AutoCodes – Cadillac – U0103 Cadillac

U0103 Cadillac Code - Lost Communication With Shift Lever Module

Quick Answer

Modules connected to the high speed General Motor Local Area Network (GMLAN) serial data circuits monitor for serial data communications during normal vehicle operation. Common causes include Faulty Shift Lever Module, Shift Lever Module harness is open or shorted, Shift Lever 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: U0103 Cadillac indicates Lost Communication With Shift Lever Module.
Common causes: Common causes include Faulty Shift Lever Module, Shift Lever Module harness is open or shorted, Shift Lever 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 640

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 Mar 30, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code U0103 Cadillac Description

Modules connected to the 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 modules have prerecorded information about what messages are needed to be exchanged on the serial data circuits, for each virtual network. The messages are supervised and also, some periodic messages are used by the receiver module as an availability indication of the transmitter module. The supervision time-out period is 250 ms. Each message contains the identification number of the transmitter module. The Diagnostic Trouble Code (DTC) sets when a periodic message from the Shift Lever Module has not been received.

OBDII Code U0103 Cadillac - Lost Communication With Shift Lever Module - AutoCodes.com — U0103 Cadillac Code - Lost Communication With Shift Lever Module

What does this mean?

What are the Possible Causes of the DTC U0103 Cadillac?

Faulty Shift Lever Module
Shift Lever Module harness is open or shorted
Shift Lever Module circuit poor electrical connection

How to Fix the DTC U0103 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 U0103 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 U0103 Cadillac Code

1. What are the common symptoms of OBDII code U0103 in a Cadillac indicating lost communication with the shift lever module?

- Common symptoms include issues with shifting gears, inability to start the vehicle, dashboard warning lights related to transmission problems, and intermittent loss of power.

2. What are some possible causes of OBDII code U0103 in a Cadillac?

- Potential causes may include faulty wiring or connectors in the communication network, a malfunctioning shift lever module, a damaged control module, or software issues.

3. How can I diagnose the root cause of OBDII code U0103 in my Cadillac?

- Diagnosing the issue typically requires a professional scan tool to communicate with the affected modules, checking the wiring and connectors for damage, and performing a thorough inspection of the shift lever module and related components.

4. Can I continue driving my Cadillac with OBDII code U0103 present?

- It is not recommended to drive the vehicle with this code present, as it may lead to potential safety hazards and further damage to the transmission system.

5. What are some repair tips for resolving OBDII code U0103 in a Cadillac?

- Repair tips may include checking and repairing any damaged wiring or connectors, replacing the shift lever module if necessary, updating software as recommended by the manufacturer, and clearing the code to reset the system.

6. Is it necessary to visit a dealership for OBDII code U0103 repair, or can an independent mechanic handle it?

- While an independent mechanic with experience in handling electronic system repairs may be able to address the issue, visiting a dealership or a specialized automotive service center with proper diagnostic equipment is recommended for accurate diagnosis and repair.

7. Are there any recalls or technical service bulletins related to OBDII code U0103 in Cadillac vehicles?

- It is advisable to check with the manufacturer or authorized service centers for any recalls or technical service bulletins related to this specific OBDII code in Cadillac vehicles.

8. Will resetting the OBDII code U0103 resolve the issue permanently?

- Simply resetting the code may temporarily clear the warning lights, but it is crucial to diagnose and address the underlying cause to prevent the code from reoccurring.

9. How much can I expect to pay for repairing OBDII code U0103 in a Cadillac?

- The cost of repair can vary depending on the root cause of the issue, parts needed for replacement, labor charges, and the service provider. It is advisable to obtain quotes from different repair shops for comparison.

10. Can a DIY enthusiast with basic automotive knowledge fix OBDII code U0103 in a Cadillac?

- While some basic troubleshooting steps can be performed by a DIY enthusiast, resolving OBDII code U0103 often requires specialized diagnostic tools and expertise, making it more suitable for professional repair.