P0642 2016 GMC Sierra Code - 5 Volt Reference 1 Circuit Low Voltage
Quick Answer
The Engine Control Module (ECM) has four (4) internal 5 Volt reference circuits (Some models have two (2) internal 5 Volt reference circuits). Common causes include Faulty Sensor on 5 Volt circuit, Sensor on 5 Volt circuit harness is open or shorted, Sensor on 5 Volt 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
- P0642 2016 GMC Sierra indicates 5 Volt Reference 1 Circuit Low Voltage.
- Common causes
- Common causes include Faulty Sensor on 5 Volt circuit, Sensor on 5 Volt circuit harness is open or shorted, Sensor on 5 Volt 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 P0642 2016 GMC Sierra Description
What are the Possible Causes of the DTC P0642 2016 GMC Sierra?
- Faulty Sensor on 5 Volt circuit
- Sensor on 5 Volt circuit harness is open or shorted
- Sensor on 5 Volt circuit poor electrical connection
- Faulty Engine Control Module (ECM)
How to Fix the DTC P0642 2016 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.
Code Tech Notes
The 5 Volt reference 1 circuit provides 5 Volt to the following sensors: (Some models may have different sensors, please consult the factory service manual for the list of sensors for your model and year)
- Air conditioning (A/C) refrigerant pressure sensor
- Camshaft position sensor
- Engine oil pressure sensor
- Fuel pressure sensor
- Fuel rail pressure sensor
- Fuel tank pressure sensor
- Multifunction intake air sensor
What is the Cost to Diagnose the Code?
Labor: 1.0
To diagnose the P0642 2016 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 P0642 2016 GMC Sierra code?
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Frequently Asked Questions about P0642 2016 GMC Sierra Code
1. What does the OBDII code P0642 mean on a 2016 GMC Sierra?
P0642 indicates a low voltage issue in the 5-volt reference 1 circuit, which supplies power to various sensors in the vehicle.
2. What are the common symptoms of code P0642 in a 2016 GMC Sierra?
Symptoms may include poor engine performance, reduced fuel efficiency, illuminated check engine light, and erratic sensor readings.
3. What causes the P0642 code on a 2016 GMC Sierra?
Common causes include a shorted sensor, damaged wiring, a faulty control module, or corrosion in the 5-volt reference circuit.
4. Can I drive my 2016 GMC Sierra with the P0642 code?
Driving with this code is not recommended as it may lead to further damage or unsafe vehicle performance due to incorrect sensor data.
5. How do I diagnose the P0642 code on my GMC Sierra?
Start by scanning the vehicle for additional codes, inspecting the wiring and sensors connected to the 5-volt reference circuit, and testing for proper voltage with a multimeter.
6. Which sensors are typically affected by the P0642 code?
Sensors such as the throttle position sensor (TPS), manifold absolute pressure (MAP) sensor, and coolant temperature sensor may be impacted.
7. Can a bad ground connection cause the P0642 code?
Yes, a poor ground connection can disrupt the 5-volt reference circuit, leading to the P0642 code.
8. How do I fix the P0642 code on a 2016 GMC Sierra?
Repairs may include replacing a shorted sensor, repairing damaged wiring, cleaning corroded connections, or replacing a faulty control module.
9. Does the P0642 code always indicate a sensor failure?
No, while a faulty sensor is a common cause, the issue could also stem from wiring issues or a malfunctioning control module.
10. How much does it cost to repair the P0642 code on a GMC Sierra?
Repair costs vary depending on the root cause, ranging from $50 for minor wiring repairs to $500 or more for control module replacement.
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