AutoCodes – Buick – P1620 Buick

P1620 Buick Code - Low Engine Coolant Circuit Conditions

Quick Answer

With the engine running, the Powertrain Control Module (PCM) detects that the Engine Coolant Switch signal was low (indicating an open circuit) for 20 seconds Common causes include Faulty Engine Coolant Switch, Engine Coolant Switch harness is open or shorted, Engine Coolant Switch 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: P1620 Buick indicates Low Engine Coolant Circuit Conditions.
Common causes: Common causes include Faulty Engine Coolant Switch, Engine Coolant Switch harness is open or shorted, Engine Coolant Switch 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 3,689

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Intermediate (2 / 3)

What is this?

Table of contents Created and updated by William Orellana on Sep 01, 2019

Description
Possible Causes
How To Fix
Cost to Diagnose
Comments
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Code P1620 Buick Description

With the engine running, the Powertrain Control Module (PCM) detects that the Engine Coolant Switch signal was low (indicating an open circuit) for 20 seconds

OBDII Code P1620 Buick - Low Engine Coolant Circuit Conditions - AutoCodes.com — P1620 Buick Code - Low Engine Coolant Circuit Conditions

What does this mean?

What are the Possible Causes of the DTC P1620 Buick?

Faulty Engine Coolant Switch
Engine Coolant Switch harness is open or shorted
Engine Coolant Switch circuit poor electrical connection

How to Fix the DTC P1620 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 P1620 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.