AutoCodes – GMC – P0381 2018 GMC Sierra

P0381 2018 GMC Sierra Code - Wait To Start Indicator Control Circuit

Quick Answer

Ignition voltage is supplied directly to the Wait To Start indicator. Common causes include Faulty Instrument Cluster, Instrument Cluster harness is open or shorted, Instrument Cluster circuit 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: P0381 2018 GMC Sierra indicates Wait To Start Indicator Control Circuit.
Common causes: Common causes include Faulty Instrument Cluster, Instrument Cluster harness is open or shorted, Instrument Cluster circuit 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 206

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Intermediate (2 / 3)

What is this?

Table of contents Created and updated by William Orellana on Jun 17, 2022

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P0381 2018 GMC Sierra Description

Ignition voltage is supplied directly to the Wait To Start indicator. The Engine Control Module (ECM) controls the lamp by grounding the control circuit via an internal switch called a driver. The primary function of the driver is to supply the ground for the component being controlled. Each driver has a fault line which is monitored by the ECM. When the ECM is commanding a component ON, the voltage of the control circuit should be low, near zero volts. When the ECM is commanding the control circuit to a component OFF, the voltage potential of the circuit should be high, near battery voltage. The Diagnostic Trouble Code (DTC) will be set when the ECM detects an open circuit on the Wait To Start Indicator Control circuit for greater than 0.2 s.

OBDII Code P0381 2018 GMC Sierra - Wait To Start Indicator Control Circuit - AutoCodes.com — P0381 2018 GMC Sierra Code - Wait To Start Indicator Control Circuit

What does this mean?

What are the Possible Causes of the DTC P0381 2018 GMC Sierra?

Faulty Instrument Cluster
Instrument Cluster harness is open or shorted
Instrument Cluster circuit poor electrical connection
Faulty Engine Control Module (ECM)

How to Fix the DTC P0381 2018 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 P0381 2018 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 P0381 2018 GMC Sierra code?

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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 P0381 2018 GMC Sierra Code

1. What does the OBDII code P0381 mean on a 2018 GMC Sierra?

P0381 indicates an issue with the Wait To Start Indicator Control Circuit, which is part of the diesel engine's glow plug system.

2. What are the symptoms of code P0381 in a 2018 GMC Sierra?

Common symptoms include the Wait To Start light not functioning, difficulty starting the engine in cold weather, or no noticeable symptoms at all.

3. What causes the P0381 code to appear?

Possible causes include a faulty Wait To Start indicator bulb, damaged wiring or connectors in the control circuit, a defective glow plug control module, or blown fuses.

4. Can I drive my 2018 GMC Sierra with a P0381 code?

Yes, you can drive with this code, but starting the engine in cold weather may become difficult, and ignoring the issue could lead to further damage over time.

5. How do I diagnose a P0381 code on my GMC Sierra?

Start by inspecting the Wait To Start indicator bulb, checking for damaged wiring or loose connectors, and testing the glow plug control module with a multimeter.

6. How do I fix the P0381 code on a 2018 GMC Sierra?

Repairs may include replacing a burnt-out indicator bulb, repairing damaged wiring or connectors, or replacing the glow plug control module if necessary.

7. What tools are needed to diagnose the P0381 code?

Youâ€™ll need an OBDII scanner, a multimeter for electrical testing, and basic tools to inspect and repair wiring or components.

8. How much does it cost to fix code P0381 on a 2018 GMC Sierra?

Repair costs vary, but replacing an indicator bulb or fixing wiring is relatively inexpensive, while a glow plug control module replacement could cost $200â€“$400 including labor.

9. Can a bad battery cause the P0381 code?

While not directly related, a weak or failing battery can affect the glow plug systemâ€™s performance, which might indirectly trigger related issues.

10. Is the P0381 code covered under warranty for a 2018 GMC Sierra?

It depends on your vehicleâ€™s warranty terms, but emissions-related components like the glow plug system may be covered under the powertrain warranty.