AutoCodes – GMC – P0AC4 2018 GMC Sierra

P0AC4 2018 GMC Sierra Code - Hybrid Powertrain Control Module Requested MIL Illumination

Quick Answer

Control modules constantly monitor the vehicle for any condition which may adversely affect vehicle performance. Common causes include Check Hybrid Powertrain Control Module for codes, Faulty Hybrid Powertrain Control Module. 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: P0AC4 2018 GMC Sierra indicates Hybrid Powertrain Control Module Requested MIL Illumination.
Common causes: Common causes include Check Hybrid Powertrain Control Module for codes, Faulty Hybrid Powertrain Control Module.
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 241

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 Jul 15, 2022

Description
Possible Causes
How To Fix
Tech Notes
Cost to Diagnose
Comments
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Code P0AC4 2018 GMC Sierra Description

Control modules constantly monitor the vehicle for any condition which may adversely affect vehicle performance. If a condition is detected, the module sets a Diagnostic Trouble Code (DTC) and sends a serial data message to the Engine Control Module (ECM). The ECM sets a DTC to inform that the module has set a DTC. The serial data message sent by the module also contains a request for the ECM to illuminate the Malfunction Indicator Lamp (MIL).
The DTC will be set when the ECM receives a serial data message from the Hybrid Powertrain Control Module indicating that DTC has been set in the module.

OBDII Code P0AC4 2018 GMC Sierra - Hybrid Powertrain Control Module Requested MIL Illumination - AutoCodes.com — P0AC4 2018 GMC Sierra Code - Hybrid Powertrain Control Module Requested MIL Illumination

What does this mean?

What are the Possible Causes of the DTC P0AC4 2018 GMC Sierra?

Check Hybrid Powertrain Control Module for codes
Faulty Hybrid Powertrain Control Module

How to Fix the DTC P0AC4 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 does this mean?

Code Tech Notes

The P0AC4 code is an information code only, if there are no other engine codes, then the Hybrid Powertrain Control Module needs to be diagnose.

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P0AC4 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 P0AC4 2018 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.