AutoCodesChevrolet – P0668 2018 Chevrolet Silverado

P0668 2018 Chevrolet Silverado Code - Control Module Temperature Sensor Circuit Low Voltage

Quick Answer

The Transmission Control Module (TCM) temperature sensor is located inside of the control solenoid valve assembly which has no serviceable parts. Common causes include Faulty Control Solenoid Valve Assembly, Control Solenoid Valve Assembly harness is open or shorted, Control Solenoid Valve 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
P0668 2018 Chevrolet Silverado indicates Control Module Temperature Sensor Circuit Low Voltage.
Common causes
Common causes include Faulty Control Solenoid Valve Assembly, Control Solenoid Valve Assembly harness is open or shorted, Control Solenoid Valve 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.
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Code Popularity 316
How popular is this code, among other codes? Low
Table of contents Created and updated by William Orellana on Sep 23, 2022
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Code P0668 2018 Chevrolet Silverado Description

The Transmission Control Module (TCM) temperature sensor is located inside of the control solenoid valve assembly which has no serviceable parts. The Transmission Control Module temperature sensor provides the temperature of the Transmission Control Module substrate. This temperature reading is used in various diagnostic routines in the Transmission Control Module software. This fault is handled inside the Transmission Control Module and no external circuits are involved. The Diagnostic Trouble Code (DTC) will be set when the TCM internal temperature is −249°C (−416°F) or less for 1 min.
OBDII Code P0668 2018 Chevrolet Silverado - Control Module Temperature Sensor Circuit Low Voltage - AutoCodes.com
P0668 2018 Chevrolet Silverado Code - Control Module Temperature Sensor Circuit Low Voltage

What are the Possible Causes of the DTC P0668 2018 Chevrolet Silverado?

  • Faulty Control Solenoid Valve Assembly
  • Control Solenoid Valve Assembly harness is open or shorted
  • Control Solenoid Valve Assembly circuit poor electrical connection

How to Fix the DTC P0668 2018 Chevrolet Silverado?

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 P0668 2018 Chevrolet Silverado 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 P0668 2018 Chevrolet Silverado code?

Need more information on how to fix the P0668 2018 Chevrolet Silverado code? Get Access to Factory Service Manuals

Need Help with the 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 P0668 2018 Chevrolet Silverado Code

1. What does OBDII code P0668 mean on a 2018 Chevrolet Silverado?

Code P0668 indicates a "Control Module Temperature Sensor Circuit Low Voltage," meaning the control module has detected a low voltage issue in the temperature sensor circuit.

2. What are the symptoms of code P0668 on a 2018 Chevrolet Silverado?

Symptoms may include reduced engine performance, poor fuel efficiency, erratic temperature readings, or the check engine light illuminating.

3. What causes code P0668 to appear on a 2018 Chevrolet Silverado?

Common causes include a faulty temperature sensor, damaged wiring or connectors in the circuit, a short to ground, or a malfunctioning control module.

4. Can I drive my 2018 Chevrolet Silverado with code P0668 active?

Driving with this code may be possible, but it can lead to reduced performance or potential engine damage if the issue is not addressed promptly.

5. How do I diagnose code P0668 on a 2018 Chevrolet Silverado?

Diagnosis involves checking the temperature sensor, inspecting the wiring and connectors for damage, testing the circuit for continuity, and verifying the control module’s functionality.

6. How do I fix code P0668 on a 2018 Chevrolet Silverado?

Repairs may include replacing the temperature sensor, repairing damaged wiring or connectors, or replacing the control module if necessary.

7. How much does it cost to repair code P0668 on a 2018 Chevrolet Silverado?

Repair costs vary but typically range from $100 to $300, depending on whether the issue is with the sensor, wiring, or control module.

8. Will clearing the code P0668 fix the problem on a 2018 Chevrolet Silverado?

Clearing the code may temporarily reset the check engine light, but the underlying issue must be resolved to prevent the code from returning.

9. Can a bad battery cause code P0668 on a 2018 Chevrolet Silverado?

While unlikely, a weak or failing battery can cause electrical issues that might contribute to circuit voltage problems.

10. Is code P0668 common for the 2018 Chevrolet Silverado?

Code P0668 is not a common issue but can occur due to wear and tear, electrical damage, or component failure over time.

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