AutoCodes – Generic – P1909

P1909 Code - Transmission Temperature Sensor Circuit Open or Shorted to Power Or Ground

Quick Answer

P1909 indicates Transmission Temperature Sensor Circuit Open or Shorted to Power Or Ground. Common causes include Faulty Transmission Temperature Sensor, Transmission Temperature Sensor harness is open or shorted, Transmission Temperature Sensor 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: P1909 indicates Transmission Temperature Sensor Circuit Open or Shorted to Power Or Ground.
Common causes: Common causes include Faulty Transmission Temperature Sensor, Transmission Temperature Sensor harness is open or shorted, Transmission Temperature Sensor 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 8,209

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 27, 2019

Description
Possible Causes
How To Fix
Cost to Diagnose
Comments
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Code P1909 Description

OBDII Code P1909 - Transmission Temperature Sensor Circuit Open or Shorted to Power Or Ground - AutoCodes.com — P1909 Code - Transmission Temperature Sensor Circuit Open or Shorted to Power Or Ground

What does this mean?

What are the Possible Causes of the DTC P1909?

Faulty Transmission Temperature Sensor
Transmission Temperature Sensor harness is open or shorted
Transmission Temperature Sensor circuit poor electrical connection

How to Fix the DTC P1909?

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 P1909 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 P1909 code?

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Need Help with the Code?

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Information for Specific Makes

P1909 Audi — Data Bus ECM 1/2 No Signal From ECM
P1909 Ford — Transmission Temperature Sensor Circuit Open or Shorted to Power Or Ground
P1909 Volkswagen — Transmission Temperature Sensor Circuit Open or Shorted to Power Or Ground

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.