AutoCodes – Chevrolet – P0843 2018 Chevrolet Silverado

P0843 2018 Chevrolet Silverado Code - Transmission Fluid Pressure Switch 1 Circuit High Voltage

Quick Answer

The Transmission Fluid Pressure (TFP) switch 1 is part of the control solenoid valve assembly, which has no serviceable parts. Common causes include Low transmission fluid level, Dirty transmission fluid, Faulty Transmission Control Solenoid Valve Assembly. 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: P0843 2018 Chevrolet Silverado indicates Transmission Fluid Pressure Switch 1 Circuit High Voltage.
Common causes: Common causes include Low transmission fluid level, Dirty transmission fluid, Faulty Transmission Control Solenoid Valve Assembly.
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 324

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 Aug 02, 2022

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P0843 2018 Chevrolet Silverado Description

The Transmission Fluid Pressure (TFP) switch 1 is part of the control solenoid valve assembly, which has no serviceable parts. The Transmission Control Module (TCM) supplies a signal circuit to the TFP Switch 1. The TFP Switch 1 has an internal case ground. TFP Switch 1 is normally closed or LOW. When oil pressure is present at the TFP Switch 1, the switch is open or HIGH. The normally high clutch pressure control (PC) solenoid 2 controls pressure to the 3-5 reverse clutch regulator valve. The TCM monitors the TFP switch 1 to determine the position of the 3-5 reverse clutch regulator valve. When the 3-5 reverse clutch is commanded OFF, pressure is present on the TFP switch 1. When the 3-5 reverse clutch is commanded ON, the 3-5 reverse clutch regulator valve moves and pressure to the TFP switch 1 is exhausted through the 3-5 reverse clutch regulator valve. The Diagnostic Trouble Code (DTC) will be set when the TCM detects that the TFP switch 1 signal voltage remains HIGH after the 3-5-R clutch transitions from a LOW pressure state to a HIGH pressure state. The TCM counts each incident. The DTC sets when 35 counts are accumulated.

OBDII Code P0843 2018 Chevrolet Silverado - Transmission Fluid Pressure Switch 1 Circuit High Voltage - AutoCodes.com — P0843 2018 Chevrolet Silverado Code - Transmission Fluid Pressure Switch 1 Circuit High Voltage

What does this mean?

What are the Possible Causes of the DTC P0843 2018 Chevrolet Silverado?

Low transmission fluid level
Dirty transmission fluid
Faulty Transmission Control Solenoid Valve Assembly
Transmission Control Solenoid Valve Assembly harness is open or shorted
Transmission Control Solenoid Valve Assembly circuit poor electrical connection

How to Fix the DTC P0843 2018 Chevrolet Silverado?

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 P0843 2018 Chevrolet Silverado 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 P0843 2018 Chevrolet Silverado code?

Need more information on how to fix the P0843 2018 Chevrolet Silverado code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P0843 2018 Chevrolet Silverado code diagnosed by a professional: Find a repair shop in your area

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.

Frequently Asked Questions about P0843 2018 Chevrolet Silverado Code

1. What does the OBDII code P0843 mean on a 2018 Chevrolet Silverado?

P0843 indicates a high voltage issue in the Transmission Fluid Pressure Switch 1 Circuit, suggesting a problem with the transmission fluid pressure sensor or its circuit.

2. What are the common symptoms of P0843 in a 2018 Chevrolet Silverado?

Symptoms may include harsh or delayed shifting, the transmission entering limp mode, poor fuel economy, or the Check Engine Light illuminating.

3. What causes the P0843 code on a 2018 Chevrolet Silverado?

Common causes include a faulty transmission fluid pressure sensor, damaged or shorted wiring in the sensor circuit, a bad connector, or a malfunctioning transmission control module (TCM).

4. Can I drive my 2018 Chevrolet Silverado with the P0843 code?

While the vehicle may still be drivable, continuing to drive with this code can cause further transmission damage or unsafe driving conditions. Prompt diagnosis and repair are recommended.

5. How is the P0843 code diagnosed on a 2018 Chevrolet Silverado?

A mechanic will check the sensor wiring, inspect the connector for damage, test the sensorâ€™s voltage and resistance, and use a scan tool to monitor transmission fluid pressure readings.

6. How do you fix the P0843 code on a 2018 Chevrolet Silverado?

Repairs may involve replacing the transmission fluid pressure sensor, repairing damaged wiring or connectors, or reprogramming the transmission control module if necessary.

7. How much does it cost to repair the P0843 code on a 2018 Chevrolet Silverado?

Repair costs vary but typically range from $150 to $400, depending on whether the issue is with the sensor, wiring, or other components.

8. Can low transmission fluid cause the P0843 code on a 2018 Chevrolet Silverado?

Low or contaminated transmission fluid is unlikely to directly cause P0843, but it can contribute to transmission issues. Always ensure proper fluid levels and quality.

9. Does the P0843 code mean my transmission is failing?

Not necessarily. P0843 often points to an electrical or sensor issue rather than complete transmission failure, but it should be addressed promptly to prevent further damage.

10. Can I clear the P0843 code without fixing the problem on my 2018 Chevrolet Silverado?

Clearing the code without fixing the issue may temporarily turn off the Check Engine Light, but the problem will likely return and could cause further damage over time.