AutoCodes – GMC – U1016 GMC

U1016 GMC Code - Lost Communications With Powertrain/Engine Control Module

Quick Answer

Modules connected to the class 2 serial data circuit monitor for serial data communications during normal vehicle operation. Common causes include Faulty Powertrain/Engine Control Module (PCM/ECM), Powertrain/Engine Control Module harness is open or shorted, Powertrain/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: U1016 GMC indicates Lost Communications With Powertrain/Engine Control Module.
Common causes: Common causes include Faulty Powertrain/Engine Control Module (PCM/ECM), Powertrain/Engine Control Module harness is open or shorted, Powertrain/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 7,705

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 Apr 22, 2020

Description
Possible Causes
How To Fix
Tech Notes
Cost to Diagnose
FAQs
Comments
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Code U1016 GMC Description

Modules connected to the class 2 serial data circuit monitor for serial data communications during normal vehicle operation. Operating information and commands are exchanged among the modules. When a module receives a message for a critical operating parameter, the module records the identification number of the module which sent the message for the state of health monitoring/node alive messages. A critical operating parameter is one which, when not received, requires that the module use a default value for that parameter. Once an identification number is learned by a module, it will monitor for that module node alive message. Each module on the class 2 serial data circuit is required to send a Node Alive message every 2 seconds. When no message is detected from a learned identification number for 5 seconds, a Diagnostic Trouble Code (DTC) U1016 is set.

OBDII Code U1016 GMC - Lost Communications With Powertrain/Engine Control Module - AutoCodes.com — U1016 GMC Code - Lost Communications With Powertrain/Engine Control Module

What does this mean?

What are the Possible Causes of the DTC U1016 GMC?

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

How to Fix the DTC U1016 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 does this mean?

Code Tech Notes

This is typically an electrical wiring connection issue at one of the controllers being monitored by the manufacturer.
It can occur if:
Someone changes a battery while the ignition switch is left on, that is, left in the RUN position.
Someone flashes/upgrades their engine controller - other modules unable to communicate with the PCM during this process - this will set U1016 at a multitude of controllers on the vehicle - all false codes. Erase and carry on.

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the U1016 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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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 U1016 GMC Code

1. What are common symptoms of OBDII code U1016 GMC?

Symptoms include engine misfires, stalling, rough idling, loss of power, and issues with the vehicle's transmission shifting smoothly.

2. What are possible causes of OBDII code U1016 GMC?

Possible causes include a faulty powertrain/engine control module (PCM/ECM), loose or corroded wiring connections, a blown fuse, or a defective communication network.

3. How can I diagnose OBDII code U1016 GMC?

Diagnosis typically involves using a diagnostic scanner to retrieve the trouble codes, checking for any other related codes, inspecting wiring connections, and testing the PCM/ECM for proper functioning.

4. Can a DIYer repair OBDII code U1016 GMC?

While some simple wiring connection issues may be resolved by a DIYer, diagnosing and repairing more complex problems with the PCM/ECM or communication network may require professional assistance.

5. How can I prevent OBDII code U1016 GMC from coming back?

Regularly inspecting and maintaining wiring connections, ensuring proper grounding, and addressing any electrical issues promptly can help prevent the recurrence of this trouble code.

6. Will driving with OBDII code U1016 GMC cause further damage to my vehicle?

Continuing to drive with this code may lead to performance issues and potential damage to the engine or transmission over time, so it is recommended to address the problem promptly.

7. Can a bad battery cause OBDII code U1016 GMC?

Yes, a weak or failing battery can sometimes trigger communication errors between the PCM/ECM and other modules in the vehicle, resulting in the U1016 trouble code.

8. How much does it typically cost to repair OBDII code U1016 GMC?

Costs can vary depending on the underlying cause of the code, but repairs for this issue may range from $100 for simple wiring repairs to several hundred dollars for PCM/ECM replacement.

9. Can resetting the trouble codes make OBDII code U1016 GMC go away permanently?

Simply resetting the trouble codes without addressing the root cause will not permanently resolve the issue. The code is likely to return until the underlying problem is fixed.

10. Is it safe to drive my vehicle with OBDII code U1016 GMC?

It is generally not recommended to drive the vehicle with this code present, as it can lead to potential safety hazards and further damage to the vehicle's components.