P0AC9 GMC Code - Hybrid/EV Battery Temperature Sensor 2 Circuit Erratic
Quick Answer
Hybrid/EV Battery Temperature Sensors are used to monitor the battery temperature. Common causes include Faulty Hybrid/EV Battery Assembly, Hybrid/EV Battery Assembly harness is open or shorted, Hybrid/EV Battery Assembly 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
- P0AC9 GMC indicates Hybrid/EV Battery Temperature Sensor 2 Circuit Erratic.
- Common causes
- Common causes include Faulty Hybrid/EV Battery Assembly, Hybrid/EV Battery Assembly harness is open or shorted, Hybrid/EV Battery Assembly 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.
Code P0AC9 GMC Description
Each Hybrid/EV Battery Interface Control Module communicates the temperature sensor values to the Hybrid/EV Powertrain Control Module via serial data.
The Hybrid/EV Powertrain Control Module uses the battery temperature sensors to determine the Hybrid/EV Battery Module temperature in order to control the battery cooling system operation.
The Diagnostic Trouble Code (DTC) will be set when the hybrid battery temperature sensor is intermittent or has changed by 10°C (18°F) or greater for 4 out of 5 seconds.
What are the Possible Causes of the DTC P0AC9 GMC?
- Faulty Hybrid/EV Battery Assembly
- Hybrid/EV Battery Assembly harness is open or shorted
- Hybrid/EV Battery Assembly circuit poor electrical connection
- Faulty Hybrid/EV Battery Interface Control Module
How to Fix the DTC P0AC9 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 P0AC9 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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Information for Specific GMC Models
- P0AC9 2014 GMC Sierra — Hybrid/EV Battery Temperature Sensor 2 Circuit Erratic
- P0AC9 2015 GMC Sierra — Hybrid/EV Battery Temperature Sensor 2 Circuit Erratic
- P0AC9 2016 GMC Sierra — Hybrid/EV Battery Temperature Sensor 2 Circuit Erratic
- P0AC9 2017 GMC Sierra — Hybrid/EV Battery Temperature Sensor 2 Circuit Erratic
- P0AC9 2018 GMC Sierra — Hybrid/EV Battery Temperature Sensor 2 Circuit Erratic
Frequently Asked Questions about P0AC9 GMC Code
1. What does the OBDII code P0AC9 mean on a GMC vehicle?
The P0AC9 code indicates an erratic signal from Hybrid/EV Battery Temperature Sensor 2, which monitors the temperature of the hybrid or EV battery pack.
2. What are the common symptoms of the P0AC9 code in GMC vehicles?
Symptoms may include the check engine light turning on, reduced hybrid or EV performance, overheating of the battery pack, or the vehicle entering limp mode.
3. What causes the P0AC9 code to appear in GMC vehicles?
Common causes include a faulty battery temperature sensor, damaged or corroded wiring, loose electrical connections, or a malfunctioning hybrid battery control module.
4. Can I drive my GMC with the P0AC9 code active?
It’s not recommended to drive for extended periods with this code active, as it could lead to further damage to the hybrid battery system or reduced vehicle performance.
5. How do you diagnose the P0AC9 code in a GMC vehicle?
Diagnosis involves using a scan tool to check for related codes, inspecting the battery temperature sensor and its wiring, and testing the sensor’s resistance and circuit integrity.
6. How is the P0AC9 code fixed on a GMC vehicle?
The fix may involve replacing the faulty temperature sensor, repairing or replacing damaged wiring, securing loose connections, or, in rare cases, replacing the hybrid battery control module.
7. Can a dead or weak 12V battery cause the P0AC9 code on a GMC?
While unlikely, a weak 12V battery can cause electrical issues that might indirectly lead to erratic signals. Checking the 12V battery is a good starting point.
8. How much does it cost to repair the P0AC9 code on a GMC vehicle?
Repair costs can vary, but replacing a battery temperature sensor typically costs between $150 and $300, depending on labor rates and parts pricing.
9. Will resetting the check engine light fix the P0AC9 code on my GMC?
Resetting the light might clear the code temporarily, but if the underlying issue isn’t resolved, the code will likely return.
10. Is the P0AC9 code specific to GMC vehicles?
No, the P0AC9 code is a generic OBDII code applicable to many hybrid and EV vehicles, but the troubleshooting steps may vary depending on the make and model.
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