AutoCodes – Chevrolet – P0873 2018 Chevrolet Silverado

P0873 2018 Chevrolet Silverado Code - Transmission Fluid Pressure Switch 3 Circuit High Voltage

Quick Answer

The transmission fluid pressure switch, also known as the pressure switch manifold, is a multiple switch assembly made up of 3 normally open pressure switches and 1 normally closed pressure switch. 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: P0873 2018 Chevrolet Silverado indicates Transmission Fluid Pressure Switch 3 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 287

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

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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 P0873 2018 Chevrolet Silverado Description

The transmission fluid pressure switch, also known as the pressure switch manifold, is a multiple switch assembly made up of 3 normally open pressure switches and 1 normally closed pressure switch. Pressure switch 1 monitors shift valve 1 positioning, pressure switch 2 monitors shift valve 2 positioning, pressure switch 3 monitors shift valve 3 positioning, and pressure switch 4 monitors the position of the manual selector valve. The TCM provides a signal circuit to each of the pressure switches. The TCM constantly monitors the circuits to determine the position of the shift valves. The position of shift valves 1, 2, and 3 is controlled by 3 normally closed shift solenoids. When energized, shift solenoid 1 directs fluid pressure to shift valve 1, shift solenoid 2 directs fluid pressure to shift valve 2, and shift solenoid 3 directs fluid pressure to shift valve 3, which strokes the shift valves. When a shift valve is stroked, an exhaust passage is blocked and fluid pressure increases, closing the normally open pressure switch. The Diagnostic Trouble Code (DTC) will be set when the TCM detects that transmission fluid pressure switch 3 signal circuit is High when shift solenoid 3 is commanded ON for 1 s.

OBDII Code P0873 2018 Chevrolet Silverado - Transmission Fluid Pressure Switch 3 Circuit High Voltage - AutoCodes.com — P0873 2018 Chevrolet Silverado Code - Transmission Fluid Pressure Switch 3 Circuit High Voltage

What does this mean?

What are the Possible Causes of the DTC P0873 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
Faulty Transmission Control Module (TCM)

How to Fix the DTC P0873 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 P0873 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 P0873 2018 Chevrolet Silverado 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.

Frequently Asked Questions about P0873 2018 Chevrolet Silverado Code

1. What does the OBDII code P0873 mean for a 2018 Chevrolet Silverado?

P0873 indicates that the Powertrain Control Module (PCM) has detected high voltage in the Transmission Fluid Pressure Switch 3 Circuit.

2. What are the symptoms of code P0873 in a 2018 Chevrolet Silverado?

Common symptoms include harsh or delayed shifting, transmission slipping, the transmission stuck in limp mode, and the illuminated check engine light.

3. What causes code P0873 in a 2018 Chevrolet Silverado?

Potential causes include a faulty transmission fluid pressure switch, damaged or corroded wiring/connectors in the circuit, or a malfunctioning PCM.

4. Can I drive my 2018 Chevrolet Silverado with a P0873 code?

Driving with code P0873 is not recommended, as it can lead to poor transmission performance and potential damage if the issue is not resolved.

5. How do you diagnose a P0873 code in a 2018 Chevrolet Silverado?

Diagnosis involves using a scan tool to verify the code, inspecting the Transmission Fluid Pressure Switch 3 Circuit wiring and connectors, and testing the pressure switch for proper operation.

6. How do you fix the P0873 code in a 2018 Chevrolet Silverado?

Repairs may include replacing the faulty transmission fluid pressure switch, repairing damaged wiring or connectors, or reprogramming or replacing the PCM if necessary.

7. Is the P0873 code related to low transmission fluid levels?

While low transmission fluid levels are not a direct cause of P0873, maintaining proper fluid levels is crucial for overall transmission performance and should be checked during diagnosis.

8. How much does it cost to fix a P0873 code in a 2018 Chevrolet Silverado?

Repair costs can vary but typically range between $100 and $400, depending on whether the issue involves replacing the pressure switch, repairing wiring, or reprogramming the PCM.

9. Can a weak battery or electrical issue cause the P0873 code?

Yes, electrical issues such as a weak battery, corroded connections, or poor grounding can contribute to high voltage readings in the circuit.

10. Do I need to replace the entire transmission if I get a P0873 code?

No, a P0873 code is usually resolved by addressing specific components like the pressure switch or wiring. Full transmission replacement is rarely required for this issue.