AutoCodes – GMC – P0A02 GMC

P0A02 GMC Code - Starter/Generator Control Module Coolant Temperature Sensor 1 Circuit Low Voltage

Quick Answer

The Starter/Generator Control Module (SGCM) monitors its internal fluid temperature sensors to control the SGCM coolant pump and SGCM cooling fan. Common causes include Faulty Starter/Generator Control Module (SGCM), Starter/Generator Control Module (SGCM) harness is open or shorted, Starter/Generator Control Module (SGCM) 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: P0A02 GMC indicates Starter/Generator Control Module Coolant Temperature Sensor 1 Circuit Low Voltage.
Common causes: Common causes include Faulty Starter/Generator Control Module (SGCM), Starter/Generator Control Module (SGCM) harness is open or shorted, Starter/Generator Control Module (SGCM) 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 1,006

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

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Table of contents Created and updated by William Orellana on Feb 22, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P0A02 GMC Description

The Starter/Generator Control Module (SGCM) monitors its internal fluid temperature sensors to control the SGCM coolant pump and SGCM cooling fan. The internal fluid temperature sensors of the SGCM are thermistors and are not serviceable. When the internal fluid temperatures are cold, the resistances of the sensors are high and the voltage signals are high. When the internal fluid temperatures are hot, the resistances of the sensors are low and the voltage signals are low. The input parameters are not displayed on the scan tool.

OBDII Code P0A02 GMC - Starter/Generator Control Module Coolant Temperature Sensor 1 Circuit Low Voltage - AutoCodes.com — P0A02 GMC Code - Starter/Generator Control Module Coolant Temperature Sensor 1 Circuit Low Voltage

What does this mean?

What are the Possible Causes of the DTC P0A02 GMC?

Faulty Starter/Generator Control Module (SGCM)
Starter/Generator Control Module (SGCM) harness is open or shorted
Starter/Generator Control Module (SGCM) circuit poor electrical connection

How to Fix the DTC P0A02 GMC?

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 P0A02 GMC 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.

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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 P0A02 GMC Code

What does the OBDII code P0A02 mean on a GMC vehicle?

Code P0A02 indicates a low voltage issue in the Starter/Generator Control Module Coolant Temperature Sensor 1 circuit, suggesting a problem with the sensor or its wiring.

What are the common symptoms of code P0A02?

Symptoms may include the check engine light turning on, reduced engine performance, possible overheating issues, or irregular operation of the starter/generator system.

What causes code P0A02 to trigger?

Common causes include a faulty coolant temperature sensor, damaged or corroded wiring, a poor electrical connection, or an issue with the Starter/Generator Control Module itself.

How can I diagnose the P0A02 code?

Diagnose the code by using a scan tool to check related data, inspecting the coolant temperature sensor and its wiring for damage, and testing the sensor's voltage and resistance.

Can I drive my GMC vehicle with the P0A02 code?

Driving with this code is not recommended, as it could lead to overheating or reduced efficiency of the starter/generator system, potentially causing further damage.

How do I fix the P0A02 code?

Repairs may include replacing the coolant temperature sensor, repairing or replacing damaged wiring or connectors, or, in rare cases, replacing the Starter/Generator Control Module.

How much does it cost to repair the P0A02 code?

Repair costs can vary, but replacing a coolant temperature sensor typically costs between $50 and $300, including parts and labor. Wiring or module repairs may increase the cost.

Can a low coolant level cause the P0A02 code?

While low coolant levels do not directly cause this code, they can lead to sensor malfunction or overheating, which might contribute to related issues.

What tools are needed to fix the P0A02 code?

Basic tools like a multimeter for testing voltage, a scan tool for reading live data, and standard hand tools for sensor replacement are typically required.

Does the P0A02 code require reprogramming the control module?

Reprogramming is usually not necessary unless the Starter/Generator Control Module itself is replaced or updated software is required.