AutoCodes – Jeep – P0840 Jeep

P0840 Jeep Code - Transmission Fluid Pressure Sensor/Switch 'A' Circuit

Quick Answer

The Transmission Control Module (TCM) monitors the Transmission Fluid Pressure Sensor/Switch signal. Common causes include Faulty Transmission Fluid Pressure Sensor/Switch 'A', Transmission Fluid Pressure Sensor/Switch 'A' harness is open or shorted, Transmission Fluid Pressure Sensor/Switch 'A' 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: P0840 Jeep indicates Transmission Fluid Pressure Sensor/Switch 'A' Circuit.
Common causes: Common causes include Faulty Transmission Fluid Pressure Sensor/Switch 'A', Transmission Fluid Pressure Sensor/Switch 'A' harness is open or shorted, Transmission Fluid Pressure Sensor/Switch 'A' 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 2,876

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 May 10, 2019

Description
Possible Causes
How To Fix
Cost to Diagnose
Comments
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Code P0840 Jeep Description

The Transmission Control Module (TCM) monitors the Transmission Fluid Pressure Sensor/Switch signal. The TCM sets the OBDII code when the Transmission Fluid Pressure Sensor/Switch is not to factory specifications.

OBDII Code P0840 Jeep - Transmission Fluid Pressure Sensor/Switch 'A' Circuit - AutoCodes.com — P0840 Jeep Code - Transmission Fluid Pressure Sensor/Switch 'A' Circuit

What does this mean?

What are the Possible Causes of the DTC P0840 Jeep?

Faulty Transmission Fluid Pressure Sensor/Switch 'A'
Transmission Fluid Pressure Sensor/Switch 'A' harness is open or shorted
Transmission Fluid Pressure Sensor/Switch 'A' poor electrical connection
Transmission Valve Body

How to Fix the DTC P0840 Jeep?

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 P0840 Jeep 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 P0840 Jeep code?

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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.