AutoCodes – Generic – P1681

P1681 Code - Control Module Not Programmed

Quick Answer

This diagnostic applies to internal microprocessor integrity conditions within the Engine Control Module (ECM). Common causes include Engine Control Module (ECM) programming error, Wrong Engine Control Module, Faulty Engine Control Module. 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: P1681 indicates Control Module Not Programmed.
Common causes: Common causes include Engine Control Module (ECM) programming error, Wrong Engine Control Module, Faulty Engine Control Module.
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 36,190

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 Aug 06, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
Comments
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Code P1681 Description

This diagnostic applies to internal microprocessor integrity conditions within the Engine Control Module (ECM). This Diagnostic Trouble Code (DTC) also addresses if the ECM is not programmed.

OBDII Code P1681 - Control Module Not Programmed - AutoCodes.com — P1681 Code - Control Module Not Programmed

What does this mean?

What are the Possible Causes of the DTC P1681?

Engine Control Module (ECM) programming error
Wrong Engine Control Module
Faulty Engine Control Module

How to Fix the DTC P1681?

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 P1681 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 P1681 code?

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Need Help with the Code?

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Information for Specific Makes

P1681 Acura — Automotic Transmission To Engine Control Module Signal 'A' Input Low
P1681 Audi — Engine Control Module Programming Incomplete
P1681 Buick — Control Module Not Programmed
P1681 Cadillac — Control Module Not Programmed
P1681 Chevrolet — Control Module Not Programmed
P1681 Chrysler — No Fuel Level Bus Message
P1681 Dodge — No Fuel Level Bus Message
P1681 GMC — Control Module Not Programmed
P1681 Honda — Automotic Transmission To Engine Control Module Signal 'A' Input Low
P1681 Isuzu — Automotic Transmission To Engine Control Module Signal 'A' Input Low
P1681 Jeep — No Fuel Level Bus Message
P1681 Mercedes-Benz — Engine Control Module Crash Signal Plausibility
P1681 Pontiac — Control Module Not Programmed
P1681 RAM — No Fuel Level Bus Message
P1681 Saturn — Control Module Not Programmed
P1681 Volkswagen — Engine Control Module Programming Incomplete

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.