AutoCodes – Cadillac – U1899 Cadillac

U1899 Cadillac 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 Cadillac 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 510

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 Jun 08, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code U1899 Cadillac 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 Cadillac - Starter/Generator Control Module Lost Communication With Powertrain Control Module - AutoCodes.com — U1899 Cadillac Code - Starter/Generator Control Module Lost Communication With Powertrain Control Module

What does this mean?

What are the Possible Causes of the DTC U1899 Cadillac?

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 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 is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the U1899 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 U1899 Cadillac Code

1. What are the common symptoms of OBDII code U1899 in a Cadillac related to the Starter/Generator Control Module losing communication with the Powertrain Control Module?

- Common symptoms may include issues with starting the vehicle, poor engine performance, and illuminated warning lights on the dashboard.

2. What are some possible causes of the U1899 code in a Cadillac?

- Possible causes include wiring or connection issues between the modules, a faulty Starter/Generator Control Module, a malfunctioning Powertrain Control Module, or software communication errors.

3. How can I diagnose the U1899 code in my Cadillac?

- Diagnosing the code typically involves using a professional OBDII scanner to retrieve the specific code, checking the connections and wiring between the modules, and performing a thorough inspection of the modules themselves.

4. Can I still drive my Cadillac with the U1899 code present?

- It is not recommended to drive the vehicle with the U1899 code present, as it can lead to further damage and potential safety hazards. It is best to address the issue promptly.

5. How can I repair the U1899 code in my Cadillac?

- Repairing the code may involve repairing or replacing any damaged wiring or connections, resetting the modules, updating software if necessary, or replacing the faulty modules.

6. Is the U1899 code specific to Cadillac vehicles only?

- The U1899 code related to the Starter/Generator Control Module losing communication with the Powertrain Control Module is specific to Cadillac vehicles.

7. Are there any recalls or technical service bulletins related to the U1899 code in Cadillacs?

- It is recommended to check with a Cadillac dealership or official service center for any recalls or technical service bulletins related to the U1899 code in specific Cadillac models.

8. How can I prevent the U1899 code from reoccurring in my Cadillac?

- Regular maintenance, checking and cleaning electrical connections, and addressing any issues promptly can help prevent the U1899 code from reoccurring in your Cadillac.

9. Can the U1899 code cause any long-term damage to my Cadillac if left unrepaired?

- Leaving the U1899 code unrepaired can potentially cause further damage to the modules involved and affect the overall performance and reliability of your Cadillac.

10. How long does it typically take to repair the U1899 code in a Cadillac?

- The time taken to repair the U1899 code can vary depending on the exact cause of the issue, but it may range from a few hours to a day, depending on the complexity of the repair needed.