures
• Neglecting to clear the code and test drive after repairs
• Skipping live data comparison of all four wheel speed sensors during diagnosis

Quick FAQ for U140A #

Q: Will clearing the code fix my ABS issue?
A: No. Clearing the code without fixing the underlying cause will only temporarily turn off warning lights. The issue will return as soon as the system detects the fault again.

Q: Can a bad wheel bearing set this code?
A: Yes, indirectly. If a wheel bearing is worn and causes the tone ring or sensor to misalign, it can lead to an implausible signal and trigger U140A.