AutoCodes – Cadillac – U1016 Cadillac

U1016 Cadillac 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 Cadillac 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 14,075

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

What does this mean?

What are the Possible Causes of the DTC U1016 Cadillac?

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 Cadillac?

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 Cadillac 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 Cadillac Code

1. What does the OBDII code U1016 Cadillac indicate?

The U1016 code means there is a communication problem between the Powertrain/Engine Control Module (PCM/ECM) and other modules in the vehicle.

2. What are common symptoms of a U1016 Cadillac code?

Common symptoms include intermittent or total loss of engine power, stalling, rough idling, and the vehicle going into "limp mode."

3. What are the possible causes of a U1016 Cadillac code?

Potential causes include damaged wiring, loose connections, a faulty PCM/ECM, software issues, or a problem with another module on the communication network.

4. How can I diagnose a U1016 Cadillac code?

Diagnosis typically involves checking for any other related trouble codes, inspecting the wiring and connections, and using a scan tool to communicate with the affected modules.

5. How can I repair a U1016 Cadillac code?

Repair options may include repairing or replacing damaged wiring, ensuring all connections are secure, reprogramming the PCM/ECM, or replacing a faulty module.

6. Can I drive my vehicle with a U1016 Cadillac code?

It is not recommended to drive your vehicle with a U1016 code present, as it can lead to potential safety hazards and further damage to the vehicle.

7. How much does it cost to fix a U1016 Cadillac code?

The cost of repairing a U1016 code can vary depending on the underlying issue, but it may range from a simple wiring repair to a more complex module replacement.

8. Will a U1016 Cadillac code cause my check engine light to illuminate?

Yes, a U1016 code will typically trigger the check engine light to come on, indicating a problem with the communication between the PCM/ECM and other modules.

9. Can a DIY enthusiast fix a U1016 Cadillac code?

While some basic troubleshooting steps can be performed by a DIY enthusiast, diagnosing and repairing a U1016 code may require specialized tools and expertise, so professional assistance is often recommended.

10. How can I prevent a U1016 Cadillac code from occurring again?

Regular vehicle maintenance, including checking and cleaning electrical connections, can help prevent communication issues that lead to a U1016 code.