P179B 2018 GMC Sierra Code - Transmission Range State Command Signal Message Counter Incorrect
Quick Answer
The diagnostic trouble code P179B on a 2018 GMC Sierra indicates that the Transmission Range State Command Signal Message Counter is incorrect. Common causes include Faulty transmission range sensor, Wiring or connection issues between TCM and ECM, Software glitches in the TCM or ECM. 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
- P179B 2018 GMC Sierra indicates Transmission Range State Command Signal Message Counter Incorrect.
- Common causes
- Common causes include Faulty transmission range sensor, Wiring or connection issues between TCM and ECM, Software glitches in the TCM or ECM.
- 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 P179B 2018 GMC Sierra Description
The diagnostic trouble code P179B on a 2018 GMC Sierra indicates that the Transmission Range State Command Signal Message Counter is incorrect. This code typically points to a communication issue between the transmission control module (TCM) and the engine control module (ECM). The TCM is responsible for controlling the transmission's shifting behavior based on various inputs, including vehicle speed, engine load, and throttle position. The ECM communicates with the TCM to ensure smooth operation of the transmission.
Common Causes of P179B 2018 GMC Sierra
- Faulty transmission range sensor
- Wiring or connection issues between TCM and ECM
- Software glitches in the TCM or ECM
- Malfunctioning TCM or ECM
- Low battery voltage affecting communication between modules
Symptoms of P179B 2018 GMC Sierra
- Erratic shifting behavior
- Harsh gear changes
- Transmission slippage
- Delayed engagement when shifting
- Illumination of the Check Engine Light
How to Fix P179B 2018 GMC Sierra
- Perform a thorough inspection of the wiring harness and connectors between the TCM and ECM to check for any loose connections or damage. Repair or replace as necessary.
- Test the transmission range sensor to ensure it is functioning correctly. Replace if faulty.
- Update the software in the TCM and ECM to the latest version provided by the manufacturer.
- Clear the diagnostic trouble codes and perform a test drive to verify that the issue has been resolved.
- If the problem persists, consider replacing either the TCM or ECM, depending on which module is determined to be faulty.
Cost to Fix P179B 2018 GMC Sierra
The typical repair costs for addressing the P179B code on a 2018 GMC Sierra can vary depending on the specific cause of the issue. On average, the parts required for this repair could range from $100 to $500, while labor costs could range from $150 to $300. It's important to note that these are rough estimates, and actual costs may vary based on factors such as location, labor rates, and the extent of the repair needed. It's recommended to consult with a qualified mechanic or dealership for a more accurate cost estimate.
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Frequently Asked Questions about P179B 2018 GMC Sierra Code
1. What does the OBDII code P179B mean on a 2018 GMC Sierra?
The code P179B indicates "Transmission Range State Command Signal Message Counter Incorrect," meaning there’s an issue with the communication between the transmission control module (TCM) and other vehicle systems.
2. What are the common symptoms of code P179B in a 2018 GMC Sierra?
Symptoms include erratic shifting, transmission slipping, delayed gear engagement, or the illumination of the check engine light.
3. What causes the P179B code in a 2018 GMC Sierra?
The code can be triggered by a faulty transmission control module (TCM), wiring issues, connector problems, or software glitches in the TCM.
4. Can driving with the P179B code damage my 2018 GMC Sierra?
Yes, prolonged driving with this code can cause further transmission damage and lead to unsafe driving conditions.
5. How is code P179B diagnosed in a 2018 GMC Sierra?
Diagnosis involves scanning the TCM for additional codes, inspecting wiring and connectors, and testing the communication signals between the modules.
6. What repairs can fix the P179B code in a 2018 GMC Sierra?
Repairs may include replacing the TCM, repairing damaged wiring or connectors, or updating the software in the control modules.
7. Can a faulty transmission control module cause the P179B code?
Yes, a malfunctioning TCM can disrupt communication signals and trigger this code.
8. How much does it cost to repair code P179B in a 2018 GMC Sierra?
Repair costs vary but can range from $300 to $1,000 depending on whether the issue involves wiring repairs or TCM replacement.
9. Can a weak battery cause the P179B code in a 2018 GMC Sierra?
While unlikely, a weak or failing battery can sometimes affect module communication and contribute to triggering this code.
10. Should I address the P179B code immediately in my 2018 GMC Sierra?
Yes, addressing the code promptly can prevent further transmission damage and ensure safe vehicle operation.
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