AutoCodes – Buick – P1690 Buick

P1690 Buick Code - Engine Control Module Loop Overrun

Quick Answer

P1690 Buick indicates Engine Control Module Loop Overrun. Common causes include Faulty Engine Control Module (ECM), Engine Control Module (ECM) harness is open or shorted, Engine Control Module (ECM) 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: P1690 Buick indicates Engine Control Module Loop Overrun.
Common causes: Common causes include Faulty Engine Control Module (ECM), Engine Control Module (ECM) harness is open or shorted, Engine Control Module (ECM) 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 3,228

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 Sep 09, 2019

Description
Possible Causes
How To Fix
Cost to Diagnose
Comments
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Code P1690 Buick Description

OBDII Code P1690 Buick - Engine Control Module Loop Overrun - AutoCodes.com — P1690 Buick Code - Engine Control Module Loop Overrun

What does this mean?

What are the Possible Causes of the DTC P1690 Buick?

Faulty Engine Control Module (ECM)
Engine Control Module (ECM) harness is open or shorted
Engine Control Module (ECM) circuit poor electrical connection

How to Fix the DTC P1690 Buick?

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 P1690 Buick 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.