P1779 GMC Code - Engine Torque Delivered To TCM Signal
Quick Answer
The Automatic Transmission Control Module (TCM) receives transmission-related information from the Engine Control Module (ECM) via serial data. Common causes include Check other engine related codes first, Faulty Engine Control Module (ECM), Engine Control Module harness is open or shorted. 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
- P1779 GMC indicates Engine Torque Delivered To TCM Signal.
- Common causes
- Common causes include Check other engine related codes first, Faulty Engine Control Module (ECM), Engine Control Module harness is open or shorted.
- 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 P1779 GMC Description
What are the Possible Causes of the DTC P1779 GMC?
- Check other engine related codes first
- Faulty Engine Control Module (ECM)
- Engine Control Module harness is open or shorted
- Engine Control Module circuit poor electrical connection
- Faulty Transmission Control Module (TCM)
How to Fix the DTC P1779 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 P1779 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 P1779 GMC Code
What does the OBDII code P1779 mean on a GMC vehicle?
1. Code P1779 indicates an issue with the "Engine Torque Delivered To TCM" signal, where the Transmission Control Module (TCM) is not receiving accurate or expected torque data from the engine. 2.
What are the common symptoms of a P1779 code on a GMC?
Symptoms may include erratic shifting, poor acceleration, reduced fuel efficiency, transmission slipping, or the activation of the Check Engine Light. 3.
What causes the P1779 code to appear on a GMC vehicle?
Common causes include a faulty engine control module (ECM), defective transmission control module (TCM), damaged wiring or connectors, or incorrect engine torque sensor readings. 4.
Can I drive my GMC with the P1779 code active?
It is not recommended to drive for extended periods with this code active, as it can cause shifting issues and potentially lead to transmission or engine damage. 5.
How do you diagnose a GMC vehicle with a P1779 code?
A technician typically uses a scan tool to check live data from the ECM and TCM, inspects wiring and connectors for damage, and tests the engine torque sensor for proper operation. 6.
How is the P1779 code fixed on a GMC?
Repairs may include replacing the engine torque sensor, repairing or replacing damaged wiring, reprogramming or replacing the ECM or TCM, or addressing any underlying engine performance issues. 7.
Can a P1779 code be caused by a software issue in my GMC?
Yes, outdated or corrupted software in the ECM or TCM can sometimes trigger this code, which may require reprogramming or updating the module's software. 8.
How much does it cost to fix a P1779 code on a GMC?
Repair costs vary depending on the cause but can range from $150 for wiring repairs to over $1,000 for ECM or TCM replacement and reprogramming. 9.
Can a dirty or failing throttle body cause the P1779 code on a GMC?
Yes, a dirty or malfunctioning throttle body can affect engine torque output, potentially leading to inaccurate signals being sent to the TCM. 10.
Will clearing the P1779 code solve the problem on my GMC?
Clearing the code may temporarily turn off the Check Engine Light, but the issue will likely return unless the root cause is properly addressed.
Discuss the causes and fixes for P1779 GMC OBDII Code
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