AutoCodes – GMC – P0989 2014 GMC Sierra

P0989 2014 GMC Sierra Code - Transmission Fluid Pressure Switch 5 Circuit Low 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
P0989 2014 GMC Sierra indicates Transmission Fluid Pressure Switch 5 Circuit Low 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.
AI answers can be wrong. Verify repairs with testing. Open full chat
Code Popularity 437
How popular is this code, among other codes? Low
Table of contents Created and updated by William Orellana on Mar 25, 2024
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Code P0989 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 LOW after the 4-5-6 clutch transitions from a HIGH pressure state to a LOW pressure state. The TCM counts each incident. The DTC sets when 18 counts are accumulated.
OBDII Code P0989 2014 GMC Sierra - Transmission Fluid Pressure Switch 5 Circuit Low Voltage - AutoCodes.com
P0989 2014 GMC Sierra Code - Transmission Fluid Pressure Switch 5 Circuit Low Voltage

What are the Possible Causes of the DTC P0989 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 P0989 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 P0989 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 P0989 2014 GMC Sierra 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 P0989 2014 GMC Sierra Code

1. What does the OBDII code P0989 mean on a 2014 GMC Sierra?

It indicates a problem with the Transmission Fluid Pressure Switch 5 Circuit, specifically low voltage being detected.

2. What are the common symptoms of P0989 in a 2014 GMC Sierra?

Symptoms may include erratic shifting, the transmission stuck in one gear, poor performance, or the Check Engine Light being illuminated.

3. What causes the P0989 code to appear?

Common causes include a faulty transmission fluid pressure switch, damaged wiring or connectors in the circuit, low transmission fluid levels, or a malfunctioning transmission control module (TCM).

4. Can low transmission fluid cause the P0989 code?

Yes, low or dirty transmission fluid can affect pressure readings and contribute to the P0989 code.

5. How do I troubleshoot the P0989 code?

Start by checking the transmission fluid level and condition, inspecting the wiring and connectors for damage or corrosion, and testing the transmission fluid pressure switch.

6. How is the P0989 code typically repaired?

Repairs may involve replacing the transmission fluid pressure switch, repairing damaged wiring or connectors, or addressing issues with the TCM.

7. Is it safe to drive with the P0989 code on a 2014 GMC Sierra?

Driving with this code can lead to poor transmission performance and potential damage, so it's best to address the issue promptly.

8. How much does it cost to fix the P0989 code on a 2014 GMC Sierra?

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

9. Can a faulty TCM trigger the P0989 code?

Yes, a malfunctioning Transmission Control Module can cause communication or voltage issues, leading to this code.

10. Does clearing the P0989 code fix the problem?

Clearing the code without addressing the underlying issue will not fix the problem, and the code is likely to return.

Discuss the causes and fixes for P0989 2014 GMC Sierra OBDII Code

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