AutoCodes – Generic – U1027

U1027 Code - Invalid Or Missing Data For Engine RPM

Quick Answer

Modules connected to the class 2 serial data circuit monitor for serial data communications during normal vehicle operation. Common causes include Faulty Anti-Lock Brake System (ABS) Control Module, Anti-Lock Brake System Control Module harness is open or shorted, Anti-Lock Brake System 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: U1027 indicates Invalid Or Missing Data For Engine RPM.
Common causes: Common causes include Faulty Anti-Lock Brake System (ABS) Control Module, Anti-Lock Brake System Control Module harness is open or shorted, Anti-Lock Brake System 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.

Save to My Repairs My Repairs

AI answers can be wrong. Verify repairs with testing. Open full chat

Code Popularity 23,159

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
Cost to Diagnose
FAQs
Comments
Add Comment

💬 Need more help? Ask Coddy for instant answers — it's free!

Code U1027 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 State of Health monitoring. A critical operating parameter is one which, when not received, requires that the module use a default value for that parameter. When a module does not associate an identification number with at least one critical parameter within 5 seconds of beginning serial data communication from Anti-Lock Brake System (ABS) Control Module, Diagnostic Trouble Code (DTC) is set.

OBDII Code U1027 - Invalid Or Missing Data For Engine RPM - AutoCodes.com — U1027 Code - Invalid Or Missing Data For Engine RPM

What does this mean?

What are the Possible Causes of the DTC U1027?

Faulty Anti-Lock Brake System (ABS) Control Module
Anti-Lock Brake System Control Module harness is open or shorted
Anti-Lock Brake System Control Module circuit poor electrical connection

How to Fix the DTC U1027?

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 U1027 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.

Need more information about the U1027 code?

Need more information on how to fix the U1027 code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the U1027 code diagnosed by a professional: Find a repair shop in your area

Information for Specific Makes

U1027 Ford — Invalid Or Missing Data For Engine RPM
U1027 Lincoln — Invalid Or Missing Data For Engine RPM
U1027 Mercury — Invalid Or Missing Data For Engine RPM

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 U1027 Code

1. What are the common symptoms of OBDII code U1027?

- Common symptoms include issues with the tachometer not working properly, engine stalling, misfires, or poor acceleration.

2. What causes the OBDII code U1027 to trigger?

- The code U1027 is triggered when the engine control module (ECM) detects invalid or missing data related to engine RPM.

3. How can I diagnose the cause of the U1027 code?

- Diagnosis typically involves checking the wiring and connectors related to the engine RPM sensor, as well as ensuring there are no loose connections or damaged components.

4. Can a faulty RPM sensor cause the U1027 code?

- Yes, a faulty RPM sensor or sensor wiring can lead to the U1027 code being triggered by the ECM.

5. What are some repair tips for resolving the U1027 code?

- Inspect the RPM sensor and its wiring for any damage or corrosion. Clear the code and monitor the system to see if it reoccurs after repairs.

6. Is it safe to continue driving with the U1027 code present?

- It is generally not recommended to drive with the U1027 code active, as it can lead to potential engine performance issues and further damage if left unresolved.

7. Can a software update fix the U1027 code?

- Sometimes, a software update to the ECM can resolve communication issues and eliminate the U1027 code.

8. How do I reset the U1027 code?

- The U1027 code can be reset using an OBDII scanner, which clears the code from the ECM's memory.

9. Will the U1027 code cause the check engine light to illuminate?

- Yes, the U1027 code will typically trigger the check engine light to illuminate on the dashboard to alert the driver of the issue.

10. Are there any recalls related to the U1027 code?

- It is always recommended to check with the vehicle manufacturer or authorized dealerships for any recalls or technical service bulletins related to the U1027 code.