AutoCodes – GMC – P0990 2014 GMC Sierra

P0990 2014 GMC Sierra Code - Transmission Fluid Pressure Switch 5 Circuit High Voltage

Quick Answer

The Transmission Fluid Pressure (TFP) switch 5 is part of the Transmission 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: P0990 2014 GMC Sierra indicates Transmission Fluid Pressure Switch 5 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 204

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 Mar 25, 2024

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P0990 2014 GMC Sierra Description

The Transmission Fluid Pressure (TFP) switch 5 is part of the Transmission Control Solenoid Valve Assembly, which has no serviceable parts. The Transmission Control Module (TCM) supplies a signal circuit to the TFP switch 5. The TFP switch 5 has an internal case ground. TFP switch 5 is normally closed or LOW. When oil pressure is present at the TFP switch 5, the switch is open or HIGH. The normally high-pressure control (PC) solenoid 3 controls pressure to the R1/4-5-6 clutch regular valve. The TCM monitors the TFP switch 5 signal circuit to determine the position of the R1/4-5-6 clutch regulator valve. When the low and reverse clutch and 4-5-6 clutch are commanded OFF, pressure is present on the TFP switch 5. When the low and reverse clutch or the 4-5-6 clutch is commanded ON, the R1/4-5-6 clutch regulator valve moves, and pressure to the TFP switch 5 is exhausted through the R1/4-5-6 clutch regulator valve. The Diagnostic Trouble Code (DTC) will be set when the TCM detects that the TFP switch 5 signal voltage remains HIGH after the 4-5-6 clutch transitions from a LOW pressure state to a HIGH pressure state. The TCM counts each incident. The DTC sets when 15 counts are accumulated.

OBDII Code P0990 2014 GMC Sierra - Transmission Fluid Pressure Switch 5 Circuit High Voltage - AutoCodes.com — P0990 2014 GMC Sierra Code - Transmission Fluid Pressure Switch 5 Circuit High Voltage

What does this mean?

What are the Possible Causes of the DTC P0990 2014 GMC Sierra?

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 P0990 2014 GMC Sierra?

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 P0990 2014 GMC Sierra 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 P0990 2014 GMC Sierra code?

Need more information on how to fix the P0990 2014 GMC Sierra code? Get Access to Factory Service Manuals

Need Help with the 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 P0990 2014 GMC Sierra Code

1. What does the OBDII code P0990 mean on a 2014 GMC Sierra?

P0990 indicates a "Transmission Fluid Pressure Switch 5 Circuit High Voltage," meaning the transmission control module (TCM) has detected a high voltage signal from the pressure switch 5 circuit.

2. What are the common symptoms of the P0990 code in a 2014 GMC Sierra?

Symptoms may include harsh or delayed shifting, transmission slipping, the check engine light turning on, and possibly entering limp mode.

3. What causes the P0990 code to appear in a 2014 GMC Sierra?

Common causes include a faulty transmission fluid pressure switch, damaged or corroded wiring in the circuit, a shorted or open circuit, or a malfunctioning TCM.

4. Can driving with the P0990 code damage my 2014 GMC Sierra?

Driving with this code may lead to further transmission damage if the underlying issue isnâ€™t resolved promptly, especially if the transmission is slipping or experiencing shifting issues.

5. How do I diagnose the P0990 code on my 2014 GMC Sierra?

Diagnosis typically involves inspecting the transmission fluid pressure switch, checking the wiring and connectors for damage or corrosion, and testing voltage and continuity in the circuit.

6. How can I fix the P0990 code on a 2014 GMC Sierra?

Repairs may include replacing the faulty pressure switch, repairing or replacing damaged wiring, cleaning corroded connections, or reprogramming or replacing the TCM if needed.

7. Can low transmission fluid cause the P0990 code in a 2014 GMC Sierra?

Low or contaminated transmission fluid typically does not directly cause this code but can contribute to transmission problems, so checking and maintaining proper fluid levels is essential.

8. How much does it cost to fix the P0990 code on a 2014 GMC Sierra?

Repair costs vary depending on the cause. Replacing a pressure switch can cost $150â€“$300, while wiring repairs or TCM replacement could be more expensive.

9. Can I reset the P0990 code without repairing the issue?

Clearing the code without fixing the problem may temporarily turn off the check engine light, but the code will likely return if the underlying issue persists.

10. Is the P0990 code specific to GMC vehicles?

No, the P0990 code is a generic OBDII code and can appear in other vehicles with similar transmission systems, but diagnostics and repairs may vary by make and model.