U1849 Code - Drive Motor Control Module 1 Lost Communication With Transmission Control Module
Quick Answer
The Drive Motor Control Modules and the Hybrid/EV Powertrain Control Module 1 are all internal to the Power Inverter Module. Common causes include Faulty Transmission Control Module (TCM), Transmission Control Module harness is open or shorted, Transmission 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
- U1849 indicates Drive Motor Control Module 1 Lost Communication With Transmission Control Module.
- Common causes
- Common causes include Faulty Transmission Control Module (TCM), Transmission Control Module harness is open or shorted, Transmission 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.
Code U1849 Description
Communication diagnostics for the serial data, including device power and ground as well as the wakeup circuits for Drive Motor Control Modules and the Hybrid/EV Powertrain Control Module 1 are all diagnosed from external sources only to the Power Inverter Module connector because any circuit fault condition within the Power Inverter Module will cause a complete replacement.
The Diagnostic Trouble Code (DTC) will set when a supervised periodic message that includes the transmitter device availability has not been received.
What are the Possible Causes of the DTC U1849?
- Faulty Transmission Control Module (TCM)
- Transmission Control Module harness is open or shorted
- Transmission Control Module circuit poor electrical connection
How to Fix the DTC U1849?
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 U1849 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 U1849 code?
Need more information on how to fix the U1849 code? Get Access to Factory Service Manuals
Need Help with the Code?
Get the U1849 code diagnosed by a professional: Find a repair shop in your area
Information for Specific Makes
- U1849 Buick — Drive Motor Control Module 1 Lost Communication With Transmission Control Module
- U1849 Cadillac — Drive Motor Control Module 1 Lost Communication With Transmission Control Module
- U1849 Chevrolet — Drive Motor Control Module 1 Lost Communication With Transmission Control Module
- U1849 GMC — Drive Motor Control Module 1 Lost Communication With Transmission Control Module
Frequently Asked Questions about U1849 Code
1. What are the common symptoms of OBDII code U1849?
When the Drive Motor Control Module 1 loses communication with the Transmission Control Module, you may experience issues such as difficulty shifting gears, rough shifting, and in some cases, the vehicle may go into a limp mode.
2. What are the possible causes of code U1849?
The code U1849 can be triggered by issues such as faulty wiring connections between the Drive Motor Control Module and Transmission Control Module, a malfunctioning control module, or a software communication error.
3. How can I diagnose the cause of OBDII code U1849?
To diagnose the cause of code U1849, you will need a professional OBDII scanner to read the specific trouble codes present in the Drive Motor Control Module and Transmission Control Module. Additionally, a thorough inspection of the wiring and connections between the modules is recommended.
4. Can I continue driving with OBDII code U1849 present?
It is not recommended to continue driving with code U1849 present, as it can lead to further damage to the transmission or drive motor system. It is best to address the issue promptly to prevent any additional complications.
5. How can I repair OBDII code U1849?
Repairing code U1849 may involve checking and repairing any damaged wiring connections, ensuring proper communication between the Drive Motor Control Module and Transmission Control Module, or replacing a faulty control module if necessary.
6. Is it possible to reset OBDII code U1849 without fixing the underlying issue?
While it is possible to clear the code temporarily with an OBDII scanner, the underlying issue causing code U1849 will persist until properly addressed. It is important to diagnose and repair the root cause to prevent the code from reoccurring.
7. Can a DIY enthusiast fix OBDII code U1849 at home?
Depending on your level of experience and access to tools, you may be able to address code U1849 at home by checking wiring connections and performing basic troubleshooting. However, for more complex issues or if you are unsure, it is recommended to seek professional assistance.
8. How much does it cost to repair OBDII code U1849?
The cost of repairing code U1849 can vary depending on the root cause of the issue. Simple fixes like repairing wiring connections may be relatively inexpensive, while replacing a control module could be more costly. It is best to consult with a mechanic for an accurate estimate.
9. Are there any preventive measures to avoid OBDII code U1849 in the future?
To prevent OBDII code U1849 from occurring in the future, regular maintenance and inspections of the drive motor and transmission systems are recommended. Keeping an eye on any warning signs or symptoms can help catch potential issues early.
10. Will OBDII code U1849 cause my vehicle to fail an emissions test?
If left unresolved, OBDII code U1849 can potentially cause your vehicle to fail an emissions test due to improper communication between critical control modules. It is important to address the issue promptly to ensure your vehicle meets emissions standards.
Discuss the causes and fixes for U1849 OBDII Code
Code U1849 comments
No comments found for this page.
Fix Your Car Smarter
Try the New AutoCodes App!
Get complete OBDII diagnostics, repair solutions, and cost estimates, plus AI chat support on demand.
