AutoCodes – Buick – P1684 Buick

P1684 Buick Code - Transmission Control Module Power Up Temperature Sensor Performance

Quick Answer

The Transmission Control Module (TCM) power up the temperature sensor is located inside of the control solenoid (w/body and TCM) valve assembly and has no serviceable parts. Common causes include Reprogram TCM and recheck code, Replace Transmission Control Module (TCM) Sensor/body assembly one piece. 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: P1684 Buick indicates Transmission Control Module Power Up Temperature Sensor Performance.
Common causes: Common causes include Reprogram TCM and recheck code, Replace Transmission Control Module (TCM) Sensor/body assembly one piece.
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 3,048

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 P1684 Buick Description

The Transmission Control Module (TCM) power up the temperature sensor is located inside of the control solenoid (w/body and TCM) valve assembly and has no serviceable parts. The TCM power up temperature sensor provides the temperature pof the TCM at TCM power up. This temperature readings is used in various shifting and diagnostic routines in the TCM software. This fault is handled inside the TCM and no external circuit are involved.

OBDII Code P1684 Buick - Transmission Control Module Power Up Temperature Sensor Performance - AutoCodes.com — P1684 Buick Code - Transmission Control Module Power Up Temperature Sensor Performance

What does this mean?

What are the Possible Causes of the DTC P1684 Buick?

Reprogram TCM and recheck code
Replace Transmission Control Module (TCM) Sensor/body assembly one piece

How to Fix the DTC P1684 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 P1684 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.