AutoCodes – Chevrolet – U1899 Chevrolet

U1899 Chevrolet Code - Starter/Generator Control Module Lost Communication With Powertrain Control Module

Quick Answer

Modules connected to the class 2 and high-speed General Motor Local Area Network (GMLAN) serial data circuits monitor for serial data communications during normal vehicle operation. Common causes include Faulty Powertrain Control Module (PCM), Powertrain Control Module harness is open or shorted, Powertrain 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: U1899 Chevrolet indicates Starter/Generator Control Module Lost Communication With Powertrain Control Module.
Common causes: Common causes include Faulty Powertrain Control Module (PCM), Powertrain Control Module harness is open or shorted, Powertrain 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 525

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

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Table of contents Created and updated by William Orellana on Jun 08, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code U1899 Chevrolet Description

Modules connected to the class 2 and high-speed General Motor Local Area Network (GMLAN) serial data circuits monitor for serial data communications during normal vehicle operation. Operating information and commands are exchanged among the modules. The Diagnostic Trouble Code (DTC) is reported on a class 2 link to the scan tool by Powertrain Control Module (PCM) even if they may be set by different modules. The DTC will set when a node alive message has not been received from an identified module within the last 5 seconds after establishing class 2 serial data communication, or a supervised high-speed GMLAN message has not been received.

OBDII Code U1899 Chevrolet - Starter/Generator Control Module Lost Communication With Powertrain Control Module - AutoCodes.com — U1899 Chevrolet Code - Starter/Generator Control Module Lost Communication With Powertrain Control Module

What does this mean?

What are the Possible Causes of the DTC U1899 Chevrolet?

Faulty Powertrain Control Module (PCM)
Powertrain Control Module harness is open or shorted
Powertrain Control Module circuit poor electrical connection
Faulty Starter/Generator Control Module (SGCM)

How to Fix the DTC U1899 Chevrolet?

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 U1899 Chevrolet 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 U1899 Chevrolet Code

What does the OBDII code U1899 mean on a Chevrolet?

1. U1899 indicates that the Starter/Generator Control Module has lost communication with the Powertrain Control Module (PCM). 2.

What are the common symptoms of the U1899 code?

Symptoms may include difficulty starting the engine, reduced fuel efficiency, illuminated check engine light, and possible battery charging issues. 3.

What causes the U1899 code to appear on a Chevrolet?

This code is often caused by a faulty Starter/Generator Control Module, wiring issues, poor electrical connections, or a malfunctioning PCM. 4.

Can a weak battery trigger the U1899 code?

Yes, a weak or failing battery can cause communication issues between the modules and trigger the U1899 code. 5.

How do you diagnose the U1899 code on a Chevrolet?

Diagnosis involves using a scan tool to check for additional codes, inspecting wiring and connectors, and testing the Starter/Generator Control Module and PCM for proper operation. 6.

Can I drive my car with the U1899 code active?

It is not recommended to drive with this code active, as it may lead to starting issues or battery charging problems, potentially leaving you stranded. 7.

How much does it cost to repair the U1899 code?

Repair costs vary depending on the cause but can range from $100 for a simple wiring fix to $1,000 or more for module replacement and reprogramming. 8.

Does the U1899 code require module reprogramming?

If the Starter/Generator Control Module or PCM is replaced, reprogramming may be necessary to ensure proper communication and functionality. 9.

Can U1899 be caused by a blown fuse?

Yes, a blown fuse in the communication or power circuit can disrupt the connection between the modules and trigger this code. 10.

What tools are needed to fix the U1899 code?

Youâ€™ll need an OBDII scan tool, a multimeter for testing electrical circuits, and potentially a programming tool for module reprogramming if replacement is required.