U1849 GMC 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 GMC 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 GMC 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 GMC?
- 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 GMC?
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 GMC 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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Frequently Asked Questions about U1849 GMC Code
1. What are the common symptoms of OBDII code U1849 GMC?
The common symptoms of code U1849 GMC include issues with shifting gears, poor acceleration, and potential stalling of the vehicle.
2. What are the possible causes of code U1849 GMC?
The code U1849 GMC is typically caused by a communication failure between the Drive Motor Control Module 1 and the Transmission Control Module. This can be due to wiring issues, a faulty module, or a malfunction in the transmission system.
3. How can I diagnose the cause of code U1849 GMC?
Diagnosing code U1849 GMC requires using an OBDII scanner to retrieve the code and then conducting a thorough inspection of the wiring connections between the Drive Motor Control Module 1 and the Transmission Control Module. It is also recommended to check for any loose or damaged wires.
4. Can I continue driving with OBDII code U1849 GMC?
It is not recommended to continue driving with code U1849 GMC present, as it can lead to further damage to the transmission system and potentially compromise the safety and performance of the vehicle.
5. How can I repair OBDII code U1849 GMC?
To repair code U1849 GMC, you may need to repair or replace any damaged wiring connections between the Drive Motor Control Module 1 and the Transmission Control Module. If the modules themselves are faulty, they may need to be replaced.
6. Are there any DIY tips for fixing OBDII code U1849 GMC?
While diagnosing and repairing code U1849 GMC may require advanced automotive knowledge and tools, you can start by checking the wiring connections for any visible damage or corrosion. If you are unsure, it is best to consult a professional mechanic.
7. How much does it cost to fix OBDII code U1849 GMC?
The cost of fixing code U1849 GMC can vary depending on the specific cause of the issue and whether any parts need to be replaced. It is recommended to obtain quotes from reputable mechanics or dealerships for an accurate estimate.
8. Can a software update fix OBDII code U1849 GMC?
In some cases, a software update provided by the manufacturer may address communication issues between the Drive Motor Control Module 1 and the Transmission Control Module. Consult with your dealership or a qualified technician for more information.
9. Will clearing the code make OBDII code U1849 GMC go away?
Clearing the code may temporarily remove the warning light, but if the underlying issue causing code U1849 GMC is not addressed, the code is likely to reappear. It is important to diagnose and repair the root cause of the problem.
10. Is OBDII code U1849 GMC a common issue in GMC vehicles?
Code U1849 GMC is not as common as some other OBDII codes, but it can occur in GMC vehicles equipped with the mentioned control modules. Proper maintenance and regular inspections can help prevent this issue from happening.
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