AutoCodes – Cadillac – U18CC Cadillac

U18CC Cadillac Code - Transmission Range Control Module Lost Communication With ECM On Powertrain Expansion Bus

Quick Answer

Devices connected to the serial data circuits monitor for serial data communications during normal vehicle operation. Common causes include Faulty Engine Control Module (ECM), Engine Control Module harness is open or shorted, Engine Control Module 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: U18CC Cadillac indicates Transmission Range Control Module Lost Communication With ECM On Powertrain Expansion Bus.
Common causes: Common causes include Faulty Engine Control Module (ECM), Engine Control Module harness is open or shorted, Engine Control Module 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 600

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 Jun 09, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code U18CC Cadillac Description

Devices connected to the serial data circuits monitor for serial data communications during normal vehicle operation. Operating information and commands are exchanged among the devices. The devices have prerecorded information about what messages are needed to be exchanged on the serial data circuits, for each virtual network. The messages are supervised and also, some periodic messages are used by the receiver device as an availability indication of the transmitter device. Each message contains the identification number of the transmitter device. The Diagnostic Trouble Code (DTC) will set a supervised periodic message that includes the transmitter device availability that has not been received.

OBDII Code U18CC Cadillac - Transmission Range Control Module Lost Communication With ECM On Powertrain Expansion Bus - AutoCodes.com — U18CC Cadillac Code - Transmission Range Control Module Lost Communication With ECM On Powertrain Expansion Bus

What does this mean?

What are the Possible Causes of the DTC U18CC Cadillac?

Faulty Engine Control Module (ECM)
Engine Control Module harness is open or shorted
Engine Control Module circuit poor electrical connection

How to Fix the DTC U18CC Cadillac?

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 U18CC Cadillac 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.

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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 U18CC Cadillac Code

1. What are the common symptoms of OBDII code U18CC in a Cadillac related to the Transmission Range Control Module lost communication with ECM on the Powertrain Expansion Bus?

- Common symptoms include transmission shifting issues, engine stalling, and illuminated warning lights on the dashboard.

2. What are some possible causes for the U18CC code in a Cadillac?

- Possible causes may include damaged wiring or connectors between the Transmission Range Control Module and ECM, a faulty module, or a communication network issue.

3. How can I diagnose the U18CC code in my Cadillac?

- Diagnosis typically involves using a diagnostic scanner to retrieve the code, checking the communication network between the modules, and inspecting the wiring and connectors for any visible damage.

4. Can I continue driving my Cadillac with the U18CC code present?

- It is not recommended to continue driving with the U18CC code as it can lead to further transmission or engine problems. It's best to address the issue promptly.

5. How can I repair the U18CC code in my Cadillac?

- Repair options may include repairing or replacing damaged wiring or connectors, replacing the Transmission Range Control Module, or addressing any communication network issues.

6. Is it possible to reset the U18CC code in a Cadillac without fixing the underlying issue?

- While you can clear the code temporarily, it will likely reappear if the root cause is not addressed. It's essential to fix the problem to prevent further issues.

7. Are there any common troubleshooting tips for the U18CC code in a Cadillac?

- Checking for any recent repairs or modifications that may have affected the communication network, ensuring all connections are secure, and performing a visual inspection of the wiring can be helpful.

8. Can a DIY enthusiast fix the U18CC code in a Cadillac?

- Depending on the skill level and access to tools, some DIY enthusiasts may be able to address the U18CC code by following repair guides or tutorials. However, complex issues may require professional assistance.

9. How long does it typically take to repair the U18CC code in a Cadillac?

- The repair time can vary based on the exact cause of the code and the complexity of the repair. It's advisable to consult with a mechanic for a more accurate estimate.

10. Will the U18CC code in a Cadillac affect vehicle performance?

- Yes, the U18CC code can impact the performance of the vehicle, especially in terms of transmission operation and engine communication. It's important to address the issue promptly to avoid further complications.