AutoCodes – Cadillac – P1AC9 Cadillac

P1AC9 Cadillac Code - HCM Service Calibration Fault

Quick Answer

Hybrid Control Module (HCM) The internal fault detection is handled inside the control module. Common causes include Faulty Hybrid Control Module (HCM), Hybrid Control Module (HCM) harness is open or shorted, Hybrid Control Module (HCM) 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: P1AC9 Cadillac indicates HCM Service Calibration Fault.
Common causes: Common causes include Faulty Hybrid Control Module (HCM), Hybrid Control Module (HCM) harness is open or shorted, Hybrid Control Module (HCM) 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 1,209

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 01, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P1AC9 Cadillac Description

Hybrid Control Module (HCM) The internal fault detection is handled inside the control module. No external circuits are involved.

OBDII Code P1AC9 Cadillac - HCM Service Calibration Fault - AutoCodes.com — P1AC9 Cadillac Code - HCM Service Calibration Fault

What does this mean?

What are the Possible Causes of the DTC P1AC9 Cadillac?

Faulty Hybrid Control Module (HCM)
Hybrid Control Module (HCM) harness is open or shorted
Hybrid Control Module (HCM) circuit poor electrical connection

How to Fix the DTC P1AC9 Cadillac?

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 P1AC9 Cadillac 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 P1AC9 Cadillac 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 P1AC9 Cadillac Code

1. What are the common symptoms of OBDII code P1AC9 Cadillac HCM Service Calibration Fault?

The common symptoms include illuminated Check Engine Light, poor vehicle performance, and potential drivability issues.

2. What causes the OBDII code P1AC9 Cadillac HCM Service Calibration Fault to trigger?

The code is usually triggered by a fault in the calibration of the Hybrid Control Module (HCM) in a Cadillac vehicle.

3. How serious is the OBDII code P1AC9 Cadillac HCM Service Calibration Fault?

This fault should be addressed promptly to prevent potential drivability issues and further damage to the vehicle's hybrid system.

4. Can I continue driving my Cadillac with the OBDII code P1AC9 HCM Service Calibration Fault?

It is not recommended to continue driving the vehicle with this fault as it can lead to performance issues and potential damage to the hybrid system.

5. How can I diagnose the OBDII code P1AC9 Cadillac HCM Service Calibration Fault?

Diagnosis typically involves using an OBDII scanner to read the code and then further testing the Hybrid Control Module for calibration issues.

6. What are the possible repair options for the OBDII code P1AC9 Cadillac HCM Service Calibration Fault?

Repair options may include recalibrating the Hybrid Control Module, updating software, or replacing the module if necessary.

7. Can I reset the OBDII code P1AC9 Cadillac HCM Service Calibration Fault myself?

While you can clear the code with an OBDII scanner, it is important to address the underlying issue causing the fault to prevent it from reoccurring.

8. How much does it cost to repair the OBDII code P1AC9 Cadillac HCM Service Calibration Fault?

The cost of repair can vary depending on the exact cause of the fault, but it is recommended to consult a professional technician for an accurate diagnosis and cost estimate.

9. Is the OBDII code P1AC9 Cadillac HCM Service Calibration Fault a common issue in Cadillac vehicles?

This code is not as common as some other OBDII codes, but it can still occur in Cadillac vehicles with hybrid systems.

10. How can I prevent the OBDII code P1AC9 Cadillac HCM Service Calibration Fault from occurring again?

Regular maintenance and inspections of the hybrid system, as well as addressing any related issues promptly, can help prevent this fault from occurring again.