AutoCodes – Jeep – U1140 Jeep

U1140 Jeep Code - Lost Communication With Active Exhaust Valve 2

Quick Answer

The purpose of the Active Exhaust Valves is to reduce exhaust noise in order to comply with pass-by noise regulations. Common causes include Faulty Active Exhaust Valve Actuator, Active Exhaust Valve Actuator harness is open or shorted, Active Exhaust Valve Actuator circuit poor electrical connection. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

What it means: U1140 Jeep indicates Lost Communication With Active Exhaust Valve 2.
Common causes: Common causes include Faulty Active Exhaust Valve Actuator, Active Exhaust Valve Actuator harness is open or shorted, Active Exhaust Valve Actuator circuit poor electrical connection.
Severity: High - diagnose this code as soon as possible.
Can I drive?: Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

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Code Popularity 1,272

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

What is this?

Table of contents Created and updated by William Orellana on Jul 02, 2024

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code U1140 Jeep Description

The purpose of the Active Exhaust Valves is to reduce exhaust noise in order to comply with pass-by noise regulations. The Active Exhaust Valves system consists of two main components. The first is the mechanical butterfly valves, which are welded into the exhaust pipe on each bank. Attached to each valve is a smart actuator. These are connected to the mechanical valves via a transmission spring to help reduce heat transfer from the butterfly valves to the actuators.
The Active Exhaust Valve actuators communicate with the Powertrain Control Module (PCM) over a LIN Bus circuit. Each Active Exhaust Valve actuator, one for the left (actuator 1) and one for the right (actuator 2), has a unique part number/internal ID. The PCM can identify each actuator's location by this unique ID. Based on engine torque, rpm, and vehicle speed, the PCM sends position commands to the Active Exhaust Valve actuators. These actuators then move the butterfly valves to the commanded positions. An internal Hall Effect sensor counts the pulses to determine the valve position. The valve actuators are calibrated at every Key-ON event; the PCM sends full open and full closed commands and checks the actual position against the commanded position. If calibration is unsuccessful for any reason, the actuators self-diagnose and report fault flags to the PCM over the LIN Bus.
If the valve position does not match the predetermined calibration, a performance code is set, and the valves will default to the full open position. If an actuator is not attached to the mechanical valve, or if the transmission spring is broken or missing, the actuator will continue to rotate indefinitely and set a fault. Additionally, if the mechanical valve is stuck and cannot move, a fault will be set.

OBDII Code U1140 Jeep - Lost Communication With Active Exhaust Valve 2 - AutoCodes.com — U1140 Jeep Code - Lost Communication With Active Exhaust Valve 2

What does this mean?

What are the Possible Causes of the DTC U1140 Jeep?

Faulty Active Exhaust Valve Actuator
Active Exhaust Valve Actuator harness is open or shorted
Active Exhaust Valve Actuator circuit poor electrical connection
Faulty Powertrain Control Module (PCM)

How to Fix the DTC U1140 Jeep?

Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the U1140 Jeep code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.

Need more information about the U1140 Jeep code?

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About the author: William Orellana is a Master Mechanic and Mechanical Engineer with over 30 years of experience diagnosing and repairing vehicles. Learn more about his background.

Frequently Asked Questions about U1140 Jeep Code

1. What are the common symptoms of OBDII code U1140 in a Jeep related to Lost Communication With Active Exhaust Valve 2?

- Common symptoms include illuminated check engine light, reduced engine performance, and possibly abnormal exhaust sounds.

2. What are some possible causes of the U1140 code in a Jeep?

- Possible causes include a faulty active exhaust valve, damaged wiring or connectors, a malfunctioning exhaust valve actuator, or a communication issue within the vehicle's network.

3. How can I diagnose the U1140 code related to Lost Communication With Active Exhaust Valve 2 in my Jeep?

- Diagnosing the issue may involve checking the exhaust valve and its components for proper function, inspecting wiring for damage, and using a diagnostic scan tool to analyze the communication network.

4. Can I drive my Jeep with the U1140 code present?

- It is generally not recommended to drive with the U1140 code present, as it can affect the engine's performance and cause further damage if left unresolved.

5. How can I repair the U1140 code in my Jeep?

- Repairing the U1140 code may involve fixing any wiring issues, replacing the active exhaust valve or its components, resetting the fault codes, and ensuring proper communication within the vehicle's system.

6. Is it safe to continue driving if the U1140 code disappears on its own?

- Even if the code disappears on its own, it is still advisable to have the vehicle inspected by a professional to prevent any potential issues from arising in the future.

7. Can a DIY enthusiast fix the U1140 code issue in a Jeep?

- Depending on the DIY enthusiast's skill level and access to tools, some simple repairs like checking wiring connections or replacing components may be possible. However, more complex diagnostics and repairs may require professional assistance.

8. How much does it typically cost to repair the U1140 code in a Jeep?

- The cost of repairing the U1140 code can vary depending on the specific issue causing the code, the parts needed for replacement, and labor costs. It is best to obtain a diagnosis from a mechanic for an accurate estimate.

9. Will resetting the check engine light resolve the U1140 code in my Jeep?

- Resetting the check engine light may temporarily clear the code, but if the underlying issue is not addressed, the code is likely to reappear. It is important to diagnose and fix the root cause of the problem.

10. Are there any preventive maintenance tips to avoid encountering the U1140 code in a Jeep?

- Regularly inspecting the exhaust system, ensuring proper wiring connections, and following the manufacturer's maintenance schedule can help prevent issues that may trigger the U1140 code related to Lost Communication With Active Exhaust Valve 2.