AutoCodes – Generic – P1AA8

P1AA8 Code - Starter/Generator Field Control Performance

Quick Answer

The Starter/Generator Control Module (SGCM) monitors the Motor Generator Unit (MGU) field coil circuit to see if the field coil current is within tolerance. Common causes include Faulty Motor Generator Unit (MGU), Motor Generator Unit (MGU) harness is open or shorted, Motor Generator Unit (MGU) 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: P1AA8 indicates Starter/Generator Field Control Performance.
Common causes: Common causes include Faulty Motor Generator Unit (MGU), Motor Generator Unit (MGU) harness is open or shorted, Motor Generator Unit (MGU) 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 1,579

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 Feb 26, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P1AA8 Description

The Starter/Generator Control Module (SGCM) monitors the Motor Generator Unit (MGU) field coil circuit to see if the field coil current is within tolerance.

OBDII Code P1AA8 - Starter/Generator Field Control Performance - AutoCodes.com — P1AA8 Code - Starter/Generator Field Control Performance

What does this mean?

What are the Possible Causes of the DTC P1AA8?

Faulty Motor Generator Unit (MGU)
Motor Generator Unit (MGU) harness is open or shorted
Motor Generator Unit (MGU) circuit poor electrical connection

How to Fix the DTC P1AA8?

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 P1AA8 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 P1AA8 code?

Need more information on how to fix the P1AA8 code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P1AA8 code diagnosed by a professional: Find a repair shop in your area

Information for Specific Makes

P1AA8 Buick — Starter/Generator Field Control Performance
P1AA8 Cadillac — Starter/Generator Field Control Performance
P1AA8 Chevrolet — Starter/Generator Field Control Performance
P1AA8 GMC — Starter/Generator Field Control Performance
P1AA8 Saturn — Starter/Generator Field Control Performance

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 P1AA8 Code

1. What are the common symptoms of OBDII code P1AA8 (Starter/Generator Field Control Performance)?

- Common symptoms include the vehicle not starting, intermittent starting issues, poor engine performance, and the illumination of the check engine light.

2. What can cause OBDII code P1AA8 to trigger?

- Possible causes of this code include a faulty starter/generator field control module, damaged wiring or connectors, low battery voltage, or issues with the engine control module.

3. How can I diagnose OBDII code P1AA8?

- Diagnosis typically involves using a scan tool to read the code, checking the battery voltage, inspecting the starter/generator field control module and related components, and performing a thorough visual inspection of wiring and connectors.

4. Can OBDII code P1AA8 be reset without fixing the underlying issue?

- Resetting the code without addressing the root cause is not recommended, as the issue may persist and potentially lead to more serious problems. It is crucial to diagnose and repair the issue triggering the code.

5. What are some repair tips for fixing OBDII code P1AA8?

- Repair tips may include replacing the faulty starter/generator field control module, repairing damaged wiring or connectors, ensuring proper battery voltage, and performing a software update if recommended by the manufacturer.

6. Is it safe to continue driving with OBDII code P1AA8 present?

- It is not recommended to drive with this code present, as it can lead to potential starting issues or engine performance issues. It is best to address the problem promptly to avoid further complications.

7. Can a DIY enthusiast fix OBDII code P1AA8 at home?

- Depending on the root cause, some DIY enthusiasts may be able to address this code at home by following proper diagnostic procedures and repair instructions. However, complex electrical issues may require professional assistance.

8. Will OBDII code P1AA8 affect fuel efficiency?

- Yes, this code can potentially affect fuel efficiency if it leads to poor engine performance or starting issues. Resolving the underlying problem can help improve fuel efficiency.

9. How long does it typically take to repair OBDII code P1AA8?

- The repair time can vary based on the specific cause of the code and the complexity of the repair. It may take anywhere from a few hours to a full day, depending on the extent of the issue.

10. Are there any recalls related to OBDII code P1AA8?

- It is recommended to check with the vehicle manufacturer or authorized dealerships for any recalls related to OBDII code P1AA8, as recalls sometimes address known issues associated with this code.